=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/less/Attic/less.nro,v retrieving revision 1.4 retrieving revision 1.5 diff -u -r1.4 -r1.5 --- src/usr.bin/less/Attic/less.nro 2002/12/31 20:24:01 1.4 +++ src/usr.bin/less/Attic/less.nro 2003/04/13 18:26:25 1.5 @@ -1,20 +1,28 @@ -.TH LESS 1 +.TH LESS 1 "Version 390: 17 Jan 2003" .SH NAME less, more \- view files on a crt .SH SYNOPSIS .B "less|more -?" .br +.B "less|more --help" +.br .B "less|more -V" .br -.B "less|more [-[+]aBcCdeEfgGiImMnNqQrsSuUVwX]" +.B "less|more --version" .br -.B " [-b \fIbufs\fP] [-h \fIlines\fP] [-j \fIline\fP] [-k \fIkeyfile\fP]" +.B "less|more [-[+]aBcCdeEfFgGiIJLmMnNqQrRsSuUVwWX~]" .br -.B " [-{oO} \fIlogfile\fP] [-p \fIpattern\fP] [-P \fIprompt\fP] [-t \fItag\fP]" +.B " [-b \fIspace\fP] [-h \fIlines\fP] [-j \fIline\fP] [-k \fIkeyfile\fP]" .br -.B " [-T \fItagsfile\fP] [-x \fItab\fP] [-y \fIlines\fP] [-[z] \fIlines\fP]" +.B " [-{oO} \fIlogfile\fP] [-p \fIpattern\fP] [-P \fIprompt\fP]" .br -.B " [+[+]\fIcmd\fP] [\fIfilename\fP]..." +.B " [-t \fItag\fP] [-T \fItagsfile\fP] [-x \fItab\fP,...] [-y \fIlines\fP]" +.br +.B " [-[z] \fIlines\fP] [-# \fIshift\fP] [+[+]\fIcmd\fP] [--]" +.br +.B " [\fIfilename\fP]..." +.sp +(See the OPTIONS section for alternate option syntax with long option names.) .SH DESCRIPTION .I Less @@ -59,48 +67,52 @@ .IP "h or H" Help: display a summary of these commands. If you forget all the other commands, remember this one. -.PP .IP "SPACE or ^V or f or ^F" Scroll forward N lines, default one window (see option -z below). If N is more than the screen size, only the final screenful is displayed. Warning: some systems use ^V as a special literalization character. -.PP .IP "z" Like SPACE, but if N is specified, it becomes the new window size. -.PP +.IP "ESC-SPACE" +Like SPACE, but scrolls a full screenful, even if it reaches +end-of-file in the process. .IP "RETURN or ^N or e or ^E or j or ^J" Scroll forward N lines, default 1. The entire N lines are displayed, even if N is more than the screen size. -.PP .IP "d or ^D" Scroll forward N lines, default one half of the screen size. If N is specified, it becomes the new default for subsequent d and u commands. -.PP .IP "b or ^B or ESC-v" Scroll backward N lines, default one window (see option -z below). If N is more than the screen size, only the final screenful is displayed. -.PP .IP "w" Like ESC-v, but if N is specified, it becomes the new window size. -.PP .IP "y or ^Y or ^P or k or ^K" Scroll backward N lines, default 1. The entire N lines are displayed, even if N is more than the screen size. Warning: some systems use ^Y as a special job control character. -.PP .IP "u or ^U" Scroll backward N lines, default one half of the screen size. If N is specified, it becomes the new default for subsequent d and u commands. -.PP +.IP "ESC-) or RIGHTARROW" +Scroll horizontally right N characters, default half the screen width +(see the -# option). +If a number N is specified, it becomes the default for future RIGHTARROW +and LEFTARROW commands. +While the text is scrolled, it acts as though the -S option +(chop lines) were in effect. +.IP "ESC-( or LEFTARROW" +Scroll horizontally left N characters, default half the screen width +(see the -# option). +If a number N is specified, it becomes the default for future RIGHTARROW +and LEFTARROW commands. .IP "r or ^R or ^L" Repaint the screen. -.PP .IP R Repaint the screen, discarding any buffered input. Useful if the file is changing while it is being viewed. -.PP .IP "F" Scroll forward, and keep trying to read when the end of file is reached. @@ -108,25 +120,17 @@ It is a way to monitor the tail of a file which is growing while it is being viewed. (The behavior is similar to the "tail -f" command.) -.PP .IP "g or < or ESC-<" Go to line N in the file, default 1 (beginning of file). (Warning: this may be slow if N is large.) -.PP .IP "G or > or ESC->" Go to line N in the file, default the end of the file. (Warning: this may be slow if N is large, or if N is not specified and standard input, rather than a file, is being read.) -.PP .IP "p or %" Go to a position N percent into the file. N should be between 0 and 100. -(This works if standard input is being read, but only if -.I less -has already read to the end of the file. -It is always fast, but not always useful.) -.PP .IP "{" If a left curly bracket appears in the top line displayed on the screen, @@ -135,7 +139,6 @@ line of the screen. If there is more than one left curly bracket on the top line, a number N may be used to specify the N-th bracket on the line. -.PP .IP "}" If a right curly bracket appears in the bottom line displayed on the screen, @@ -144,19 +147,14 @@ line of the screen. If there is more than one right curly bracket on the top line, a number N may be used to specify the N-th bracket on the line. -.PP .IP "(" Like {, but applies to parentheses rather than curly brackets. -.PP .IP ")" Like }, but applies to parentheses rather than curly brackets. -.PP .IP "[" Like {, but applies to square brackets rather than curly brackets. -.PP .IP "]" Like }, but applies to square brackets rather than curly brackets. -.PP .IP "ESC-^F" Followed by two characters, acts like {, but uses the two characters as open and close brackets, @@ -172,7 +170,6 @@ .IP m Followed by any lowercase letter, marks the current position with that letter. -.PP .IP "'" (Single quote.) Followed by any lowercase letter, returns to the position which @@ -183,10 +180,8 @@ file respectively. Marks are preserved when a new file is examined, so the ' command can be used to switch between input files. -.PP .IP "^X^X" Same as single quote. -.PP .IP /pattern Search forward in the file for the N-th line containing the pattern. N defaults to 1. @@ -199,74 +194,77 @@ if entered at the beginning of the pattern; they modify the type of search rather than become part of the pattern: .RS -.IP ! +.IP "^N or !" Search for lines which do NOT match the pattern. -.IP * +.IP "^E or *" Search multiple files. -That is, if the search reaches the end of the current file +That is, if the search reaches the END of the current file without finding a match, the search continues in the next file in the command line list. -.IP @ -Begin the search at the first line of the first file +.IP "^F or @" +Begin the search at the first line of the FIRST file in the command line list, regardless of what is currently displayed on the screen or the settings of the -a or -j options. +.IP "^K" +Highlight any text which matches the pattern on the current