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diff --git a/doc/grep.in.1 b/doc/grep.in.1 new file mode 100644 index 0000000..1a3b7d2 --- /dev/null +++ b/doc/grep.in.1 @@ -0,0 +1,1139 @@ +.\" GNU grep man page +.if !\n(.g \{\ +. if !\w|\*(lq| \{\ +. ds lq `` +. if \w'\(lq' .ds lq "\(lq +. \} +. if !\w|\*(rq| \{\ +. ds rq '' +. if \w'\(rq' .ds rq "\(rq +. \} +.\} +. +.ie \n[.g] .mso www.tmac +.el \{\ +. de MTO +\\$2 \(laemail: \\$1 \(ra\\$3 +.. +. de URL +\\$2 \(laURL: \\$1 \(ra\\$3 +.. +.\} +. +.TH GREP 1 \*(Dt "GNU grep @VERSION@" "User Commands" +.hy 0 +. +.SH NAME +grep, egrep, fgrep \- print lines matching a pattern +. +.SH SYNOPSIS +.B grep +.RI [ OPTIONS ] +.I PATTERN +.RI [ FILE .\|.\|.] +.br +.B grep +.RI [ OPTIONS ] +.RB [ \-e +.I PATTERN +| +.B \-f +.IR FILE ] +.RI [ FILE .\|.\|.] +. +.SH DESCRIPTION +.B grep +searches the named input +.IR FILE s +for lines containing a match to the given +.IR PATTERN . +If no files are specified, or if the file +.RB "\*(lq" \- "\*(rq" +is given, +.B grep +searches standard input. +By default, +.B grep +prints the matching lines. +.PP +In addition, the variant programs +.B egrep +and +.B fgrep +are the same as +.B "grep\ \-E" +and +.BR "grep\ \-F" , +respectively. +These variants are deprecated, but are provided for backward compatibility. +. +.SH OPTIONS +.SS "Generic Program Information" +.TP +.B \-\^\-help +Output a usage message and exit. +.TP +.BR \-V ", " \-\^\-version +Output the version number of +.B grep +and exit. +.SS "Matcher Selection" +.TP +.BR \-E ", " \-\^\-extended\-regexp +Interpret +.I PATTERN +as an extended regular expression (ERE, see below). +.TP +.BR \-F ", " \-\^\-fixed\-strings +Interpret +.I PATTERN +as a list of fixed strings (instead of regular expressions), +separated by newlines, +any of which is to be matched. +.TP +.BR \-G ", " \-\^\-basic\-regexp +Interpret +.I PATTERN +as a basic regular expression (BRE, see below). +This is the default. +.TP +.BR \-P ", " \-\^\-perl\-regexp +Interpret the pattern as a Perl-compatible regular expression (PCRE). +This is highly experimental and +.B "grep \-P" +may warn of unimplemented features. +.SS "Matching Control" +.TP +.BI \-e " PATTERN" "\fR,\fP \-\^\-regexp=" PATTERN +Use +.I PATTERN +as the pattern. +If this option is used multiple times or is combined with the +.B \-f +.RB ( \-\-file ) +option, search for all patterns given. +This option can be used to protect a pattern beginning with \*(lq\-\*(rq. +.TP +.BI \-f " FILE" "\fR,\fP \-\^\-file=" FILE +Obtain patterns from +.IR FILE , +one per line. +If this option is used multiple times or is combined with the +.B \-e +.RB ( \-\-regexp ) +option, search for all patterns given. +The empty file contains zero patterns, and therefore matches nothing. +.TP +.BR \-i ", " \-\^\-ignore\-case +Ignore case distinctions in both the +.I PATTERN +and the input files. +.TP +.BR \-v ", " \-\^\-invert\-match +Invert the sense of matching, to select non-matching lines. +.TP +.BR \-w ", " \-\^\-word\-regexp +Select only those lines containing matches that form whole words. +The test is that the matching substring must either be at the +beginning of the line, or preceded by a non-word constituent +character. +Similarly, it must be either at the end of the line +or followed by a non-word constituent character. +Word-constituent characters are letters, digits, and the underscore. +.TP +.BR \-x ", " \-\^\-line\-regexp +Select only those matches that exactly match the whole line. +For a regular expression pattern, this is like parenthesizing the +pattern and then surrounding it with +.B ^ +and +.BR $ . +.TP +.B \-y +Obsolete synonym for +.BR \-i . +.SS "General Output Control" +.TP +.BR \-c ", " \-\^\-count +Suppress normal output; instead print a count of +matching lines for each input file. +With the +.BR \-v ", " \-\^\-invert\-match +option (see below), count non-matching lines. +.TP +.BR \-\^\-color [ =\fIWHEN\fP "], " \-\^\-colour [ =\fIWHEN\fP ] +Surround the matched (non-empty) strings, matching lines, context lines, +file names, line numbers, byte offsets, and separators (for fields and +groups of context lines) with escape sequences to display them in color +on the terminal. +The colors are defined by the environment variable +.BR GREP_COLORS . +The deprecated environment variable +.B GREP_COLOR +is still supported, but its setting does not have priority. +.I WHEN +is +.BR never ", " always ", or " auto . +.TP +.BR \-L ", " \-\^\-files\-without\-match +Suppress normal output; instead print the name +of each input file from which no output would +normally have been printed. +The scanning will stop on the first match. +.TP +.BR \-l ", " \-\^\-files\-with\-matches +Suppress normal output; instead print +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 +.BR \-o ", " \-\^\-only\-matching +Print only the matched (non-empty) parts of a matching line, +with each such part on a separate output line. +.TP +.BR \-q ", " \-\^\-quiet ", " \-\^\-silent +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. +.TP +.BR \-s ", " \-\^\-no\-messages +Suppress error messages about nonexistent or unreadable files. +.SS "Output Line Prefix Control" +.TP +.BR \-b ", " \-\^\-byte\-offset +Print the 0-based byte offset within the input file +before each line of output. +If +.B \-o +.RB ( \-\^\-only\-matching ) +is specified, +print the offset of the matching part itself. +.TP +.BR \-H ", " \-\^\-with\-filename +Print the file name for each match. +This is the default when there is more than one file to search. +.TP +.BR \-h ", " \-\^\-no\-filename +Suppress the prefixing of file names on output. +This is the default when there is only one file +(or only standard input) to search. +.TP +.BI \-\^\-label= LABEL +Display input actually coming from standard input as input coming from file +.IR LABEL . +This is especially useful when implementing tools like +.BR zgrep , +e.g., +.BR "gzip -cd foo.gz | grep --label=foo -H something" . +See also the +.B \-H +option. +.TP +.BR \-n ", " \-\^\-line\-number +Prefix each line of output with the 1-based line number +within its input file. +.TP +.BR \-T ", " \-\^\-initial\-tab +Make sure that the first character of actual line content lies on a +tab stop, so that the alignment of tabs looks normal. +This is useful with options that prefix their output to the actual content: +.BR \-H , \-n , +and +.BR \-b . +In order to improve the probability that lines +from a single file will all start at the same column, +this also causes the line number and byte offset (if present) +to be printed in a minimum size field width. +.TP +.BR \-u ", " \-\^\-unix\-byte\-offsets +Report Unix-style byte offsets. +This switch causes +.B grep +to report byte offsets as if the file were a Unix-style text file, +i.e., with CR characters stripped off. +This will produce results identical to running +.B grep +on a Unix machine. +This option has no effect unless +.B \-b +option is also used; +it has no effect on platforms other than \s-1MS-DOS\s0 and \s-1MS\s0-Windows. +.TP +.BR \-Z ", " \-\^\-null +Output a zero byte (the \s-1ASCII\s0 +.B NUL +character) instead of the character that normally follows a file name. +For example, +.B "grep \-lZ" +outputs a zero byte after each file name instead of the usual newline. +This option makes the output unambiguous, even in the presence of file +names containing unusual characters like newlines. +This option can be used with commands like +.BR "find \-print0" , +.BR "perl \-0" , +.BR "sort \-z" , +and +.B "xargs \-0" +to process arbitrary file names, +even those that contain newline characters. +.SS "Context Line Control" +.TP +.BI \-A " NUM" "\fR,\fP \-\^\-after\-context=" NUM +Print +.I NUM +lines of trailing context after matching lines. +Places a line containing a group separator +.RB ( \-\^\- ) +between contiguous groups of matches. +With the +.B \-o +or +.B \-\^\-only\-matching +option, this has no effect and a warning is given. +.TP +.BI \-B " NUM" "\fR,\fP \-\^\-before\-context=" NUM +Print +.I NUM +lines of leading context before matching lines. +Places a line containing a group separator +.RB ( \-\^\- ) +between contiguous groups of matches. +With the +.B \-o +or +.B \-\^\-only\-matching +option, this has no effect and a warning is given. +.TP +.BI \-C " NUM" "\fR,\fP \-" NUM "\fR,\fP \-\^\-context=" NUM +Print +.I NUM +lines of output context. +Places a line containing a group separator +.RB ( \-\^\- ) +between contiguous groups of matches. +With the +.B \-o +or +.B \-\^\-only\-matching +option, this has no effect and a warning is given. +.SS "File and Directory Selection" +.TP +.BR \-a ", " \-\^\-text +Process a binary file as if it were text; this is equivalent to the +.B \-\^\-binary\-files=text +option. +.TP +.BI \-\^\-binary\-files= TYPE +If the first few bytes of a file indicate that the file contains binary +data, assume that the file is of type +.IR TYPE . +By default, +.I TYPE +is +.BR binary , +and +.B grep +normally outputs either +a one-line message saying that a binary file matches, or no message if +there is no match. +If +.I TYPE +is +.BR without-match , +.B grep +assumes that a binary file does not match; this is equivalent to the +.B \-I +option. +If +.I TYPE +is +.BR text , +.B grep +processes a binary file as if it were text; this is equivalent to the +.B \-a +option. +When processing binary data, +.B grep +may treat non-text bytes as line terminators; for example, the pattern +.RB ' . '\& +(period) might not match a null byte, as the null byte might be +treated as a line terminator. +.I Warning: +.B "grep \-\^\-binary\-files=text" +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 \-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 +to process it. +By default, +.I ACTION +is +.BR read , +i.e., read directories just as if they were ordinary files. +If +.I ACTION +is +.BR skip , +silently skip directories. +If +.I ACTION +is +.BR recurse , +read all files under each directory, recursively, +following symbolic links only if they are on the command line. +This is equivalent to the +.B \-r +option. +.TP +.BI \-\^\-exclude= GLOB +Skip files whose base name matches +.I GLOB +(using wildcard matching). +A file-name glob can use +.BR * , +.BR ? , +and +.BR [ ... ] +as wildcards, and +.B \e +to quote a wildcard or backslash character literally. +.TP +.BI \-\^\-exclude-from= FILE +Skip files whose base name matches any of the file-name globs read from +.I FILE +(using wildcard matching as described under +.BR \-\^\-exclude ). +.TP +.BI \-\^\-exclude-dir= DIR +Exclude directories matching the pattern +.I DIR +from recursive searches. +.TP +.BR \-I +Process a binary file as if it did not contain matching data; this is +equivalent to the +.B \-\^\-binary\-files=without-match +option. +.TP +.BI \-\^\-include= GLOB +Search only files whose base name matches +.I GLOB +(using wildcard matching as described under +.BR \-\^\-exclude ). +.TP +.BR \-r ", " \-\^\-recursive +Read all files under each directory, recursively, +following symbolic links only if they are on the command line. +Note that if no file operand is given, grep searches the working directory. +This is equivalent to the +.B "\-d recurse" +option. +.TP +.BR \-R ", " \-\^\-dereference\-recursive +Read all files under each directory, recursively. +Follow all symbolic links, unlike +.BR \-r . +.SS "Other Options" +.TP +.BR \-\^\-line\-buffered +Use line buffering on output. +This can cause a performance penalty. +.TP +.BR \-U ", " \-\^\-binary +Treat