Power-Programmierung

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

/ Power-Programmierung / CD2.mdf / c / library / os2 / elvis / options.doc < prev next >

Wrap

Text File | 1992-06-20 | 28.0 KB | 793 lines

_5. _O_P_T_I_O_N_S Options may be set or examined via the colon command "set". The values of options will affect the operation of later commands. For convenience, options have both a long descriptive name and a short name which is easy to type. You may use either name interchangably. I like the short names, myself. There are three types of options: Boolean, string, and numeric. Boolean options are made TRUE by giving the name of the option as an argument to the "set" command; they are made FALSE by prefixing the name with "no". For example, "set autoindent" makes the autoindent option TRUE, and "set noautoindent" makes it FALSE. Elvis also allows boolean options to be toggled by prefixing the name with "neg". So, ":map g :set neglist^M" will cause the <g> key to alter- nately toggle the "list" option on and off. (The "neg" pre- fix is an extension; the real vi doesn't support it.) To change the value of a string or numeric option, pass the "set" command the name of the option, followed by an "=" sign and the option's new value. For example, "set tabstop=8" will give the tabstop option a value of 8. For string options, you may enclose the new value in quotes. NNNNAAAAMMMMEEEESSSS TTTTYYYYPPPPEEEE DDDDEEEEFFFFAAAAUUUULLLLTTTT MMMMEEEEAAAANNNNIIIINNNNGGGG autoindent, ai Bool noai auto-indent during input autoprint, ap Bool ap in EX, print the current line autotab, at Bool at auto-indent allowed to use tabs? autowrite, aw Bool noaw auto-write when switching files beautify, bf Bool nobf strip control chars from file? charattr, ca Bool noca interpret \fX sequences? cc, cc Str cc="cc -c" name of the C compiler columns, co Num co=80 width of the screen digraph, dig Bool nodig recognize digraphs? directory, dir Str dir="/usr/tmp"where tmp files are kept edcompatible, ed Bool noed remember ":s//" options equalprg, ep Bool ep="fmt" program to run for = operator errorbells, eb Bool eb ring bell on error exrc, exrc Bool noexrc read "./.exrc" file? exrefresh, er Bool er write lines indiviually in EX flash, vbell Bool flash use visible alternative to bell flipcase, fc Str fc="" non-ASCII chars flipped by ~ hideformat, hf Bool hf hide text formatter commands ignorecase, ic Bool noic upper/lowercase match in search inputmode, im Bool noim start vi in insert mode? keytime, kt Num kt=2 timeout for mapped key entry keywordprg, kp Str kp="ref" full pathname of shift-K prog lines, ln Num ln=25 number of lines on the screen list, li Bool noli display lines in "list" mode magic, ma Bool ma use regular expression in search make, mk Str mk="make" name of the "make" program June 13, 1992 5-2 OPTIONS 5-2 mesg, ms Bool ms allow messages from other users? modelines, ml Bool noml are modelines processed? more, more Bool more pause between messages? nearscroll, ns Num ns=15 when to scroll vs. redraw novice, nov Bool nonovice set options for ease of use number, nu Bool nonumber show line numbers paragraphs, para Str para="PPppIPLPQP"names of "paragraph" nroff cmd prompt, pr Bool pr show ':' prompt in _e_x mode readonly, ro Bool noro prevent overwriting of orig file remap, rem Bool remap allow key maps to call key maps report, re Num re=5 report when 5 or more changes ruler, ru Bool noru display line/column numbers scroll, sc Num sc=12 scroll amount for ^U and ^D sections, sect Str sect="NHSHSSSEse"names of "section" nroff cmd shell, sh Str sh="/bin/sh" full pathname of the shell showmatch, sm Bool nosm show matching ()[]{} showmode, smd Bool nosmd say when we're in input mode shiftwidth, sw Num sw=8 shift amount for < and > sidescroll, ss Num ss=8 amount of sideways scrolling sync, sy Bool nosy call sync() often tabstop, ts Num ts=8 width of tab characters taglength, tl Num tl=0 significant chars in tag name term, te Str te="$TERM" name of the termcap entry terse, tr Bool notr give shorter error messages timeout, to Bool to distinguish <esc> from <arrow>? warn, wa Bool wa warn for ! if file modified window, wi Num wi=24 lines to redraw after long move wrapmargin, wm Num wm=0 wrap long lines in input mode wrapscan, ws Bool ws at EOF, searches wrap to line 1 writeany, wr Bool nowr allow :w to clobber files autoindent, ai During input mode, the autoindent option will cause each added line to begin with the same amount of lead- ing whitespace as the line above it. Without autoin- dent, added lines are initially empty. autoprint, ap This option only affects EX mode. If the autoprint option on, and either the cursor has moved to a dif- ferent line or the previous command modified the file, then Elvis will print the current line. autotab, at This option