screen, +but don't move to the first match (KEEP current position). +.IP "^R" +Don't interpret regular expression metacharacters; +that is, do a simple textual comparison. .RE -.PP .IP ?pattern Search backward in the file for the N-th line containing the pattern. The search starts at the line immediately before the top line displayed. .sp Certain characters are special as in the / command: .RS -.IP ! +.IP "^N or !" Search for lines which do NOT match the pattern. -.IP * +.IP "^E or *" Search multiple files. That is, if the search reaches the beginning of the current file without finding a match, the search continues in the previous file in the command line list. -.IP @ +.IP "^F or @" Begin the search at the last line of the last file in the command line list, regardless of what is currently displayed on the screen or the settings of the -a or -j options. +.IP "^K" +As in forward searches. +.IP "^R" +As in forward searches. .RE -.PP .IP "ESC-/pattern" Same as "/*". -.PP .IP "ESC-?pattern" Same as "?*". -.PP .IP n Repeat previous search, for N-th line containing the last pattern. -If the previous search was modified by !, the search is made for the +If the previous search was modified by ^N, the search is made for the N-th line NOT containing the pattern. -If the previous search was modified by *, the search continues +If the previous search was modified by ^E, the search continues in the next (or previous) file if not satisfied in the current file. -There is no effect if the previous search was modified by @. -.PP +If the previous search was modified by ^R, the search is done +without using regular expressions. +There is no effect if the previous search was modified by ^F or ^K. .IP N Repeat previous search, but in the reverse direction. -.PP .IP "ESC-n" Repeat previous search, but crossing file boundaries. The effect is as if the previous search were modified by *. -.PP .IP "ESC-N" Repeat previous search, but in the reverse direction and crossing file boundaries. -.PP .IP "ESC-u" Undo search highlighting. Turn off highlighting of strings matching the current search pattern. If highlighting is already off because of a previous ESC-u command, turn highlighting back on. Any search command will also turn highlighting back on. -(Highlighting can also be disabled by toggling the -G flag; +(Highlighting can also be disabled by toggling the -G option; in that case search commands do not turn highlighting back on.) -.PP .IP ":e [filename]" Examine a new file. If the filename is missing, the "current" file (see the :n and :p commands @@ -274,30 +272,40 @@ A percent sign (%) in the filename is replaced by the name of the current file. A pound sign (#) is replaced by the name of the previously examined file. +However, two consecutive percent signs are simply +replaced with a single percent sign. +This allows you to enter a filename that contains a percent sign +in the name. +Similarly, two consecutive pound signs are replaced with a single pound sign. The filename is inserted into the command line list of files so that it can be seen by subsequent :n and :p commands. If the filename consists of several files, they are all inserted into the list of files and the first one is examined. -.PP +If the filename contains one or more spaces, +the entire filename should be enclosed in double quotes +(also see the -" option). .IP "^X^V or E" Same as :e. Warning: some systems use ^V as a special literalization character. -.PP +On such systems, you may not be able to use ^V. .IP ":n" Examine the next file (from the list of files given in the command line). If a number N is specified, the N-th next file is examined. -.PP .IP ":p" Examine the previous file in the command line list. If a number N is specified, the N-th previous file is examined. -.PP .IP ":t" -Go to supplied tag. -.PP +Go to the specified tag. .IP ":x" Examine the first file in the command line list. If a number N is specified, the N-th file in the list is examined. -.PP +.IP ":d" +Remove the current file from the list of files. +.IP "t" +Go to the next tag, if there were more than one matches for the current tag. +See the \-t option for more details about tags. +.IP "T" +Go to the previous tag, if there were more than one matches for the current tag. .IP "= or ^G or :f" Prints some information about the file being viewed, including its name @@ -305,57 +313,67 @@ If possible, it also prints the length of the file, the number of lines in the file and the percent of the file above the last displayed line. -.PP .IP \- -Followed by one of the command line option letters (see below), +Followed by one of the command line option letters (see OPTIONS below), this will change the setting of that option and print a message describing the new setting. +If a ^P (CONTROL-P) is entered immediately after the dash, +the setting of the option is changed but no message is printed. If the option letter has a numeric value (such as -b or -h), or a string value (such as -P or -t), a new value may be entered after the option letter. If no new value is entered, a message describing the current setting is printed and nothing is changed. -.PP +.IP \-\- +Like the \- command, but takes a long option name (see OPTIONS below) +rather than a single option letter. +You must press RETURN after typing the option name. +A ^P immediately after the second dash suppresses printing of a +message describing the new setting, as in the \- command. .IP \-+ -Followed by one of the command line option letters (see below), +Followed by one of the command line option letters this will reset the option to its default setting and print a message describing the new setting. (The "\-+\fIX\fP" command does the same thing as "\-+\fIX\fP" on the command line.) This does not work for string-valued options. -.PP -.IP \-\- -Followed by one of the command line option letters (see below), +.IP \-\-+ +Like the \-+ command, but takes a long option name +rather than a single option letter. +.IP \-! +Followed by one of the command line option letters, this will reset the option to the "opposite" of its default setting and print a message describing the new setting. -(The "\-\-\fIX\fP" command does the same thing -as "\-\fIX\fP" on the command line.) This does not work for numeric or string-valued options. -.PP +.IP \-\-! +Like the \-! command, but takes a long option name +rather than a single option letter. .IP _ (Underscore.) -Followed by one of the command line option letters (see below), +Followed by one of the command line option letters, this