Fritz: All Fritz/All Fritz.zip/All Fritz/FILES/PROGMISC/FPCDOCS.LZH/EDITOR.DOC

Text File | 1988-06-01 | 18KB | 421 lines

IV.  SED, THE EDITOR



SED is a sequential file text editor implemented in F-PC by Tom
Zimmer.  The editor is WordStar compatible from a cursor control
key stand point, with the keypad functions fully supported, along
with some function keys.  Full search, replace, and global replace
are provided, along with copy and paste of text segments within a
file as well as between files.

SED was developed to provide an easy way to create and modify
source and documentation files for building substantial
application packages in F-PC.  You can enter the editor from F-PC
and return to F-PC with very few key strokes so that program can be
modified and tested quickly.  It has the convenience of the block
based F83 source loading mechanism, but not limited by the small
block size.  It also has the advantage of using standard
sequential text file common to most DOS word processors.

SED allocates a 64K byte segment to store text file in RAM.  The
file is edited in RAM and saved back to disk when returning to
F-PC.  However, when a source file is compiled, the source code is
extacted from the RAM storage one line at a time and compiled line
by line.  Thus complilation is very fast, averaged to about 10,000
lines per minute.

Due to the fact that a 64K byte segment is allocated for text
during editing, SED handles files up to 64K bytes.  As files
generally should be used as a mechanism for modularizing source
code, it is a bad style and poor design to allow source files to
grow bigger than 10K bytes.  The purpose of SED is not for general
word processing but for program development, although one can do
substantial text manipulation with it, up to 64K byte limit. Yes.
Tom got rid of BLOCK.  But in a sense, BLOCK creeps back, 64 times
bigger.



1.  SELECTING A FILE TO EDIT



To enter the editor for an editing session, type the following:

               SED <filespec> <enter>

A filename can be specified on the command line when starting SED,
and may include a directory specification.  If no file name is
given after SED, the editor will request a file name.  If the file
does not exist, a new file will be created for entering fresh
text.  If the file extension is not specified, SED uses the .SEQ
extension as default.  The editor then clear the screen and
displays the top 20 lines of the file in a window like display as
shown in Figure 1.  A line can be as long as 128 characters, of
which only 72 are visible in the window.

The top line of the display shows the current edit status,
starting with INSERT/OVERWRITE status, which is also shown by a
thicker cursor for insert mode.  The current Column and Line
number are then displayed, followed by the page number, total
lines in file and total characters in file.  The directory path
and the name of the current file under editing appear at the
bottom of the display 1.

A new file selection mechanism has been added.  When you are being
asked to enter a new filename, if you press ENTER without entering
a filename, a window will pop up allowing you to select a file
from the directory.  If you are in a sub-directory when the window
appears, then a file named "." and a file named ".." will appear
at the top of the file list.  These files, along with any
directories below the current directory, will display a graphic
"infinity" symbol "∞" to the right of the filename.  If you press
<return> while positioned on the "." name you will select the ROOT
directory.  The ".." name will pop up one level of directory, and
any other name with the "infinity" symbol next to it will step you
down one level to that directory.  You can move between files in
the list, with the keypad arrow keys, and select a file by
pressing ENTER.  Escape can be used to abort file selection.
While in the pop up file selection mode, you can also set the
current drive by pressing a letter key between A and G.  This
drive must exist and have a disk in it, or a system error will
result.  The path and the current drive is displayed in the lower
right.  The path can be changed by pressing the "\" key, then
typing the new path followed by the return key.

Pressing ESC key terminates the editing session and returns to
F-PC, after saving the modified text to disk.

Pressing F1 function key will replace the display with a help
screen as in Figure 2, showing variaous control keys for editing
functions in the WORDSTAR style.

SED is designed to use most WORDSTAR control keys to move the
cursor and manipulate the text.  However, on an IBM-PC, it is most
convenient to use the cursor keys to position the cursor and then
insert new text or type over old text.  It is very easy to master
this editor without much effort.  The F1 help screen is always
ready for consultation.  For more sophisticated operations, refer
to Section 3 for details.

To re-enter SED and edit the currently openned text file, type

               ED

in F-PC without a file specification.  SED will display the text
with the cursor positioned at the position when you left the last
editing session.  When the source file was compiled and an error
was detected, ED will place the cursor on the first character of
the offending word so that you can examine the situation and make
appropriate correction.  This way SED is tightly integrated into
F-PC as seamless as the block editor in F83.



2.  WORDSTART KEY FUNCTIONS



SED tries somewhat half heartedly to be WordStar compatible. The
cursor movement keys, Control A,S,D,F,E,X,C,R,W and Z have been
maintained, as have the delete keys Control G,T,Y, and Del.