affects the behaviour of the autoindent mode. If autoindent is turned off, then autotab has no effect. When autotab is turned on, elvis will use a mixture of spaces and tabs to create the proper amount of indenta- tion. This is the default. When autotab is turned off, elvis will only use spaces June 13, 1992 5-3 OPTIONS 5-3 for auto-indent. Elvis will still insert a real tab character when you hit the <Tab> key, though; the auto- tab option only affects _a_u_t_o_m_a_t_i_c indentation. autowrite, aw When you're editing one file and decide to switch to another - via the :tag command, or :next command, perhaps - if your current file has been modified, then Elvis will normally print an error message and refuse to switch. However, if the autowrite option is on, then Elvis will write the modified version of the current file and suc- cessfully switch to the new file. beautify, bf This option causes all control characters to be deleted from the text file, at the time when you start editing it. If you're already editing a file when you turn on the beautify option, then that file won't be affected. cc The :cc command runs the C compiler. This option should be set to the name of your compiler. charattr, ca Many text formatting programs allow you to designate portions of your text to be underlined, italicized, or boldface by embedding the special strings \fU, \fI, and \fB in your text. The special string \fP marks the end of underlined or boldface text. Elvis normally treats those special strings just like any other text. However, if the charattr option is on, then Elvis will interpret those special strings correctly, to display underlined or boldface text on the screen. (This only works, of course, if your terminal can display under- lined and boldface, and if the TERMCAP entry says how to do it.) columns, co This option shows how wide your screen is. digraph, dig This option is used to enable/disable recognition of digraphs. The default value is nodigraph, which means that digraphs will not be recognized. directory, dir Elvis stores text in temporary files. This option allows you to control which directory those temporary files will appear in. The default is /usr/tmp. June 13, 1992 5-4 OPTIONS 5-4 This option can only be set in a .exrc file; after that, Elvis will have already started making temporary files in some other directory, so it would be too late. edcompatible, ed This option affects the behaviour of the ":s/regexp/text/options" command. It is normally off (:se noed) which causes all of the substitution options to be off unless explicitly given. However, with edcompatible on (:se ed), the substitu- tion command remembers which options you used last time. Those same options will continue to be used until you change them. In edcompatible mode, when you explicitly give the name of a substitution option, you will toggle the state of that option. This all seems very strange to me, but its implementa- tion was almost free when I added the ":&" command to repeat the previous substitution, so there it is. equalprg, ep This holds the name & arguments of the external filter program used the the visual = operator. The defualt value is "fmt", so the = operator will adjust line breaks in text. errorbells, eb Elvis normally rings a bell when you do something wrong. This option lets you disable the bell. exrc This option specifies whether a .exrc file in the current directory should be executed. By default, this option is off (":set noexrc") which prevents elvis from executing .exrc in the current directory. If the .exrc file in your home directory turns this option on (":set exrc") then the Elvis will attempt to execute the .exrc file in the current directory. This option exist mainly for security reasons. A mean-spirited person could do something like echo >/tmp/.exrc '!rm -rf $HOME' and then anybody who attempted to edit or view a file in the /tmp directory would lose most of their files. With the exrc option turned off, this couldn't happen to you. exrefresh, er The EX mode of Elvis writes many lines to the screen. You can make Elvis either write each line to the screen separately, or save up many lines and write them all at once. The exrefresh option is normally on, so each line is June 13, 1992 5-5 OPTIONS 5-5 written to the screen separately. You may wish to turn the exrefresh option off (:se noer) if the "write" system call is costly on your machine, or if you're using a windowing environment. (Windowing environments scroll text a lot faster when you write many lines at once.) This option has no effect in visual command mode or input mode. flash, vbell If your termcap entry describes a visible alternative to ringing your terminal's bell, then this option will say whether the visible version gets used or not. Nor- mally it will be. If your