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SuperSET (Version 1.61) SuperSET is a DOS environment utility which does many of the same things the internal SET command does, and a few more. ABOUT THE SET COMMAND (If the DOS SET command holds no mysteries for you, please skip ahead to page 4.) SET is an internal DOS command which, as outlined in the IBM Disk Operating System(tm) manual (version 3.20), "inserts strings into the command processor's environment. A copy of the entire series of strings in the environment is made available to all commands and applications." This means that at boot time, or any time thereafter that COMMAND.COM is run, an area of the computer's random access memory (RAM, or "user memory") is reserved as a sort of board room where you and DOS can get together to agree on certain things. DOS uses the environment, even if you don't, by automatically generating a string giving the name and location of COMMAND.COM. This is necessary because COMMAND will relinquish a portion of its own memory if required by your programs and must be able to find itself on disk afterward to reload its missing code. If you enter "SET" from the "A>" prompt after booting from your original DOS diskette, you will see something like: A>set PATH= COMSPEC=A:\COMMAND.COM If you alter your DOS prompt via the PROMPT command to "$p$g", it will look like this: A:\> and your environment will look like this: PATH= COMSPEC=A:\COMMAND.COM PROMPT=$p$g The PATH is where DOS will look for any .COM, .EXE, or .BAT file you enter from the command line if it's not in your current directory. The "PATH=" string has no value (or perhaps I should say it has a null value), so DOS would give up looking for a program if it was not in the current directory. Why DOS bothers to put a null variable in the environment escapes me, but it does. You can eliminate the "PATH=" string from the environment all together by running: 1 SET PATH= and it will be gone with no (apparent) adverse effects. Using the SET command (as well as the PATH and PROMPT commands), we can add environment strings, delete them, or replace them. The syntax for doing so is: SET [<name>=[<parameter>]] or, as I prefer to think of it: SET [<variable>=[<value>]] When run, the "<variable>" portion of the string will be capital- ized by DOS, but otherwise the string will appear as entered the next time you run SET by itself. A few programs, notably C language compilers, require that cer- tain strings be SET before they are run. DOS passes a copy of the environment to each program it runs, and these programs ex- tract user-specific information from this copy to "customize" the way they work. Here is an example used with Microsoft QuickC: set INCLUDE=c:\include set LIB=c:\lib set TMP=c:\tmp In this case, each of the programs associated with the QuickC compiler will know which directories on which drives certain programs are stored in by checking the values of INCLUDE, LIB, and TMP. Environment variables can be used in batch files for most ver- sions of DOS (excepting 3.0 -- I'd upgrade if I owned it), by using the "%<variable>%" construction. For example, consider the following segment of a batch file: set oldpath=%path% path c:\docs;c:\dict;c:\thes;c:\outliner;%path% cd wordproc myword cd\ path %oldpath% set oldpath= In this case, the current value of "PATH=" from the environment is stored in a new variable called "OLDPATH". The PATH is changed to prepare for the requirements of the word processing program that is run next. Upon exiting the word processor, the 2 PATH is restored to the value of OLDPATH, which is then deleted by the last line, and the environment is returned to its previous state. A problem users face when working with the environment (and, perhaps, a reason it is often largely ignored) is the stiffness of the SET command itself. If you view your environment as a sort of database of strings, which it is, the SET command does not rate well as a database manager. It allows appends, replacements and deletions, one at a time, and will generate complete listings of the current contents of the environment. For a very small data base, this may be enough, but it is possible to expand the DOS environment (up to 32 kilobytes in DOS 3.2 and up) to include many dozens of strings of various lengths. (For a quick course on achieving an environ- ment larger than the default size with old versions of DOS, lo- cate a copy of PC Magazine, April 14, 1987, Volume 6, Number 7 which contains an article entitled "Expanding the DOS Environ- ment". DOS versions 2.0 to 3.1 are capable of working with en- vironment sizes up to 