will print a message describing the current setting of that option. The setting of the option is not changed. -.PP +.IP __ +(Double underscore.) +Like the _ (underscore) command, but takes a long option name +rather than a single option letter. +You must press RETURN after typing the option name. .IP +cmd Causes the specified cmd to be executed each time a new file is examined. For example, +G causes .I less to initially display each file starting at the end rather than the beginning. -.PP .IP V Prints the version number of .I less being run. -.PP -.IP "q or :q or :Q or ZZ" +.IP "q or Q or :q or :Q or ZZ" Exits .I less. .PP The following -three +four commands may or may not be valid, depending on your particular installation. .PP .IP v @@ -364,7 +382,6 @@ or EDITOR if VISUAL is not defined, or defaults to "vi" if neither VISUAL nor EDITOR is defined. See also the discussion of LESSEDIT under the section on PROMPTS below. -.PP .IP "! shell-command" Invokes a shell to run the shell-command given. A percent sign (%) in the command is replaced by the name of the @@ -372,9 +389,9 @@ A pound sign (#) is replaced by the name of the previously examined file. "!!" repeats the last shell command. "!" with no shell command simply invokes a shell. -In all cases, the shell is taken from the environment variable SHELL, +On Unix systems, the shell is taken from the environment variable SHELL, or defaults to "sh". -.PP +On MS-DOS and OS/2 systems, the shell is the normal command processor. .IP "| shell-command" represents any mark letter. Pipes a section of the input file to the given shell command. @@ -382,6 +399,9 @@ the current screen and the position marked by the letter. may also be ^ or $ to indicate beginning or end of file respectively. If is . or newline, the current screen is piped. +.IP "s filename" +Save the input to a file. +This only works if the input is a pipe, not an ordinary file. .PP .SH OPTIONS Command line options are described below. @@ -389,11 +409,24 @@ .I less is running, via the "\-" command. .PP -Options are also taken from the environment variable "LESS" if the -command is -.I less -, or from the environment variable "MORE" if the command is -.I more. +Most options may be given in one of two forms: +either a dash followed by a single letter, +or two dashes followed by a long option name. +A long option name may be abbreviated as long as +the abbreviation is unambiguous. +For example, --quit-at-eof may be abbreviated --quit, but not +--qui, since both --quit-at-eof and --quiet begin with --qui. +Some long option names are in uppercase, such as --QUIT-AT-EOF, as +distinct from --quit-at-eof. +Such option names need only have their first letter capitalized; +the remainder of the name may be in either case. +For example, --Quit-at-eof is equivalent to --QUIT-AT-EOF. +.PP +Options are also taken from the environment variable "LESS" +if the command is +.IR less , +or from the environment variable "MORE" if the command is +.IR more . For example, to avoid typing "less -options ..." each time .I less @@ -407,61 +440,80 @@ .sp LESS="-options"; export LESS .sp +On MS-DOS, you don't need the quotes, but you should replace any +percent signs in the options string by double percent signs. +.sp The environment variable is parsed before the command line, so command line options override the LESS environment variable. If an option appears in the LESS variable, it can be reset -to its default on the command line by beginning the command -line option with "-+". +to its default value on the command line by beginning the command +line option with "\-+". .sp -A dollar sign ($) may be used to signal the end of an option string. -This is important only for options like -P which take a -following string. -.IP -? +For options like -P or -D which take a following string, +a dollar sign ($) must be used to signal the end of the string. +For example, to set two -D options on MS-DOS, you must have +a dollar sign between them, like this: +.sp +LESS="-Dn9.1$-Ds4.1" +.sp +.IP "-? or --help" This option displays a summary of the commands accepted by .I less (the same as the h command). -If this option is given, all other options are ignored, and -.I less -exits after the help screen is viewed. (Depending on how your shell interprets the question mark, -it may be necessary to quote the question mark, thus: "-\\?".) -.IP -a +it may be necessary to quote the question mark, thus: "-\e?".) +.IP "-a or --search-skip-screen" Causes searches to start after the last line displayed on the screen, thus skipping all lines displayed on the screen. By default, searches start at the second line on the screen (or after the last found line; see the -j option). -.IP -b\fIn\fP -Specifies the number of buffers +.IP "-b\fIn\fP or --buffers=\fIn\fP" +Specifies the amount of buffer space .I less -will use for each file. -Buffers are 1K, and by default 10 buffers are used for each file -(except if the file is a pipe; see the -B option). -The number \fIn\fP specifies a different number of buffers to use. -.IP -B +will use for each file, in units of kilobytes (1024 bytes). +By default 64K of buffer space is used for each file +(unless the file is a pipe; see the -B option). +The -b option specifies instead that \fIn\fP kilobytes of +buffer space should be used for each file. +If \fIn\fP is -1, buffer space is unlimited; that is, +the entire file is read into memory. +.IP "-B or --auto-buffers" By default, when data is read from a pipe, buffers are allocated automatically as needed. If a large amount of data is read from the pipe, this can cause a large amount of memory to be allocated. The -B option disables this automatic allocation of buffers for pipes, -so that only the number of buffers specified by the -b option are used. +so that only 64K +(or the amount of space specified by the -b option) +is used for the pipe. Warning: use of -B can result in erroneous display, since only the most recently viewed part of the file is kept in memory; any earlier data is lost. -.IP -c +.IP "-c or --clear-screen" Causes full screen repaints to be painted from the top line down. By default, full screen repaints are done by scrolling from the bottom of the screen. -.IP -C +.IP "-C or --CLEAR-SCREEN" The -C option is like -c, but the screen is cleared before it is repainted. -.IP -d -The -d option causes the default prompt to include the basic directions -``[Press space to continue, 'q' to quit.]''