termcap does NOT include a visible bell capa- bility, then the flash option will be off, and you can't turn it on. flipcase, fc The flipcase option allows you to control how the non- ASCII characters are altered by the "~" command. The string is divided into pairs of characters. When "~" is applied to a non-ASCII character, Elvis looks up the character in the flipcase string to see which pair it's in, and replaces it by the other character of the pair. hideformat, hf Many text formatters require you to embed format com- mands in your text, on lines that start with a "." character. Elvis normally displays these lines like any other text, but if the hideformat option is on, then format lines are displayed as blank lines. ignorecase, ic Normally, when Elvis searches for text, it treats uppercase letters as being different for lowercase letters. When the ignorecase option is on, uppercase and lower- case are treated as equal. inputmode, im This option allows you to have Elvis start up in insert mode. You can still exit insert mode at any time by hitting the ESC key, as usual. Usually, this option would be set in your ".exrc" file. keytime, kt The arrow keys of most terminals send a multi-character June 13, 1992 5-6 OPTIONS 5-6 sequence. It takes a measurable amount of time for these sequences to be transmitted. The keytime option allows you to control the maximum amount of time to allow for an arrow key (or other mapped key) to be received in full. On most systems, the setting is the number of tenths of a second to allow between characters. On some other systems, the setting is in whole seconds. Try to avoid setting keytime=1. Most systems just count clock beats, so if you tried to read a character shortly before a clock beat, you could allow almost no time at all for reading the characters. For higher keytime settings, the difference is less critical. If your system's response time is poor, you might want to increase the keytime. In particular, I've found that when keystrokes must be sent through a network (via X windows, rlogin, or telnet, for example) the keytime should be set to at least 1 second. As a special case, you can set keytime to 0 to disable this time limit stuff altogether. The big problem here is: If your arrow keys' sequences start with an ESC, then every time you hit your ESC key Elvis will wait... and wait... to see if maybe that ESC was part of an arrow key's sequence. NOTE: this option is a generalization of the timeout option of the real vi. keywordprg, kp Elvis has a special keyword lookup feature. You move the cursor onto a word, and hit shift-K, and Elvis uses another program to look up the word and display infor- mation about it. This option says which program gets run. The default value of this option is "ref", which is a program that looks up the definition of a function in C. It looks up the function name in a file called "refs" which is created by ctags. You can subtitute other programs, such as an English dictionary program or the online manual. Elvis runs the program, using the keyword as its only argument. The program should write information to stdout. The program's exit status should be 0, unless you want Elvis to print "<<< failed >>>". lines, ln This option says how many lines you screen has. June 13, 1992 5-7 OPTIONS 5-7 list, li In nolist mode (the default), Elvis displays text in a "normal" manner -- with tabs expanded to an appropriate number of spaces, etc. However, sometimes it is useful to have tab characters displayed differently. In list mode, tabs are displayed as "^I", and a "$" is displayed at the end of each line. magic, ma The search mechanism in Elvis can accept "regular expressions" -- strings in which certain characters have special meaning. The magic option is normally on, which causes these characters to be treated specially. If you turn the magic option off (:se noma), then all characters except ^ and $ are treated literally. ^ and $ retain their special meanings regardless of the set- ting of magic. make, mk The :make command runs your "make" program. This option defines the name of your "make" program. mesg With the real vi, running under real UNIX, ":set nomesg" would prevent other users from sending you mes- sages. Elvis ignores it, though. modelines, ml Elvis supports modelines. Modelines are lines near the beginning or end of your text file which contain "ex:yowza:", where "yowza" is any EX command. A typi- cal "yowza" would be something like "set ts=5 ca kp=spell wm=15". Other text may also appear on a mode- line, so you can place the "ex:yowza:" in a comment: /* ex:set sw=4 ai: */ Normally these lines are ignored, for security reasons, but if you have "set modelines" in your .exrc file then "yowza" is executed. nearscroll, ns The line that contains the cursor will always