992 characters. The article refers to the (Microsoft) DOS SETENV utility, has an undocumented CONFIG.SYS command for DOS 3.0 and 3.1, and DEBUG patches for COMMAND.COM as well. Anyone with DOS versions 3.2 or greater can use the "SHELL=" with the "/E" parameter as outlined in their DOS manuals. I find an environment of 512 bytes adequate for any- thing I'd like to do.) 3 ABOUT SUPERSET And so we come to SuperSET. This utility, written in Turbo Pas- cal, is a management tool for your DOS environment. It does most of the same things SET does, and many more. It will, on demand, sort your environment alphabetically by variable name, allow you to prompt for new environment strings from a batch file, store your current drive, directory, the date and the time in the en- vironment, save your environment to a disk file or recall it from one, clear your environment entirely or selectively, display values for all or specific variables, create files with unique names for your batch files, and allow you to process a number of environment commands on a single command line. I have already noted the %<variable>% construction most DOS ver- sions use in batch files. If you try using this construction on the command line (that is, from the DOS prompt), it won't work, except with SuperSET. Whenever SuperSET encounters an even num- ber of per-cent signs in a command line instruction, it will per- form the appropriate substitutions. If there is an odd number of per-cent signs in the instruction, the first occurrence of '%' within the instruction is deleted, and the rest of the instruc- tion is treated without substitutions. Confused? Of course! You may never understand nor use this feature, but just for fun try this from the DOS prompt: C:\>sset 123=%%456% 456=789 %123%=123 @dsp You should get a nice display of your environment with the fol- lowing strings added: 123=%456% 456=789 789=123 To make this feature useful in batch files (where DOS gets first shot at per-cent signs), a tilde ('~') may be substituted for any '%': @echo off rem Fakes a DOS "$p$g" prompt :DosPrompt sset @drv @dir @inp("~currdrv~~currdir~>"^doscom^c) if errorlevel 255 goto end if !%doscom%==! goto end call %doscom% goto DosPrompt :end The syntax for SuperSET is: [d:][path]SSET [<command> [<command>...]] 4 where "command" is one of the following: 1. Not given. If SSET is entered without parameters, it will display the contents of the entire environment. Unlike the DOS SET com- mand, however, SuperSET displays the location of the en- vironment in RAM, the size of the environment, the number of characters and variables used, and the number of characters remaining for use. (See the @DSP function, below, for a way to emulate the SET command output.) See also: @DSP 2. <variable>=[<value>] Space permitting, if <value> is given then a string is ap- pended to the end of the environment in the form: <variable>=<value> <variable> will be converted to its upper case equivalent if need be. If <variable> is already in the environment, the original record of it will be deleted, together with its old value. If <value> is not given, then <variable> is deleted from the environment. An asterisk ("*") wild card is allowed at the end of each <variable>=, so a number of strings with names that begin the same way may be deleted in one command. For example: sset temp*= would delete environment strings with such names as TEMP, TEMP1, TEMP VAR, TEMPEST, and TEMPORARY. A major difference in the way SuperSET and SET handle as- signments of this sort is caused by SuperSET's ability to handle more than one command in a single command line. Be- cause SuperSET parses spaces as parameter separators, it is necessary to enclose multiple word parameters in quotation marks. Thus: set query=What is your name? can be emulated by: sset query="What is your name?" 5 If you need to enter a quotation mark into the environment, use two quotation marks together in your command line: sset riddle="Who wrote ""The Lost Chord?"" The DOS SET command, because it is contained in the resident portion of DOS and is therefore faster, should be used wherever practical for routine changes to the environment. (Incidentally, Sir Arthur Sullivan wrote "The Lost Chord.") See also: @ZAP 3. @BOT All subsequent commands will work with the environment created by the last PERMANENTLY loaded copy of COMMAND.COM. To see the effect of this, type the following at the DOS prompt: C:\>set this=that C:\>sset C:\>command C:\>sset C:\>sset @dsp @bot this= C:\>sset C:\>exit C:\>sset See also: @TOP 4. @DAT Places a variable called DATE into the environment whose value is the