. The -d +.IP "-d or --dumb (less only)" +The -d option suppresses the error message +normally displayed if the terminal is dumb; +that is, lacks some important capability, +such as the ability to clear the screen or scroll backward. +The -d option does not otherwise change the behavior of +.I less +on a dumb terminal. +This option is on by default when invoked as +.IR more . +.IP "-d (more only)" +The -d option causes the default prompt to include the +basic directions ``[Press space to continue, 'q' to quit.]''. The -d option also causes the message ``[Press 'h' for instructions.]'' to be displayed when an invalid command is entered (normally, the bell is rung). This option is useful in environments where users may not be experienced with pagers. -.IP -D\fBx\fP\fIcolor\fP +.IP "-D\fBx\fP\fIcolor\fP or --color=\fBx\fP\fIcolor\fP" [MS-DOS only] Sets the color of the text displayed. \fBx\fP is a single character which selects the type of text whose color is @@ -470,57 +522,58 @@ The first number selects the foreground color and the second selects the background color of the text. A single number \fIN\fP is the same as \fIN.0\fP. -.IP -e +.IP "-e or --quit-at-eof" Causes .I less to automatically exit the second time it reaches end-of-file. By default, the only way to exit .I less -is via the "q" command, except in -.I more -mode, where -.I less -will exit at the end of a file. -.IP -E +is via the "q" command. +.IP "-E or --QUIT-AT-EOF" Causes .I less to automatically exit the first time it reaches end-of-file. -.IP -f +.IP "-f or --force" Forces non-regular files to be opened. (A non-regular file is a directory or a device special file.) Also suppresses the warning message when a binary file is opened. By default, .I less will refuse to open non-regular files. -.IP -g +.IP "-F or --quit-if-one-screen" +Causes +.I less +to automatically exit +if the entire file can be displayed on the first screen. +.IP "-g or --hilite-search" Normally, .I less will highlight ALL strings which match the last search command. -The -g flag changes this behavior to highlight only the particular string +The -g option changes this behavior to highlight only the particular string which was found by the last search command. This can cause .I less to run somewhat faster than the default. -.IP -G -The -G flag suppresses all highlighting of strings found by search commands. -.IP -h\fIn\fP +.IP "-G or --HILITE-SEARCH" +The -G option suppresses all highlighting of strings found by search commands. +.IP "-h\fIn\fP or ---max-back-scroll=\fIn\fP" Specifies a maximum number of lines to scroll backward. If it is necessary to scroll backward more than \fIn\fP lines, the screen is repainted in a forward direction instead. (If the terminal does not have the ability to scroll backward, -h0 is implied.) -.IP -i +.IP "-i or --ignore-case" Causes searches to ignore case; that is, uppercase and lowercase are considered identical. This option is ignored if any uppercase letters appear in the search pattern; in other words, if a pattern contains uppercase letters, then that search does not ignore case. -.IP -I +.IP "-I or --IGNORE-CASE" Like -i, but searches ignore case even if the pattern contains uppercase letters. -.IP -j\fIn\fP +.IP "-j\fIn\fP or --jump-target=\fIn\fP" Specifies a line on the screen where the "target" line is to be positioned. A target line is the object of a text search, @@ -536,18 +589,32 @@ For example, if "-j4" is used, the target line is the fourth line on the screen, so searches begin at the fifth line on the screen. -.IP -k\fIfilename\fP +.IP "-J or --status-column" +Displays a status column at the left edge of the screen. +The status column shows the lines that matched the current search. +The status column is also used if the -w or -W option is in effect. +.IP "-k\fIfilename\fP or --lesskey-file=\fIfilename\fP" Causes .I less to open and interpret the named file as a .I lesskey (1) file. Multiple -k options may be specified. -If a file called .less exists in the user's home directory, this -file is also used as a +If the LESSKEY or LESSKEY_SYSTEM environment variable is set, or +if a lesskey file is found in a standard place (see KEY BINDINGS), +it is also used as a .I lesskey file. -.IP -m +.IP "-L or --no-lessopen" +Ignore the LESSOPEN environment variable +(see the INPUT PREPROCESSOR section below). +This option can be set from within \fIless\fP, +but it will apply only to files opened subsequently, not to the +file which is currently open. +When invoked as +.IR more , +the LESSOPEN environment variable is ignored by default. +.IP "-m or --long-prompt" Causes .I less to prompt verbosely (like \fImore\fP), @@ -555,25 +622,25 @@ By default, .I less prompts with a colon. -.IP -M +.IP "-M or --LONG-PROMPT" Causes .I less to prompt even more verbosely than .I more. -.IP -n +.IP "-n or --line-numbers" Suppresses line numbers. The default (to use line numbers) may cause .I less to run more slowly in some cases, especially with a very large input file. -Suppressing line numbers with the -n flag will avoid this problem. +Suppressing line numbers with the -n option will avoid this problem. Using line numbers means: the line number will be displayed in the verbose prompt and in the = command, and the v command will pass the current line number to the editor (see also the discussion of LESSEDIT in PROMPTS below). -.IP -N +.IP "-N or --LINE-NUMBERS" Causes a line number to be displayed at the beginning of each line in the display. -.IP -o\fIfilename\fP +.IP "-o\fIfilename\fP or --log-file=\fIfilename\fP" Causes .I less to copy its input to the named file as it is being viewed. @@ -582,7 +649,7 @@ If the file already exists, .I less will ask for confirmation before overwriting it. -.IP -O\fIfilename\fP +.IP "-O\fIfilename\fP or --LOG-FILE=\fIfilename\fP" The -O option is like -o, but it will overwrite an existing file without asking for confirmation. .sp @@ -593,13 +660,13 @@ Without a file name, they will simply report the name of the log file. The "s" command is equivalent to specifying -o from within .I less. -.IP -p\fIpattern\fP +.IP "-p\fIpattern\fP or --pattern=\fIpattern\fP" The -p option on the command line is equivalent to specifying +/\fIpattern\fP; that is, it tells .I less to start at the first occurrence of \fIpattern\fP in the file. -.IP -P\fIprompt\fP +.IP "-P\fIprompt\fP or --prompt=\fIprompt\fP" Provides a way to tailor the three prompt styles to your own preference. This option would normally be put in the LESS environment @@ -608,14 +675,17 @@ command. Such an option must either be the last option in the