Programmer 7500

home *** CD-ROM | disk | FTP | other *** search

/ Programmer 7500 / MAX_PROGRAMMERS.iso / INFO / EDITOR / STEVIE.ZIP / STEVIE.DOC < prev next >

Wrap

Text File | 1988-06-09 | 15.8 KB | 510 lines

STEVIE - An Aspiring VI Clone User Reference Tony Andrews 3/6/88 Overview -------- STEVIE is an editor designed to mimic the interface of the UNIX editor 'vi'. The name (ST Editor for VI Enthusiasts) is due to the fact that the editor was first written for the Atari ST. The current version has been ported to UNIX and OS/2, but I've left the name intact for now. I've labelled STEVIE an 'aspiring' vi clone as a warning to those who may expect too much. On the whole, the editor is pretty complete. Almost all of the visual mode commands are supported. The biggest failing at the moment is that the undo command is currently in a state of disrepair. Recent enhancements in other areas have required the undo command to be mostly disabled until it can catch up with the other changes. But don't be discouraged. I've tried very hard to capture the 'feel' of vi by getting the little things right. Making lines wrap correctly, supporting true operators, and even getting the cursor to land on the right place for tabs are all a real pain, but do much to make the editor feel right. This program is the result of many late nights of hacking over the last several months. The first version was written by Tim Thompson and posted to USENET. From there, I reworked the data structures completely, added LOTS of features, and generally improved the overall performance in the process. STEVIE may be freely distributed. The source isn't copyrighted or restricted in any way. If you pass the program along, please include all the documentation and, if practical, the source as well. I'm not fanatical about this, but I tried to make STEVIE fairly portable and that doesn't do any good if the source isn't available. The remainder of this document describes the operation of the editor. This is intended as a reference for users already familiar with the real vi editor. Starting the Editor ------------------- The following command line forms are supported: vi [file ...] Edit the specified file(s) vi -t tag Start at location of the given tag vi + file Edit file starting at end vi +n file Edit file starting a line number 'n' vi +/pat file Edit file starting at pattern 'pat' If multiple files are given on the command line (using the first form), the ":n" command goes to the next file, ":p" goes backward in the list, and ":rew" can be used to rewind back to the start of the file list. Set Command Options ------------------- The ":set" command works as usual to set parameters. Each parameter has a long and an abbreviated name, either of which may be used. Boolean parameters are set as in: set showmatch or cleared by: set noshowmatch Numeric parameters are set as in: set scroll=5 Several parameters may be set with a single command: set novb sm report=1 To see the status of all parameters use ":set all". Typing ":set" with no arguments will show only those parameters that have been changed. The supported parameters, their names, defaults, and descriptions are shown below: Full Name Short Default Description ------------------------------------------------------------------------------ vbell vb vb Use visual bell (novb for audible bell) showmatch sm nosm Showmatch mode wrapscan ws ws Wrapscan (searches cross file start/end) errorbells eb noeb Ring bell when error messages are shown showmode mo nomo Show on status line when in insert mode backup bk nobk Leave backup in *.bak on file writes return cr cr End lines with cr-lf when writing list list nolist Show tabs and newlines graphically scroll scroll 12 Number of lines to scroll for ^D and ^U tabstop ts 8 Number of spaces in a tab report report 5 Min # of lines to report operations on lines lines 25 Number of lines on the screen The EXINIT environment variable can be used to modify the default values on startup as in: setenv EXINIT="set sm ts=4" The 'backup' parameter, if set, causes the editor to retain a backup of any files that are written. During file writes, a backup is always kept for safety until the write is completed. At that point, the 'backup' parameter determines whether the backup file is deleted. In environments (e.g. OS/2 or TOS) where lines are normally terminated by CR-LF, the 'return' parameter allows files to be written with only a LF terminator (if the parameter is cleared). The 'lines' parameter tells the editor how many lines there are on the screen. This is useful on systems like the ST where various screen resolutions may be used. By using the 'lines' parameter, different screen sizes can be easily handled. File Manipulation Commands -------------------------- The following table shows the supported file manipulation commands as well as some other 'ex' commands that aren't described elsewhere: :w write the current file :wq write and quit :x write (if necessary) and quit ZZ same as ":x" :e file edit the named file :e! re-edit the current file, discarding any changes :e # edit the alternate file :w file write the buffer to the named file :x,y w file write lines x through y to the named file :r file read the named file into the buffer :n edit the next file :p edit the previous file :rew rewind the file list :f show the current file name :f name change the current file name :ta tag go to the named tag ^] like ":ta" using the current word as the tag :help display a command summary The ":help" command can also be invoke with the <HELP> key on the Atari ST. This actually displays a pretty complete summary of the real vi with unsupported features indicated appropriately. The commands above work pretty much like they do in 'vi'. Most of the commands support a '!' suffix (if appropriate) to discard any pending changes. When writing just part of the buffer, the following address forms are supported: addr [+- number] where 'addr' may be one of the following: a line number a mark (as in 'a or 'b) '.' (the current line) '$' (the last line) String Searches --------------- String searches are supported, as in vi, accepting the usual regular expression syntax. This was done using Henry Spencer's regular expression library without modification. I added code outside the library to support the '\<' and '\>' extensions. This actually turned out to be pretty easy. Operators --------- The vi operators (d, c, y, <, and >) work as true operators. The only exception is that the change operator works only for character-oriented changes (like cw or c%) and not for line-oriented changes (like cL or c3j). Tags ---- Tags are implemented and a fairly simple version of 'ctags' is supplied with the editor. The current version of ctags will find functions and macros following a specific (but common) form. See 'ctags.doc' for a complete discussion. [The full Ctags program is in the public domain; contact your nearest comp.sources.unix archive site; the primitive tags has been taken out of this c.s.u distribution.] System-Specific Comments ------------------------ The following sections provide additional relevant information for the systems to which STEVIE has been ported. Atari ST -------- The editor has been tested in all three resolutions, although low and high res. are less tested than medium. The 50-line high res. mode can be used by setting the 'lines' parameter to 50. Alternatively, the environment variable 'LINES' can be set. The editor doesn't actively set the number of lines on the screen. It just operates using the number of lines it was told. The arrow keys, as well as the <INSERT>, <HELP>, and <UNDO> keys are all mapped appropriately. UNIX ---- The editor has been ported to UNIX System V release 3. This was done mainly to get some profiling data so I haven't put much effort into doing the UNIX version right. It's hard-coded for ansi-style escape sequences and doesn't use the termcap/terminfo routines at all. OS/2 ---- This port was done because the editor that comes with the OS/2 developer's kit really sucks. Make sure 'ansi' mode is on (using the 'ansi' command). The OS/2 ansi driver doesn't support insert/delete line, so the display updates are a little rough, but the editor is fast enough that it isn't too bothersome. The arrow keys are NOT mapped, so they don't currently do anything reasonable. Missing Features ---------------- 1. Counts aren't yet supported everywhere that they should be. 2. Macros with support for the ST function keys. 3. More "set" options. 4. Auto-indent. 5. Many others... Known Bugs and Problems ----------------------- 1. Undo is partially disabled until I can re-work some of the code for undoing certain edit operations. Undo is enabled for those operations where I've specifically checked out the code. All other cases print an apologetic message for the time being. Recent changes to the editor broke some of the old 'undo' code. This is a temporary hack until I can check out all the undo code. 2. The change operator is only half-way implemented. It works for character motions but not line motions. This isn't so bad since most change operations are character oriented anyway. 3. The yank buffer uses statically allocated memory, so yanks of more than 1K of text will fail. If a delete spans more than 1K, the program asks for confirmation before proceeding. That way, if you were moving text, you don't get screwed by the limited yank buffer. You just have to move smaller chunks at a time. All the internal buffers (yank, redo, etc.) need to be reworked to allocate memory dynamically. 