Night Owl 6/Night Owl's Shareware - PDSI-006 - Night Owl Corp (1990).iso/025a/vpi1330b.zip/PART1.MAN

Text File | 1991-12-25 | 206KB | 6,534 lines

                                VP-Info Level 1

                              Command and Function

                                Reference Manual




                    by Sidney L. Bursten and Bernard Melman

                                      for

                            Sub Rosa Publishing Inc.
                                      and
                                 Sub Rosa Corp.














     1992 Edition





                                 The next best thing to knowing something
                                 is knowing where to find it.

                                 - Dr. Samuel Johnson (1709-1784)








     First printing
     January, 1992


     Copyright (c) 1992 Sub Rosa Publishing Inc.
                        Unit 34-1170 Sheppard Ave. West.
                        Downsview, ON, Canada    M3K 2A3
                             Phone: [phone]
                             Fax:   [phone]

     Incorporating material previously published in
          MAX and VP-Info manuals, Copyright (c)
          1984, 1985, 1986, 1989, 1990, 1991 Sub Rosa International Inc.

     VP-Info Level 1 Copyright (c) 1984, 1985,
          1986, 1987, 1988, 1989, 1990, 1991, 1991 Sub Rosa International Inc.


     Trademarks:

     SR-Info is a trademark of Sub Rosa Publishing Inc.
     dCOMP and MAX are trademarks of Sub Rosa Inc.
     Sub Rosa Publishing Inc. is an authorized user of
          the VP-Info trademark, a trademark of Paperback
          Software International
     dBASE, dBASE II, dBASE III, dBASE III+ and dBASE IV
          are trademarks of Ashton-Tate
     IBM is a trademark of IBM Corporation

     10 9 8 7 6 5 4 3 2 1



                                  INTRODUCTION




          VP-Info was the first and, we believe, is still the best
     compiled data base management language designed for IBM-compatible
     DOS computers.

          VP-Info (which, for the balance of this manual, will be
     called just Info when referring generally to all versions of the
     language) shares many of the language features and keywords of the
     popular dBASE family of languages, so dBASE users can learn it in a
     matter of hours, but has many novel features resulting in very fast
     program execution and much reduced programming time.

          If this is your first exposure to Info, you may wish to put this
     manual aside for a while and take it for a "test drive" with the help
     of the brief instructions in the file FASTART on the distribution
     disk.  But don't forget to come back to the full manual to take
     advantage of the full power and versatility of Info.

          This release of the language represents its fifth major revision
     and enhancement since its original publication by Sub Rosa Inc. in
     1984 under the name dCOMP.  Sub Rosa Inc. published a major upgrade
     under the name MAX in 1985, which in turn was followed in 1986 by
     Paperback Software International's publication of a major new version
     of the language under its own name, VP-Info.

          Paperback issued a major upgrading in 1988 and a brand new
     version (2.0) in 1989, followed by this enhanced new version by Sub
     Rosa Publishing Inc. in 1990.

          Our goal at Sub Rosa Publishing Inc. is to provide you, the user,
     with the finest database management tool . . . one that will continue
     to grow in power and utility through the coming years.  You can help
     us achieve this goal in various ways.

          First of all, Info is a rich language with many useful features.
     To make many of these available to you, peruse this Command and
     Function Reference Manual.  Whether you are using Info as an
     interactive data base management tool or as a full programming
     language, periodic rereading of this manual will enable you to get
     more out of Info.

          A Reference Manual is like a dictionary and a grammar; it is not
     meant for the first time user.  The complete VP-Info manual, provided
     to all registered users, includes not only the "dictionary" reference
     section provided on disk with VP-Info Level 1, but a complete
     tutorial and several appendixes as well.  This printed and bound manual
     is a major benefit of registration!



          Second, we would like to hear from you.  Whether it is errors in
     the program or the manual, or suggestions for improvements, write or
     fax us, or direct comments to us through CompuServe or the conference
     on your major public-access bulletin board.

          Third, fill out the VP-Info SOFTWARE LICENSE AGREEMENT
     AND REGISTRATION provided to you (it's on your disk under the name
     ORDER.DOC) and mail it in.  We are unable to provide technical
     assistance and program updates to non-registered users.

          The language is available in several versions to meet the varying
     needs of individuals, organizations and businesses:

          A.   VP-Info Level 1 is an excellent choice for many individuals,
               corresponding to the original release of VP-Info by
               Paperback Software International, but with many added
               features, more power and complete upward compatibility with
               our more powerful versions.

                    VP-Info Level 1 is widely available through users' groups                 and public bulletin boards as a "shareware" product, giving
               you the opportunity to "try before you buy."  Users who decide
               to upgrade from Level 1 to one of the other versions are
               given full credit for registration fees paid toward their
               purchase of VP-Info Professional or VP-Info Professional II,
               in either the Single-User or Network Editions.

                    VP-Info Level 1 may be freely copied and distributed to
                others in the United States  Canada, Great Britain and
               Australia only in its complete, unaltered, compressed form,
               and provided that no fee (other than a nominal copying fee) is
               charged, that no printed  manual is supplied with the disk(s),
               and no representation is made that the recipient has any right
               to use the software without registration for more than
               evaluation purposes for a period limited to 60 days.

                    Those making use of Level 1 in commercial and other
               serious environments are expected to register their copies,
               thus entitling them to their own bound manuals and the
               opportunity to get telephone support and consultations.

          B.   VP-Info Professional and VP-Info Professional II are enhanced
               versions of the language, offering access to many more files,
               more records, more features and more power.

                    These enhanced versions are not available as a "shareware"
               product, and distribution of the software or manuals by
               anyone except authorized VP-Info Professional Resellers is
               strictly prohibited.  One registered copy is required for
               each computer on which VP-Info Professional is run.



          C.   VP-Info Professional Network Edition and VP-Info Professional
               II Network Edition are the full network and multi-user versions
               of the language, conforming to the file-sharing and locking
               conventions of Microsoft DOS, versions 3.1 and above, and
               compatible with a host of DOS network products including
               Novell Netware, LanTastic and Corvus ReadiNet.

                    Unlike most network applications software, the two
               Network Editions come with a license for all users
               on each server.  If a network includes multiple network
               servers, one copy is required for each server.

          If you have any difficulty in meeting your objectives with Info,
     we invite you to call on us for assistance.  All users registered with
     Sub Rosa Publishing Inc. or Sub Rosa Corp. are entitled to obtain
     technical support and consulting by telephone.  Consult your
     Registration Certificate for hours, specific entitlements, and charges
     for additional consultations.

          Please remember that Info is not an application program; it's
     actually a rich and powerful computer language that makes looking
     after your data a lot easier that available alternatives.  But putting
     all this power into your hands does carry a price: mistakes can result
     in loss of data or erroneous results.  Sub Rosa Corp. and Sub Rosa
     Publishing Inc. assume no liability or responsibility for any damages
     whatsoever (including, without limitation, damages for loss of
     business profits, business interruption, loss of business information,
     or other pecuniary loss) arising out of the use of or inability to use
     this software.  Additional information is contained in the limited
     warrantee attached to the license agreement provided to you.

          Users who are members of major public bulletin boards may find
     their local BBS carries a conference dealing with Info.  Sub Rosa
     regularly downloads questions from a number of BBS systems
     and uploads answers, comments and suggestions.  Call our office for
     assistance in locating an appropriate BBS.

          In addition, the best of our bulletin-board and other
     correspondence, plus articles and program examples are published on
     our semi-annual "VP-Info Diskozine", our magazine-on-a-disk.
     Subscriptions are available from our office.

          We hope you will find Info useful and fun to use, and get years
     of satisfaction from it.

                    Sidney L. Bursten and Bernard Melman
     Sub Rosa Corp.                     Sub Rosa Publishing Inc.
     1313 Fifth Street SE               Unit 34-1170 Sheppard Ave. West.
     Minneapolis, MN  55414             Downsview, ON, Canada    M3K 2A3
     Phone: [phone]              Phone: [phone]
     Fax:   [phone]              Fax:   [phone]




                                    TABLE OF CONTENTS



          SECTION 1. USING Info
             1.1. Setting up Info
             1.2. Conversational Info
             1.3. Running Programs with Info
             1.4. Compiling with Info
             1.5. The Configuration File
             1.6. The SET File


          SECTION 2. Info FILES AND VARIABLES
             2.1. Files
             2.2. Selecting Data Files
             2.3. Variables
                Memo Fields
             2.4. Variable Look-Up Rules
             2.5. Matrix Variables
             2.6. System Variables
                Function keys
                :DATE and :TIME
                :PICTURE
                Other system variables


          SECTION 3. Info FUNCTIONS
             3.1. Constants
             3.2. Operations
             3.3. Relations
             3.4. Functions
             3.5. Expressions
             3.6. Rules of Precedence


          SECTION 4. Info COMMANDS
             4.1. The Form of the Commands
             4.2. Symbols
             4.3. Command List
     VP-Info Level 1 Reference Manual             Page 1  SECTION 1


                    SECTION 1. USING VP-Info Level 1


          Before you can start running VP-Info Level 1 (which, for the
     balance of this manual, we'll call Info by itself), you should
     familiarize yourself with some basic topics.  These are discussed in
     this section, beginning with "what is a data base anyway?" and
     continuing with getting Info into operation, and using Info without
     and with programs.

          This sections also covers installation of Info on your computer,
     and customizing the installation to meet your specific needs.

          Finally, some considerations for advanced users are discussed,
     and the several different versions of Info are compared.
     VP-Info Level 1 Reference Manual             Page 2        SECTION 1










                      1.1. Basic Concepts and Orientation


          There are some basic concepts and vocabulary that are fundamental
     to getting maximum results from using Info.

          These are discussed here, including records and fields, file
     names and field names, your keyboard and the way we use and refer to
     its various keys.

          Records and Fields.  Everybody keeps information on file cards.
     Here is a 3x5 card kept on an employee in a small company:

              ┌───────────────────────────────────────────┬───┐
              │ Name: Marek, Joe                          │ 1 │
              │ Address: 231 River Drive                  └───┤
              │          Broomsdale, MD                       │
              │          02110                                │
              │ Telephone number: 566-7012                    │
              │ Married: Y                                    │
              │ Salary: 25,800.00                             │
              │ Year employed: 1981                           │
              │ Department: Maintenance                       │
              └───────────────────────────────────────────────┘

          Now learn some computer jargon: the electronic version of a
     filing box (containing such cards) is called a data file; a card
     itself is called a record.  The number in the upper-right corner of
     the card identifies the card as card number 1.  The same way, records
     are numbered by record number.

          A card has separate areas for the various pieces of information
     you want to collect.  We call these areas fields.  Each field is
     identified by its name.  In this example, for instance, "Department"
     is a field name, while "Maintenance" is the contents of the field.

          You identify records by their number, fields by their names.  How
     do you identify data files?  By their names, of course.  For instance,
     all the cards of your employees could be sitting in a box labelled
     "Employee Records."  Unfortunately, the name you can give to a data
     file in your computer is rather restrictive: only 8 letters or numbers
     can be used.  So EMPLOYEE will have to do; EMP1, EMP2 are also good





     Basic Concepts and Orientation          Basic Concepts and Orientation
     VP-Info Level 1 Reference Manual             Page 3         SECTION 1


     file names.  (Do not use COMP for the first four letters of a data or
     index file name; Info is unable to open such a file.)

          A file is actually identified by its drive designation, its
     directory, its file name,  and its extension.  For example, the full
     designation of our employee file could be C:\DATA\EMPLOYEE.DBF.

          File names.  A file name can have at most 8 characters.  You can
     use all the letters of the alphabet, the digits 0 to 9, and the
     underscore character (_).  You can use both capital and lower-case
     letters, but the lower-case letters will be replaced by their
     upper-case version.

          The restrictions on a file name are imposed by the operating
     system of your computer.  (Check your Operating System Manual.  In
     this book it is assumed that you have a little familiarity with your
     computer and operating system.  Specifically, you should know the
     drive designations, the operating system prompt, the DIR command, and
     how to handle floppy disks.)  It may allow you to use some other
     characters as well.  However, you cannot go wrong following the rules
     as they were stated above.

          Note that the blank (the character you get by pressing the
     spacebar), some punctuation symbols (. , :) , and most special
     characters (< > | + and so on) are always prohibited.  For instance,
     you are never allowed to use as a file name two short words separated
     by a blank, such as CAR NAME.

          The data file we mentioned before, EMPLOYEE, also has an
     extension, "DBF".  When you type in the full name, the extension is
     separated from the file name by a period, though when you see it
     listed by DIR, the extension will be separated from the name by one or
     more spaces.  The extension may have at most three characters; all
     Info file extensions have exactly three letters.

          The extension DBF stands for Data Base File.  There are many
     other file types used by Info.  The extension always reveals the type
     of the Info file.  Most of the commands do not require the extension.
     For instance, when you create a data file, Info adds the extension DBF
     unless you provide another one specifically.

          When you use a data file, just give the file name (with or
     without the drive designation), and Info adds the DBF extension to
     look the file up.  As a rule, when Info asks for a file name, do not
     bother to give the extension.

          Field names.  A field name has at most 10 characters (two more
     than file names); you can use all the letters, the digits 0 to 9, the
     colon (:), and the underline (_).  The first character must be a
     letter.  Again, you can use lower-case letters, but Info will convert
     them to upper case.  Just as for file names, blanks cannot be used.




     Basic Concepts and Orientation          Basic Concepts and Orientation
     VP-Info Level 1 Reference Manual             Page 4       SECTION 1



          You have just read the formal rules for file and field names.
     The most important rule, however, is the following:

               Always use file names and field names that are easy to
          remember, names that remind you of what is in the data file and
          field.

          So FILE1, as a rule, is a bad name, EMPLOYEE is good.  NAME1ST is
     good for first name (and so is FNAME), FIELD2 is bad.

          How do you test whether a file or a field name is good by this
     rule?  If you do not have to look up the file and field names when you
     use them, they were named well.  If you have to look the names up all
     the time, use better names.

          Field Types.  In setting up the data file (our electronic 3x5
     cards), we first chose a name for it: EMPLOYEE.  Next we choose the
     field names.

          For the name (Marek, Joe), NAME is fine, but hard to handle.
     Later, we may need reports in which the first name and the family name
     are displayed differently. So we split up the name into two fields:
     NAME for the family name and FNAME for the first name.

          The address is in three lines.  Since you cannot put three lines
     in a field (and also to gain flexibility in reporting), we split the
     address up into four fields: ADDR, CITY, STATE, and ZIP.

          Telephone number becomes TEL:NO; married can stay MARRIED; Salary
     can stay SALARY; Department is too long, so use DEPT instead.
     Finally, we shorten Year employed to YEAR:EMP. (Note that ":" or "_"
     is used in place of the blank, which is not allowed.)

          The fields NAME, FNAME, ADDR, CITY, STATE, ZIP, TEL:NO, DEPT will
     be filled with text; anything that can be typed can go into these
     fields.  You tell this to Info by saying that the field type is
     character, or the field is a character field.  The abbreviation for
     character type is C.

          It is not enough to say that NAME is a character field; Info also
     wants to know how many characters you want to allow in the field.
     This number is called the width of the field.  For instance, if we
     specify 15, that means that any text of up to 15 characters can be
     typed into NAME.  We can always type less.  (Info will fill what is
     left of the field with blanks.)

          It is not always easy to decide the width of a field.  What is
     the longest family name we'll have to use?  Don't worry, we can make
     changes later.





     Basic Concepts and Orientation          Basic Concepts and Orientation
     VP-Info Level 1 Reference Manual             Page 5     SECTION 1



          In this example, we use the CREATE command (see Section 4.3):

     1>CREATE employee

     and enter the following:

     Field:         Type:          Width:

     NAME           C              15
     FNAME          C              10
     ADDR           C              20
     CITY           C              20
     STATE          C               2
     ZIP            C               5
     TEL:NO         C               8
     DEPT           C              15

          SALARY and YEAR:EMP are numbers.  Of course, we could define them
     as character fields, but then we could not do mathematical operations
     on them.  Since they are, by their nature, numbers, it is more natural
     to define them as such, so we define them as numeric fields, type N.

          The width of YEAR:EMP is 4; you also have to tell Info how many
     digits are allowed after the decimal point; in this case there is no
     decimal point, so we say 0.

          The width of SALARY should be 9 to take salaries over
     $100,000.00.  When counting for the width, we count all the digits and
     the decimal point.  You are not allowed to type in 120000.00 as
     120,000.00, so we do not make room for the comma; the width of SALARY
     is 9, with 2 decimals.

     Field:         Type:          Width:         Decimals:

     YEAR:EMP       N              4              0
     SALARY         N              9              2

          Finally, there is the field MARRIED.  You could define it as a
     character field of width 1.  If you do this, Info will accept any
     character for MARRIED.  You can restrict the characters accepted to
     "Y" (yes) "N" (no) by declaring MARRIED a logical field (L).  In fact,
     you can use any of  "Y", "y", "T", or "t" for true, and any of "N",
     "n", "F", or "f" for false.

          A logical field is always of width 1.