be on the screen. If you move the cursor to a line that isn't on the screen, then elvis will either scroll (if the cursor's line is nearly on the screen already) or redraw the screen completely with the cursor's line centered (if the cursor line is _n_o_t near the screen already). June 13, 1992 5-8 OPTIONS 5-8 This option allows you to control elvis' idea of "near". A value of 15 is typical. A value of 1 would cause elvis to scroll no more that one line. A value of 0 disables scrolling. novice, nov The command ":set novice" is equivelent to ":set nomagic report=1 showmode". number, nu The "number" option causes Elvis to display line numbers at the start of each line. The numbers are not actually part of the text; when the file is written out, it will be written without line numbers. paragraphs, pa The { and } commands move the cursor forward or back- ward in increments of one paragraph. Paragraphs may be separated by blank lines, or by a "dot" command of a text formatter. Different text formatters use dif- ferent "dot" commands. This option allows you to con- figure Elvis to work with your text formatter. It is assumed that your formatter uses commands that start with a "." character at the front of a line, and then have a one- or two-character command name. The value of the paragraphs option is a string in which each pair of characters is one possible form of your text formatter's paragraph command. more When Elvis must display a sequence of messages at the bottom line of the screen in visual mode, it normally pauses after all but the last one, so you have time to read them all. If you turn off the "more" option, then Elvis will not pause. This means you can only read the last message, but it is usually the most important one anyway. prompt, pr If you ":set noprompt", then Elvis will no longer emit a ':' when it expects you to type in an _e_x command. This is slightly useful if you're using an astonish- ingly slow UNIX machine, but the rest of us can just ignore this one. readonly, ro Normally, Elvis will let you write back any file to which you have write permission. If you don't have write permission, then you can only write the changed version of the file to a _d_i_f_f_e_r_e_n_t file. If you set the readonly option, then Elvis will pretend June 13, 1992 5-9 OPTIONS 5-9 you don't have write permission to _a_n_y file you edit. It is useful when you really only mean to use Elvis to look at a file, not to change it. This way you can't change it accidentally. This option is normally off, unless you use the "view" alias of Elvis. "View" is like "vi" except that the readonly option is on. remapThe ":map" command allows you to convert one key sequence into another. The remap option allows you to specify what should happen if portions of that other sequence are also in the map table. If remap is on, then those portions will also be mapped, just as if they had been typed on the keyboard. If remap is off, then the matching portions will not be mapped. For example, if you enter the commands ":map A B" and ":map B C", then when remap is on, A will be converted to C. But when remap is off, A will be converted only to B. report, re Commands in Elvis may affect many lines. For commands that affect a lot of lines, Elvis will output a message saying what was done and how many lines were affected. This option allows you to define what "a lot of lines" means. The default is 5, so any command which affects 5 or more lines will cause a message to be shown. ruler, ru This option is normally off. If you turn it on, then Elvis will constantly display the line/column numbers of the cursor, at the bottom of the screen. scroll, sc The ^U and ^D keys normally scroll backward or forward by half a screenful, but this is adjustable. The value of this option says how many lines those keys should scroll by. If you invoke ^U or ^D with a count argu- ment (for example, "33^D") then this option's value is set to the count. sections, se The [[ and ]] commands move the cursor backward or for- ward in increments of 1 section. Sections may be del- imited by a { character in column 1 (which is useful for C source code) or by means of a text formatter's "dot" commands. This option allows you to configure Elvis to work with your text formatter's "section" command, in exectly the same way that the paragraphs option makes it work with the formatter's "paragraphs" command. June 13, 1992 5-10 OPTIONS 5-10 shell, sh When Elvis forks a shell (perhaps for the :! or :shell commands) this is the program that is uses as a shell. This is "/bin/sh" by default, unless you have set the SHELL (or COMSPEC, for MS-DOS) environment variable, it which case the default value is copied from the environment. shiftwidth, sw The < and > commands shift text left or right by some uniform number