the file(s) as binary. +By default, under \s-1MS-DOS\s0 and \s-1MS\s0-Windows, +.BR grep +guesses the file type by looking at the contents of the first 32KB +read from the file. +If +.BR grep +decides the file is a text file, it strips the CR characters from the +original file contents (to make regular expressions with +.B ^ +and +.B $ +work correctly). +Specifying +.B \-U +overrules this guesswork, causing all files to be read and passed to the +matching mechanism verbatim; if the file is a text file with CR/LF +pairs at the end of each line, this will cause some regular +expressions to fail. +This option has no effect on platforms +other than \s-1MS-DOS\s0 and \s-1MS\s0-Windows. +.TP +.BR \-z ", " \-\^\-null\-data +Treat the input as a set of lines, +each terminated by a zero byte (the \s-1ASCII\s0 +.B NUL +character) instead of a newline. +Like the +.B -Z +or +.B \-\^\-null +option, this option can be used with commands like +.B sort -z +to process arbitrary file names. +. +.SH "REGULAR EXPRESSIONS" +A regular expression is a pattern that describes a set of strings. +Regular expressions are constructed analogously to arithmetic +expressions, by using various operators to combine smaller expressions. +.PP +.B grep +understands three different versions of regular expression syntax: +\*(lqbasic\*(rq (BRE), \*(lqextended\*(rq (ERE) and \*(lqperl\*(rq (PCRE). +In +.RB "\s-1GNU\s0\ " grep , +there is no difference in available functionality between basic and +extended syntaxes. +In other implementations, basic regular expressions are less powerful. +The following description applies to extended regular expressions; +differences for basic regular expressions are summarized afterwards. +Perl-compatible regular expressions give additional functionality, and are +documented in pcresyntax(3) and pcrepattern(3), but work only if +PCRE is available in the system. +.PP +The fundamental building blocks are the regular expressions +that match a single character. +Most characters, including all letters and digits, +are regular expressions that match themselves. +Any meta-character with special meaning +may be quoted by preceding it with a backslash. +.PP +The period +.B .\& +matches any single character. +.SS "Character Classes and Bracket Expressions" +A +.I "bracket expression" +is a list of characters enclosed by +.B [ +and +.BR ] . +It matches any single +character in that list; if the first character of the list +is the caret +.B ^ +then it matches any character +.I not +in the list. +For example, the regular expression +.B [0123456789] +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:] , +.BR [:cntrl:] , +.BR [:digit:] , +.BR [:graph:] , +.BR [:lower:] , +.BR [:print:] , +.BR [:punct:] , +.BR [:space:] , +.BR [:upper:] , +and +.BR [:xdigit:]. +For example, +.B [[:alnum:]] +means the character class of numbers and +letters in the current locale. In the C locale and \s-1ASCII\s0 +character set encoding, this is the same as +.BR [0\-9A\-Za\-z] . +(Note that the brackets in these class names are part of the symbolic +names, and must be included in addition to the brackets delimiting +the bracket expression.) +Most meta-characters lose their special meaning inside bracket expressions. +To include a literal +.B ] +place it first in the list. +Similarly, to include a literal +.B ^ +place it anywhere but first. +Finally, to include a literal +.B \- +place it last. +.SS Anchoring +The caret +.B ^ +and the dollar sign +.B $ +are meta-characters that respectively match the empty string at the +beginning and end of a line. +.SS "The Backslash Character and Special Expressions" +The symbols +.B \e< +and +.B \e> +respectively match the empty string at the beginning and end of a word. +The symbol +.B \eb +matches the empty string at the edge of a word, +and +.B \eB +matches the empty string