     Basic Concepts and Orientation          Basic Concepts and Orientation
     VP-Info Level 1 Reference Manual             Page 6   SECTION 1



     Field:         Type:          Width:         Decimals:

     MARRIED        L              1

          The Keyboard.  The next step is to create the EMPLOYEE file.  But
     before you do that, familiarize yourself with your keyboard (yours may
     have more keys than this representation of the original standard IBM
     PC keyboard, but all these keys are on your keyboard, and these are
     the only ones you need for Info):

     ┌──┬──┐ ┌──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬──┬────╥───────┬───────┐
     │F1│F2│ │Es│1 │2 │3 │4 │5 │6 │7 │8 │9 │0 │- │= │ <- ║NumLock│ Break │
     ├──┼──┤ ├──┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴─┬──╫───┬───┼───┬───┤
     │F3│F4│ │Tab│q │w │e │r │t │y │u │i │o │p │[ │]  │` ║Hom│Up │PgU│ - │
     ├──┼──┤ ├───┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬──┴──╫───┼───┼───┼───┤
     │F5│F6│ │Ctrl│a │s │d │f │g │h │j │k │l │; │' │ <─┘ ║<--│   │-->│   │
     ├──┼──┤ ├──┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴┬─┴──┬──╫───┼───┼───┤   │
     │F7│F8│ │\ │Sh│z │x │c │v │b │n │m │, │. │/ │Shft│* ║End│ Dn│PgD│ + │
     ├──┼──┤ ├──┴┬─┴──┴──┴──┴──┴──┴──┴──┴──┴──┴┬─┴────┼──╨───┼───┴───┤   │
     │F9│F0│ │Alt│          Space Bar          │CpsLck│ Ins  │  Del  │   │
     └──┴──┘ └───┴─────────────────────────────┴──────┴──────┴───────┴───┘
     Function            Typewriter Keyboard              Cursor Keypad &
      Keys                                                 Numeric Keypad

          There are a few special keys you have to know.  <ENTER> refers to
     the key usually called ENTER or RETURN, marked on some computers with
     a hooked backarrow:  <─┘.  Some keyboards have both a RETURN and an
     ENTER key; they are interchangeable.

          At the right is a set of keys called the numeric keypad and/or
     the cursor keypad.  With the <Num Lock> key switched on or with the
     <Shift> key depressed, these keys output numbers; otherwise they
     control the cursor (the flashing rectangle that indicates where the
     next character we press will appear on the screen) and other actions.

          The key <End> is used to indicate the end of a Info procedure,
               such as APPEND, BROWSE, CREATE, EDIT, WRITE.

          The four arrow keys are referred to as <Up>, <Dn>, <Left>, and
               <Right>.  They are used to move the cursor around the
               screen.  The keys <Home>, <PgUp>, and <PgDn> are used for
               some commands, such as EDIT, BROWSE, READ, and WRITE.

          The left arrow on your cursor pad, <Left>, should not be confused
               with the fat back arrow,  <-,  at the top of the keyboard,
               called <Backspace>. <Left> moves left without affecting the
               characters under it, <Backspace> "swallows up" each
               character it moves over.






     Basic Concepts and Orientation          Basic Concepts and Orientation
     VP-Info Level 1 Reference Manual             Page 7     SECTION 1


          The delete key <Del>, and the insert key <Ins>, are used to
               delete and insert characters on the command line and during
               data entry and editing.  Each time <Del> is pressed, one
               character is removed at the cursor, and anything to the
               right moves over to take its place.  The <Ins> key is a
               "toggle," meaning that if insert mode is on, pressing <Ins>
               turns it off, and vice versa.

          Your keyboard also has ten or more function keys at the left or
     along the top; the ten marked <F1> to <F10> have pre-assigned roles
     which can be changed by the user.

          The escape key, <Esc>, can be used to escape from a command.

          Sometime two keys have to be pressed at the same time.  Ctrl-W
     means press the control key (marked as Ctrl) and the W key at the same
     time (there is no harm done pressing the control key first).  Alt-F10
     means press the <Alt> key and <F10> at the same time.










                              1.2. Setting up Info


          To run Info, you need an IBM PC, XT, AT, or compatible MS-DOS
     computer with two disk drives, at least 512K memory, and DOS 2.0 or
     later.

          To use Info, you need the following files, all having a
     three-or-four-character name indication which version it is for, and
     an extension descriptive of its contents.

          A.   All required or optional files for Level 1 have the name VPI1

          B.   All those for VP-Info Professional have the name VPI

          C.   All those for all those for VP-Info Professional Network
               Edition have the name VPIN (except for VPI.HLP)

          The extensions for these files are as follows:

          A.   The EXE file and the MSG file. Each version of Info has its
               own set of matching executable and message files, both of





     Setting up Info                                        Setting up Info
     VP-Info Level 1 Reference Manual             Page 8       SECTION 1


               which must be in the same place, either in the current
               directory or in any directory on the DOS PATH (see your DOS
               manual for details on PATH).  Info cannot be run without
               both of these files.

                    In addition, both files are internally matched, so that
               an EXE of one version or date of issue cannot be run without
               the MSG file generated for that version on the same day.

                    To avoid errors, there should not be more than one copy
               of each of these files anywhere in your hard disk.

                    The EXE file may be renamed if you desire, but the MSG
               and all the following files must retain both their name and
               extension.

          B.   The HLP file.  Info has an excellent on-line help system
               that can be run at any time you are in conversational
               (interactive) mode.  It is optional; to run it, the HLP file
               must be in the same directory as the MSG file.  If it is not
               present, the HELP command does not work.

          C.   The CNF file. An optional configuration file generated by
               the user.  This is a regular Info program file (uncompiled),
               residing in the subdirectory where Info is executed.

                    It is typically used to invoke the SET flags to suit
               your needs, to define the function keys and such system
               variables as :COMPANY and :TITLE (see Section 2.6), and to
               establish where Info can expect to find files outside the
               current directors (see FILES ... ENDFILES structure in
               Section 4.3).

          D.   The SET file.  (VP-Info Professional and VP-Info
               Professional Network Edition only.)  An optional file that,
               if used, must reside in the directory where VP-Info is
               executed.  The SET file is discussed in detail in Section
               1.6.

          E.   The SGN file.  (VP-Info Professional and VP-Info
               Professional Network Edition only.)   An optional file
               supplied with the system, providing an attractive sign-on
               for the user each time VP-Info is executed.

                    The SGN file normally goes in the same directory as the
               MSG file, but if you want it to be executed only in some
               directories and not in others, you will have to put it in
               each directory from which you want it executed, and make
               sure it is not in any directory listed in the DOS PATH.






     Setting up Info                                        Setting up Info
     VP-Info Level 1 Reference Manual             Page 9       SECTION 1


          In addition, you must have a CONFIG.SYS file (in the root
     directory of your boot disk, see the DOS Reference Manual) containing
     the lines:

     FILES=20
     BUFFERS=20

     If you are running VP-Info Professional under DOS 3.3 or above, you
     may open as many as 65 files at the same time, provided the FILES=
     command in both your CONFIG.SYS and the SET file is set that high.




                            1.3. Conversational Info


          After you start Info, you see the copyright notice, and the Info
     prompt:

     1>

          This prompt is Info's way of asking: What now?  You can issue any
     commands (as listed in Section 4.3) or you can write and run a Info
     program.

          Conversational VP-Info Level 1 (also called interactive mode) is
     the use of Info by directly entering commands instead of using
     programs.

          Info has a number of features to help you along.  There are a few
     hints to help you get into Info quickly.

          Type in a command line; pressing <ENTER> executes the command:

     1>DIR

          The command line can be fully edited.  Use the cursor keys
     described in the keyboard section above, or the full list of editing
     keys listed under the WRITE command in Section 4.3.

          If there is an error in the command, the command line is
     redisplayed; the cursor is placed on the first word after the word
     that is the likely cause of the trouble.  Use the editing keys to
     change the command line; then press <ENTER> to try executing it again.

          There are 78 characters on the command line available for a
     command.  If you type in a longer command line, these 78 characters
     will act as a window, with some characters disappearing off the left
     or right edge of the screen.  You always see 78 characters of the long
     command line.




     Conversational VP-Info                          Conversational VP-Info
     VP-Info Level 1 Reference Manual             Page 10       SECTION 1



          Info stores away the last five command lines (up to 75 characters
     each).  You can get the previous command line back by pressing <Up> or
     Ctrl-E.  If you press the key twice, you get back the second last
     command line, and so on.  You can execute the recalled command by
     pressing <ENTER>; you can edit the command before executing it just as
     though you had typed it yourself.

          Pressing a function key is the same as typing in a command line
     or lines stored in a matching system variable.  For example, :F1
     usually contains the string "HELP ", so pressing the <F1> key is
     exactly the same as typing in "HELP " (see Section 2.6).

          Two special characters are used in defining the function keys:
     semicolon (;) causes Info to issues an <ENTER> code and execute
     everything already put into the command line, and the caret (^) stands
     for "hold down the control key while pressing the next character in
     the string".  Examples:

               <F2> usually contains "LIST STRU;", which means: enter the
                         string LIST STRU into the command line and
                         execute.  This command lists the structure of the
                         selected data file
               <F10> usually contains "EDIT;", which means: enter the
                         string EDIT into the command line and execute.
                         This command begins to edit the selected data file

           To redefine the function key <F7> to contain a string causing
     Info to go to the nearest record after an unsuccessful FIND and
     immediately start to edit that record:

     1>:F7='GOTO :near;edit;'

     (see Section 2.3 and the = and FIND commands in Section 4.3).  You may
     also redefine a function key on the fly: if the command is already
     typed in, just place your cursor at the end of the command line and
     press Alt-F7 to capture everything to the left of the cursor into :F7.

          Short programs (with no loops) can be stored in the function
     keys, and executed by pressing the function keys.

          The most important commands for a beginner becoming familiar with
     Info are (see the alphabetical command reference in Section 4.3):

          CREATE    - create a new data file
          MODIFY    - change the structure on an existing data file
          APPEND    - add records to a data file
          EDIT      - view and change fields in a data file
          BROWSE    - view and change some fields in many records of a data
                        file





     Conversational VP-Info                          Conversational VP-Info
     VP-Info Level 1 Reference Manual             Page 11       SECTION 1


          LOCATE FOR - goto a record that meets some condition
          CONTINUE  - goto the next record that meets the same condition
          LIST      - list the fields of all or some records in a data file
          DISPLAY   - list the fields in the current record of a data file
          COUNT     - count the records in a data file
          SUM       - add up the values of a numeric field in a data file
          SORT      - sort a data file into a new file with a new order
          INDEX     - create a separate file that maintains the apparent
                        order of a data file without sorting the file
          FIND      - find a record in an indexed file by the value of its
                        "key"
          REPORT    - produce a formatted list of a data file with optional
                        headings, subtotals, and totals
          STATUS    - check what files are open, the setting of SET
                        commands, and the value of memory variables
          LIST STRUCTURE - check the structure of the current data file
          WRITE     - create or edit a text file or program

          The forthcoming Sub Rosa Publishing Inc. manual Conversational
     VP-Info Level 1 explains use of these commands and many of the
     interactive features in greater detail.




                        1.4. Running Programs with Info


          When you see the operating system prompt (A> or C> for example),
     you can run the Info program MENU by typing

     C>VPI menu

     (or SRI menu, or VPIN menu as the case may be).  Info will load itself
     into memory, execute the CNF file if found, and then run MENU.

          From within Info, that is, when you see the Info 1> prompt (or
     2>,...,10>), run a program with the DO command:

     1>DO menu

          In either case, Info will first look for a compiled program:
     MENU.CPL; if it is found, Info will run it.  If there is no MENU.CPL,
     Info will look for an uncompiled program, MENU.PRG, which it will
     compile on-the-fly and immediately execute.  The program name may not
     have an extension in the command line.

          There are two other types of program which can be run by Info:
     standard EXE, COM, and BAT programs with the RUN command, and (in
     VP-Info only) binary file (assembly language) programs with the CALL
     command.  See RUN and CALL in the command reference section.




     Running Programs                                      Running Programs
     VP-Info Level 1 Reference Manual             Page 12       SECTION 1





                            1.5. Compiling with Info


          There are two ways to compile a program.  The first is on the
     command line itself:

     1>COMPILE menu

          Alternately, you can compile many programs in one step by
     creating and running a program containing a set of COMPILE commands.
     For example, PROJ.PRG may consist of the following commands:

     COMPILE prog1
     COMPILE prog2
     COMPILE prog3
     CHAIN proj1

          Then

     1>DO proj

     will compile PROG1, PROG2, and PROG3, and immediately execute PROJ1.
     (The command DO issued at the command line is equivalent to CHAIN;
     inside a program, its meaning is different.)




                    1.6. The Configuration and Setting Files


          When Info is invoked, it first looks for some special files that
     are used to customize its installation to meet the user's special
     needs.

          The SET file.  VP-Info Professional and VP-Info Professional
     Network Edition allow a settings file with the extension SET, used by
     Info primarily to allocate memory during loading.  The five commands
     supported by the SET file permit the user to:

               1.   Set the maximum amount of memory to be used by VP-Info
                    (see MEMORY= command in Section 4.3)

               2.   Set the maximum amount of memory to be allocated for
                    loading binary files (assembly-language routines) that
                    can be executed from within VP-Info (see BINSPACE=
                    command in Section 4.3)





     Configuration File                                  Configuration File
     VP-Info Level 1 Reference Manual             Page 13       SECTION 1



               3.   Set the maximum number of files that can be opened at
                    one time by VP-Info (see the FILES= command in
                    Section 4.3)

               4.   Set the maximum number of fields there can be in all
                    data files opened at any one time (see FIELDS= command
                    in Section 4.3)

               5.   Suppress special screen and sound effects accessed
                    through the SCREEN, SOUND and RING commands (see
                    NOEFFECTS command in Section 4.3)

          The SET file is completely optional, but users of certain
     computers not 100% compatible with the IBM AT, or using certain
     operating systems, may find it necessary to suppress the special
     effects with the NOEFFECTS command.  See NOEFFECTS in the command
     reference section of this manual for more details.

          Level 1 does not support binary programs or the special screen
     and sound effects, and uses default settings for all the other
     commands used in the SET files of VP-Info Professional and VP-Info
     Professional Network Edition.  No SET file is used with Level 1.

          The CNF file.  Level 1 and all other versions of VP-Info allow a
     configuration file with the extension CNF.  The CNF file is a regular
     Info program file (uncompiled), residing in the subdirectory where
     Info is executed.

          The CNF file is completely optional, but it is extremely useful
     to define the SET flags to suit your needs, to define the function
     keys and such system variables as :COMPANY and :TITLE (see Section
     2.6), and to establish where Info can expect to find files outside the
     current directors (see FILES ... ENDFILES structure in Section 4.3).

          Any command can be used in the CNF file, but since it is compiled
     anew every time you enter Info, it should be kept as short as
     possible.

          If the last line of the file is a CHAIN command, the program
     chained to will be executed immediately, even if the DOS command that
     started Info names another program (see Section 1.4).













     Configuration File                                  Configuration File
     VP-Info Level 1 Reference Manual             Page 14       SECTION 1





                  1.7. Some Considerations For Advanced Users


          How to have different versions of Info coexist with one another.
     There are actually several different situations, all of which have to
     be discussed separately:

          A.   Running two or more of the following -- Level 1, VP-Info
               Professional, and  VP-Info Professional Network Edition --
               on the same computer:

               1.   If no two versions access the same data or programs,
                    there is no problem.  Just load all of the appropriate
                    files into the proper directories as shown in
                    Section 1.2.

               2.   If no network is involved, and the same programs are to
                    be executed two or more different versions of the
                    above, it is only necessary to provide a different
                    directory for each version's CPL files, and use the
                    FILES ... ENDFILES structure in each version's CNF file
                    to direct Info to the correct set of compiled programs.

                         If programs for the different versions are not
                    limited to the commands and functions available to the
                    lowest-power version, separate directories for the
                    programs may also be necessary.

               3.   There is no safe way to allow single-user versions to
                    operate in a network environment; do not try it except
                    in a completely private directory, and do not access
                    any files of any type which may also be accessed by
                    VP-Info Professional Network Edition.

          B.   Running VP-Info Version 1 together with one or more of the
               following -- VP-Info Level 1, VP-Info Professional, and VP-Info
               Professional Network Edition -- on the same computer:

               1.   The only files compatible between Version 1 and the
                    current versions are text files and libraries, report
                    form files, and data files.  All other files must be
                    segregated into separate directories for each version
                    if they are to be shared by the two versions.

               2.   Running Version 1 and VP-Info Professional is more
                    difficult than other combinations, since the main file
                    name is the same in both cases, VPI.EXE, and both look





     For Advanced Users                                  For Advanced Users
     VP-Info Level 1 Reference Manual             Page 15       SECTION 1


                    for VPI.CNF.  Therefore, these two versions must be
                    started in separate directories, and access to the
                    shared files coordinated through the FILES ... ENDFILES
                    structures in their respective CNF files.

          C.   Networking under Version 1 and VP-Info Professional Network
               Edition is incompatible and can cause catastrophic failure
               and data corruption if an attempt is made to share data
               files between them.