4. If you stay in insert mode for a long time, the insert buffer can overflow. The editor will print a message and dump you back into command mode. 5. Puts are very slow. 6. Several other less bothersome glitches... Conclusion ---------- I'm still working on the program pretty actively, although the farther I get with it, the harder it is to get motivated to work on it. I've been using it as my standard editor for a long time, and I suppose I'm coming to accept its deficiencies more than I should. Fortunately, I use the real vi every day at work, so I'm constantly reminded of the work that remains to be done. I'd like to thank Tim Thompson for writing the original version of the editor. His program was well structured and quite readable. Thanks for giving me a good base to work with. If you're reading this file, but didn't get the source code for STEVIE, it can be had by sending a disk with return postage to the address given below. I can write disks for the Atari ST (SS or DS) or MSDOS (360K or 1.2M). Please be sure to include the return postage. I don't intend to make money from this program, but I don't want to lose any either. I'm not planning to try to coordinate the various ports of STEVIE that may occur. I just don't have the time. But if you do port it, I'd be interested in hearing about it. I will be doing a port for Minix on the ST when that becomes available later this year. So if anyone does a Minix port on the PC, I'd be especially interested. Tony Andrews UUCP: onecom!wldrdg!tony 5902E Gunbarrel Ave. Boulder, CO 80301 Character Function Summary -------------------------- The following list describes the meaning of each character that's used by the editor. In some cases characters have meaning in both command and insert mode; these are all described. ^@ The null character. Not used in any mode. This character may not be present in the file, as is the case with vi. ^B Backward one screen. ^D Scroll the window down one half screen. ^E Scroll the screen up one line. ^F Forward one screen. ^G Same as ":f" command. Displays file information. ^H (BS) Moves cursor left one space in command mode. In insert mode, erases the last character typed. ^J Move the cursor down one line. ^L Clear and redraw the screen. ^M (CR) Move to the first non-white character in the next line. In insert mode, a carriage return opens a new line for input. ^N Move the cursor down a line. ^P Move the cursor up a line. ^U Scroll the window up one half screen. ^Y Scroll the screen down one line. ^[ Escape cancels a pending command in command mode, and is used to terminate insert mode. ^] Moves to the tag whose name is given by the word in which the cursor resides. ^` Same as ":e #" if supported (system-dependent). SPACE Move the cursor right on column. $ Move to the end of the current line. % If the cursor rests on a paren '()', brace '{}', or bracket '[]', move to the matching one. ' Used to move the cursor to a previously marked position, as in 'a or 'b. The cursor moves to the start of the marked line. The special mark '' refers to the "previous context". + Same as carriage return, in command mode. , Reverse of the last t, T, f, or F command. - Move to the first non-white character in the previous line. . Repeat the last edit command. / Start of a forward string search command. String searches may be optionally terminated with a closing slash. To search for a slash use '\/' in the search string. 0 Move to the start of the current line. Also used within counts. 1-9 Used to add 'count' prefixes to commands. : Prefix character for "ex" commands. ; Repeat last t, T, f, or F command. < The 'left shift' operator. > The 'right shift' operator. ? Same as '/', but search backward. A Append at the end of the current line. B Backward one blank-delimited word. C Change the rest of the current line. D Delete the rest of the current line. E End of the end of a blank-delimited word. F Find a character backward on the current line. G Go to the given line number (end of file, by default). H Move to the first non-white char. on the top screen line. I Insert before the first non-white char. on the current line. J Join two lines. L Move to the first non-white char. on the bottom screen line. M Move to the first non-white char. on the middle screen line. N Reverse the last string search. O Open a new line above the current line, and start inserting. P Put the yank/delete buffer before the current cursor position. T Reverse search 'upto' the given character. W Move forward one blank-delimited word. X Delete one character before the cursor. Y Yank the current line. Same as 'yy'. ZZ Exit from the editor, saving changes if necessary. [[ Move backward one C function. ]] Move forward one C function. ^ Move to the first non-white on the current line. ` Move to the given mark, as with '. The distinction between the two commands is important when used with operators. I support the difference correctly. If you don't know what I'm talking about, don't worry, it won't matter to you. a Append text after the cursor. b Back one word. c The change operator. d The delete operator. e Move to the end of a word. f Find a character on the current line. h Move left one column. i Insert text before the cursor. j Move down one line. k Move up one line. l Move right one column. m Set a mark at the current position (e.g. ma or mb). n Repeat the last string search. o Open a new line and start inserting text. p Put the yank/delete buffer after the cursor. r Replace a character. s Replace characters. t Move forward 'upto' the given character on the current line. u Undo the last edit. This isn't currently supported very well. w Move forward one word. x Delete the character under the cursor. y The yank operator. z Redraw the screen with the current line at the top (zRETURN), the middle (z.), or the bottom (z-). | Move to the column given by the preceding count.