provided it's +.I not +at the edge of a word. +The symbol +.B \ew +is a synonym for +.B [_[:alnum:]] +and +.B \eW +is a synonym for +.BR [^_[:alnum:]] . +.SS Repetition +A regular expression may be followed by one of several repetition operators: +.PD 0 +.TP +.B ? +The preceding item is optional and matched at most once. +.TP +.B * +The preceding item will be matched zero or more times. +.TP +.B + +The preceding item will be matched one or more times. +.TP +.BI { n } +The preceding item is matched exactly +.I n +times. +.TP +.BI { n ,} +The preceding item is matched +.I n +or more times. +.TP +.BI {, m } +The preceding item is matched at most +.I m +times. +This is a \s-1GNU\s0 extension. +.TP +.BI { n , m } +The preceding item is matched at least +.I n +times, but not more than +.I m +times. +.PD +.SS Concatenation +Two regular expressions may be concatenated; the resulting +regular expression matches any string formed by concatenating +two substrings that respectively match the concatenated +expressions. +.SS Alternation +Two regular expressions may be joined by the infix operator +.BR | ; +the resulting regular expression matches any string matching +either alternate expression. +.SS Precedence +Repetition takes precedence over concatenation, which in turn +takes precedence over alternation. +A whole expression may be enclosed in parentheses +to override these precedence rules and form a subexpression. +.SS "Back References and Subexpressions" +The back-reference +.BI \e n\c +\&, where +.I n +is a single digit, matches the substring +previously matched by the +.IR n th +parenthesized subexpression of the regular expression. +.SS "Basic vs Extended Regular Expressions" +In basic regular expressions the meta-characters +.BR ? , +.BR + , +.BR { , +.BR | , +.BR ( , +and +.BR ) +lose their special meaning; instead use the backslashed +versions +.BR \e? , +.BR \e+ , +.BR \e{ , +.BR \e| , +.BR \e( , +and +.BR \e) . +. +.SH "ENVIRONMENT VARIABLES" +The behavior of +.B grep +is affected by the following environment variables. +.PP +The locale for category +.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 the Brazilian Portuguese locale is used for the +.B LC_MESSAGES +category. +The C locale is used if none of these environment variables are set, +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 explicit options. +As this causes problems when writing portable scripts, +this feature will be removed in a future release of +.BR grep , +and +.B grep +warns if it is used. +Please use an alias or script instead. +.TP +.B GREP_COLOR +This variable specifies the color used to highlight matched (non-empty) text. +It is deprecated in favor of +.BR GREP_COLORS , +but still supported. +The +.BR mt , +.BR ms , +and +.B mc +capabilities of +.B GREP_COLORS +have priority over it. +It can only specify the color used to highlight +the matching non-empty text in any matching line +(a selected line when the +.B -v +command-line option is omitted, +or a context line when +.B -v +is specified). +The default is +.BR 01;31 , +which means a bold red foreground text on the terminal's default background. +.TP +.B GREP_COLORS +Specifies the colors and other attributes +used to highlight various parts of the output. +Its value is a colon-separated list of capabilities +that defaults to +.B ms=01;31:mc=01;31:sl=:cx=:fn=35:ln=32:bn=32:se=36 +with the +.B rv +and +.B ne +boolean capabilities omitted (i.e., false). +Supported capabilities are as follows. +.RS +.TP +.B sl= +SGR substring for whole selected lines +(i.e., +matching lines when the +.B \-v +command-line option is omitted, +or non-matching lines when +.B \-v +is specified). +If however the boolean +.B rv +capability +and the +.B \-v +command-line option are both specified, +it applies to context matching lines instead. +The default is