          Differences between the various versions of the language.  There
     are five versions to consider; in increasing level of power they are:

          A.   VP-Info Version 1.  Main technical specifications:

               Maximum 65,536 records in a data file
               Maximum 6 open data files
               Maximum 20 files open at one time, including DOS files
               Index structure incompatible with other four versions
               Included network facilities
               Temporary files (those with extension starting with $)
                    cannot be redirected with FILES ... ENDFILES structure
                    to ramdisk or disk with more space
               Expression lists could be separated either by commas or
                    spaces in many commands; now only commas are allowed
               Following functions substantially modified or not carried
                    forward to newer versions:
                       CONVERT(    split into two new functions, CTONUM(
                                     and NUMTOC(
                       DBF(        split into DBF( and FLD(
                       DIR(        split into DIR( and DIRX(
               Following commands substantially modified or not carried
                    forward to new versions:
                       :TERMINAL=  terminals no longer supported
                       SET ANSI    no longer supported
                       SET COLON   now use SET DELIMITER
                       SET FIELDS  now use FIELD= in SET file
                       SET MEMORY  now use MEMORY= in SET file

          B.   VP-Info Level 1 (previously distributed as SR-Info):

               Same number of files and records as Version 1
               Creates index files compatible with products C, D and E
               No network facilities
               EDIT allows appending records, and APPEND allows editing
                    existing records
               EDIT and BROWSE allow editing with a user-designed screen,
                    even from command line
               INDEX FROM allows a new index file, with same or different
                    name, to be created using expression of existing Info,
                    dBASE or Clipper index file




     For Advanced Users                                  For Advanced Users
     VP-Info Level 1 Reference Manual             Page 16       SECTION 1


               New scanning commands: MAXIMUM, MINIMUM
               Other new commands include:
                       LIMIT
                       SET CARRY
                       SET DIR
                       SET HEADING
               new functions implemented include:

                       ASC(
                       AT(
                       DELETED(
                       EOF(
                       IFF(
                       MAX(
                       MENU(
                       MIN(
                       NUMTOC(
                       SUBSTR(
                       UPPER(
               Some advanced functions, commands and options present in C,
                    D and E are not implemented in this version

          C.   VP-Info Version 2.  All features of VP-Info Level 1 plus:

               Unlimited number of records
               Maximum index size 32Mb; large enough for over 1,000,000
                    records with 15-character key
               Up to 10 data files open at one time
               EDIT and BROWSE allow editing with both a user-designed
                    screen and an ON FIELDS structure in programs
               SET file gives user control over how Info is loaded into
                    memory, including:
                       Up to 65 files open at one time
                       Up to 1000 fields in all data files open at one time
                       Special screen and sound effects implemented
                       Loading and running binary programs
               New commands implemented include:
                       New FIND variants: NEAREST, LAST, SEEK
                       MAXIMUM
                       MINIMUM
                       SET DIVZERO
               New functions implemented include:
                       CTONUM(
                       DBFX(
                       DIRX(
                       NDX(
                       RAND(
                       RECNO(

          D.   VP-Info Professional





     For Advanced Users                                  For Advanced Users
     VP-Info Level 1 Reference Manual             Page 16.1       SECTION 1


               Allow even larger index files
               New command:
                       OVERWRITE to
               New function:
                       IFKEY(

          E.   VP-Info Professional Network Edition
               Full support for DOS 3.1 and above network facilities,
                    including data and index files opened in LOCK, WRITE,
                    SHARE, and READ modes
               FILES and FILES ... ENDFILES structure enhanced to support
                    file modes and well as file redirection
               Commands implemented include:
                       LOCK
                       LOCK INDEXES
                       SET LOCK
                       SET NETWORK
                       UNLOCK
                       UNLOCK INDEXES                 SECTION 2. VP-Info Level 1 FILES AND VARIABLES



          In Conversational VP-Info Level 1 (interactive) and in
     VP-Info Level 1 programming, you deal with various file and variable
     types.  These are discussed in this section.



                                   2.1. Files


          VP-Info Level 1 uses different types of files; the type of the
     file is shown by the extension of the file name (this is the default
     extension; the commands allow the user to change the extensions with
     two exceptions: PRG and CPL).

          Data files (also called the database files) contain the data of
     the database.  The default extension is DBF.  Data files are created
     with the COPY, CREATE, and COPY STRUCTURE TO commands.  (See also
     MODIFY.)

          A data file contains a header describing the structure of the
     data file: the number of records, the number of fields in a record,
     and a description of each field (name, type, width, and for numerical





     Files                          VPI  VPIN                         Files          VP-Info Level 1 Reference Manual         Page 17        SECTION 2


     fields, the number of decimals).  The header is followed by the
     records.

          There are three types of data files used by VP-Info Level 1: Type
     1, Type 2, and Type 3.  From the user's point of view, it very seldom
     matters which type is used, and the type is "transparent."

          Type 1 data files can have up to 256 fields per record.  The size
     of the header is commensurate with the number of fields.  To create
     and use such data files, the SET FIELDS TO command has to be used.

          Type 2 data files are restricted to 32 fields per record.  The
     size of the header is fixed, it does not depend on the number of
     fields actually used.  Type 2 data files are identical with dBASE II
     data files.

          Type 3 data files can have up to 300 fields per record.  The size
     of the header is commensurate with the number of fields (but much
     larger than the header of a Type 1 data file with the same number of
     fields.  Type 3 data files are identical with dBASE III and IV data
     files without memo fields, although VP-Info permits more fields in a
     file than dBASE.

          The command CREATE can create data files of Types I and 2,
     although the default is Type 3.  The type can be changed in MODIFY,
     but the default is to leave type unchanged.  All commands can use data
     files of all three types.

          Index files are used to facilitate rapid access to the data in
     data files in a predetermined order for processing and reporting.  The
     default extension is NDX.  Index files are created with the INDEX
     command.

          Program files contain the programs.  There are two kinds: the
     source program (a text file with VP-Info Level 1 commands as text)
     with extension PRG and compiled program with extension CPL.  These
     extensions are compulsory!  (There is one exception, the CNF
     configuration file; see Section 1.5.)

          Report form files contain the specifications of a report.  The
     default extension is FRM.  These files are used by the REPORT command.

          Memory variable files contain the memory variables saved by the
     SAVE TO command.  The default extension is MEM.

          Sequential files (also called text files) contain "lines"; the
     end of line is marked by carriage return (ASCII code 13) and line feed
     (ASCII code 10).  A line can contain at most 254 characters.  The end
     of the file is marked by EOF (26).

          A set of functions -- ROPEN(, WOPEN(, READ(, WRITE(, IN(, OUT(,
     SSEEK(, and CLOSE( -- is provided to create, read, and write




     Files                          VPI  VPIN                         Files          VP-Info Level 1 Reference Manual         Page 18        SECTION 2


     sequential files in VP-Info Level 1 programs  Most word processors
     create (or have an option to create) sequential files.  Such files can
     then be utilized by VP-Info Level 1 programs.

          The WRITE command of VP-Info Level 1 creates and edits sequential
     files.  Since it is used primarily to work with program files, the
     default extension is PRG.

          There are text files with default extension TXT used by the SET
     ALTERNATE TO <file> command.

          Finally, VP-Info Level 1 can manipulate arbitrary DOS files with
     another set of functions -- ROPEN(, WOPEN(, GET(, PUT(, SEEK(, and
     CLOSE(.  A typical application of the use of DOS files is the
     conversion of a data file from one type to another.

          File names are requested by <file> in the command descriptions.
     <file> is the file name, usually, without extension.  If no extension
     is given, then the default extension is added by VP-Info Level 1.
     However, if the user types in an extension, this overrules the
     VP-Info Level 1 default extension (exceptions: PRG, CPL, and CNF are
     compulsory).

          The file name has to follow the rules set out by the operating
     system: there are at most 8 characters in a file name.  You cannot go
     wrong if the first character is a letter and the other characters are
     letters and numbers; spaces are never permitted.

          DOS devices include such names as PRN, CON, AUX, LPT1, COM2, etc.
     Any sequential or arbitrary file function, and most of the copy and
     spool commands, allow you to specify either an actual file or a
     device.

          Technically, input/output involving files is buffered, while
     input/output involving devices is not.  In VP-Info Level 1 you may
     choose to treat any device as either buffered or unbuffered, merely by
     adding a colon to the end of the name to have DOS treat it as an
     unbuffered device, and without a colon to designate a buffered file.

          In most cases it makes little difference how you treat a device;
     rules for when one technique is better than another is outside the
     scope of this manual.

          See your DOS manual for a complete list of DOS device names.












     Files                          VPI  VPIN                         Files          VP-Info Level 1 Reference Manual         Page 19        SECTION 2





                           2.2. Selecting Data Files


          Level 1 can use up to 6 data files at the same time, while both
     VP-Info Professional and VP-Info Professional Network Edition can use
     up to 10 at a time.  Each data file used is assigned a file number by
     which the data file can be referenced.  File number may be assigned in
     an arbitrary manner, subject to the cautions contained in Appendix A.

          Before activating a file, select a file number with the SELECT
     command.  To activate the first file as the data file CUST, and third
     file as the data file TRANS:

     1>SELECT 1
     1>USE cust
     1>SELECT 3
     3>USE trans

     Note how the VP-Info Level 1 prompt shows the file number selected.

          There are three ways to indicate which file in use is referenced:

          a. Choose the file number.  The choice remains in effect until
     otherwise specified.  This is done with the SELECT command.

     1>SELECT 2

     selects file 2.  All commands refer to it, all field names are checked
     in it.

          b. Choose a file number for one command only.  This is done by
     following the first word of the command by # and the file number.  For
     instance,

     1>LIST#2

     lists file 2, regardless of which one is presently selected.  (Note:
     there is no space before or after the # sign.)  Even if the command
     requires two or more words (e.g., COPY STRUCTURE TO), the first-word
     rule applies: COPY#2 STRUCTURE TO temp.

          This technique, called command redirection, can even be used to
     open the data files themselves, as follows:

     1>USE#1 cust
     1>USE#2 inven
     1>USE#3 trans






     Selecting Data Files           VPI  VPIN          Selecting Data Files          VP-Info Level 1 Reference Manual         Page 20        SECTION 2


          c. Refer to one field in a file.  This is done by field
     redirection, following the field with # and the file number.  For
     instance,

     DAVID#4

     refers to the field DAVID in file 4.

          In this manual, "the selected file" refers to the data file
     currently selected.  In the last series of commands, at the start,
     CUST is the selected file.  After the command:

     1>SELECT 3

     TRANS is the selected file.  Note that a SELECT command only selects a
     new file number; there may be no file used under that file number.



                                 2.3. Variables


          A VP-Info Level 1 variable is a storage area in which changing
     values can be stored.  If the storage is in a data file, the variable
     is called a field; if the storage is temporary, in the memory only,
     the variable is called a memory variable.

          VP-Info Level 1 also has a special type of variable called a
     system variable, including the contents of the ten function keys, date
     and time, default report title, and so on.  System variables are
     discussed in Section 2.6.  The name of a system variable starts with a
     colon.

          There can be only 128 active memory variables.  Since any one of
     these can be a matrix variable (see Section 2.5), only the available
     memory limits the number of memory variables.

          A variable is identified by its name.  A name is 1 to 10
     characters long; the first character must be a letter; the other
     characters are letters (converted to upper case), digits, :, and _
     (underline).

          Here are some examples of valid variable names:

     cost
     cost2
     m:cost
     first_name

          But note:






     Variables                      VPI  VPIN                     Variables          VP-Info Level 1 Reference Manual         Page 21        SECTION 2


     prof 2          invalid; space is not allowed in a name
     2cost           invalid; the first character must not be 2
     profitcenter    invalid; more than 10 characters

          If the variable name is too long, only the first 10 characters
     are used (so PROFITCENTER1 and PROFITCENTER2 are the same for
     VP-Info Level 1, and will be stored as PROFITCENT).

          VP-Info Level 1 uses a number of words in its vocabulary, the so
     called VP-Info Level 1 keywords (see Appendix B).  It is suggested
     that keywords not be used as variable names.  In fact, the first four
     letters of a variable name should be different from the first four
     letters of a VP-Info Level 1 keyword, since VP-Info Level 1 identifies
     a keyword by its first four letters.  See, however, Section A.

          A variable has a type: character, numeric, or logical.

          A.   A variable of character type is also called a string
               variable.  A string variable contains a string (a text
               line); it has a width, the number of characters it contains.

          B.   A numeric variable contains a number; it has a width (the
               number of digits and, optionally, a decimal point), and the
               number of decimals.

          C.   A logical variable contains a logical value: T (true, also
               t, Y, y) or F (false, also f, N, n).

          For a field, the type and the width (and for numeric fields, the
     decimals) are fixed by the structure of the data file.  For a memory
     variable, all these may change any time a new value is stored to the
     variable.

          Fields are defined with the CREATE command, when the data file is
     set up, or with the MODIFY STRUCTURE command when the structure of the
     data file is modified.  The value of fields may be changed by a number
     of commands: REPLACE, EDIT, BROWSE, @ GET, and so on.

          Fields can also be referenced with the file name: MENU[2] is the
     second field of the data file MENU; TEST[210] is field 210 of the data
     file TEST.  Thus fields can be referenced as elements of a matrix.

          Memory variables are defined (and redefined) with the commands:
     =, STORE, ACCEPT, AVERAGE, COUNT, INPUT, READ(), SUM, WAIT.  WRAP()
     redefines the value of a memory variable.  @ GET redefines the value
     of a memory variable but does not change its characteristics.

          Matrix variables are handled somewhat differently; see
     Section 2.5.

          A memory variable can be declared GLOBAL.  This means that when a
     program is chained to another, GLOBAL variables are passed to the new
     program.  See the commands GLOBAL and CHAIN in Section 4.3.



     Variables                      VPI  VPIN                     Variables          VP-Info Level 1 Reference Manual         Page 22        SECTION 2


     MEMO FIELDS.  Memo fields are a special form that allows variable-length
     text of up to about 20,000 characters to be added to a record.  The memo
     is actually kept in a file associated with the data file, sharing the
     same name but with a DBT extension. See WRITE, EDIT and TEXT for details.


                          2.4. Variable Look-Up Rules


          When VP-Info Level 1 finds an expression in a command, it has to
     work out its value.  It follows a strict order as follows to determine
     what the item is:

               1.   Is it a function?
               2.   Is it a numeric constant?
               3.   Is it a string constant?
               4.   Is it a system variable?
               5.   Is it a matrix variable?
               6.   Is it a redirected field (e.g. name#3)?
               7.   Is it a field in the selected data file?
               8.   Is it a memory variable?
               9.   Is it a logical constant?

     If still not found, VP-Info Level 1 gives up and issues a Variable not
     found" error message.

          Note that a variable should not have the same name as a field,
     and neither variables nor fields should have the same name as one of
     the logical constants Y, N, T, or F.  The potential for puzzling
     behavior is obvious.



                             2.5. Matrix Variables


          A memory variable can be defined as a matrix with the DIM
     command.  A matrix variable is counted as only one memory variable
     within the 128 limit on the number of memory variables.

          Any one matrix variable can occupy up to 64K memory in high
     memory.  The available high memory is shown by the STATUS command.
     See the command DIM on how to compute the memory requirement, and
     Appendix 1 (Section A.1) on how VP-Info Level 1 uses memory.

          Here is an example on how to define a matrix:

     1>DIM NUM a[2,5]
     1>a[1,1]=34.78
     1>a[1,2]=45.7
     1>a[2,2]=1234.71





     Matrix Variables               VPI  VPIN              Matrix Variables          VP-Info Level 1 Reference Manual         Page 23        SECTION 2


     1>a[1,1]=34.78
     1>a[1,2]=45.7
     1>a[2,2]=1234.71
     1>a[2,4]=1000
     1>? a
         34.78     45.70      0.00      0.00      0.00
          0.00   1234.71      0.00   1000.00      0.00

          The SET WIDTH TO command can be used to influence how many items
     from the matrix are displayed in a line.

          Matrix variables can be assigned values only with the = and STORE
     commands.  Instead of

     ok=READ(a[5])

     write

     ok=READ(temp)
     a[5]=temp

          There is no limitation on the use of matrix variables in
     expressions.  A matrix variable may occur at any place where a
     function may occur.  You may think of a matrix variable as a special
     type of function that can store values.

          The REPEAT loop is convenient to manipulate matrix variables.


                             2.6. System Variables


          System variables carry information necessary for the running of
     VP-Info Level 1.  The command LIST SYSTEM lists the system variables
     (with the exception of :TERMINAL):





















     System Variables               VPI  VPIN              System Variables          VP-Info Level 1 Reference Manual         Page 24        SECTION 2



     1>LIST SYSTEM

     Name          Type    Width    Contents
     :F1             C       5      HELP
     :F2             C      10      LIST STRU;
     :F3             C       6      WRITE
     :F4             C      10      LIST MEMO;
     :F5             C       7      BROWSE;
     :F6             C       5      STAT;
     :F7             C      12      ^wCONT;EDIT;
     :F8             C      11      LOCATE FOR
     :F9             C       5      FIND
     :F10            C       5      EDIT;
     :TIME           C       8      16:45:20
     :DATE           C      21      Monday, July 30, 1990
     :VERSION        C       4      510
     :SERIAL         C      10      2934906400
     :COMPANY        C      14      D&G Book Store
     :PICTURE        C      10      9999999.99
     :TITLE          C       1
     :UNDOC          C       1
     :KEY            N       8      13
     :AVAIL          N       8      0
     :FIELD          N       8      0
     :ERROR          N       8      0
     :MESSAGE        C       1
     :RETRY          N       8      25
     :USER           N       8      1
     :DIR            C       6      C:\TMP
     :NEAR           N       8      0
     :COLOR          N       8      48
     ** Total ** 28  variables... 216  bytes


          Function keys.  :F1 to :F10 are the system variables activated by
     pressing the keys <F1> to <F10>.  They can be assigned values with the
     commands =:

     :F1='street'

     or with the combination of Alt and function key.  For instance, Alt-
     F10 assigns the contents of the command line or editing field from the
     beginning to the cursor to <F10>.  See Section 1.2.