of columns. The shiftwidth option defines that "uniform number". The default is 8. showmatch, sm With showmatch set, in input mode every time you hit one of )}], Elvis will momentarily move the cursor to the matching ({[. showmode, smd In visual mode, it is easy to forget whether you're in the visual command mode or input/replace mode. Nor- mally, the showmode option is off, and you haven't a clue as to which mode you're in. If you turn the showmode option on, though, a little message will appear in the lower right-hand corner of your screen, telling you which mode you're in. sidescroll, ss For long lines, Elvis scrolls sideways. (This is dif- ferent from the real vi, which wraps a single long line onto several rows of the screen.) To minimize the number of scrolls needed, Elvis moves the screen sideways by several characters at a time. The value of this option says how many characters' widths to scroll at a time. Generally, the faster your screen can be redrawn, the lower the value you will want in this option. sync, sy If the system crashes during an edit session, then most of your work can be recovered from the temporary file that Elvis uses to store changes. However, sometimes the OS will not copy changes to the hard disk immedi- ately, so recovery might not be possible. The [no]sync option lets you control this. In nosync mode (which is the default, for UNIX), Elvis lets the operating system control when data is written to the disk. This is generally faster. In sync mode (which is the default for MS-DOS, Amiga- Dos, and Atari TOS), Elvis forces all changes out to June 13, 1992 5-11 OPTIONS 5-11 disk every time you make a change. This is generally safer, but slower. It can also be a rather rude thing to do on a multi-user system. tabstop, ts Tab characters are normally 8 characters wide, but you can change their widths by means of this option. taglength, tl This option allows you to specify how many characters of a tag's name must match when performing tag lookup. As a special case, ":set taglength=0" means that all characters of a tag's name must match. Note: some configurations of Elvis don't support this option. term, te This read-only option shows the name of the termcap entry that Elvis is using for your terminal. terse, tr The real vi uses this option to select longer vs. shorter error messages. Elvis has only one set of error messages, though, so this option has no effect. timeout, to The command ":set notimeout" is equivelent to ":set keytime=0", and ":set timeout" is equivelent to ":set keytime=1". This affects the behaviour of the <Esc> key. See the discussion of the "keytime" option for more information. warn, wa If you have modified a file but not yet written it back to disk, then Elvis will normally print a warning before executing a ":!cmd" command. However, in nowarn mode, this warning is not given. Elvis also normally prints a message after a successful search that wrapped at EOF. The [no]warn option can also disable this warning. window, wi This option controls how many lines are redrawn after a long move. On fast terminals, this is usually set to the number of rows that the terminal can display, minus one. This causes the entire screen to be filled with text around the cursor. On slow terminals, you may wish to reduce this value to about 7 or so. That way, if you're doing something June 13, 1992 5-12 OPTIONS 5-12 like repeatedly hitting 'n' to search for each occurrence of some string and trying to find a particu- lar occurrence, then you don't need to wait as long for Elvis to redraw the screen after each search. wrapmargin, wm Normally (with wrapmargin=0) Elvis will let you type in extremely long lines, if you wish. However, with warpmargin set to something other that 0 (wrapmargin=10 is nice), Elvis will automatically cause long lines to be "wrapped" on a word break for lines come too close to the right-hand margin. For example: On an 80-column screen, ":set wm=10" will cause lines to wrap when their length exceeds 70 columns. wrapscan, ws Normally, when you search for something, Elvis will find it no matter where it is in the file. Elvis starts at the cursor position, and searches forward. If Elvis hits EOF without finding what you're looking for, then it wraps around to continue searching from line 1. If you turn off the wrapscan option (:se nows), then when Elvis hits EOF during a search, it will stop and say so. writeany, wr With "writeany" turned off, elvis will prevent you from accidentally overwriting a file. For example, if "foo" exists then ":w foo" will fail. If you turn on the "writeany" option, then ":w foo" will work. Regardless of the setting of "writeany", though, ":w! foo" will work. The '!' forces the ":w" command to write the file unless the operating system won't allow it. June 13, 1992