LESS variable, or be terminated by a dollar sign. --P followed by a string changes the default (short) prompt to that string. --Pm changes the medium (-m) prompt to the string, and +-Ps followed by a string changes the default (short) prompt +to that string. +-Pm changes the medium (-m) prompt. -PM changes the long (-M) prompt. -Also, -P= changes the message printed by the = command to the given string. +-Ph changes the prompt for the help screen. +-P= changes the message printed by the = command. +-Pw changes the message printed while waiting for data (in the F command). All prompt strings consist of a sequence of letters and special escape sequences. See the section on PROMPTS for more details. -.IP -q +.IP "-q or --quiet or --silent" Causes moderately "quiet" operation: the terminal bell is not rung if an attempt is made to scroll past the end of the file @@ -624,50 +694,74 @@ The bell will be rung on certain other errors, such as typing an invalid character. The default is to ring the terminal bell in all such cases. -.IP -Q +.IP "-Q or --QUIET or --SILENT" Causes totally "quiet" operation: the terminal bell is never rung. -.IP -r +.IP "-r or --raw-control-chars" Causes "raw" control characters to be displayed. The default is to display control characters using the caret notation; for example, a control-A (octal 001) is displayed as "^A". -Warning: when the -r flag is used, +Warning: when the -r option is used, .I less cannot keep track of the actual appearance of the screen (since this depends on how the screen responds to each type of control character). Thus, various display problems may result, such as long lines being split in the wrong place. -.IP -s +.IP "-R or --RAW-CONTROL-CHARS" +Like -r, but tries to keep track of the screen appearance where possible. +This works only if the input consists of normal text and possibly some +ANSI "color" escape sequences, which are sequences of the form: +.sp + ESC [ ... m +.sp +where the "..." is zero or more characters other than "m". +For the purpose of keeping track of screen appearance, +all control characters and all ANSI color escape sequences are +assumed to not move the cursor. +You can make +.I less +think that characters other than "m" can end ANSI color escape sequences +by setting the environment variable LESSANSIENDCHARS to the list of +characters which can end a color escape sequence. +.IP "-s or --squeeze-blank-lines" Causes consecutive blank lines to be squeezed into a single blank line. This is useful when viewing .I nroff output. -.IP -S +.IP "-S or --chop-long-lines" Causes lines longer than the screen width to be chopped rather than folded. -That is, the remainder of a long line is simply discarded. +That is, the portion of a long line that does not fit in +the screen width is not shown. The default is to fold long lines; that is, display the remainder on the next line. -.IP -t\fItag\fP +.IP "-t\fItag\fP or --tag=\fItag\fP" The -t option, followed immediately by a TAG, will edit the file containing that tag. -For this to work, there must be a file called "tags" in the -current directory, which was previously built by the +For this to work, tag information must be available; +for example, there may be a file in the current directory called "tags", +which was previously built by .I ctags -(1) command. -This option may also be specified from within +(1) or an equivalent command. +If the environment variable LESSGLOBALTAGS is set, it is taken to be +the name of a command compatible with +.I global +(1), and that command is executed to find the tag. +(See http://www.gnu.org/software/global/global.html). +The -t option may also be specified from within .I less (using the \- command) as a way of examining a new file. The command ":t" is equivalent to specifying -t from within .I less. -.IP -T\fItagsfile\fP +.IP "-T\fItagsfile\fP or --tag-file=\fItagsfile\fP" Specifies a tags file to be used instead of "tags". -.IP -u +.IP "-u or --underline-special" Causes backspaces and carriage returns to be treated as printable characters; that is, they are sent to the terminal when they appear in the input. -.IP -U -Causes backspaces and carriage returns to be treated as control characters; +.IP "-U or --UNDERLINE-SPECIAL" +Causes backspaces, tabs and carriage returns to be +treated as control characters; that is, they are handled as specified by the -r option. .sp By default, if neither -u nor -U is given, @@ -681,33 +775,50 @@ using the terminal's hardware boldface capability. Other backspaces are deleted, along with the preceding character. Carriage returns immediately followed by a newline are deleted. -Other carriage returns are handled as specified by the -r option. +other carriage returns are handled as specified by the -r option. Text which is overstruck or underlined can be searched for if neither -u nor -U is in effect. -.IP -V +.IP "-V or --version" Displays the version number of .I less. -.IP -w -Causes blank lines to be used to represent lines -past the end of the file. -By default, -a tilde character (~) is used. -.IP -x\fIn\fP -Sets tab stops every \fIn\fP positions. +.IP "-w or --hilite-unread" +Temporarily highlights the first "new" line after a forward movement +of a full page. +The first "new" line is the line immediately following the line previously +at the bottom of the screen. +Also highlights the target line after a g or p command. +The highlight is removed at the next command which causes movement. +The entire line is highlighted, unless the -J option is in effect, +in which case only the status column is highlighted. +.IP "-W or --HILITE-UNREAD" +Like -w, but temporarily highlights the first new line after any +forward movement command larger than one line. +.IP "-x\fIn\fP,... or --tabs=\fIn\fP,..." +Sets tab stops. +If only one \fIn\fP is specified, tab stops are set at multiples of \fIn\fP. +If multiple values separated by commas are specified, tab stops +are set at those positions, and then continue with the same spacing as the +last two. +For example, \fI-x9,17\fP will set tabs at positions 9, 17, 25, 33, etc. The default for \fIn\fP is 8. -.IP -X +.IP "-X or --no-init" Disables sending the termcap initialization and deinitialization strings to the terminal. This is sometimes desirable if the deinitialization string does something unnecessary, like clearing the screen. -.IP -y\fIn\fP +.IP "--no-keypad" +Disables sending the keypad initialization and deinitialization strings +to the terminal. +This is sometimes useful if the keypad strings make