          :DATE and :TIME.  VP-Info Level 1 stores the date and time
     internally.  When VP-Info Level 1 is started, it reads the system date
     and time.  If you have a calendar card, the system date and time is
     the current date and time; otherwise, the date is 01/01/80 (or later)
     and the time is 00:00:00 at the time the computer was started.  (You
     can reset the system date and time with the operating system DATE and
     TIME commands.)




     System Variables               VPI  VPIN              System Variables          VP-Info Level 1 Reference Manual         Page 25        SECTION 2



          You can set VP-Info Level 1's date and time:

     1>:DATE='04/05/84'
     1>:TIME='08:12:56'

     (mm/dd/yy and hh:mm:ss format).

          The function TIME( returns the system time and sets :TIME to the
     system time.  The function DATE( with one parameter (the format)
     returns the date from :DATE in a specific format and rewrites :DATE to
     this format.  (See Section 3.4.)

          For instance,

     1>stamp=TIME()

     stores current system time to the memory variable STAMP, and resets
     :TIME.  The command

     1>REPLACE stamp WITH TIME()

     does the same for the field STAMP.

          :PICTURE. The :PICTURE system variable is a format for numbers
     (see Formatting numbers under the @ command).  This formats the
     display of all numeric memory variables and numeric expressions.  This
     format can be overridden by a format clause in TEXT or an @ command,
     or with the PIC( function.

          The system comes with :PICTURE as '999999.99'.  If you want
     higher precision, say three decimals:

     1>:PICTURE='999999.999'

          If you do not want fractions, but want millions:

     1>:PICTURE='9999999'

          The :PICTURE variable can contain format clauses with up to 12
     9s, with at many as 6 on the right side of the decimal point.

          It should be emphasized that the :PICTURE does not influence how
     VP-Info Level 1 stores or computes numbers; it only tells the language
     how to display them.

          Other system variables.  :VERSION contains the current version
     number of VP-Info Level 1.

          :SERIAL may contain the serial number.  Once VP-Info Level 1 is
     loaded, you may use this as a variable that survives a CLEAR command.





     System Variables               VPI  VPIN              System Variables          VP-Info Level 1 Reference Manual         Page 26        SECTION 2



          :COMPANY contains the company name.  This is used by the REPORT
     command.  (It can be changed to the name of the company you are
     reporting on.)

          :TITLE is the default title of a report.  See the REPORT command.

          :KEY is a numeric variable.  It contains the number generated by
     the last keystroke used to exit a process or execute a command.  See
     the function INKEY( for the definition of this number.  :KEY is used
     in VP-Info Level 1 programming to find out which key was pressed to
     abort or interrupt a procedure.

          :AVAIL contains the number of the next available volume in the
     current library file.  See SET LIBRARY command.

          :FIELD contains the number of the Get Table entry currently being
     processed. See ON FIELD command; VP-Info Professional only.

          :ERROR The current value of VP-Info Level 1's internal error
     variable.  Shows why execution of the last command failed.

          :MESSAGE The message from the MSG file associated with the error
     number contained in :ERROR

          :RETRY Controls what happens during network operations under VP-
     Info Professional Network Edition; has no meaning under other
     versions.

          :USER A number between 1 and 999 assigned to each user on a
     network under VP-Info Professional Network Edition.

          :DIR The user's current drive letter and directory.

          :NEAR The number of the record containing a key equal to or
     greater than the last FIND's FIND string.  See FIND command.

          :COLOR The current value of the color attribute written into the
     screen memory for every byte of screen display; set with SET COLOR TO
     or :COLOR= command.
















     System Variables               VPI  VPIN              System Variables
     VP-Info Level 1 Reference Manual           Page 27           SECTION 3





              SECTION 3. VP-Info Level 1 FUNCTIONS AND EXPRESSIONS


          In VP-Info Level 1, expressions are formed from variables and
     constants using operations, relations, and functions.  Section 2.3
     introduced variables.  In this section, you will find the other
     ingredients of expressions: constants, operations, relations, and
     functions.  Finally, the expressions themselves are discussed.



                                 3.1. Constants


          There are three types of constants: numeric, logical, and string.

          A numeric constant is a number (the minus sign is a part of it):

     12.78
     0.00064
     -3.14

          There are only two logical constants:  T (true, also written as
     t, Y, and y) and F (false, also written as f, N, and n).

          A string constant is a string in quotation marks:

     "This is a character constant."
     'This is another one, delimited with single quotation marks.'
     "Here's another one, enclosing a single quotation mark (apostrophe)
          within double quotes."
     "This is incorrect because the quotation marks do not match.'



                                3.2. Operations


          There are three types of operations: numeric, logical, and
     string.   Each works with constants and variables of that type, and
     yields a value of that type.

          The numeric operations are

     +     addition
     -     subtraction
     *     multiplication





     Operations                                                  Operations
     VP-Info Level 1 Reference Manual           Page 28           SECTION 3


     /     division

     2+3.2          yields 5.2
     10/4           yields 2.5

          All numeric operations require two numbers to act on.  - is also
     used to indicate that a number is negative: -2, -3.14.  Instead of
      -QTY, write 0-QTY or -1*QTY.

          There are three logical operations:

     .AND.
     .OR.
     .NOT.

          .AND. and .OR. take two logical values and yield a logical value:

     T.AND.T        yields:  T
     T.AND.F        yields:  F
     F.AND.T        yields:  F
     F.AND.F        yields:  F

     T.OR.T         yields:  T
     T.OR.F         yields:  T
     F.OR.T         yields:  T
     F.OR.F         yields:  F

          .NOT. takes a logical value and yields a logical value (the
     opposite):

     .NOT.T         yields:  F
     .NOT.F         yields:  T

          There is only one string operation:

     +     concatenation (placing one string after another)

     'This is a'+' sentence.'

     yields the value:

     This is a sentence.

          Note that one cannot mix numbers and strings:

     2+'string'

     will give a syntax error message (Error 1, see Appendix C).







     Operations                                                  Operations
     VP-Info Level 1 Reference Manual           Page 29           SECTION 3



                                 3.3. Relations


          A relation takes two numbers or two strings (compares them), and
     yields a logical value (true or false).

          There are six relations that compare numbers or strings:

     =     equal
     <     less than
     <=    less than or equal to
     >     greater than
     >=    greater than or equal to
     <>    not equal

          For numbers, these have their usual meaning:

     1<2            is true
     2<1            is false
     1.2<>5         is true
     1.2>=1         is true

          You should be careful when using = for numbers.  Two numbers may
     be displayed as equal while, in fact, they differ in the third or
     fourth decimal place.  Instead of

     num1=num2

     in many instances you could use

     ABS(num1-num2) < 0.01

     or

     (PIC(num1-num2,'9999.99'))=0

          For strings, string1=string2 is true if string2 is of the same
     length as string1, and the characters of string1 equal the
     corresponding characters of string2; if string2 has more characters,
     string1=string2 is always false.

          However, the result of comparing strings of unequal length, in
     which all of string2 is exactly the same as the beginning of string1,
     is affected by the setting of the "exact switch."  If SET EXACT OFF,
     then such string1=string2 is true,; with SET EXACT ON, it is false.

     Examples:

                           SET EXACT OFF       SET EXACT ON





     Relations                                                    Relations
     VP-Info Level 1 Reference Manual           Page 30           SECTION 3



          'abc'='abc'         true                true
          'abc '='abc'        true                false
          'abc'='abc '        false               false
          'abc'='ab'          true                false
          'ab'='abc'          false               false

          To make sure that two strings are really equal, write

     (string1=string2) .AND. (string2=string1)

     or SET EXACT ON.

          One way of remembering the above rule, is that string1=string2 if
     FIND with string2 finds string1.

          Although this definition of string1=string2 may at first sight
     seem awkward, it may really be quite useful both in Conversational
     VP-Info Level 1 and in VP-Info Level 1 programs.  For instance, the
     condition to select all customers (field: CUST) whose name starts with
     P:

     LEFT(cust,1)='P'         (or less efficiently SUBSTR(cust,1,1)='P')

     or

     cust='P'

     if SET EXACT OFF.

          For strings, string1 < string2 means: in a dictionary, string1
     would come before string2.  Single characters are compared by their
     ASCII value, see the functions CHR( and RANK(.  string1 is compared to
     string2 by comparing their first characters; if the first character of
     string1 is less than the first character of string2, then string1 <
     string2;  if they are equal, then the second character of string1 is
     compared to the second character of string 2, and so on.  Examples:

     'I am smaller' < 'I am bigger'    is false
     'David' < 'david'                 is true
     '122' > '17'                      is false
     '122' > '017'                     is true
     'seven' > '7'                     is true

          Note that in the ASCII sequence, all digits, 0 to 9, come before
     all upper-case letters, A to Z, which, in turn, come before all lower-
     case letters, a to z.

          Note that strings and numbers cannot be mixed in these relations:






     Relations                                                    Relations
     VP-Info Level 1 Reference Manual           Page 31           SECTION 3


     2 < '123'

     gives a syntax error message (Error 1, see list of error messages in
     Appendix).



                                 3.4. Functions


          A function is just like an operation; the addition operation (+)
     requires two arguments (numbers) and returns their sum; a function
     requires some arguments (0 to 3) and returns some value.

          Every function has a type: numeric, string, or logical, depending
     on the values it returns.

          A function has arguments; the values put into the function
     between the parentheses, separated by commas.  VP-Info Level 1
     functions have at most three arguments; a few have none.  Some
     arguments may be optional.

          The arguments can be variables or expressions of type string:
     <str var> or <str exp>, or of type numeric: <num var> or <num exp>.
     (Expressions are discussed in Section 3.5.)






























     Functions                                                    Functions
     VP-Info Level 1 Reference Manual           Page 32           SECTION 3



                                       !(

     Converts a string to upper case.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ !(<str exp>)                                                       ║
     ║                                                                    ║
     ║ <str exp>    the text to be converted to upper case                ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          All lower-case letters in the <str exp> are converted into upper
     case by the !( function.  See also the LOWER( function.

          Examples:

     1>a='Aa12b'
     1>? !(a)
     AA12B
     1>? !('David!')
     DAVID!

          Note that only the lower-case letters are changed.




























     !(                         VPI1  VPI  VPIN                          !(
     VP-Info Level 1 Reference Manual           Page 33           SECTION 3



                                       #

     Gets the current record number.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ #                                                                  ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function returns the record number of the current record of
     the selected file.  Note that ? # displays the current record number
     in the form specified by the system variable :PICTURE (see Section
     2.7).  VP-Info Level 1 also has a more general form of this function,
     RECNO(, which allows the user to specify file other than the selected
     file.

          When used with the option RECNO(filenum), it gives the record
     number of the current record in file filenum.

          Examples:

     1>USE employee
     1>? #
          1.00
     1>GO BOTTOM
     1>? #
          6.00
     1>GO TOP
     1>? #
          1.00
     1>SKIP 2
     1>? #
          3.00


















                                VPI1  VPI  VPIN                           #
     VP-Info Level 1 Reference Manual           Page 34           SECTION 3



                                       $(

     Gets a substring of a string.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ $(<str exp>, <start num exp>, <width num exp>)                     ║
     ║                                                                    ║
     ║ <str exp>         the string from which the new string is formed   ║
     ║ <start num exp>   the position from which the new string is        ║
     ║                     taken                                          ║
     ║ <width num exp>   the number of characters to place in the         ║
     ║                     new string                                     ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function takes the string in <str exp> from position <start
     num exp> (fractions are thrown away); the number of characters taken
     is <width num exp>.  (In both numeric expressions, the fractions are
     disregarded).

          Examples:

     1>name='David Barberr'
     1>? $(name, 7,3)
     Bar
     1>? $(name, 7,12)
     Barberr
     1>? LEN($(name,7,12))
           7.00

          Note that $(name,7,12) is of width 7, not 12; there are only 7
     letters left in name from position 7.

     1>s=3
     1>t=1
     1>? $(name+name, (s+t)/2, 1.9)
     a

          Note that 1.9 was taken as 1.












     $(                         VPI1  VPI  VPIN                          $(
     VP-Info Level 1 Reference Manual           Page 35           SECTION 3



                                       *

     Determines whether a record is deleted.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ *                                                                  ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          In the selected file, the current record pointer points at a
     record.  If this record has been marked for deletion (in BROWSE or
     EDIT, or with the DELETE command), then * gives the value T;
     otherwise, it is false.

          Example:


     1>USE employee
     1>DELETE RECORD 2
           1 DELETE(S)
     1>GO 2
     1>? *
     T




























     *                          VPI1  VPI  VPIN                           *
     VP-Info Level 1 Reference Manual           Page 36           SECTION 3



                                       @(

     Gets the location of a substring.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ @(<find str exp>, <str exp>)                                       ║
     ║                                                                    ║
     ║ <find str exp>    the string searched for                          ║
     ║ <str exp>         the text to be searched                          ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function finds out whether a string: <find str exp> occurs
     in the string: <str exp>.  If it occurs, the function returns the
     character position of the first (left-most) substring of <str exp>
     which is the same as <find str exp>; if it does not occur, the
     function returns a 0.

          Examples:

     1>greeting='Good morning'
     1>? @('oo', greeting)
           2.00
     1>? @('good',greeting)
           0.00

     In a program:

     IF @(answer,'YNQynq')=0

     checks whether the user response is correct.




















     @(                         VPI1  VPI  VPIN                          @(
     VP-Info Level 1 Reference Manual           Page 37           SECTION 3



                                      ASC(

     Converts a character to its ASCII number.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ ASC(<str exp>)                                                     ║
     ║                                                                    ║
     ║ <str exp>         the first character of this string is converted  ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          The characters in the character set used by the computer are
     numbered from 0 to 255.  For the first character of the string
     <str exp>, ASC( returns the corresponding number.  RANK( is a synonym
     for ASC(.  See also the functions CHR(, CTONUM(, and NUMTOC(.

          Examples:

     1>? ASC('x')
        120.00
     1>? ASC('xyz')
        120.00

          Note that only the first character of the string matters.



























     ASC(                       VPI1  VPI  VPIN                        ASC(
     VP-Info Level 1 Reference Manual           Page 38           SECTION 3



                                      AT(

     Gets the location of a substring . . . a synonym for @(

     ╔════════════════════════════════════════════════════════════════════╗
     ║ AT(<find str exp>, <str exp>)                                      ║
     ║                                                                    ║
     ║ <str exp>         the text to be searched                          ║
     ║ <find str exp>    the string searched for                          ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function is merely a synonym for @(. See @(.






































     AT(                        VPI1  VPI  VPIN                         AT(
     VP-Info Level 1 Reference Manual           Page 39           SECTION 3



                                      BIT(

     Bit-set function determines if a given bit is 0 or 1

     ╔════════════════════════════════════════════════════════════════════╗
     ║ BIT(<string>,<bit position>)                                       ║
     ║                                                                    ║
     ║ <string>          a string or string variable to test              ║
     ║ <bit position>    a numeric expression; position of a given bit    ║
     ║                      within <string>                               ║
     ╟─────────────────┐                                                  ║
     ║ Type: logical   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          Each character in the ASCII character set is identified by an
     eight-bit binary number from 0 to 255 inclusive.  Each bit may be
     either 0 or 1; for example, the letter A has a decimal value of 65 and
     a binary value of 01000001.

          When used with the SET( and RESET( functions, which turn specific
     bits to 1 or 0 respectively, the BIT( function can be used to access
     large amounts of logical data much more compactly than in a set of
     logical variables.  BIT( returns T (true) if the specified bit is set
     (0), F (false) if not set (0).

          Note: Bit positions are counted differently than in some other
     schemes. In these functions, all bits are counted from the left of the
     string starting at 1, so that each character contains bits numbered as
     follows:

          1.   Bits 1 to 8.
          2.   Bits 9 to 16.
          3.   Bits 17 to 24.
          . . . and so on

          Example in a program:

          To print the binary value of each character in an input string:

     SET RAW ON         ;eliminates spaces between listed output
     DO WHILE t
        ACCEPT 'Enter a short string for binary representation: ' TO string
        IF string=' '
           BREAK
        ENDIF
        ?
        REPEAT LEN(string)*8 TIMES VARYING position
           ?? IFF(BIT(string,position),'1','0')
           IF MOD(position,8)=0





     BIT(                       VPI1  VPI  VPIN                        BIT(
     VP-Info Level 1 Reference Manual           Page 40           SECTION 3


              ?? ' '
           ENDIF
        ENDREPEAT
     ENDDO

          Now run the program:

     Enter a short string for binary representation: Bit
     01000010 01101001 01110100
     Enter a short string for binary representation:











































     BIT(                       VPI1  VPI  VPIN                        BIT(
     VP-Info Level 1 Reference Manual           Page 41           SECTION 3



                                     BLANK(

     Creates a string of blanks or other specified characters.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ BLANK(<num exp>[,<charnum>])                                       ║
     ║                                                                    ║
     ║ <num exp>    a number from 0 to 255                                ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║ <charnum>    the ASCII number of the character used to fill the    ║
     ║                blank string; default is 32, the blank character    ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function creates a string of <num exp> blanks or other
     specified characters.

          When charnum is specified, many interesting effects can be
     created, particularly by using the special pattern characters in the
     IBM screen character set, 176-178, and the solid block character, 219.

