CVSROOT: /webcvs/grep Module name: grep Changes by: Jim Meyering <meyering> 25/04/11 13:06:09
Index: grep.html =================================================================== RCS file: /webcvs/grep/grep/manual/grep.html,v retrieving revision 1.35 retrieving revision 1.36 diff -u -b -r1.35 -r1.36 --- grep.html 13 May 2023 09:23:47 -0000 1.35 +++ grep.html 11 Apr 2025 17:06:04 -0000 1.36 @@ -1,11 +1,11 @@ <!DOCTYPE html> <html> -<!-- Created by GNU Texinfo 7.0dev, https://www.gnu.org/software/texinfo/ --> +<!-- Created by GNU Texinfo 7.1.1, https://www.gnu.org/software/texinfo/ --> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <!-- This manual is for grep, a pattern matching engine. -Copyright © 1999-2002, 2005, 2008-2023 Free Software Foundation, +Copyright © 1999-2002, 2005, 2008-2025 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document @@ -14,10 +14,10 @@ Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License". --> -<title>GNU Grep 3.11</title> +<title>GNU Grep 3.12</title> -<meta name="description" content="GNU Grep 3.11"> -<meta name="keywords" content="GNU Grep 3.11"> +<meta name="description" content="GNU Grep 3.12"> +<meta name="keywords" content="GNU Grep 3.12"> <meta name="resource-type" content="document"> <meta name="distribution" content="global"> <meta name="Generator" content="makeinfo"> @@ -69,11 +69,11 @@ <p><code class="command">grep</code> prints lines that contain a match for one or more patterns. </p> -<p>This manual is for version 3.11 of GNU Grep. +<p>This manual is for version 3.12 of GNU Grep. </p> <p>This manual is for <code class="command">grep</code>, a pattern matching engine. </p> -<p>Copyright © 1999–2002, 2005, 2008–2023 Free Software Foundation, +<p>Copyright © 1999–2002, 2005, 2008–2025 Free Software Foundation, Inc. </p> <blockquote class="quotation"> @@ -173,7 +173,7 @@ <p>The general synopsis of the <code class="command">grep</code> command line is </p> <div class="example"> -<pre class="example-preformatted">grep [<var class="var">option</var>...] [<var class="var">patterns</var>] [<var class="var">file</var>...] +<pre class="example-preformatted">grep [<var class="var">option</var>]... [<var class="var">patterns</var>] [<var class="var">file</var>]... </pre></div> <p>There can be zero or more <var class="var">option</var> arguments, and zero or more @@ -232,19 +232,17 @@ <h4 class="subsection" id="Generic-Program-Information-1"><span>2.1.1 Generic Program Information<a class="copiable-link" href="#Generic-Program-Information-1"> ¶</a></span></h4> <dl class="table"> -<dt><samp class="option">--help</samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dhelp"></a> -<a class="index-entry-id" id="index-usage-summary_002c-printing"></a> -<p>Print a usage message briefly summarizing the command-line options +<dt><a class="index-entry-id" id="index-usage-summary_002c-printing"></a> +<a id="index-_002d_002dhelp"></a><span><samp class="option">--help</samp><a class="copiable-link" href="#index-_002d_002dhelp"> ¶</a></span></dt> +<dd><p>Print a usage message briefly summarizing the command-line options and the bug-reporting address, then exit. </p> </dd> -<dt><samp class="option">-V</samp></dt> -<dt><samp class="option">--version</samp></dt> -<dd><a class="index-entry-id" id="index-_002dV"></a> -<a class="index-entry-id" id="index-_002d_002dversion"></a> +<dt><a class="index-entry-id" id="index-_002d_002dversion"></a> <a class="index-entry-id" id="index-version_002c-printing"></a> -<p>Print the version number of <code class="command">grep</code> to the standard output stream. +<a id="index-_002dV"></a><span><samp class="option">-V</samp><a class="copiable-link" href="#index-_002dV"> ¶</a></span></dt> +<dt><samp class="option">--version</samp></dt> +<dd><p>Print the version number of <code class="command">grep</code> to the standard output stream. This version number should be included in all bug reports. </p> </dd> @@ -260,12 +258,11 @@ <h4 class="subsection" id="Matching-Control-1"><span>2.1.2 Matching Control<a class="copiable-link" href="#Matching-Control-1"> ¶</a></span></h4> <dl