the numeric +keypad behave in an undesirable manner. +.IP "-y\fIn\fP or --max-forw-scroll=\fIn\fP" Specifies a maximum number of lines to scroll forward. If it is necessary to scroll forward more than \fIn\fP lines, the screen is repainted instead. The -c or -C option may be used to repaint from the top of the screen if desired. By default, any forward movement causes scrolling. -.IP -[z]\fIn\fP +.IP "-[z]\fIn\fP or --window=\fIn\fP" Changes the default scrolling window size to \fIn\fP lines. The default is one screenful. The z and w commands can also be used to change the window size. @@ -721,6 +832,32 @@ For example, if the screen is 24 lines, \fI-z-4\fP sets the scrolling window to 20 lines. If the screen is resized to 40 lines, the scrolling window automatically changes to 36 lines. +.IP "-\fI\(dqcc\fP\ or\ --quotes=\fIcc\fP" +Changes the filename quoting character. +This may be necessary if you are trying to name a file +which contains both spaces and quote characters. +Followed by a single character, this changes the quote character to that +character. +Filenames containing a space should then be surrounded by that character +rather than by double quotes. +Followed by two characters, changes the open quote to the first character, +and the close quote to the second character. +Filenames containing a space should then be preceded by the open quote +character and followed by the close quote character. +Note that even after the quote characters are changed, this option +remains -" (a dash followed by a double quote). +.IP "-~ or --tilde" +Normally lines after end of file are displayed as a single tilde (~). +This option causes lines after end of file to be displayed as blank lines. +.IP "-# or --shift" +Specifies the default number of positions to scroll horizontally +in the RIGHTARROW and LEFTARROW commands. +If the number specified is zero, it sets the default number of +positions to one half of the screen width. +.IP -- +A command line argument of "--" marks the end of option arguments. +Any arguments following this are interpreted as filenames. +This can be useful when viewing a file whose name begins with a "-" or "+". .IP + If a command line option begins with \fB+\fP, the remainder of that option is taken to be an initial command to @@ -782,13 +919,17 @@ If it matches more than one filename, the first match is entered into the command line. Repeated TABs will cycle thru the other matching filenames. +If the completed filename is a directory, a "/" is appended to the filename. +(On MS-DOS systems, a "\e" is appended.) +The environment variable LESSSEPARATOR can be used to specify a +different character to append to a directory name. .IP "BACKTAB [ ESC-TAB ]" -Like TAB, but cycles in the reverse direction thru the matching filenames. +Like, TAB, but cycles in the reverse direction thru the matching filenames. .IP "^L" Complete the partial filename to the left of the cursor. If it matches more than one filename, all matches are entered into the command line (if they fit). -.IP "^U (Unix) or ESC (MS-DOS)" +.IP "^U (Unix and OS/2) or ESC (MS-DOS)" Delete the entire command line, or cancel the command if the command line is empty. If you have changed your line-kill character in Unix to something @@ -800,15 +941,55 @@ commands by using the program .I lesskey (1) -to create a file called ".less" in your home directory. +to create a lesskey file. This file specifies a set of command keys and an action associated with each key. You may also use .I lesskey -to change the line-editing keys (see LINE EDITING). +to change the line-editing keys (see LINE EDITING), +and to set environment variables. +If the environment variable LESSKEY is set, +.I less +uses that as the name of the lesskey file. +Otherwise, +.I less +looks in a standard place for the lesskey file: +On Unix systems, +.I less +looks for a lesskey file called "$HOME/.less". +On MS-DOS and Windows systems, +.I less +looks for a lesskey file called "$HOME/_less", and if it is not found there, +then looks for a lesskey file called "_less" in any directory specified +in the PATH environment variable. +On OS/2 systems, +.I less +looks for a lesskey file called "$HOME/less.ini", and if it is not found, +then looks for a lesskey file called "less.ini" in any directory specified +in the INIT environment variable, and if it not found there, +then looks for a lesskey file called "less.ini" in any directory specified +in the PATH environment variable. See the .I lesskey manual page for more details. +.P +A system-wide lesskey file may also be set up to provide key bindings. +If a key is defined in both a local lesskey file and in the +system-wide file, key bindings in the local file take precedence over +those in the system-wide file. +If the environment variable LESSKEY_SYSTEM is set, +.I less +uses that as the name of the system-wide lesskey file. +Otherwise, +.I less +looks in a standard place for the system-wide lesskey file: +On Unix systems, the system-wide lesskey file is /usr/local/etc/sysless. +(However, if +.I less +was built with a different sysconf directory than /usr/local/etc, +that directory is where the sysless file is found.) +On MS-DOS and Windows systems, the system-wide lesskey file is c:\e_sysless. +On OS/2 systems, the system-wide lesskey file is c:\esysless.ini. .SH "INPUT PREPROCESSOR" You may define an "input preprocessor" for @@ -817,7 +998,7 @@ .I less opens a file, it first gives your input preprocessor a chance to modify the way the contents of the file are displayed. -An input preprocessor is simply an executable program (or shell script) +An input preprocessor is simply an executable program (or shell script), which writes the contents of the file to a different file, called the replacement file. The contents of the replacement file are then displayed @@ -867,17 +1048,15 @@ .br case "$1" in .br - *.Z|*.gz) TFILE=`mktemp /tmp/less.XXXXXX` || exit 1 + *.Z) uncompress -c $1 >/tmp/less.$$ 2>/dev/null .br - gunzip -c $1 >${TFILE} 2>/dev/null + if [ -s /tmp/less.$$ ]; then .br - if [ -s ${TFILE} ]; then + echo /tmp/less.$$ .br - echo ${TFILE} -.br else .br - rm -f ${TFILE} + rm -f /tmp/less.$$ .br fi .br @@ -920,7 +1099,7 @@ .PP lesspipe.sh: .br - !