          Examples:

     1>name='DAVID'
     1>? name+BLANK(15)+name
     DAVID               DAVID
     1>num=23
     1>? name+BLANK(num+5)+name
     DAVID                            DAVID
     1>? BLANK(20,65)
     AAAAAAAAAAAAAAAAAAAA



















     BLANK(                     VPI1  VPI  VPIN                      BLANK(
     VP-Info Level 1 Reference Manual           Page 42           SECTION 3



                                      CEN(

     Centers a line of text.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ CEN(<str exp>,<num exp>)                                           ║
     ║                                                                    ║
     ║ <str exp>    the text to be centered                               ║
     ║ <num exp>    the line width                                        ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function centers (from the present position) the text
     <str exp> in a line (column) with <num exp> characters.

          Examples:

     1>compiler='VP-Info Level 1'
     1>? CEN(compiler,40)
               VP-Info Level 1
     1>@ 10,20 SAY CEN('Center this',40)

          Note: the last command centers the text between columns 20 and
     60.



























     CEN(                       VPI1  VPI  VPIN                        CEN(
     VP-Info Level 1 Reference Manual           Page 43           SECTION 3



                                      CHR(

     Converts an ASCII number to character.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ CHR(<num exp>)                                                     ║
     ║                                                                    ║
     ║ <num exp>    a number from 0 to 255                                ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          The characters in the character set used by the computer are
     numbered from 0 to 255; this number for a character is called the
     ASCII number.  For a given <num exp> in this range, CHR(<num exp>) is
     the corresponding character.

          This function is useful to send control codes to the printer.
     For instance,

     1>? CHR(27)+CHR(120)+CHR(1)

     puts the Epson LQ-1500 printer into letter quality mode.

          The functions ASC( and RANK( do the reverse.  These functions
     combine nicely.  If the memory variable LETTER contains a letter of
     the alphabet (other than z or Z), then

     LETTER=CHR(ASC(LETTER)+1)

     places in LETTER the next letter of the alphabet.

          Examples:

          1.

     1>? CHR(120)
     x
     1>letter='C'
     1>? CHR(RANK(letter)+1)
     D

          2. To set a standard IBM or Epson printer into double-wide mode:

     1>SET PRINT ON
     1>? CHR(14)+'First line.'

     prints:




     CHR(                       VPI1  VPI  VPIN                        CHR(
     VP-Info Level 1 Reference Manual           Page 44           SECTION 3


     First line.                    in double-wide characters




















































     CHR(                       VPI1  VPI  VPIN                        CHR(
     VP-Info Level 1 Reference Manual           Page 45           SECTION 3



                                     CLOSE(

     Closes a DOS file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ CLOSE([filenum])                                                   ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>      the DOS file number (between 1 and 4)               ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function closes the DOS file (in particular, the sequential
     file) opened with the ROPEN( or WOPEN( function.  It returns T if
     successful, F otherwise.  See the functions ROPEN(, WOPEN(, SEEK(,
     SSEEK(, READ(, WRITE(, GET(, PUT(, IN(, OUT(, and CLOSE).

          If filenum is not specified, filenum=1 is the default.

          Example:

     1>ok=ROPEN('a:label.prg',3)
     1>? ok
     T
     1>ok=CLOSE(3)

























     CLOSE(                     VPI1  VPI  VPIN                      CLOSE(
     VP-Info Level 1 Reference Manual           Page 46           SECTION 3



                                      COL(

     Gets print column position.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ COL()                                                              ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function gives the current column position of the cursor; if
     the printer is on, it returns the column position of the printer head.
     See the commands SET PRINT ON and SET FORMAT TO PRINT, and the
     function ROW(.

          Example:

     @ ROW(),COL()+3 SAY 'Hello'

     prints 'Hello' starting three characters to the right of the end of
     the last printing.































     COL(                       VPI1  VPI  VPIN                        COL(
     VP-Info Level 1 Reference Manual           Page 47           SECTION 3



                                    CTONUM(

     Convert a hexadecimal string into a decimal number.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ CTONUM(<type>,<string exp>)                                        ║
     ║                                  VP-Info Professional only         ║
     ║ <type>         the length of the numeric value to be returned      ║
     ║ <string exp>   the string to be evaluated as a hexadecimal value   ║
     ╟─────────────────┐                                                  ║
     ║ Type: numeric   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          A general conversion function for converting hexadecimal values
     into decimal numbers.  Input can be any length string or string
     variable up to eight characters as follows:

           Type     String Length  Returns

             1      1 byte         integer 0 to 255
             2      2 bytes        integer -32768 to 32767
             4      4 bytes        integer +/- 2 billion
             8      8 bytes        a floating point number

          If string is shorter, conversion still assumes the string is the
     format of the given width.  When <type> is 1, this function is
     equivalent to RANK( or ASC(.

          The NUMTOC( and CHR( functions convert numbers into strings.

          Do not confuse these function with STR( and VAL(, which convert
     decimal numbers into their string representations, and vice versa.

          Examples:

     1>? CTONUM(1,'a')
          97.00
     1>? CTONUM(2,'ab')
       25185.00
     1>? CTONUM(4,'abc')
     6513249.00
     1>? CTONUM(4,'abcd')        ;number too large for format in :PICTURE
     **********









     CTONUM(                        VPI  VPIN                       CTONUM(
     VP-Info Level 1 Reference Manual           Page 48           SECTION 3


          Note to users of VP-Info Version 1:

           Though not in the original Version 1 documentation, a function
     called CONVERT( was added and documented in a disk file supplied to
     later purchasers.  This function was broken into two separate
     functions, CTONUM( and NUMTOC(, in the current version.  Existing
     programs that use CONVERT( will have to be modified to work as
     expected under the current versions.













































     CTONUM(                        VPI  VPIN                       CTONUM(
     VP-Info Level 1 Reference Manual           Page 49           SECTION 3



                                     DATE(

     Displays a date in a specific format.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ DATE(<type>[,<str exp>])                                           ║
     ║                                                                    ║
     ║ <type>           one of 9 type basic date-output formats           ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <str exp>        the date to be converted                          ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function with only <type> specified rewrites the current
     system date in :DATE in the format specified by the <type>, and
     displays the result.

          This function with two parameters  (the format and the date)
     returns the given date in the specified format.  :DATE is not
     effected.

          The <type> can be given in either of two forms, a name or number
     (numeric expression) as follows:

          Type           Date-output format

          1 or YMD       6-character format without slashes: yymmdd
          2 or MDY       8-character format with slashes: mm/dd/yy
          3 or Char      Spelled out: Month dd, yyyy
          4 or Full      Spelled out: Weekday, Month dd, yyyy; valid only
                            for years 1980-2079
          5 or Lchar     Last day of month spelled out in format 3 (Char)
          6 or DMY       11-byte string in format dd-MMM-yyyy (example
                            03-NOV-1990)
          7 or Variable  formatted without slashes according to SET DATE TO
                            command (See SET DATE TO)
          8 or Long      8-character format without slashes: yyyymmdd
          9 or Last      Last day of month in format 1 (YMD) or 8 (Long),
                            depending on whether SET DATE TO command set
                            year to YY or YYYY

          Shortcut: When specifying type by name, only the first character
          is usually required. The exception is for Lchar, Long and Last,
          which require two characters to resolve ambiguity. If only one is
          given, Lchar is assumed.




     DATE(                      VPI1  VPI  VPIN                       DATE(
     VP-Info Level 1 Reference Manual           Page 50           SECTION 3


          <str exp> must contain the date in one of the following formats:
               mmddyy     ddmmyy     yymmdd
               mmddyyyy   ddmmyyyy   yyyymmdd

          Optionally, a slash, a hyphen, or a space may be used to separate
     the elements of these formats.  For example, YY/MM/DD, YY-MM-DD,
     DD MM YYYY are all equally valid.

          There should be two digits each for month and the day, and two or
     four digits for the year.  01 3 92 is not acceptable.  If <str exp> is
     not acceptable, then DATE( returns a string of blanks.

          In the event of ambiguity, dates will be decoded in accordance
     with the format set in the SET DATE TO command.  For example:

          SET DATE TO      date          is interpreted as  Comment

          'ddmmyy'         11/03/90      March 11, 1990
          'mmddyy'         11/03/90      November 3, 1990
          'mmddyy'         11/03/60      November 3, 2060   all dates
                                                            converted to
                                                            range 1980-2079

          See also the system variable :DATE in Section 2 and the command
     SET DATE TO.

          Examples:

     1>:DATE= '10/05/90'
     1>? :DATE
     10/05/90
     1>? DATE()
     19901005
     1>? :DATE
     19901005
     1>? DATE(1)
     901005
     1>? :DATE
     901005
     1>? DATE(2)
     10/05/90
     1>? :DATE
     10/05/90
     1>? DATE(3)
     October 5, 1990
     1>? :DATE
     October 5, 1990
     1>? DATE(4)
     Saturday, October 5, 1990
     1>? :DATE



     DATE(                      VPI1  VPI  VPIN                       DATE(
     VP-Info Level 1 Reference Manual           Page 51           SECTION 3


     Saturday, October 5, 1990
     1>? DATE(4,'12/08/90')
     Sunday, December 8, 1990
     1>? :DATE
     Saturday, October 5, 1990
     1>? DATE(5,'90-30-27')
     March 31, 1990
     1>? DATE(6,'03  27 90')
     27-Mar-1990
     1>? :DATE
     Saturday, October 5, 1990










































     DATE(                      VPI1  VPI  VPIN                       DATE(
     VP-Info Level 1 Reference Manual           Page 52           SECTION 3



                                     DAYS(

     Computes dates and date differences in days.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ DAYS(<str exp1>,<str exp2>)                                        ║
     ║ DAYS(<str exp>,<num exp>)                                          ║
     ║                                                                    ║
     ║ In the first form:                                                 ║
     ║      <str exp1> and <str exp2> are dates                           ║
     ║ In the second form:                                                ║
     ║      <str exp> is a date and <num exp> is a number                 ║
     ║─────────────────────────┐                                          ║
     ║ Type: numeric/character │                                          ║
     ╚═════════════════════════╧══════════════════════════════════════════╝

          In the first form, DAYS( returns the number of days between the
     two dates.  The result is an integer.

          In the second form, DAYS( returns the date (as a string) which is
     <num exp> days past or before the date <str exp>.

          The string expressions containing dates can be of many different
     formats (see the DATE( function for more examples):

                    yy/mm/dd    yy-mm-dd    yyyy mm dd
                    mm/dd/yy    mm-dd-yy    mm dd yy

          There should be two digits each for yy, mm, and dd, and four
     digits for yyyy.  01 3 90 is not acceptable.

          In the second form, the date is returned in the format set with
     the SET DATE TO command (default: mmddyyyy).  If you wish a different
     format, use the DATE( function.  See also MONTHS( and SET DATE TO.

          Examples:

     1>? DAYS('04 06 90','04 29 90')
          23.00
     1>? DAYS('01/01/88','01 23 90')
         753.00
     1>? DAYS('01/01/90','01 23 88')
        -708.00
     1>? DAYS('01/01/91','01 02 91')
           1.00
     1>? DAYS('01/02/91','01 01 91')
          -1.00
     1>? DAYS('02/28/88','03 01 88')    ;leap year
           2.00



     DAYS(                      VPI1  VPI  VPIN                       DAYS(
     VP-Info Level 1 Reference Manual           Page 53           SECTION 3


     1>? DAYS('02/28/90','03 01 90')    ;not a leap year
           1.00
     1>? DAYS('04 03 90',30)
     050290
     1>? DAYS('02 03 90',30)
     030590
     1>? DAYS('02 03 90',-3)
     010490
     1>? DAYS('020390',-30)
     010490
     1>monthday='0203'
     1>offset=30
     1>? DAYS(monthday+'90',offset+1)
     030690

          DAYS( and DATE( may be combined to form complex expressions.  For
     instance, the end of the month closest to today in the form set in the
     SET DATE TO command:

     DATE(7,DAYS(DATE(2),-15))

          See DATE( and MONTHS( functions, and SET DATE TO command.































     DAYS(                      VPI1  VPI  VPIN                       DAYS(
     VP-Info Level 1 Reference Manual           Page 54           SECTION 3



                                      DBF(

     Allows access to data-file attributes of a file in use.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ DBF(<type>[,<filenum>])                                            ║
     ║                                                                    ║
     ║ <type>      the information required from the data file header     ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>   the data file number; default is the currently         ║
     ║               selected data file                                   ║
     ╟─────────────────────────┐                                          ║
     ║ Type: character/numeric │                                          ║
     ╚═════════════════════════╧══════════════════════════════════════════╝

          Each data file has a file head which contains information about
     its structure, most of which is displayed with the LIST STRUCTURE
     command.

          Using the DBF(, DBFX( and FLD( functions provides users access to
     this information in a programmable form suitable for display and use
     in expressions.

          The <type> can be given in either of two forms, a name or number
     (numeric expression) as follows:

          Type           Explanation                        Result

          1 or Type      file type ("1", "2" or "3")        string
          2 or Name      data file name                     string
          3 or Fields    number of fields in structure      integer
          4 or Records   number of records in file          integer
          5 or Indexes   number of indexes currently open   integer
          6 or Master    index number of master index       integer

          Shortcut: When specifying type by name, only the first character
          is required.

          Example:

     1>? DBF(type),DBF(n),DBF(fields),DBF(recs),DBF(indexes),DBF(master)
     1 CUSTOMER.DBF       9.00       4.00       2.00       1.00








     DBF(                       VPI1  VPI  VPIN                        DBF(
     VP-Info Level 1 Reference Manual           Page 55           SECTION 3


          Note to users of VP-Info Version 1:

          The DBF( function, though not in the original Version 1
     documentation, was added and documented in a disk file supplied to
     later purchasers.  Types 1 to 3 remain unchanged, but types 4 to 7 in
     the original DBF( function are now types 1 to 4 of the FLD( function.
     Existing programs that use DBF( may have to be modified to work as
     expected under the current versions.













































     DBF(                       VPI1  VPI  VPIN                        DBF(
     VP-Info Level 1 Reference Manual           Page 56           SECTION 3



                                     DBFX(

     Gives additional information about an open data file; an extension to
     the DBF( function.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ DBFX(<type> [,<filenum>])                                          ║
     ║                                  VP-Info Professional only         ║
     ║ <type>      one of three types of information as listed below      ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>   the data file number; default is the currently         ║
     ║               selected data file                                   ║
     ╟─────────────────┐                                                  ║
     ║ Type: logical   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          The DBF( and FLD( functions, available in both Level 1 and VP-Info
     Professional, provide information contained in the data file headers.

          VP-Info Professional provides this extended function to give
     three additional types of information in a programmable form suitable
     for display and use in expressions.

          The <type> can be given in either of two forms, a name or number
     (numeric expression) as follows:

          Type           Explanation

          1 or Filter    TRUE if a FILTER is in effect
          2 or Limit     TRUE if a LIMIT is in effect
          3 or Relation  TRUE if file is related to another

          Shortcut: When specifying type by name, only the first character
          is required.


          Examples:

     1>SET FILTER TO state='CA'
     1>? DBFX(filter)
     T
     1>? DBFX(r)
     F







     DBFX(                          VPI  VPIN                         DBFX(
     VP-Info Level 1 Reference Manual           Page 57           SECTION 3



                                    DELETED(

     Determines whether a record is deleted.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ DELETED(<filenum>)                                                 ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>    the number of the data file to be checked             ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          In a specified data file, the current record pointer points at a
     record.  If this record has been marked for deletion (in BROWSE or
     EDIT, or with the DELETE command), then DELETED( gives the value T;
     otherwise, it is false.

          This is a more general firm of the * function, which operates the
     same way as DELETED( but, because it allows no parameter, works only
     with the currently selected data file.

          Examples:

     1>? DELETED(4)
     T

























     DELETED(                   VPI1  VPI  VPIN                    DELETED(
     VP-Info Level 1 Reference Manual           Page 58           SECTION 3



                                      DIR(

     Get file information from disk directory.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ DIR([<filespec>])                                                  ║
     ║                                                                    ║
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filespec>    a string or string expression containing a file name ║
     ║                 (or skeleton using ? and/or * wildcards), with     ║
     ║                 optional drive and/or path specification           ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          Searches for specific files specified by the drive path,
     subdirectory and/or filename and provides specific information on
     files found.

          If an argument is given, it must be a string or string expression
     naming a file, with * and ? wildcards optional). Returns the first
     file name found matching <filespec>. If no match was found, blank is
     returned.

          If no argument is given, the previous <filespec> is used to find
     the next matching file. If no more matching file names are found,
     blank is returned.

          Examples:

     DIR('c:\path\*.bak')

     locates the first file with extension BAK in the subdirectory \PATH,
     while

     DIR('*.bak')

     locates the first file with extension BAK in the current directory.

          If a file is found with Form 1, entering DIR() with no parameters
     will locate the next file meeting the <filespec>.  This will continue
     until the response is a blank, indicating there are no more files
     meeting the <filespec>.