KEY DEFINITION INDEX


Control keys

        A       Previous word.
        B       ..
        C       Next page, Page Down.
        D       Right one character.
        E       Previous line, Up Line.
        F       Forward, Next word.
        G       Delete the character UNDER the cursor.
        H       Move left one character non-destructively.
        I       Same as TAB.
        J       ..
        K       ..
        L       ..
        M       Like the <return> key.
        N       Split line at cursor.  See also Alt-N (join line).
        O       ..
        P       ..
        Q       ..
        R       Previous page, Page Up.
        S       Left one character.
        T       Delete the word to the right.
        U       Update, save changes up to this moment.
        V       Insert/ Overwrite mode toggle.
        W       Scroll screen down.
        X       Next line, Down Line.
        Y       Cut/Delete the current Line.
        Z       Scroll the screen up.

Keypad Functions

        ESC         Exit SED and Save changes.
        Shift-ESC   Exit SED and Don't save changes.
        Home        Goto beginning of line.
        End         Goto end of line.
        PgUp        Go back towards beginning of document 12
                    lines.
        PgDn        Go towards end of document 12 lines.
        Ctrl-Home   Go to First line of document.
        Ctrl-End    Goto last line of document.
        Ins         Toggle between Insert and Overwrite mode.
        Del         Delete the character under the cursor.

Alternate Keys

        A       ..
        B       ..
        C       Insert the next key pressed into the document.
        D       ..
        E       ..
        F       ..
        G       ..
        H       ..
        I       ..
        J       ..
        K       Expand imbedded TAB characters to spaces.
        L       ..
        M       ..
        N       Join Lines, the inverse of Control N.
        O       ..
        P       ..
        Q       ..
        R       ..
        S       ..
        T       Set the TAB key to expand to the current column.
        U       Word Undelete, undeletes the last 10 words or so.
        V       Import a file, pops up a selection window.
        W       Write entire file to a new file.
        X       Export lines from mark to cursor.
        Y       Un-delete lines.
        Z       ..

Function Keys

        F1      ..
        F2      ..
        F3      Mark line, for copy lines, and export lines.
        F4      ..
        F5      Get a line from the mark.
        F6      Search, prompts for search text.
        F7      ..
        F8      Replace, prompts for replace text, must do F6
                first.
        F9      ..
        F10     ..

        Alt-F1  ..
        Alt-F2  ..
        Alt-F3  ..
        Alt-F4  ..
        Alt-F5  ..
        Alt-F6  Search for same text again, no prompt.
        Alt-F7  ..
        Alt-F8  Replace with same text again, no prompt and do
                Alt-F6.
        Alt-F9  ..
        Alt-F10 ..

        Shift-F6
                Search for text backwards, CaSe sensitive.
        Shift-F8
                Replace all occurrences, use after F6 and F8.

        Shift-Alt-F6
                Search for same text again, no prompt Case
                sensitive.
        Shift-Alt-F8
                Replace with same text again, no prompt Case
                sensitive.



3.  GLOSSARY OF EDITING OPERATIONS



Copying Lines                           F3 & F5

Lines can be copied from one place in a file to another, with the
Mark-F3, and Copy Line-F5 commands.  Move to the first line of the
block of text you wish to copy, and Mark the start of the copy
with Mark-F3, now move to the place where you want to copy the
text to, and press Copy-F5 once for each line you want to copy.

Delete and Un-Delete lines              Control-Y  &  Alt-Y

Lines can be deleted with Ctrl-Y, and un-deleted with Alt-Y.  Any
lines which are deleted are saved in a line delete buffer which
currently has room for 50 lines.  This is also the number of line
deletes which can be un-deleted.

Exporting a block of Text               Alt-X and Shift Alt-X

SED can export lines of text to another file.  With Alt-X, first
go to the first line of text you want to export, and press F3 mark
to mark the start of the block export.  Then move to the last line
of text you want to export, and press Alt-X. This will cause all
of the lines between and including the start and end line to be
written out to the file TEMP.SEQ. To specify a different filename
to export to, press Shift-Alt-X, instead of Alt-X, and you will be
prompted for a name to write to.  See also "Importing a File".

Exporting to another file               Alt-W

The current edit file can be written out to another file. By
pressing Alt-W, you will be asked for the name of the file to
write out to.  The entire file contents in memory will be written
out to the new filename.  If you want to export a small amount of
text to another file, you can use the Alt-X Export function.

HELP, on line                           F1

Press F1 for on-line help on the various commands available.

Importing a File                        Alt-V

Text which has been exported with the Alt-X (export) command to
the TEMP.SEQ file can be imported with Alt-V, the import command.
If you want to import a file other than TEMP.SEQ, you can press
Shift-Alt-V, and a window will pop-up for you to select a file
from.  If you press Esc during the import, or while in the file
selection window, the import operation will be aborted.  See also
"Exporting a block of Text".