# /bin/sh + #! /bin/sh .br case "$1" in .br @@ -955,20 +1134,32 @@ The LESSCHARSET environment variable may be used to select a character set. Possible values for LESSCHARSET are: .IP ascii -The default character set. BS, TAB, NL, CR, and formfeed are control characters, -all chars with values between 127 and 255 are binary, -and all others are normal. -.IP latin1 -Selects the ISO 8859/1 character set. -latin-1 is the same as ASCII, except characters between 161 and 255 are +all chars with values between 32 and 126 are normal, +and all others are binary. +.IP iso8859 +Selects an ISO 8859 character set. +This is the same as ASCII, except characters between 160 and 255 are treated as normal characters. +.IP latin1 +Same as iso8859. +.IP latin9 +Same as iso8859. .IP dos Selects a character set appropriate for MS-DOS. +.IP ebcdic +Selects an EBCDIC character set. +.IP IBM-1047 +Selects an EBCDIC character set used by OS/390 Unix Services. +This is the EBCDIC analogue of latin1. You get similar results +by setting either LESSCHARSET=IBM-1047 or LC_CTYPE=en_US +in your environment. .IP koi8-r Selects a Russian character set. .IP next Selects a character set appropriate for NeXT computers. +.IP utf-8 +Selects the UTF-8 encoding of the ISO 10646 character set. .PP In special cases, it may be desired to tailor .I less @@ -992,22 +1183,40 @@ .sp ascii\ 8bcccbcc18b95.b .br - latin1 8bcccbcc18b95.33b. -.br dos\ \ \ 8bcccbcc12bc5b95.b. .br + ebcdic 5bc6bcc7bcc41b.9b7.9b5.b..8b6.10b6.b9.7b +.br + \ \ \ \ \ \ 9.8b8.17b3.3b9.7b9.8b8.6b10.b.b.b. +.br + IBM-1047 4cbcbc3b9cbccbccbb4c6bcc5b3cbbc4bc4bccbc +.br + \ \ \ \ \ \ 191.b +.br + iso8859 8bcccbcc18b95.33b. +.br koi8-r 8bcccbcc18b95.b128. .br + latin1 8bcccbcc18b95.33b. +.br next\ \ 8bcccbcc18b95.bb125.bb .PP -If neither LESSCHARSET nor LESSCHARDEF is set, -but your system supports the +If neither LESSCHARSET nor LESSCHARDEF is set, +but the string "UTF-8" is found in the LC_ALL, LC_TYPE or LANG +environment variables, then the default character set is utf-8. +.PP +If that string is not found, but your system supports the .I setlocale interface, .I less will use setlocale to determine the character set. -setlocale is controlled by setting the LANG or LC_CTYPE environment variables. +setlocale is controlled by setting the LANG or LC_CTYPE environment +variables. .PP +Finally, if the +.I setlocale +interface is also not available, the default character set is latin1. +.PP Control and binary characters are displayed in standout (reverse video). Each such character is displayed in caret notation if possible (e.g. ^A for control-A). Caret notation is used only if @@ -1017,13 +1226,14 @@ setting the LESSBINFMT environment variable. LESSBINFMT may begin with a "*" and one character to select the display attribute: -"*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout. +"*k" is blinking, "*d" is bold, "*u" is underlined, "*s" is standout, +and "*n" is normal. If LESSBINFMT does not begin with a "*", normal attribute is assumed. The remainder of LESSBINFMT is a string which may include one printf-style escape sequence (a % followed by x, X, o, d, etc.). For example, if LESSBINFMT is "*u[%x]", binary characters are displayed in underlined hexadecimal surrounded by brackets. -The default if no LESSBINFMT is specified is "*d<%X>". +The default if no LESSBINFMT is specified is "*s<%X>". .SH "PROMPTS" The -P option allows you to tailor the prompt to your preference. @@ -1047,6 +1257,15 @@ and a "j" means use the "target" line, as specified by the -j option. .IP "%B" Replaced by the size of the current input file. +.IP "%c" +Replaced by the column number of the text appearing in the first +column of the screen. +.IP "%d\fIX\fP" +Replaced by the page number of a line in the input file. +The line to be used is determined by the \fIX\fP, as with the %b option. +.IP "%D" +Replaced by the number of pages in the input file, +or equivalently, the page number of the last line in the input file. .IP "%E" Replaced by the name of the editor (from the VISUAL environment variable, or the EDITOR environment variable if VISUAL is not defined). @@ -1064,8 +1283,11 @@ .IP "%m" Replaced by the total number of input files. .IP "%p\fIX\fP" -Replaced by the percent into the current input file. +Replaced by the percent into the current input file, based on byte offsets. The line used is determined by the \fIX\fP as with the %b option. +.IP "%P\fIX\fP" +Replaced by the percent into the current input file, based on line numbers. +The line used is determined by the \fIX\fP as with the %b option. .IP "%s" Same as %B. .IP "%t" @@ -1095,6 +1317,10 @@ True if the byte offset of the specified line is known. .IP "?B" True if the size of current input file is known. +.IP "?c" +True if the text is horizontally shifted (%c is not zero). +.IP "?d\fIX\fP" +True if the page number of the specified line is known. .IP "?e" True if at end-of-file. .IP "?f" @@ -1109,8 +1335,11 @@ .IP "?n" True if this is the first prompt in a new input file. .IP "?p\fIX\fP" -True if the percent into the current input file +True if the percent into the current input file, based on byte offsets, of the specified line is known. +.IP "?P\fIX\fP" +True if the percent into the current input file, based on line numbers, +of the specified line is known. .IP "?s" Same as "?B". .IP "?x" @@ -1130,7 +1359,7 @@ This prompt prints the filename, if known; otherwise the string "Standard input". .sp -?f%f .?ltLine %lt:?pt%pt\\%:?btByte %bt:-... +?f%f .?ltLine %lt:?pt%pt\e%:?btByte %bt:-... .sp This prompt would print the filename, if known. The filename is followed by the line number, if known, @@ -1140,7 +1369,7 @@ and how the % after the %pt is included literally by escaping it with a backslash. .sp -?n?f%f\ .?m(file\ %i\ of\ %m)\ ..?e(END)\ ?x-\ Next\\:\ %x..%t +?n?f%f\ .?m(file\ %i\ of\ %m)\ ..?e(END)\ ?x-\ Next\e:\ %x..%t .sp This prints the filename if this is the first prompt in a file, followed by the "file N of N" message if there is more @@ -1154,18 +1383,18 @@ Each is broken into two lines here for readability only. .nf .sp -?n?f%f\ .?m(file\ %i\ of\ %m)\ ..?e(END)\ ?x-\ Next\\:\ %x.: - ?pB%pB\\%:byte\ %bB?s/%s...%t +?n?f%f\ .?m(file\ %i\ of\ %m)\ ..?e(END)\ ?x-\ Next\e:\ %x.: + ?pB%pB\e%:byte\ %bB?s/%s...%t .sp -?f%f\ .?n?m(file\ %i\ of\ %m)\ ..?ltline\ %lt?L/%L.\ :byte\ %bB?s/%s.\ . - ?e(END)\ ?x-\ Next\\:\ %x.:?pB%pB\\%..%t +?f%f\ .?n?m(file\ %i\ of\ %m)\ ..?ltlines\ %lt-%lb?L/%L.\ : + byte\ %bB?s/%s.\ .?e(END)\ ?x-\ Next\e:\ %x.:?pB%pB\e%..%t .sp .fi And here is the default message produced by the = command: .nf .sp -?f%f\ .?m(file\ %i\ of\ %m)\ .?ltline\ %lt?L/%L.\ . - byte\ %bB?s/%s.\ ?e(END)\ :?pB%pB\\%..%t +?f%f\ .?m(file\ %i\ of\ %m)\ .?ltlines\ %lt-%lb?L/%L.\ . + byte\ %bB?s/%s.\ ?e(END)\ :?pB%pB\e%..