          Note to users of VP-Info Version 1:

          The DIR( function, though not in the original Version 1
     documentation, was added and documented in a disk file supplied to


     DIR(                       VPI1  VPI  VPIN                        DIR(
     VP-Info Level 1 Reference Manual           Page 59           SECTION 3


     later purchasers.  One of the forms of the original DIR( function has
     been made into a separate function, DIRX(.  Existing programs that use
     DBF( may have to be modified to work as expected under the current
     versions.

















































     DIR(                       VPI1  VPI  VPIN                        DIR(
     VP-Info Level 1 Reference Manual           Page 60           SECTION 3



                                     DIRX(

     Obtain additional information about file located with the DIR(
     function.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ DIRX(<type>)                                                       ║
     ║                                  VP-Info Professional only         ║
     ║ <type>    the name or number of the information required about     ║
     ║             a file                                                 ║
     ╟─────────────────────────┐                                          ║
     ║ Type: character/numeric │                                          ║
     ╚═════════════════════════╧══════════════════════════════════════════╝

          Once a file is identified with DIR(, additional information can
     be obtained from the DOS directory in a form suitable for use in a
     program.

          The <type> can be given in either of two forms, a name or number
     (numeric expression) as follows:

          Type           Explanation                         Result

          1 or Name      last file name found with DIR(      string
          2 or Size      size in bytes of last name found
                              with DIR(                      integer
          3 or Attribute DOS file attribute as follows       integer
                              1 - directory
                              2 - system
                              3 - hidden
                              4 - read only
                              5 - normal
          4 or Time      time file created or last updated   string
          5 or Date      date file created or last updated   string

          Shortcut: When specifying type by name, only the first character
          is required.

          These functions have many uses. Use them to write a program that
     backs up recently modified files, a program that lists files so the
     user can pick one, etc.

          Examples:

     DIR(n) returns the filename
     DIR(a) returns 4 if the file is read only






     DIRX(                          VPI  VPIN                         DIRX(
     VP-Info Level 1 Reference Manual           Page 61           SECTION 3



                                      EOF

     Gives the end-of-file flag for the currently selected data file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ EOF                                                                ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          If the current record pointer is on the last record of the file
     in use and a SKIP is issued, EOF returns T (true); otherwise it is F
     (false).  Since SKIP n is treated as n SKIP commands, EOF returns true
     if SKIP n goes past the last record.  Also, if a LOCATE or CONTINUE
     command is unsuccessful, or if NEAREST does not find an index key
     equal to or greater than the FIND string, EOF returns T.

          Examples:

     1>USE employee
     1>GO 4
     1>SKIP 2
     1>? #
           6.00
     1>? EOF
     F
     1>SKIP
     1>? EOF
     T
     1>GO 4
     1>SKIP 3
     1>? #
           6.00
     1>? EOF
     T

















     EOF                        VPI1  VPI  VPIN                         EOF
     VP-Info Level 1 Reference Manual           Page 62           SECTION 3



                                      EOF(

     Gives the end-of-file flag for a specified data file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ EOF([<filenum>])                                                   ║
     ║                                                                    ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>    the number of the data file to be checked             ║
     ╟─────────────────┐                                                  ║
     ║ Type: logical   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          For the data file number specified, if the current record pointer
     is on the last record and a SKIP is issued, EOF( returns T (true);
     otherwise it is F (false).  Since SKIP n is treated as n SKIP
     commands, EOF( returns true if SKIP n goes past the last record.

          Also, if a LOCATE or CONTINUE command is unsuccessful, or if
     NEAREST does not find an index key equal to or greater than the FIND
     string, EOF( returns T.

          An extended form of the EOF( function which, since it takes no
     parameter, works only on the currently selected data file.  If no
     <filenum> is specified, the current file is assumed.

          Examples:

     1>USE employee
     1>GO 4
     1>SKIP 2
     1>? #
           6.00
     1>? EOF()
     F
     1>SELECT 2
     2>SKIP
     2>? EOF()
     T
     2>GO BOTTOM
     2>SKIP
     2>? #
           6.00
     2>SELECT 1
     1>? EOF(2)
     T




     EOF(                       VPI1  VPI  VPIN                        EOF(
     VP-Info Level 1 Reference Manual           Page 63           SECTION 3



                                     FIELD(

     Get the number of the Get Table entry corresponding to a variable or
     field name.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ FIELD(<name>)                                                      ║
     ║                                                                    ║
     ║ <name>    the name of field or variable in a Get Table             ║
     ╟─────────────────┐                                                  ║
     ║ Type: numeric   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          While in full-screen editing mode (with READ, BROWSE, EDIT,
     etc.), each input variable and field is put into a Get Table that can
     be controlled with an ON FIELD structure.

          FIELD( returns the number from 1 to 64 of any editing field on
     screens created with @ GET and TEXT macros.  This function is usually
     used on an ON FIELD structure to redirect the sequence of data entry.

          See READ and ON FIELD in the Command Reference section.

          Example in a program:

     ON FIELD
     FIELD qty
        IF qty<0
           @ 22,0 say CEN('Quantity cannot be negative. Press any key',80)
           cc=INKEY()
           ERASE 22,22
           :FIELD=FIELD(qty)
        ENDIF
     ENDON


















     FIELD(                     VPI1  VPI  VPIN                      FIELD(
     VP-Info Level 1 Reference Manual           Page 64           SECTION 3



                                     FILE(

     Verifies whether a file exists.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ FILE(<str exp>)                                                    ║
     ║                                                                    ║
     ║ <str exp>         file name                                        ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function looks up the file whose name is given by <str exp>;
     if the file is found, the function returns T, otherwise it returns F.

          If no extension is given in the file name, DBF is assumed (a data
     file is looked for).  See also SET DEFAULT TO for the default drive.

          Examples:

     1>? FILE('employee')
     T
     1>? FILE('a:read.me')
     T
     1>mfile='read.me'
     1>? FILE(mfile)
     F
     1>? FILE('a:'+mfile)
     T























     FILE(                      VPI1  VPI  VPIN                       FILE(
     VP-Info Level 1 Reference Manual           Page 65           SECTION 3



                                      FLD(

     Get information about a field in a data file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ FLD(<type>,<fieldnum> [,<filenum>])                                ║
     ║                                                                    ║
     ║ <type>       one of the four attributes of a field                 ║
     ║ <fieldnum>   the number of the field to be checked                 ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>    the number of the data file to be checked             ║
     ╟─────────────────────────┐                                          ║
     ║ Type: character/numeric │                                          ║
     ╚═════════════════════════╧══════════════════════════════════════════╝

          Each field in a data file has four attributes as shown with the
     LIST STRUCTURE command: name, type, width and (for numeric variables)
     number of decimal places.  The FLD( function is often used in
     conjunction with the DBF( function.

          These attributes can be retrieved in a form suitable for use in a
     program with the FLD( function.

          The <type> can be given in either of two forms, a name or number
     (numeric expression) as follows:

          Type           Explanation                              Result


          1 or Name      string containing field name             string
          2 or Type      string containing field type             string
          3 or Width     number containing width of field         integer
          4 or Decimals  number of decimal places in field        integer

          Shortcut: When specifying type by name, only the first character
          is required.


          Example in a program:

     REPEAT DBF(records) TIMES varying fldnum
        REPEAT 4 times VARYING type
           ?? FLD(type,fldnum)
        ENDREPEAT
        ?
     ENDREPEAT




     FLD(                       VPI1  VPI  VPIN                        FLD(
     VP-Info Level 1 Reference Manual           Page 66           SECTION 3



                                      GET(

     Gets a string from a DOS file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ GET(<str var>,<width num exp>[,filenum])                           ║
     ║                                                                    ║
     ║ <str var>          stores the string                               ║
     ║ <width num exp>    the width of the string requested;              ║
     ║                      must be in range 1 to 254                     ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ filenum            the DOS file number (between 1 and 4)           ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function imports a string of <width num exp> characters from
     a DOS file opened with the ROPEN( function; the character number
     pointer is normally positioned with the SEEK( function.

          If successful in getting all the bytes requested, GET( returns T
     (true) and sets <str var> to the string imported from the file.  If
     <str var> does not exist, GET( will create it.

          If the function is unsuccessful, it returns F (false).  This will
     be the result if the GET( function tries to get data beyond the end of
     the file.  Note, however, that even if GET( returns F, one of more
     characters may still have been imported from the file; it is wise to
     check the value and width of <str var> to ensure part of a file is not
     lost.

          If filenum is not given, filenum=1 is assumed.

          GET( READ(, IN(, and WRAP( are the only functions that change the
     contents of the memory variable used as an argument.

          See also the functions ROPEN(, WOPEN(, CLOSE(, SEEK(, PUT(.

          Example in a program:

     IF ROPEN('test',3)
        DO WHILE GET(string,80,3)
           ? string
        ENDDO
     ENDIF
     ok=CLOSE(3)




     GET(                       VPI1  VPI  VPIN                        GET(
     VP-Info Level 1 Reference Manual           Page 67           SECTION 3



                                      IFF(

     Allows IF...THEN logic in expressions.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ IFF(<cond>,<exptrue>,<expfalse>)                                   ║
     ║                                                                    ║
     ║ <cond>       a logical expression                                  ║
     ║ <exptrue>    the expression to be returned if <cond> is TRUE       ║
     ║ <expfalse>   the expression to be returned if <cond> is FALSE      ║
     ╟─────────────────────────────────┐                                  ║
     ║ Type: character/numeric/logical │                                  ║
     ╚═════════════════════════════════╧══════════════════════════════════╝

          This function returns <exptrue> if <cond> is true, <expfalse>
     otherwise. The type of the value returned is the same as the
     expression selected by the condition.

     IFF( is very useful in the FIELDS line of reports or in commands such
     as SUM, AVERAGE, REPLACE, or LIST.

          Examples:

     1>? IFF(married,'Married','Single ')
     1>SUM IFF(quant>500, quant*price, 0),IFF(state='NY',1,0)

          The first command prints "Married" or "Single" according to the
     value of a logical field named MARRIED. The second command will return
     the sum of all quantities for transactions where quantity is greater
     than 500, and a count of all records where STATE='NY', thus combining
     two separate commands (SUM FOR and COUNT FOR) into one.

               Caution: do not use expressions of different types or widths
          in reports, since this may cause the REPORT command to fail.


















     IFF(                       VPI1  VPI  VPIN                        IFF(
     VP-Info Level 1 Reference Manual           Page 68           SECTION 3



                                      IN(

     Inputs a single character from a sequential file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ IN(<str var>[,<filenum>])                                          ║
     ║                                                                    ║
     ║ <str var>      stores the character                                ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>      the DOS file number (between 1 and 4)               ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function reads the next character of the DOS file (opened
     with the ROPEN( function) into the string variable <str var>; if
     <str var> does not exist, it will be created.  <str var> cannot be a
     matrix variable.

          If filenum is not given, filenum=1 is assumed.  IN( returns T if
     successful, F otherwise.

          This function is especially useful to communicate over the
     standard COM1, COM2 devices, for conversion of Word Star or other non-
     standard files to standard ASCII files, to encrypt/decrypt a file
     through a translation table.

          IN(, GET(, READ(, and WRAP( are the only functions that change
     the contents of the memory variable used as an argument.

          See the functions OUT(, ROPEN(, WOPEN(, SEEK(, SSEEK(, and
     CLOSE(.


















     IN(                        VPI1  VPI  VPIN                         IN(
     VP-Info Level 1 Reference Manual           Page 69           SECTION 3



                                     IFKEY(

     Tests if a character is waiting in the keyboard buffer.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ IFKEY()                                                            ║
     ║                                  VP-Info Professional only         ║
     ╟─────────────────┐                                                  ║
     ║ Type: logical   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          It is often useful to test whether a key has been pressed on the
     keyboard without waiting indefinitely if a key is not pressed.

          The IFKEY( function returns T (true) if a keystroke is waiting in
     the keyboard buffer, F (false) if not.  The keyboard buffer is not
     affected.

          Example in a program, to create a timing loop that ends as soon
     as any key is pressed:

     start=VAL(TIME(seconds))
     DO WHILE VAL(TIME(seconds))-start<3
        IF IFKEY()
           BREAK
        ENDIF
     ENDDO

























     IFKEY(                         VPI  VPIN                        IFKEY(
     VP-Info Level 1 Reference Manual           Page 70           SECTION 3



                                     INKEY(

     Waits and gets numeric value of keyboard entry.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ INKEY()                                                            ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function suspends program execution until a key is pressed.
     It returns a number identifying the key.  Nothing is displayed on the
     screen.  Any key can be read (except Alt, Ctrl, and shift which merely
     affect the characters produced by other keys) including all function
     keys, editing keys, and alternate keys.  (Function keys F11 and F12
     are not recognized by many computers' BIOS programs, and are ignored
     by VP-Info Level 1.)

          Standard keys are identified with their ASCII number; see the
     functions CHR( and ASC(.  Other keys return values between 256 and
     511.

          Examples:


                    Key                     INKEY()

                    Ctrl-C                    3
                    A                        65
                    Alt-A                   285
                    <F1>                    315
                    Shift-<F1>              340
                    Ctrl-<F1>               350
                    Alt-<F1>                360


          To find out the number identifying a key, give the command:

     1>? INKEY()

     and press <ENTER>, then the key; the character's number will be
     displayed.

          Using INKEY() the user can program his own EDIT, set up cursor
     controlled menus, and so on.







     INKEY(                     VPI1  VPI  VPIN                      INKEY(
     VP-Info Level 1 Reference Manual           Page 71           SECTION 3



                                    INSERT(

     Overwrites a string at a given position with another string.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ INSERT(<str expover>,<str exp>,<num exp>)                          ║
     ║                                                                    ║
     ║ <str expover>   the string expression to overwrite                 ║
     ║ <str exp>       the string expression to overwrite with            ║
     ║ <num exp>       the position                                       ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function takes the string in <str expover> and overwrites
     the string with <str exp> starting at position <num exp>.

          Examples:

     1>line='                              '
     1>customer='John Smith'
     1>ponumber='32109'
     1>amount='910.56'
     1>line=INSERT(line,customer,1)
     1>? line
     John Smith
     1>line=INSERT(line,ponumber,15)
     1>? line
     John Smith    32109
     1>line=INSERT(line,amount,25)
     1>? line
     John Smith    32109     910.56
     1>line='            c                 '
     1>newline=INSERT(line,customer,@('c',line))
     1>? newline
                 John Smith

          Note: The last example shows the use of INSERT( with "templates".
     The line variable is the template.  The character "c" in it designates
     the place where the customer has to be inserted.  Such templates are
     useful in report generators or for creating screen displays.











     INSERT(                    VPI1  VPI  VPIN                     INSERT(
     VP-Info Level 1 Reference Manual           Page 72           SECTION 3



                                     LEFT(

     Gets the left part of a string.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ LEFT(<str exp>, <num exp>)                                         ║
     ║                                                                    ║
     ║ <str exp>   the string from which the new string is formed         ║
     ║ <num exp>   the number of characters to place in the new string    ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function takes the first <num exp> characters from the
     string <str exp>.  It is equivalent to, but more efficient than,
     $(<str exp>, 1, <num exp>).

          If <num exp> is greater than the width of <str exp>, this
     function returns all of <str exp>.

          Wherever an expression calls for a substring starting at the
     beginning, use LEFT instead of $( or SUBSTR(.

          Example:

     1>a='David Bark'
     1>? LEFT(a,5)
     David
     1>? LEFT(a,50)
     David Bark






















     LEFT(                      VPI1  VPI  VPIN                       LEFT(
     VP-Info Level 1 Reference Manual           Page 73           SECTION 3



                                      LEN(

     Gets the width (length) of a string.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ LEN(<str exp>)                                                     ║
     ║                                                                    ║
     ║ <str exp>      the string                                          ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function returns the width (including trailing blanks) of
     the string <str exp>.

          Examples:

     1>name='David Barberr'
     1>? LEN(name)
         13.00
     1>? LEN(name+' is a nice boy')
         27.00

          Note that the width of a string is at least 1!




























     LEN(                       VPI1  VPI  VPIN                        LEN(
     VP-Info Level 1 Reference Manual           Page 74           SECTION 3



                                      LOC(

     Gets the current byte position in a file opened with ROPEN( or WOPEN(.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ LOC([<filenum>])                                                   ║
     ║                                                                    ║
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>    the number of the sequential or random file, 1 to 4   ║
     ║                (default 1)                                         ║
     ╟─────────────────┐                                                  ║
     ║ Type: numeric   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          Whenever a file is opened with the ROPEN( or WOPEN( function,
     VP-Info Level 1 maintains a pointer at a current position, which is
     where any PUT( or GET( function would take effect.  The position
     pointer is set with the SEEK( and SSEEK( functions, and reset every
     time the IN(, OUT, READ(, WRITE(, PUT(, and GET( function is used.

          If filenum is not given, filenum=1 is assumed.

          A common use of LOC( is to get the current position before a
     SEEK( so that the pointer can be reset to the original position after
     some operation.


























     LOC(                       VPI1  VPI  VPIN                        LOC(
     VP-Info Level 1 Reference Manual           Page 75           SECTION 3



                                     LOWER(

     Converts a string to lower case.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ LOWER(<str exp>)                                                   ║
     ║                                                                    ║
     ║ <str exp>        the text to be converted to lower case            ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          All upper-case letters in the <str exp> are converted into lower
     case by the LOWER( function.  See also the !( and UPPER( functions.

          Examples:

     1>a='Aa12b'
     1>? LOWER(a)
     aa12b
     1>? LOWER('David!')
     david!

          Note that only the upper-case letters, A-Z, are changed (to a-z).
     No other characters are affected.



























     LOWER(                     VPI1  VPI  VPIN                      LOWER(
     VP-Info Level 1 Reference Manual           Page 76           SECTION 3



                                     LTRIM(

     Trims blanks from the left-hand side of a string.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ LTRIM(<str exp>)                                                   ║
     ║                                                                    ║
     ║ <str exp>        the string to be trimmed                          ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function gets rid of the blanks on the left of a string.
     See also TRIM(.