Inserting Special characters in SED     Alt-C char

The Alt-C function allows any single character which can be
generated by the keyboard to be inserted into SED.  Simply press
Alt-C followed by the key you want to insert.  Function keys are
mapped to characters above 127, so they will show up as graphics
characters.

Left Margin                             Ctrl-L

The left margin on the screen defaults to column zero, but when
printed, defaults to 2 spaces, so it is not normally necessary to
insert a left margin.  However, when TAB is pressed, the left
margin on screen is expanded by 8 characters.  Any subsequent
lines typed in will maintain this margin.  The left margin can be
set at any column position. Move the cursor to the column where
you want the left margin set and press Ctrl-L.

MACROS and F-PC                           Alt-M, Alt-1..5

SED does not have macros built into it, but a file is provided
called MACROS.SEQ, which implements macros in Forth that can be
used in SED.  These macros work exactly the same as they work in
ZED.  That is, you use Alt-M to start defining a macro, followed
by one of the Alt-1 to Alt-5 keys for the macro you are defining.
Next you enter any keys you want included in the macro, and
finally press Alt-M again to complete the macro definition.  To
perform a macro, simply press one of the Alt-1 through Alt-5 keys
by it self, and the keys saved will be performed.

Marker, Page Break  (a down pointing arrow head)

The down pointing arrow head symbol is used by SED to mark the
first line of a NEW page, so you will notice this symbol appears
at the left edge of the screen at the top of the document.

Marker, End of File (an up  pointing arrow head)

The up pointing arrow head symbol is used by SED to mark the last
line of text in the file.

Printing Documents                      Alt-P

Printing can be initiated Alt-P.  It will take you to a screen
where you can set the printing parameters, like first and last
page to print, copies to print, etc.  These values default to the
most common situation, which is to print all of a document once.
To start printing, press "P", or press ESC to abort.

Reading Foreign documents               Alt-K  Tab expansion

If you want to read a text file from an editor which imbeds Tabs,
you will see this character " " in many places in the file when
you first start editing it.  If you do see these Tab characters,
press Alt-K, and these characters will be expanded to spaces
properly.  This process will increase the size of the file
somewhat, so if you are doing this to a very large file, you may
run out of the 64000 character memory space available. WordStar
document files will need to passed through a conversion utility
before being edited by SED.

You can import a Forth BLOCK file by specifying the file and
extension on the file prompt line.  SED will not find any line
feeds in the file, so it will automatically split the file at 64
characters per line  After this is done, trailing blanks will be
stripped from each line, and trailing blank lines will be removed
from the file.  The resulting file will be much smaller, typically
50 percent or less.  The original file is not modified, and the
new file is created with the extension ".TMP".

Replacing Text                          F8-Replace & Alt-F8

After a Search has been done, you can replace the text found.
Press F8.  You will be asked for a replacement string, which will
be used to replace the found text, when return is pressed.  To
search for the next occurrence of the same text, press Alt-F6, and
to replace the next found occurrence with the same replacement
text, press Alt-F8.

Replacing All Occurrences of Text       Shift-F8

Having already performed a Search (F6) and Replace (F8) once, you
can replace all occurrences of search text with replacement text
by pressing Shift-F8.

Searching for Text                      F6-Search & Alt-F6

You can look for any sequence of characters in SED with the
Search-F6 key.  When F6 is pressed, you are asked to enter a text
string to look for.  SED will look for that string of characters
when you press <return>.  When SED searches for text, it ignores
the case of the letters.  If you want SED to look at the CaSe of
the text it searches, hold down SHIFT while pressing <return>.
This search is much faster.  To search for another occurrence of
the same text string, press Alt-F6 (or SHIFT Alt-F6 if you want
only an exact match). See also the earlier section on Replacing
Text.

Searching for Text Backwards            Shift-F6

Having already done a search using F6 above, you can also search
backwards with Shift-F6, which searches backwards from the cursor
with a CaSe sensitive search.

The straight key, F6 or F8 will perform the specified operation,
with a prompt for a text string parameter.  The operation is
performed with a case insensitive search.  That is, "CaSe" is the
same as "case".

The Alt-F6 or Alt-F8 performs the same function, but with the same
text string as was entered with the non-Alt key. Again, the search
is case insensitive.

Holding down Shift while pressing return on F6, Alt-F6 or Alt-F8
will cause the search to be done CASE SENSITIVE.  That is, "CaSe"
is NOT the same as "case".

And finally, pressing Shift-F8, WITHOUT ALT, causes a global
replace all occurrences to be performed. While the above may seem
confusing at first, it provides a lot of flexibility and power for
search and replace operations.  Try these commands on a junk file
until you become familiar with their operation.

Tab setting                             Alt-T

Set the TAB key to tab to the current column, if you are on column
4, TABS will occur at column 4, 8, 12, 16, etc.