current date as reported by DOS. The date is stored in a format compatible with the DOS DATE command and will vary according to the version of DOS used and the value of the COUNTRY= line (if present) in your CONFIG.SYS file. See also: @TIM 5. @DIR The current directory will be placed in the environment, as- signed the variable name "CURRDIR". See also: @DRV 6 6. @DOW Places a variable called DAY OF WEEK into the environment whose value is the name (i.e., Sunday, Monday, etc.) of the current day as reported by DOS. 7. @DRV The current drive letter (and accompanying colon) will be placed in the environment, assigned the variable name "CURRDRV". The @DIR and @DRV functions are useful for batch files on your PATH that might be run from any directory or drive. If such a batch file changes drives or directories mid- operation, CURRDIR and CURRDRV will help to restore the user to his or her original location. Consider the following batch file: echo off cls sset @drv @dir c: cd \sk sk cd \ %currdrv% cd %currdir% Assume you have Borland's SideKick in a directory on drive C: called \SK and you wanted to start it from your work directory , A:\WORK. This batch file, SK.BAT, resides in a directory listed in your PATH environment variable. Super- SET places the strings, "CURRDRV=A:" and "CURRDIR=\WORK" in the environment before the batch logs on to C:, changes the active directory there, and runs SideKick. "A:" is automatically substituted for %currdrv% on the next line, logging us back onto A:, and "\WORK" is substituted for %currdir% on the last line, giving us back our original directory. See also: @DIR 8. @DSP[(<variable>[^<variable>...])] Generates a list of existing environment strings. Without parameters, @DSP is identical in function to SuperSET without parameters. If a variable or variables are specified, a simple list of corresponding variables and values is displayed, in the same format used by the DOS SET command, although a note is generated for any variable named in the command line that is not in the environment. This is 7 a quick way to determine whether or not a specific variable is in the environment without scanning a lengthy list. An asterisk ("*") wild card is allowed at the end of each <variable> (see item 2, above for more details regarding the functioning of wild cards). The command: sset @dsp(*) simulates (albeit slowly) the SET command run without parameters (although I can't imagine why you'd want to do this). 9. @FIL Adds a number of strings to the environment of the form: !FILLxxx=▓▓▓...▓▓▓ where xxx is an hexadecimal number. You may want to issue this command prior to loading a program which allows you to shell to DOS. Such programs typically do not give you a full environment to work in when they load COMMAND.COM on top of themselves. Instead, they will give you your current environment strings and however many additional bytes it takes to round the environment size out to a multiple of 16. The @FIL function will ensure that enough space is taken up in your current environment (with a minimum of 3 free bytes, including the two "end-of-environment" markers) to guarantee a full-sized copy when you shell to a new one. To free the room up in the new copy, use: sset !fill*= having ensured, of course, that you won't simultaneously erase an important string that also begins with "!FILL". Remember to issue the same command when you quit your ap- plication to clear the unwanted strings from your root en- vironment. 10. @GET[(<filespec>)] Unless a different <filespec> is specified, appends all strings listed in a file in the root directory of the cur- rent drive called "ENVIRON.TXT" to the environment. This is the logical companion to the @SAV function, and uses files in the format specified for that function. See also: @SAV 8 11. @INP[([<prompt>^]<variable>[^<switch>])] If <prompt> exists, it will be displayed as entered on the user's screen. <prompt> may be up to 64 characters in length The cursor waits to the immediate right of <prompt> for user input, or at the left edge of the screen if no <prompt> is given. INP is the default variable name. The user's entry will be placed into the environment, as- signed to <variable>. One switch may be used. It must consist of a "/" followed by a single character (upper or lower case). Valid choices are: C Do a carriage return/line feed at end of entry. U Convert the whole entry to upper case. L Convert the whole entry to lower case. F Convert the first letter of the entry to upper case, and the rest to lower case. I Convert the first letter of each word in the entry to upper case and the rest to lower