          Examples:

     1>a='    David     '
     1>? a
         David
     1>? LEN(a)
         14.00
     1>? LTRIM(a)+' is trimmed on the left'
     David      is trimmed on the left
     1>? LEN(LTRIM(a))
          9.00
     1>blank='     '
     1>? LEN(LTRIM(blank))
          1.00

          Note: LTRIM(blank) is a single blank.





















     LTRIM(                     VPI1  VPI  VPIN                      LTRIM(
     VP-Info Level 1 Reference Manual           Page 77           SECTION 3



                                 Math Functions

     Mathematical functions package.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ Logarithmic functions:                                             ║
     ║    EXP(            e-th power                                      ║
     ║    LOG(            natural logarithmic function                    ║
     ║    LOG10(          base 10 logarithmic function                    ║
     ║    POW(            power                                           ║
     ║    SQRT(           square root                                     ║
     ║                                                                    ║
     ║ Trigonometric functions:                                           ║
     ║    SIN(            sine                                            ║
     ║    COS(            cosine                                          ║
     ║    TAN(            tangent                                         ║
     ║    ASIN(           arc sine                                        ║
     ║    ACOS(           arc cosine                                      ║
     ║    ATAN(           arc tangent                                     ║
     ║                                                                    ║
     ║ Hyperbolic functions:                                              ║
     ║    SINH(           hyperbolic sine                                 ║
     ║    COSH(           hyperbolic cosine                               ║
     ║    TANH(           hyperbolic tangent                              ║
     ║                                                                    ║
     ║ Integer valued functions:                                          ║
     ║                                                                    ║
     ║    CEIL(           ceiling integer                                 ║
     ║    FLOOR(          floor integer                                   ║
     ║    INT(            integer part                                    ║
     ║                                                                    ║
     ║  Real valued functions:                                            ║
     ║    ABS(            absolute value                                  ║
     ║    MOD(            modulo value                                    ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          The mathematical functions are divided into five groups:

     Logarithmic functions:

        EXP(<num exp>)               e to the power <num exp>
        LOG(<num exp>)               natural logarithm of <num exp>
        LOG10(<num exp>)             base 10 logarithm of <num exp>
        POW(<num exp1>,<num exp2>)   <num exp1> to the power <num exp2>
        SQRT(<num exp>)              square root of <num exp>





     Math Functions             VPI1  VPI  VPIN              Math Functions
     VP-Info Level 1 Reference Manual           Page 78           SECTION 3


     Trigonometric functions:

        SIN(<num exp>)               sine of <num exp> in radians
        COS(<num exp>)               cosine of <num exp> in radians
        TAN(<num exp>)               tangent of <num exp> in radians
        ASIN(<num exp>)              arc sine of <num exp>; returns a value
                                        in radians between -π/2 and π/2
        ACOS(<num exp>)              arc cosine of <num exp>; returns a
                                        value in radians between 0 and π
        ATAN(<num exp>)              arc tangent of <num exp>; returns a
                                        value in radians between -π/2 and
                                        π/2


     Hyperbolic functions:

        SINH(<num exp>)              hyperbolic sine of <num exp>
        COSH(<num exp>)              hyperbolic cosine of <num exp>
        TANH(<num exp>)              hyperbolic tangent of <num exp>


     Integer-valued functions:

         CEIL(<num exp>)             ceiling integer: the integer equal to
                                        or just above <num exp>
         FLOOR(<num exp>)            floor integer: the integer equal to or
                                        just below <num exp>
         INT(<num exp>)              the integer part of <num exp> (the
                                        fractional part is discarded)
                         Note that for positive numbers, INT( and FLOOR
                         return the same result, but for negative numbers,
                         INT( and CEIL( produce the same result.  This is
                         because discarding the decimal part of a real
                         number reduces its distance from zero.


     Real-valued functions:

         ABS(<num exp>)              absolute value of <num exp>
         MOD(<num exp1>,<num exp2>)  <num exp1> modulo <num exp1>: returns
                                        0 if <num exp2> is 0; returns the
                                        value num with the same sign as
                                        <num exp1>, less than <num exp2>,
                                        satisfying

                                            <num exp1>=i*<num exp2>+num

                                        for some integer i.






     Math Functions             VPI1  VPI  VPIN              Math Functions
     VP-Info Level 1 Reference Manual           Page 79           SECTION 3


          Examples:

     1>:PICTURE='999.999999'
     1>? EXP(1)
       2.718282                      this is the value of e
     1>? LOG(3)
       1.098612
     1>? LOG10(3)
       0.477121
     1>? POW(2,4)
      16.000000
     1>? POW(2,.5)
       1.414214
     1>? SQRT(4)
       2.000000
     1>? SQRT(2)
       1.414214
     1>? SIN(2)                      2 is in radians
       0.909297
     1>? ASIN(1)
       1.570796
     1>? 2*ASIN(1)
       3.141593                      this is, of course, π; store this to
                                        a variable if you need π
     1>? CEIL(3.14)
       4.000000
     1>? FLOOR(3.14)
       3.000000
     1>? INT(23.45)
      23.000000
     1>? INT(-23.45)
     -23.000000
     1>x=23.45
     1>? INT(10*x)
     234.000000
     1>x=23.999
     1>? INT(x)
      23.000000
     1>? INT(3.14)
       3.000000
     1>? FLOOR(-3.14)
      -4.000000
     1>? INT(-3.14)                  note that for negative numbers, INT(
      -3.000000                         and FLOOR( give different values
     1>? MOD(5,2)                    this is the remainder of 5
       1.000000                         divided by 2
     1>? MOD(-3.14, .7)
      -0.340000
     1>? ABS(-3.14)
       3.140000



     Math Functions             VPI1  VPI  VPIN              Math Functions
     VP-Info Level 1 Reference Manual           Page 80           SECTION 3


     1>:PICTURE='9999999.99'
     1>x=15.689
     1>? INT(x*100+.5)/100      Note: this is how to round to the
          15.69                        nearest penny
     1>x=15.244
     1>? INT(x*100+.5)/100
          15.24














































     Math Functions             VPI1  VPI  VPIN              Math Functions
     VP-Info Level 1 Reference Manual           Page 81           SECTION 3



                                      MAX(

     Compare two expressions of any type and return the larger.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ MAX(<exp1>,<exp2>)                                                 ║
     ║                                                                    ║
     ║ <exp1>    any expression                                           ║
     ║ <exp2>    any expression of the same type as <exp1                 ║
     ╟─────────────────────────────────┐                                  ║
     ║ type: character/numeric/logical │                                  ║
     ╚═════════════════════════════════╧══════════════════════════════════╝

          Given any two expressions of the same type, MAX( returns the
     higher value.  It must be remembered that string comparisons are based
     on the ASCII value of the characters in the two strings.  Comparing
     two logical expressions has no meaning.

          Examples:

     1>? MAX('hello','goodbye')
     hello






























     MAX(                       VPI1  VPI  VPIN                        MAX(
     VP-Info Level 1 Reference Manual           Page 82           SECTION 3



                                     MENU(

     Lightbar menu function; allows point-and-shoot selection from an on-
     screen menu.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ MENU(<choices>,<width>)                                            ║
     ║                                                                    ║
     ║ <choices>    the number of choices offered by the menu             ║
     ║ <width>      the width of the menu lightbar                        ║
     ╟─────────────────┐                                                  ║
     ║ Type: numeric   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          The MENU( function pauses program execution and superimposes a
     movable lightbar (reverse-video line) over a menu of selections
     previously written to the screen, usually with TEXT.

          The menu lightbar is moved up and down with the <Up> and <Dn>
     keys.  If you press <Dn> while on the bottom, the lightbar cycles
     automatically to the top.  Similarly, pressing <Up> while on the top
     cycles to the bottom.

          The user can select any item by moving the lightbar over it and
     pressing <ENTER>, or entering its line number as a one-digit number.
     In either case, the line number selected is returned by the function,
     and the key pressed stored in the system variable :KEY.  Both the
     function value and :KEY can be tested in a subsequent DO CASE
     structure to determine the program's next actions.

          If the user presses 0 or <Home>, MENU( returns zero, although the
     first line covered by the lightbar is 1.  Options over 9 can be
     accessed only by the lightbar.

          If any cursor key except <Up>, <Dn> and <Home> is pressed, MENU(
     returns the number of the line highlighted by the lightbar, and :KEY
     contains the key number that would be returned by the INKEY( function.
     (If SET FUNCTION OFF, all function keys have the same effect as these
     cursor keys.)

          While the MENU( function is active, all other typewriter keys are
     ignored.

          Examples:

          1. This is a program which shows specifically the values returned
     by Menu( when any key is pressed:





     MENU(                      VPI1  VPI  VPIN                       MENU(
     VP-Info Level 1 Reference Manual           Page 83           SECTION 3


     CLS
     @ 19,46 say 'Returns'
     @ 19,64 say ':KEY'
     DO WHILE t
        CURSOR 5,20
        var=MENU(10,20)
        @ 20,50 say var
        @ 20,65 say :KEY
     ENDDO

          2. In a real-life program:

     ERASE
     WINDOW 1,2,23,77 double            ;draw frame around screen
     @ 1,3 say DATE(full)
     @ 3,3 say CEN(:company,74)
     @ 5,3 say CEN('Payroll Menu',74)
     WINDOW 8,25,22,75 blank            ;use WINDOW to position TEXT
     TEXT paymenu                       ;menu text in external file
     WINDOW
     CURSOR 10,23
     ans=MENU(8,35)
     IF ans=0 .or. :key=335
        CHAIN MENU
     ENDIF
     @ ans+9,23 say CHR(16)             ; character as pointer
     DO CASE
     CASE ans=1
        ... etc.
























     MENU(                      VPI1  VPI  VPIN                       MENU(
     VP-Info Level 1 Reference Manual           Page 84           SECTION 3



                                      MIN(

     Compare two expressions of any type and return the smaller.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ MIN(<exp1>,<exp2>)                                                 ║
     ║                                                                    ║
     ║ <exp1>    any expression                                           ║
     ║ <exp2>    any expression of the same type as <exp1>                ║
     ╟─────────────────────────────────┐                                  ║
     ║ Type: character/numeric/logical │                                  ║
     ╚═════════════════════════════════╧══════════════════════════════════╝

          Given any two expressions of the same type, MIN( returns the
     lower value.  It must be remembered that string comparisons are based
     on the ASCII value of the characters in the two strings.  Comparing
     two logical expressions has no meaning.

          Examples:

     1>? MIN('Hello','Goodbye')
     Goodbye






























     MIN(                       VPI1  VPI  VPIN                        MIN(
     VP-Info Level 1 Reference Manual           Page 85           SECTION 3



                                    MONTHS(

     Computes date differences in months.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ MONTHS(<date1>,<date2>/<num exp>)                                  ║
     ║                                                                    ║
     ║ <date1>      a string expression containing a valid date           ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Options:                                                           ║
     ║                                                                    ║
     ║ <date2>      a string expression containing a valid date; when     ║
     ║                <date2> is specified, MONTHS( returns number of     ║
     ║                months between the two dates                        ║
     ║ <num exp>    number of months before or after date1; when          ║
     ║                specified, MONTHS( returns date that many months    ║
     ║                away                                                ║
     ╟──────────────────────────┐                                         ║
     ║ Type: character/numeric  │                                         ║
     ╚══════════════════════════╧═════════════════════════════════════════╝

          MONTHS( computes the difference between the two dates in months,
     or computes a date a given number of months before or after a
     specified date.  Fractional parts of months are discarded.

          If a computed date is after the last date of the month, the date
     will be adjusted to the last day of the month.  For example,
     MONTHS('013190',1) results in 022890.

          Examples:

     1>? MONTHS('04 06 90','04 29 90')
           0.00
     1>? MONTHS('01/01/90','02/01/90')
           1.00
     1>? MONTHS('02/01/90','01/01/90')
          -1.00
     1>? MONTHS('01/01/90','01/01/92')
          24.00
     1>? MONTHS('02/01/90',10)
     120190
     1>? MONTHS('01/01/90',-6)
     070189









     MONTHS(                    VPI1  VPI  VPIN                     MONTHS(
     VP-Info Level 1 Reference Manual           Page 86           SECTION 3



                                      NDX(

     Get information on index files in use.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ NDX(<type>,<indexnum> [,<filenum>])                                ║
     ║                                  VP-Info Professional only         ║
     ║ <type>       the name or number of the information required        ║
     ║ <indexnum>   the number of the index being checked (1 to 7)        ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>    the number of the data file to be checked             ║
     ╟─────────────────────────┐                                          ║
     ║ Type: character/logical │                                          ║
     ╚═════════════════════════╧══════════════════════════════════════════╝

          NDX( is used to primarily in programs to get the information on
     the current environment in a form suitable for use in expressions.

          The <type> can be given in either of two forms, a name or number
     (numeric expression) as follows:

          Type           Explanation                         Result

          1 or Name      name of index file                   string
          2 or Key       key on which index was created       string
          3 or DBF_Name  name of data file on which index
                           was created                        string
          4 or Filter    TRUE if filter or FOR clause was
                          in effect when index was created    logical

          Shortcut: When specifying type by name, only the first character
          is required.


          Examples:

     1>? NDX(n),NDX(key),NDX(dbf),NDX(filter)
     CUST1.NDX CUSTNUM  CUSTOMER.DBF F












     NDX(                           VPI  VPIN                          NDX(
     VP-Info Level 1 Reference Manual           Page 87           SECTION 3



                                    NUMTOC(

     Convert a decimal number to a hexadecimal string.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ NUMTOC(<type>,<number>)                                            ║
     ║                                  VP-Info Professional only         ║
     ║ <type>      the length of the string to be created                 ║
     ║ <number>    the number to be converted                             ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          A general conversion function for converting decimal numbers into
     hexadecimal values.  Input can be any number, and the returned string
     length can be up to eight characters as follows:

          The <type> can be given in either of two forms, a name or number
     (numeric expression) as follows:

           Type      Range of Number            String Length Returned

             1      integer 0 to 255            1 byte
             2      integer -32768 to 32767     2 bytes
             4      integer +/- 2 billion       4 bytes
             8      a floating point number     8 bytes

          Shortcut: When specifying type by name, only the first character
          is required.

          Types 1, 2 and 4 return hexadecimal integers.  Any fractional
     parts are ignored.

          When <type> is 1, this function is equivalent to CHR(.  Values
     outside the range of 0 to 155 return the modulus of 256 for type 1.

          The CTONUM(, RANK( and ASC( functions convert strings into
     numbers.

          Do not confuse these function with STR( and VAL(, which convert
     decimal numbers into their string representations, and vice versa.

          Examples:

     1>? NUMTOC(1,97)
     a
     1>? NUMTOC(2,25185)
     ab
     1>? NUMTOC(4,6513249)



     NUMTOC(                        VPI  VPIN                       NUMTOC(
     VP-Info Level 1 Reference Manual           Page 88           SECTION 3


     abc


          Note to users of VP-Info Version 1:

           Though not in the original Version 1 documentation, a function
     called CONVERT( was added and documented in a disk file supplied to
     later purchasers.  This function was broken into two separate
     functions, CTONUM( and NUMTOC(, in the current version.  Existing
     programs that use CONVERT( will have to be modified to work as
     expected under the current versions.










































     NUMTOC(                        VPI  VPIN                       NUMTOC(
     VP-Info Level 1 Reference Manual           Page 89           SECTION 3



                                      OUT(

     Outputs a single character to a sequential file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ OUT(<str var> [,<filenum>])                                        ║
     ║                                                                    ║
     ║ <str var>      contains the character                              ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ (filenum>      the DOS file number (between 1 and 4)               ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function outputs the character in <str var> to the
     sequential file (opened with the WOPEN( function).

          If filenum is not given, filenum=1 is assumed.  OUT( returns T if
     successful, F otherwise.

          This function is especially useful to communicate over the
     standard COM1, COM2 devices, for conversion of Word Star or other non-
     standard files to standard ASCII files, to encrypt/decrypt a file
     through a translation table.

          See the functions IN(, ROPEN(, WOPEN(, CLOSE(, SEEK(, SSEEK(,
     READ(, and WRITE(.























     OUT(                       VPI1  VPI  VPIN                        OUT(
     VP-Info Level 1 Reference Manual           Page 90           SECTION 3



                                      PIC(

     Formats a number or string.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ PIC(<exp>,<format>)                                                ║
     ║                                                                    ║
     ║ <exp>                 is the number or string to be formatted      ║
     ║ <format>              the format clause                            ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function returns the <exp> formatted with the format clause
     <format>.  See the command @ for the description of the format
     clauses.  PIC( is especially useful in preparing numeric values for
     printing.

          PIC( always returns a string, even when a number or numeric
     expression is being formatted.

