diff options
Diffstat (limited to 'gnu/usr.bin/grep/grep.1')
| -rw-r--r-- | gnu/usr.bin/grep/grep.1 | 212 |
1 files changed, 174 insertions, 38 deletions
diff --git a/gnu/usr.bin/grep/grep.1 b/gnu/usr.bin/grep/grep.1 index 37460a6cb30e..a8320178287b 100644 --- a/gnu/usr.bin/grep/grep.1 +++ b/gnu/usr.bin/grep/grep.1 @@ -12,7 +12,7 @@ .de Id .ds Dt \\$4 .. -.Id $Id: grep.1,v 1.11 2000/02/26 03:18:40 alainm Exp $ +.Id $Id: grep.1,v 1.23 2002/01/22 13:20:04 bero Exp $ .TH GREP 1 \*(Dt "GNU Project" .SH NAME grep, egrep, fgrep \- print lines matching a pattern @@ -62,6 +62,9 @@ is the same as Print .I NUM lines of trailing context after matching lines. +Places a line containing +.B \-\^\- +between contiguous groups of matches. .TP .BR \-a ", " \-\^\-text Process a binary file as if it were text; this is equivalent to the @@ -72,11 +75,17 @@ option. Print .I NUM lines of leading context before matching lines. +Places a line containing +.B \-\^\- +between contiguous groups of matches. .TP -\fB\-C\fP [\fINUM\fP], \fB\-\fP\fINUM\fP, \fB\-\^\-context\fP[\fB=\fP\fINUM\fP] +.BI \-C " NUM" "\fR,\fP \-\^\-context=" NUM Print .I NUM -lines (default 2) of output context. +lines of output context. +Places a line containing +.B \-\^\- +between contiguous groups of matches. .TP .BR \-b ", " \-\^\-byte-offset Print the byte offset within the input file before @@ -117,6 +126,11 @@ might output binary garbage, which can have nasty side effects if the output is a terminal and if the terminal driver interprets some of it as commands. .TP +.BI \-\^\-colour[=\fIWHEN\fR] ", " \-\^\-color[=\fIWHEN\fR] +Surround the matching string with the marker find in +.B GREP_COLOR +environment variable. WHEN may be `never', `always', or `auto' +.TP .BR \-c ", " \-\^\-count Suppress normal output; instead print a count of matching lines for each input file. @@ -124,6 +138,20 @@ With the .BR \-v ", " \-\^\-invert-match option (see below), count non-matching lines. .TP +.BI \-D " ACTION" "\fR,\fP \-\^\-devices=" ACTION +If an input file is a device, FIFO or socket, use +.I ACTION +to process it. By default, +.I ACTION +is +.BR read , +which means that devices are read just as if they were ordinary files. +If +.I ACTION +is +.BR skip , +devices are silently skipped. +.TP .BI \-d " ACTION" "\fR,\fP \-\^\-directories=" ACTION If an input file is a directory, use .I ACTION @@ -163,6 +191,10 @@ Interpret .I PATTERN as a list of fixed strings, separated by newlines, any of which is to be matched. +.BR \-P ", " \-\^\-perl-regexp +Interpret +.I PATTERN +as a Perl regular expression. .TP .BI \-f " FILE" "\fR,\fP \-\^\-file=" FILE Obtain patterns from @@ -208,6 +240,39 @@ the name of each input file from which output would normally have been printed. The scanning will stop on the first match. .TP +.BI \-m " NUM" "\fR,\fP \-\^\-max-count=" NUM +Stop reading a file after +.I NUM +matching lines. If the input is standard input from a regular file, +and +.I NUM +matching lines are output, +.B grep +ensures that the standard input is positioned to just after the last +matching line before exiting, regardless of the presence of trailing +context lines. This enables a calling process to resume a search. +When +.B grep +stops after +.I NUM +matching lines, it outputs any trailing context lines. When the +.B \-c +or +.B \-\^\-count +option is also used, +.B grep +does not output a count greater than +.IR NUM . +When the +.B \-v +or +.B \-\^\-invert-match +option is also used, +.B grep +stops after outputting +.I NUM +non-matching lines. +.TP .B \-\^\-mmap If possible, use the .BR mmap (2) @@ -227,21 +292,43 @@ is operating, or if an I/O error occurs. Prefix each line of output with the line number within its input file. .TP +.BR \-o ", " \-\^\-only-matching +Show only the part of a matching line that matches +.I PATTERN. +.TP +.BI \-\^\-label= LABEL +Displays input actually coming from standard input as input coming from file +.I LABEL. +This is especially useful for tools like zgrep, e.g. +.B "gzip -cd foo.gz |grep --label=foo something" +.TP +.BR \-\^\-line-buffering +Use line buffering, it can be a performance penality. +.TP .BR \-q ", " \-\^\-quiet ", " \-\^\-silent -Quiet; suppress normal output. The scanning will stop -on the first match. +Quiet; do not write anything to standard output. +Exit immediately with zero status if any match is found, +even if an error was detected. Also see the .B \-s or .B \-\^\-no-messages -option below. +option. .TP -.BR \-r ", " \-\^\-recursive +.BR \-R ", " \-r ", " \-\^\-recursive Read all files under each directory, recursively; this is equivalent to the .B "\-d recurse" option. .TP +.BR "\fR \fP \-\^\-include=" PATTERN +Recurse in directories only searching file matching +.I PATTERN. +.TP +.BR "\fR \fP \-\^\-exclude=" PATTERN +Recurse in directories skip file matching +.I PATTERN. +.TP .BR \-s ", " \-\^\-no-messages Suppress error messages about nonexistent or unreadable files. Portability note: unlike \s-1GNU\s0 @@ -358,11 +445,13 @@ a single character. Most characters, including all letters and digits, are regular expressions that match themselves. Any metacharacter with special meaning may be quoted by preceding it