case. The following example uses @INP to prompt for a person's name in a batch file and issue an appropriate greeting: echo off cls sset @inp(User Name^Hello. What's your name? ^/i) :: Note the space after "name?" in the above line. :: If left out there would be no space between :: the question and answer. echo Greetings and felicitations, %User Name%. See also: @KEY 12. @KEY[([<prompt>^]<variable>[^<switch>[/h])] Works like @INP, above, but for single character input The user's next keystroke is returned to the environment. If this is a "control" character (ASCII 1 to 26) or [Esc] (ASCII 27), the environment entry will be a "#" followed by a decimal representation of the ASCII code. If the key pressed was a function or cursor key, the environment entry will be a decimal representation of the scan code of the key pressed. KEY is the default variable name. Two switches are allowed, consisting of "/" followed by a single character (upper or lower case). The first may be one of: U Convert the character to upper case (if required). 9 L Convert the character to lower case (if required). The second, if used, must be: H Hide, or don't display the keystroke. See also: @INP 13. @MID(<string>,<start position>,<length>) Has the same effect on <string> as Turbo Pascal's COPY pro- cedure or BASIC's MID$ function. In other words, the func- tion returns a substring of <string> to the environment, as- signed to the variable name MIDSTRING. The value returned will be that portion of <string> which begins at <start position> and encompasses <length> characters. Thus, the command: sset @mid(albatross^3^3) A more complex example is: sset @tim @mid(~time~^1^5) time=~midstring~ which returns the current hour and minute to the environment variable TIME instead of the usual @TIM function format. 14. @SAV[(<filespec>)] Unless a different <filespec> is specified, stores all en- vironment strings in a file in the root directory of the current drive called "ENVIRON.TXT". The file is a simple ASCII sequential file in which each line contains one en- vironment string and ends with a carriage return. It may be edited with any ASCII-only text editor (like QEdit, or even EDLIN), and any number of files created to suit a variety of requirements. If you aren't doing anything more with Super- SET than using @SAV (i.e., if there is nothing else on your command line), the DOS SET command will be faster: C:\>set > c:\environ.txt Here, the normal output from the SET command (identical to that of @SAV) is redirected to the file C:\ENVIRON.TXT. See also: @GET 15. @SRT Sorts all environment strings alphabetically by variable name. 10 16. @TIM Places a variable called TIME into the environment whose value is the current time as reported by DOS. The time is stored in a format compatible with the DOS TIME command and will vary according to the version of DOS used and the value of the COUNTRY= line (if present) in your CONFIG.SYS file. See also: @DAT 17. @TOP All subsequent commands will work with the environment created by the last loaded copy of COMMAND.COM. You should only need to use this function to switch back to your tem- porary environment after using @BOT previously on the same command line. To see the effect of this, type the following at the DOS prompt: C:\>set this=that C:\>sset C:\>command C:\>sset C:\>sset @dsp @bot this= @top @dsp C:\>exit C:\>sset See also: @BOT 18. @TRU[(<file name>)] THIS FUNCTION ONLY WORKS IN DOS VERSIONS 3.0 AND GREATER. If no parameter is given, then a path to the current direc- tory is returned to the environment. If a parameter is given, it will be capitalized and expanded to a full path name in the environment. In either case, the associated variable name will be TRUENAME. This function makes use of an undocumented DOS function (60h). 19. @UNA(<0..50>) Creates an environment variable, UNARY, which has a string of n 1s as its value where n is the value of the parameter. n must be an integer value in the range 0 to 50 (inclusive). This feature is included to permit FOR loops, and even nested FOR loops within batch files. Consider this simple example: @echo off sset counter= @una(%1) :looptop 11 echo %1 %counter%1 set counter=%counter%1 if not !%counter%==!%unary% goto looptop shift set unary= set counter= if not !%1==! sset @una(%1) if not !%unary%==! goto looptop echo Done! which you might try running with the following command line parameters: 50 50 50 50 50 5 This will produce 255 iterations of the "echo %1 %counter%1" command. A more complex example, one with a nested FOR loop, is the following: @echo off sset @inp("1st num: "^n1^/c) @inp("2nd num: "^n2^/c) sset @una(~n1~) n1=~unary~ @una(~n2~) n2=~unary~ set unary= set c1= set c2= set mc= :loop1top :loop2top set mc=%mc%1 echo Iterations through inner loop: %mc% set c2=%c2%1 if not !