          Examples:

     1>number=1123.89
     1>format='9,999.99'
     1>? PIC(number,format)
     1,123.89
     1>format='9999'
     1>? PIC(number,format)
     1123
     1>format='$$$,$$$.99'
     1>? PIC(number,format)
      $1,123.89
     1>format='$$$,$$$.999'
     1>? PIC(number,format)
      $1,123.89
     1>string='abcd'
     1>format='xX9!'
     1>? PIC(string,format)
     abcd
     1>format='X-X-X-X'
     1>? PIC(string,format)
     a-b-c-d
     1>SET ZERO ON
     1> ? 0,'|',str(0,5,2),'|',pic(0,'99.99'),'|','0'
           0.00 |  0.00 |  0.00 | 0
     1>SET ZERO OFF
     1> ? 0,'|',str(0,5,2),'|',pic(0,'99.99'),'|','0'
                |  0.00 |       | 0



     PIC(                       VPI1  VPI  VPIN                        PIC(
     VP-Info Level 1 Reference Manual           Page 91           SECTION 3























































     PIC(                       VPI1  VPI  VPIN                        PIC(
     VP-Info Level 1 Reference Manual           Page 92           SECTION 3



                                    PRINTER(

     Test whether a printer is ready to print.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ PRINTER([<printernum>])                                            ║
     ║                                                                    ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <printernum>  the number of the LPT port (1 or 2)                  ║
     ╟─────────────────┐                                                  ║
     ║ Type: logical   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          Whenever a program has to print, it needs a printer turned on and
     on-line.  When it is unsuccessful in printing, VP-Info Level 1
     intercepts the customary DOS error (the infamous "Abort, Retry,
     Ignore?") and ends execution.

          The PRINTER( function gives programmers a way to ensure the
     printer is correctly set up before sending output to the screen.  This
     makes it possible to suspend execution under program control, prompt
     for correction action, or even SPOOL the output to a disk file instead
     of the printer.

          Examples in programs:

     DO WHILE .NOT. PRINTER()
        WINDOW 10,10,15,69 DOUBLE
        @ 12,10 SAY CEN('Turn on printer and press any key . . .',60)
        RING
        CURSOR 13,39
        cc=INKEY()
        WINDOW
     ENDDO

     IF .NOT. PRINTER(2)                 ;test LPT2
        SPOOL printfil
     ENDIF

     IF PRINTER()
        SET PRINT ON
     ENDIF








     PRINTER(                   VPI1  VPI  VPIN                    PRINTER(
     VP-Info Level 1 Reference Manual           Page 93           SECTION 3



                                      PUT(

     Puts a string into a DOS file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ PUT(<str exp>[,filenum])                                           ║
     ║                                                                    ║
     ║ <str exp>         the string to overwrite with                     ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>         the DOS file number (between 1 and 4)            ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          A DOS file was opened with the WOPEN( function; the character
     number pointer was normally positioned with the SEEK( function.  This
     function overwrites the file from the character chosen by the
     character number pointer with the string <str exp>.

          If filenum is not given, filenum=1 is assumed.  PUT( returns T if
     successful, F otherwise.

          See also the functions ROPEN(, WOPEN(, CLOSE(, SEEK(, and GET(.

          Examples:

     1>byte=CHR(13)
     1>ok=WOPEN('test',3)
     1>ok=SEEK(5221)
     1>ok=PUT(byte,3)




















     PUT(                       VPI1  VPI  VPIN                        PUT(
     VP-Info Level 1 Reference Manual           Page 94           SECTION 3



                                     RAND(

     Gives a random number in the range 0<=n<1.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ RAND([<seed>])                                                     ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <seed>    a number used to initiate the random series              ║
     ╟─────────────────┐                                                  ║
     ║ Type: numeric   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          A series of successive calls to the RAND( function will return a
     uniform distribution of random numbers.

          The first time RAND( is called, <seed> -- any numeric expression
     -- may be specified. All subsequent calls should be without the seed.
     If no initial seed is provided, a random seed is chosen by the
     program.

          RAND( always returns a number equal to or greater than 0 and less
     than 1.  If you need a random series of integers between zero and
     5000, use 5000*RAND().

          Note: if you provide the initial seed, every execution of RAND()
     will return the same series of numbers.
























     RAND(                    VPI1  VPI  VPIN                         RAND(
     VP-Info Level 1 Reference Manual           Page 95           SECTION 3



                                     RANK(

     Converts a character to its ASCII number.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ RANK(<str exp>)                                                    ║
     ║                                                                    ║
     ║ <str exp>      the first character of this string is converted     ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          The characters in the character set used by the computer are
     numbered from 0 to 255.  For the first character of the string
     <str exp>, RANK( returns the corresponding number.  See also the
     function CHR(.  See also the functions CHR(, CTONUM(, and NUMTOC(.

          Examples:

     1>? RANK('x')
        120.00
     1>? RANK('xyz')
        120.00

          Note that only the first character of the string matters.



























     RANK(                      VPI1  VPI  VPIN                       RANK(
     VP-Info Level 1 Reference Manual           Page 96           SECTION 3



                                     READ(

     Reads a line of a sequential file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ READ(<str var>[,<filenum>])                                        ║
     ║                                                                    ║
     ║ <str var>      stores the line read in                             ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>      the DOS file number (between 1 and 4)               ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function reads the next line of the sequential file (opened
     with the ROPEN( function) into the string variable <str var>.  If
     <str var> does not exist, it will be created;  <str var> cannot be a
     matrix variable.

          A line is terminated by the carriage return character (ASCII 13).
     Since the line is read into a string variable, it cannot be longer
     than 254 characters.

          If filenum is not given, filenum=1 is assumed.  READ( returns T
     if successful, F otherwise.

          In VP-Info Level 1 programs, READ( normally appears in an IF or
     DO WHILE command.

          READ(, IN(, GET(, and WRAP( are the only functions that change
     the contents of the memory variable used as an argument.

          See Programming VP-Info Level 1 for sequential file handling and
     examples, and++ the functions WRITE(, ROPEN(, WOPEN(, CLOSE(, IN(,
     OUT(, and SSEEK(.

          Examples:

          1. In Conversational VP-Info Level 1:

     1>ok=ROPEN('a:label.prg')
     1>ok=READ(line)
     1>? line

          2. Two programs to print a text file, TEST (in the second version
     it is assumed that TEST has no more than 20 lines):




     READ(                      VPI1  VPI  VPIN                       READ(
     VP-Info Level 1 Reference Manual           Page 97           SECTION 3


     SET WIDTH TO 80
     SET PRINT ON
     IF ROPEN('test')
        DO WHILE READ(line)
           ? line
        ENDDO
        ok=CLOSE()
     ENDIF

     DIM CHAR 80 matrix[20]
     SET WIDTH TO 80
     SET PRINT ON
     IF ROPEN('test',1)
        REPEAT 20 times VARYING num
           IF READ(input,1)
              matrix[num]=input,
           ELSE
              BREAK
           ENDIF
        ENDREPEAT
        IF CLOSE(1)
           ? matrix
        ENDIF
     ENDIF





























     READ(                      VPI1  VPI  VPIN                       READ(
     VP-Info Level 1 Reference Manual           Page 98           SECTION 3



                                     RECNO(

     Gets the current record number in any open data file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ RECNO([<filenum>])                                                 ║
     ║                                                                    ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>    the number of any open data file; default is the      ║
     ║                selected data file                                  ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function returns the record number of the current record of
     any specified data file; if no <filenum> is given, returns the record
     number the selected file.  Note that ? RECNO() displays the current
     record number in the form specified by the system variable :PICTURE
     (see Section 2.7).

          VP-Info Level 1 also has a more limited form of this function,
     RECNO(, which applies only to the selected data file.

          Examples:

     1>USE employee
     1>USE#2 customer
     1>? RECNO(1)
          1.00
     1>GO BOTTOM
     1>? RECNO(1)
          6.00
     1>GO TOP
     1>? RECNO()
          1.00
     1>SKIP#2 2
     1>? RECNO(2)
          3.00












     RECNO(                     VPI1  VPI  VPIN                      RECNO(
     VP-Info Level 1 Reference Manual           Page 99           SECTION 3



                                    REMLIB(

     Removes a library entry.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ REMLIB(<volume>)                                                   ║
     ║                                                                    ║
     ║ <volume>        the number of the library entry to be removed.     ║
     ╟─────────────────┐                                                  ║
     ║ Type: logical   │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function deletes a library entry.  The function accepts the
     library volume number you wish to delete as its argument and returns T
     (true) if the delete operation was successful, F (false) if not.

          Once a library entry (volume) is deleted, its space in the
     library is made available for new text.

          Libraries are created with the SET LIBRARY TO command. See TEXT
     and WRITE commands.

          Example:

     1>? REMLIB(50)
     T


























     REMLIB(                    VPI1  VPI  VPIN                     REMLIB(
     VP-Info Level 1 Reference Manual           Page 100          SECTION 3



                                    REPLACE(

     Replaces, in a string expression, all occurrences of a string with
     another string.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ REPLACE(<str exp>,<str exp1>,<str exp2>)                           ║
     ║                                                                    ║
     ║ <str exp>      replace in this string expression                   ║
     ║ <str exp1>     all occurrences of this string                      ║
     ║ <str exp2>     with this string                                    ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function looks up the first occurrence of <str exp1> in the
     string <str exp>.  This occurrence is replaced with <str exp2>.  This
     process continues as long as <str exp1> occurs in <str exp>.

          Examples:

          1. A field contains a number as right justified characters,
     padded on the left with blanks.  The following REPLACE( changes these
     numbers to right justified numbers padded on the left with zeros.

     1>number='     123'
     1>number=REPLACE(number,' ','0')
     1>? number
     00000123

          2. In writing checks, dollar amounts may be left padded with
     dollar signs:

     1>number='     123.11'
     1>number=REPLACE(number,' ','$')
     1>? number
     $$$$$123.11

          3. Renaming a variable in a program line.  The variable OLDN is
     renamed FIRSTNUMB.

     1>line='newn=oldn+oldn+(oldn/3)'
     1>line=REPLACE(line,'oldn','firstnumb')
     1>? line
     newn=firstnumb+firstnumb+(firstnumb/3)







     REPLACE(                   VPI1  VPI  VPIN                    REPLACE(
     VP-Info Level 1 Reference Manual           Page 101          SECTION 3



                                     RESET(

     Sets a bit in a string to 0.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ RESET(<str exp>,<bit position>)                                    ║
     ║                                                                    ║
     ║ <str exp>       the string or string expression on which the       ║
     ║                   function is to act                               ║
     ║ <bit position>  the number of the bit, numbered from the left      ║
     ║                   starting at 1, which is to be set to zero        ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          A bit is any of the eight binary digits in a character's ASCII
     number representation.  Each bit can have only one of two possible
     values, 0 and 1.

          The SET( and RESET( functions are used to manipulate the bits
     within a string or string expression.  SET( makes a bit 1, and RESET(
     makes a bit 0.  The BIT( function tests the value of a specific bit.

          Among the chief uses for these functions is compression of
     logical (true/false) data by using just one bit for each data item
     instead of an entire byte for a logical field or two bytes for a
     logical variable.

          See the BIT( function for programming examples.

          Examples:

     1>str='PS'
     1>? BIT(str,15)
     T
     1>str=RESET(str,15)
     1>? str,BIT(str,15)
     PQ F














     RESET(                     VPI1  VPI  VPIN                      RESET(
     VP-Info Level 1 Reference Manual           Page 102          SECTION 3



                                     RIGHT(

     Gets the right-hand part of a string.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ RIGHT(<str exp>, <num exp>)                                        ║
     ║                                                                    ║
     ║ <str exp>   the string from which the new string is formed         ║
     ║ <num exp>   the number of characters to place in the new string    ║
     ╟─────────────────┐                                                  ║
     ║ Type: character │                                                  ║
     ╚═════════════════╧══════════════════════════════════════════════════╝

          This function returns the last (that is, the rightmost) <num exp>
     characters from the string <str exp>.

          If <num exp> is greater than the width of <str exp>, this
     function returns all of <str exp>.

          Example:

     1>a='David Bark'
     1>? RIGHT(a,5)
      Bark
     1>? RIGHT(a,50)
     David Bark


























     RIGHT(                     VPI1  VPI  VPIN                      RIGHT(
     VP-Info Level 1 Reference Manual           Page 103          SECTION 3



                                     ROPEN(

     Opens a DOS file for reading.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ ROPEN(<str exp> [,filenum])                                        ║
     ║                                                                    ║
     ║ <str exp>      the file name                                       ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ filenum        the DOS file number (between 1 and 4)               ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function opens <str exp>, a DOS file (in particular, a
     sequential file or input device, such as COM1), for reading only.  The
     current position pointer (see the SEEK( function) is set to the
     beginning of the file.

          If filenum is not given, filenum=1 is assumed.  If no file
     extension is given, the extension TXT is used.

          ROPEN( returns T if successful, F otherwise.

          See the functions WOPEN(, CLOSE(, READ(, WRITE(, IN(, OUT(, GET(,
     PUT(, SEEK(, and SSEEK(.

          Examples:

     1>? ROPEN('a:label.prg')
     T

          In a VP-Info Level 1 program, ROPEN( normally appears in an IF
     command:

     IF ROPEN('file',2)
        DO WHILE READ(data,2)
           ? data
        ENDDO
        ok=CLOSE(2)
     ENDIF









     ROPEN(                     VPI1  VPI  VPIN                      ROPEN(
     VP-Info Level 1 Reference Manual           Page 104          SECTION 3



                                      ROW(

     Gets print row position.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ ROW()                                                              ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function gives the current row (line) position of the
     cursor; if the printer is on, it returns the column position of the
     printer head.  See the commands SET PRINT ON and SET FORMAT TO PRINT,
     and the function COL(.

          Example:

     @ ROW()+1,COL()+3 SAY 'Hello'

     prints 'Hello' starting on the next line three characters to the right
     of the end of the last printing.































     ROW(                       VPI1  VPI  VPIN                        ROW(
     VP-Info Level 1 Reference Manual           Page 105          SECTION 3



                                     SEEK(

     Goes to a given character number in a DOS file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ SEEK(<num exp> [,filenum])                                         ║
     ║                                                                    ║
     ║ <num exp>      the character number                                ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>      the DOS file number (between 1 and 4)               ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function repositions the character number pointer in the DOS
     file (opened with the ROPEN( or WOPEN( function) to the value given by
     <num exp>.

          If filenum is not given, filenum=1 is assumed.  If no file
     extension is given, the extension TXT is used.

          If SEEK( is successful, it returns T (true); otherwise F (false).
     In a VP-Info Level 1 program, SEEK( normally occurs in an IF or DO
     WHILE command.

          Once the character pointer is properly positioned, use the GET(
     and PUT( functions to manipulate the characters.

          See the functions SSEEK(, ROPEN(, WOPEN(, CLOSE(, GET(, and PUT(.

          Example:

     1>ok=ROPEN('a:label.prg',4)
     1>ok=SEEK(522,4)
















     SEEK(                      VPI1  VPI  VPIN                       SEEK(
     VP-Info Level 1 Reference Manual           Page 106          SECTION 3



                                      SET(

     Sets a bit in a string to 1.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ SET(<str exp>,<bit position>)                                      ║
     ║                                                                    ║
     ║ <str exp>       the string or string expression on which the       ║
     ║                   function is to act                               ║
     ║ <bit position>  the number of the bit, numbered from the left      ║
     ║                   starting at 1, which is to be set to 1           ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          A bit is any of the eight binary digits in a character's ASCII
     number representation.  Each bit can have only one of two possible
     values, 0 and 1.

          The SET( and RESET( functions are used to manipulate the bits
     within a string or string expression.  SET( makes a bit 1, and RESET(
     makes a bit 0.  The BIT( function tests the value of a specific bit.

          Among the chief uses for these functions is compression of
     logical (true/false) data by using just one bit for each data item
     instead of an entire byte for a logical field or two bytes for a
     logical variable.

          See the BIT( function for programming examples.

          Examples:

     1>str='PQ'
     1>? BIT(str,15)
     F
     1>str=RESET(str,15)
     1>? str,BIT(str,15)
     PS T














     SET(                       VPI1  VPI  VPIN                        SET(
     VP-Info Level 1 Reference Manual           Page 107          SECTION 3



                                     SPACE(

     Gets the amount of space left in the data space.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ SPACE()                                                            ║
     ╟───────────────┐                                                    ║
     ║ Type: numeric │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function returns the available memory in the 64K data space
     (see Appendix A).

          Example:

     1>SPACE()
      27155.00



































     SPACE(                     VPI1  VPI  VPIN                      SPACE(
     VP-Info Level 1 Reference Manual           Page 108          SECTION 3



                                     SSEEK(

     Goes to a given line number in a sequential file.

     ╔════════════════════════════════════════════════════════════════════╗
     ║ SSEEK(<num exp> [,<filenum>])                                      ║
     ║                                                                    ║
     ║ <num exp>      the line number                                     ║
     ╟────────────────────────────────────────────────────────────────────╢
     ║ Option:                                                            ║
     ║                                                                    ║
     ║ <filenum>      the DOS file number (between 1 and 4)               ║
     ╟───────────────┐                                                    ║
     ║ Type: logical │                                                    ║
     ╚═══════════════╧════════════════════════════════════════════════════╝

          This function repositions the line number pointer in the
     sequential file (opened with the ROPEN( function) to the value given
     by <num exp>.

          If filenum is not given, filenum=1 is assumed.  If no file
     extension is given, the extension TXT is used.

          If filenum is not given, filenum=1 is assumed.  If no file
     extension is given, the extension TXT is used.

          See the functions SEEK(, ROPEN(, WOPEN(, CLOSE(, READ(,  IN(, and
     OUT(.

          Example:

     1>ok=ROPEN('a:label.prg',4)
     1>line=''
     1>ok=SSEEK(5,4)
     1>? ok
     T
     1>ok=READ(line,4)
     1>? line
     GOTO top
     1>ok=SSEEK(900,4)
     1>? ok
     F










     SSEEK(                     VPI1  VPI  VPIN                      SSEEK(