empty (i.e., the terminal's default color pair). +.TP +.B cx= +SGR substring for whole context lines +(i.e., +non-matching lines when the +.B \-v +command-line option is omitted, +or matching lines when +.B \-v +is specified). +If however the boolean +.B rv +capability +and the +.B \-v +command-line option are both specified, +it applies to selected non-matching lines instead. +The default is empty (i.e., the terminal's default color pair). +.TP +.B rv +Boolean value that reverses (swaps) the meanings of +the +.B sl= +and +.B cx= +capabilities +when the +.B \-v +command-line option is specified. +The default is false (i.e., the capability is omitted). +.TP +.B mt=01;31 +SGR substring for matching non-empty text in any matching line +(i.e., +a selected line when the +.B \-v +command-line option is omitted, +or a context line when +.B \-v +is specified). +Setting this is equivalent to setting both +.B ms= +and +.B mc= +at once to the same value. +The default is a bold red text foreground over the current line background. +.TP +.B ms=01;31 +SGR substring for matching non-empty text in a selected line. +(This is only used when the +.B \-v +command-line option is omitted.) +The effect of the +.B sl= +(or +.B cx= +if +.BR rv ) +capability remains active when this kicks in. +The default is a bold red text foreground over the current line background. +.TP +.B mc=01;31 +SGR substring for matching non-empty text in a context line. +(This is only used when the +.B \-v +command-line option is specified.) +The effect of the +.B cx= +(or +.B sl= +if +.BR rv ) +capability remains active when this kicks in. +The default is a bold red text foreground over the current line background. +.TP +.B fn=35 +SGR substring for file names prefixing any content line. +The default is a magenta text foreground over the terminal's default background. +.TP +.B ln=32 +SGR substring for line numbers prefixing any content line. +The default is a green text foreground over the terminal's default background. +.TP +.B bn=32 +SGR substring for byte offsets prefixing any content line. +The default is a green text foreground over the terminal's default background. +.TP +.B se=36 +SGR substring for separators that are inserted +between selected line fields +.RB ( : ), +between context line fields, +.RB ( \- ), +and between groups of adjacent lines when nonzero context is specified +.RB ( \-\^\- ). +The default is a cyan text foreground over the terminal's default background. +.TP +.B ne +Boolean value that prevents clearing to the end of line +using Erase in Line (EL) to Right +.RB ( \\\\\\33[K ) +each time a colorized item ends. +This is needed on terminals on which EL is not supported. +It is otherwise useful on terminals +for which the +.B back_color_erase +.RB ( bce ) +boolean terminfo capability does not apply, +when the chosen highlight colors do not affect the background, +or when EL is too slow or causes too much flicker. +The default is false (i.e., the capability is omitted). +.PP +Note that boolean capabilities have no +.BR = ... +part. +They are omitted (i.e., false) by default and become true when specified. +.PP +See the Select Graphic Rendition (SGR) section +in the documentation of the text terminal that is used +for permitted values and their meaning as character attributes. +These substring values are integers in decimal representation +and can be concatenated with semicolons. +.B grep +takes care of assembling the result +into a complete SGR sequence +.RB ( \\\\\\33[ ... m ). +Common values to concatenate include +.B 1 +for bold, +.B 4 +for underline, +.B 5 +for blink, +.B 7 +for inverse, +.B 39 +for default foreground color, +.B 30 +to +.B 37 +for foreground colors, +.B 90 +to +.B 97 +for 16-color mode foreground colors, +.B 38;5;0 +to +.B 38;5;255 +for 88-color and 256-color modes foreground