%c2%==!%n2% goto loop2top set c2= set c1=%c1%1 if not !%c1%==!%n1% goto loop1top set c1= set c2= set n1= set n2= set mc= echo Done! 20. @UNI[(<dos directory>)] THIS FUNCTION ONLY WORKS IN DOS VERSIONS 3.0 AND GREATER. Creates a 0-length file with a unique name and returns the file name to the environment variable UNIQUE. If a target directory is not specified, the file will be created in the root directory of the current disk. This may be useful in batch files which require the creation of temporary files. As a demonstration, try keying in the following batch file: 12 @echo off sset @uni(dos) echo Now you see it, > %unique% type %unique% echo on dir %unique% @echo off del %unique% echo: echo Now you don't! echo on dir %unique% @echo off set unique= 21. @ZAP[(<variable>[^<variable>...][^/n])]│[(/n)] Erases all environment variables unless they are specifi- cally listed as parameters. Potentially dangerous, but very useful for wholesale changes to the environment. A warning message is displayed and a confirmation prompt presented when @ZAP is used, unless the "/n" parameter is given. An asterisk ("*") wild card is allowed at the end of each <variable> (see item 2, above for more details regarding the functioning of wild cards, and note that *= has the same ef- fect as @ZAP(/n)). For example, to erase all environment variables except COMSPEC, PATH, and PROMPT use sset @zap(comspec^path^prompt) or, if you are sure other variables won't match the wildcards, you might save some typing with something like: sset @zap(co*^p*) See also: <variable>=[<value>] MESSAGES SuperSET will generate an error message if there are syntax er- rors in the command line, if there is no room left in the en- vironment when an append is being attempted, when you are working with the environment set up by a copy of COMMAND.COM and when the file named in the @GET or @SAV functions can't be opened. As the latter function often precedes a @ZAP or some other drastic en- vironment change, an error here terminates the program. All of these errors will set the DOS ERRORLEVEL to 255 when the program exits, a value your batch files can test for. Other messages, regarding variable names not found in the environment, are presented for information only, and do not set ERRORLEVEL. 13 Output from SuperSET may be redirected to a printer, a disk file, or another DOS "device", or piped through a command like MORE using the ">" and "|" characters respectively. You will likely want to use MORE if you've got a lengthy environment and you want to examine it screen by screen. There is one occasion, in batch file operation, where it is es- sential to use SET instead of SuperSET. That is when environment variables require setting in the middle of a "cascade" of ERROR- LEVEL checks. SuperSET, and any other program external to DOS, resets the ERRORLEVEL to 0 on entry. IMPORTANT DISTINCTIONS The DOS SET command affects the environment established only by the most recently loaded copy of COMMAND.COM. Many application programs permit users to "shell out" to DOS, by running a second instance (i.e., copy in memory) of COMMAND.COM. Changes made with SET to the shell environment disappear when the user types EXIT. If SuperSET is run on such occasions without the @BOT function, it will affect the newly created environment (if suffi- ciently large for the operations selected). SuperSET issues a warning message if you are working with a temporary environment. An interesting feature of the SET command (not incorporated into SuperSET for a variety of reasons) is its ability to expand the environment. SET can only accomplish this by the addition of strings beyond the "end" of the current environment and ONLY IF no other programs (like TSRs) are sitting on top of the environ- ment in memory. Since the environment size for the first (permanent) copy of COMMAND.COM is usually determined by the SHELL statement in CONFIG.SYS, this is really only a problem with temporary environments. To compensate for SuperSET's deficiency in this area, refer to the @FIL function, described above. SuperSET Version 1.61 is Copyright (c), 1991, by Richard Linley. Please distribute it, in unaltered form and accompanied by this help file, to anyone you like. The program is presented "as is" and guarantees nothing. Watch for upgrades. If you have sug- gestions or requests for new features, please write to: Richard Linley 641 Sussex Blvd. Kingston, Ontario Canada K7M 5A9 14