with a backslash. .PP -A list of characters enclosed by +A +.I "bracket expression" +is a list of characters enclosed by .B [ and -.B ] -matches any single +.BR ] . +It matches any single character in that list; if the first character of the list is the caret .B ^ @@ -371,10 +460,32 @@ then it matches any character in the list. For example, the regular expression .B [0123456789] -matches any single digit. A range of characters -may be specified by giving the first and last characters, separated -by a hyphen. -Finally, certain named classes of characters are predefined. +matches any single digit. +.PP +Within a bracket expression, a +.I "range expression" +consists of two characters separated by a hyphen. +It matches any single character that sorts between the two characters, +inclusive, using the locale's collating sequence and character set. +For example, in the default C locale, +.B [a\-d] +is equivalent to +.BR [abcd] . +Many locales sort characters in dictionary order, and in these locales +.B [a\-d] +is typically not equivalent to +.BR [abcd] ; +it might be equivalent to +.BR [aBbCcDd] , +for example. +To obtain the traditional interpretation of bracket expressions, +you can use the C locale by setting the +.B LC_ALL +environment variable to the value +.BR C . +.PP +Finally, certain named classes of characters are predefined within +bracket expressions, as follows. Their names are self explanatory, and they are .BR [:alnum:] , .BR [:alpha:] , @@ -391,8 +502,8 @@ and For example, .B [[:alnum:]] means -.BR [0-9A-Za-z] , -except the latter form depends upon the \s-1POSIX\s0 locale and the +.BR [0\-9A\-Za\-z] , +except the latter form depends upon the C locale and the \s-1ASCII\s0 character encoding, whereas the former is independent of locale and character set. (Note that the brackets in these class names are part of the symbolic @@ -539,6 +650,29 @@ instead of reporting a syntax error in the regular expression. \s-1POSIX.2\s0 allows this behavior as an extension, but portable scripts should avoid it. .SH "ENVIRONMENT VARIABLES" +Grep's behavior is affected by the following environment variables. +.PP +A locale +.BI LC_ foo +is specified by examining the three environment variables +.BR LC_ALL , +.BR LC_\fIfoo\fP , +.BR LANG , +in that order. +The first of these variables that is set specifies the locale. +For example, if +.B LC_ALL +is not set, but +.B LC_MESSAGES +is set to +.BR pt_BR , +then Brazilian Portuguese is used for the +.B LC_MESSAGES +locale. +The C locale is used if none of these environment variables are set, +or if the locale catalog is not installed, or if +.B grep +was not compiled with national language support (\s-1NLS\s0). .TP .B GREP_OPTIONS This variable specifies default options to be placed in front of any @@ -556,28 +690,29 @@ Option specifications are separated by whitespace. A backslash escapes the next character, so it can be used to specify an option containing whitespace or a backslash. .TP -\fBLC_ALL\fP, \fBLC_MESSAGES\fP, \fBLANG\fP +.B GREP_COLOR +Specifies the marker for highlighting. +.TP +\fBLC_ALL\fP, \fBLC_COLLATE\fP, \fBLANG\fP These variables specify the -.B LC_MESSAGES -locale, which determines the language that -.B grep -uses for messages. -The locale is determined by the first of these variables that is set. -American English is used if none of these environment variables are set, -or if the message catalog is not installed, or if -.B grep -was not compiled with national language support (\s-1NLS\s0). +.B LC_COLLATE +locale, which determines the collating sequence used to interpret +range expressions like +.BR [a\-z] . .TP \fBLC_ALL\fP, \fBLC_CTYPE\fP, \fBLANG\fP These variables specify the .B LC_CTYPE locale, which determines the type of characters, e.g., which characters are whitespace. -The locale is determined by the first of these variables that is set. -The \s-1POSIX\s0 locale is used if none of these environment variables -are set, or if the locale catalog is not installed, or if +.TP +\fBLC_ALL\fP, \fBLC_MESSAGES\fP, \fBLANG\fP +These variables specify the +.B LC_MESSAGES +locale, which determines the language that .B grep -was not compiled with national language support (\s-1NLS\s0). +uses for messages. +The default C locale uses American English messages. .TP .B POSIXLY_CORRECT If set, @@ -618,13 +753,14 @@ when is not set. .SH DIAGNOSTICS .PP -Normally, exit status is 0 if matches were found, -and 1 if no matches were found. (The -.B \-v -option inverts the sense of the exit status.) -Exit status is 2 if there were syntax errors -in the pattern, inaccessible input files, or -other system errors. +Normally, exit status is 0 if selected lines are found and 1 otherwise. +But the exit status is 2 if an error occurred, unless the +.B \-q +or +.B \-\^\-quiet +or +.B \-\^\-silent +option is used and a selected line is found. .SH BUGS .PP Email bug reports to @@ -633,7 +769,7 @@ Be sure to include the word \*(lqgrep\*(rq somewhere in the \*(lqSubject:\*(rq field. .PP Large repetition counts in the -.BI { m , n } +.BI { n , m } construct may cause grep to use lots of memory. In addition, certain other obscure regular expressions require exponential time |