%t .fi .PP The prompt expansion features are also used for another purpose: @@ -1184,7 +1413,43 @@ differences in invocation syntax, the LESSEDIT variable can be changed to modify this default. +.SH SECURITY +When the environment variable LESSSECURE is set to 1, +.I less +runs in a "secure" mode. +This means these features are disabled: +.RS +.IP "!" +the shell command +.IP "|" +the pipe command +.IP ":e" +the examine command. +.IP "v" +the editing command +.IP "s -o" +log files +.IP "-k" +use of lesskey files +.IP "-t" +use of tags files +.IP " " +metacharacters in filenames, such as * +.IP " " +filename completion (TAB, ^L) +.RE +.PP +Less can also be compiled to be permanently in "secure" mode. + .SH "ENVIRONMENT VARIABLES" +Environment variables may be specified either in the system environment +as usual, or in a +.I lesskey +(1) file. +If environment variables are defined in more than one place, +variables defined in a local lesskey file take precedence over +variables defined in the system environment, which take precedence +over variables defined in the system-wide lesskey file. .IP COLUMNS Sets the number of columns on the screen. Takes precedence over the number of columns specified by the TERM variable. @@ -1194,19 +1459,25 @@ .IP EDITOR The name of the editor (used for the v command). .IP HOME -Name of the user's home directory (used to find a .less file). +Name of the user's home directory +(used to find a lesskey file on Unix and OS/2 systems). +.IP "HOMEDRIVE, HOMEPATH" +Concatenation of the HOMEDRIVE and HOMEPATH environment variables is +the name of the user's home directory if the HOME variable is not set +(only in the Windows version). +.IP INIT +Name of the user's init directory (used to find a lesskey file on OS/2 systems). .IP LANG Language for determining the character set. .IP LC_CTYPE Language for determining the character set. .IP LESS -Flags which are passed to +Options which are passed to .I less automatically. -.IP MORE -Flags which are passed to -.I more -automatically. +.IP LESSANSIENDCHARS +Characters which are assumed to end an ANSI color escape sequence +(default "m"). .IP LESSBINFMT Format for displaying non-printable, non-control characters. .IP LESSCHARDEF @@ -1215,16 +1486,45 @@ Selects a predefined character set. .IP LESSCLOSE Command line to invoke the (optional) input-postprocessor. +.IP LESSECHO +Name of the lessecho program (default "lessecho"). +The lessecho program is needed to expand metacharacters, such as * and ?, +in filenames on Unix systems. .IP LESSEDIT Editor prototype string (used for the v command). See discussion under PROMPTS. -.IP LESSHELP -Name of the help file. +.IP LESSGLOBALTAGS +Name of the command used by the -t option to find global tags. +Normally should be set to "global" if your system has the +.I global +(1) command. If not set, global tags are not used. +.IP LESSKEY +Name of the default lesskey(1) file. +.IP LESSKEY_SYSTEM +Name of the default system-wide lesskey(1) file. +.IP LESSMETACHARS +List of characters which are considered "metacharacters" by the shell. +.IP LESSMETAESCAPE +Prefix which less will add before each metacharacter in a +command sent to the shell. +If LESSMETAESCAPE is an empty string, commands containing +metacharacters will not be passed to the shell. .IP LESSOPEN Command line to invoke the (optional) input-preprocessor. +.IP LESSSECURE +Runs less in "secure" mode. +See discussion under SECURITY. +.IP LESSSEPARATOR +String to be appended to a directory name in filename completion. .IP LINES Sets the number of lines on the screen. Takes precedence over the number of lines specified by the TERM variable. +(But if you have a windowing system which supports TIOCGWINSZ or WIOCGETD, +the window system's idea of the screen size takes precedence over the +LINES and COLUMNS environment variables.) +.IP PATH +User's search path (used to find a lesskey file +on MS-DOS and OS/2 systems). .IP SHELL The shell used to execute the ! command, as well as to expand filenames. .IP TERM @@ -1239,8 +1539,8 @@ .SH WARNINGS The = command and prompts (unless changed by -P) -report the line number of the line at the top of the screen, -but the byte and percent of the line at the bottom of the screen. +report the line numbers of the lines at the top and bottom of the screen, +but the byte and percent of the line after the one at the bottom of the screen. .PP If the :e command is used to name more than one file, and one of the named files has been viewed previously, @@ -1254,7 +1554,53 @@ In certain cases, when search highlighting is enabled and a search pattern begins with a ^, more text than the matching string may be highlighted. +(This problem does not occur when less is compiled to use the POSIX +regular expression package.) +.PP +When viewing text containing ANSI color escape sequences using the -R option, +searching will not find text containing an embedded escape sequence. +Also, search highlighting may change the color of some of the text +which follows the highlighted text. +.PP +On some systems, +.I setlocale +claims that ASCII characters 0 thru 31 are control characters +rather than binary characters. +This causes +.I less +to treat some binary files as ordinary, non-binary files. +To workaround this problem, set the environment variable +LESSCHARSET to "ascii" (or whatever character set is appropriate). +.PP +See http://www.greenwoodsoftware.com/less for the latest list of known bugs in this +version of less. - .SH COPYRIGHT -Copyright (c) 1984,1985,1989,1994,1995 Mark Nudelman +Copyright (C) 2002 Mark Nudelman +.PP +less is part of the GNU project and is free software. +You can redistribute it and/or modify it +under the terms of either +(1) the GNU General Public License as published by +the Free Software Foundation; or (2) the Less License. +See the file README in the less distribution for more details +regarding redistribution. +You should have received a copy of the GNU General Public License +along with the source for less; see the file COPYING. +If not, write to the Free Software Foundation, 59 Temple Place, +Suite 330, Boston, MA 02111-1307, USA. +You should also have received a copy of the Less License; +see the file LICENSE. +.PP +less is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +or FITNESS FOR A PARTICULAR PURPOSE. +See the GNU General Public License for more details. + +.SH AUTHOR +.PP +Mark Nudelman +.br +Send bug reports or comments to the above address or to bug-less@gnu.org. +.br +For more information, see the less homepage at http://www.greenwoodsoftware.com/less.