colors, +.B 49 +for default background color, +.B 40 +to +.B 47 +for background colors, +.B 100 +to +.B 107 +for 16-color mode background colors, and +.B 48;5;0 +to +.B 48;5;255 +for 88-color and 256-color modes background colors. +.RE +.TP +\fBLC_ALL\fP, \fBLC_COLLATE\fP, \fBLANG\fP +These variables specify the locale for the +.B LC_COLLATE +category, +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 locale for the +.B LC_CTYPE +category, +which determines the type of characters, +e.g., which characters are whitespace. +.TP +\fBLC_ALL\fP, \fBLC_MESSAGES\fP, \fBLANG\fP +These variables specify the locale for the +.B LC_MESSAGES +category, +which determines the language that +.B grep +uses for messages. +The default C locale uses American English messages. +.TP +.B POSIXLY_CORRECT +If set, +.B grep +behaves as \s-1POSIX\s0 requires; otherwise, +.B grep +behaves more like other \s-1GNU\s0 programs. +\s-1POSIX\s0 requires that options that follow file names must be +treated as file names; by default, such options are permuted to the +front of the operand list and are treated as options. +Also, \s-1POSIX\s0 requires that unrecognized options be diagnosed as +\*(lqillegal\*(rq, but since they are not really against the law the default +is to diagnose them as \*(lqinvalid\*(rq. +.B POSIXLY_CORRECT +also disables \fB_\fP\fIN\fP\fB_GNU_nonoption_argv_flags_\fP, +described below. +.TP +\fB_\fP\fIN\fP\fB_GNU_nonoption_argv_flags_\fP +(Here +.I N +is +.BR grep 's +numeric process ID.) If the +.IR i th +character of this environment variable's value is +.BR 1 , +do not consider the +.IR i th +operand of +.B grep +to be an option, even if it appears to be one. +A shell can put this variable in the environment for each command it runs, +specifying which operands are the results of file name wildcard +expansion and therefore should not be treated as options. +This behavior is available only with the \s-1GNU\s0 C library, and only +when +.B POSIXLY_CORRECT +is not set. +. +.SH "EXIT STATUS" +Normally the exit status is 0 if a line is selected, 1 if no lines +were selected, and 2 if an error occurred. However, if the +.B \-q +or +.B \-\^\-quiet +or +.B \-\^\-silent +is used and a line is selected, the exit status is 0 even if an error +occurred. +. +.SH COPYRIGHT +Copyright 1998-2000, 2002, 2005-2016 Free Software Foundation, Inc. +.PP +This is free software; +see the source for copying conditions. +There is NO warranty; +not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. +. +.SH BUGS +.SS "Reporting Bugs" +Email bug reports to +.MTO bug-grep@gnu.org "the bug-reporting address" . +An +.URL http://lists.gnu.org/mailman/listinfo/bug-grep "email archive" +and a +.URL http://debbugs.gnu.org/cgi/pkgreport.cgi?package=grep "bug tracker" +are available. +.SS "Known Bugs" +Large repetition counts in the +.BI { n , m } +construct may cause +.B grep +to use lots of memory. +In addition, +certain other obscure regular expressions require exponential time +and space, and may cause +.B grep +to run out of memory. +.PP +Back-references are very slow, and may require exponential time. +. +.SH "SEE ALSO" +.SS "Regular Manual Pages" +awk(1), cmp(1), diff(1), find(1), gzip(1), +perl(1), sed(1), sort(1), xargs(1), zgrep(1), +read(2), +pcre(3), pcresyntax(3), pcrepattern(3), +terminfo(5), +glob(7), regex(7). +.SS "\s-1POSIX\s0 Programmer's Manual Page" +grep(1p). +.SS "Full Documentation" +A +.URL http://www.gnu.org/software/grep/manual/ "complete manual" +is available. +If the +.B info +and +.B grep +programs are properly installed at your site, the command +.IP +.B info grep +.PP +should give you access to the complete manual. +. +.SH NOTES +This man page is maintained only fitfully; +the full documentation is often more up-to-date. +.\" Work around problems with some troff -man implementations. +.br |