class="table"> -<dt><samp class="option">-e <var class="var">patterns</var></samp></dt> -<dt><samp class="option">--regexp=<var class="var">patterns</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002de"></a> -<a class="index-entry-id" id="index-_002d_002dregexp_003dpatterns"></a> +<dt><a class="index-entry-id" id="index-_002d_002dregexp_003dpatterns"></a> <a class="index-entry-id" id="index-patterns-option"></a> -<p>Use <var class="var">patterns</var> as one or more patterns; newlines within +<a id="index-_002de"></a><span><samp class="option">-e <var class="var">patterns</var></samp><a class="copiable-link" href="#index-_002de"> ¶</a></span></dt> +<dt><samp class="option">--regexp=<var class="var">patterns</var></samp></dt> +<dd><p>Use <var class="var">patterns</var> as one or more patterns; newlines within <var class="var">patterns</var> separate each pattern from the next. If this option is used multiple times or is combined with the <samp class="option">-f</samp> (<samp class="option">--file</samp>) option, search for all patterns given. @@ -274,12 +271,11 @@ (<samp class="option">-e</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">-f <var class="var">file</var></samp></dt> -<dt><samp class="option">--file=<var class="var">file</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002df"></a> -<a class="index-entry-id" id="index-_002d_002dfile"></a> +<dt><a class="index-entry-id" id="index-_002d_002dfile"></a> <a class="index-entry-id" id="index-patterns-from-file"></a> -<p>Obtain patterns from <var class="var">file</var>, one per line. +<a id="index-_002df"></a><span><samp class="option">-f <var class="var">file</var></samp><a class="copiable-link" href="#index-_002df"> ¶</a></span></dt> +<dt><samp class="option">--file=<var class="var">file</var></samp></dt> +<dd><p>Obtain patterns from <var class="var">file</var>, one per line. If this option is used multiple times or is combined with the <samp class="option">-e</samp> (<samp class="option">--regexp</samp>) option, search for all patterns given. When <var class="var">file</var> is ‘<samp class="samp">-</samp>’, read patterns from standard input. @@ -287,57 +283,55 @@ (<samp class="option">-f</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">-i</samp></dt> -<dt><samp class="option">-y</samp></dt> -<dt><samp class="option">--ignore-case</samp></dt> -<dd><a class="index-entry-id" id="index-_002di"></a> -<a class="index-entry-id" id="index-_002dy"></a> +<dt><a class="index-entry-id" id="index-_002dy"></a> <a class="index-entry-id" id="index-_002d_002dignore_002dcase"></a> <a class="index-entry-id" id="index-case-insensitive-search"></a> -<p>Ignore case distinctions in patterns and input data, +<a id="index-_002di"></a><span><samp class="option">-i</samp><a class="copiable-link" href="#index-_002di"> ¶</a></span></dt> +<dt><samp class="option">-y</samp></dt> +<dt><samp class="option">--ignore-case</samp></dt> +<dd><p>Ignore case distinctions in patterns and input data, so that characters that differ only in case match each other. Although this is straightforward when letters differ in case only via lowercase-uppercase pairs, the behavior is unspecified in other situations. For example, uppercase “S” has an -unusual lowercase counterpart “Å¿” (Unicode character U+017F, LATIN +unusual lowercase counterpart +“Å¿” +(Unicode character U+017F LATIN SMALL LETTER LONG S) in many locales, and it is unspecified whether this unusual character matches “S” or “s” even though uppercasing it yields “S”. Another example: the lowercase German letter “Ô -(U+00DF, LATIN SMALL LETTER SHARP S) is normally capitalized as the +(U+00DF LATIN SMALL LETTER SHARP S) is normally capitalized as the two-character string “SS” but it does not match “SS”, and it might not match the uppercase letter “Ẕ -(U+1E9E, LATIN CAPITAL LETTER +(U+1E9E LATIN CAPITAL LETTER SHARP S) even though lowercasing the latter yields the former. </p> <p><samp class="option">-y</samp> is an obsolete synonym that is provided for compatibility. (<samp class="option">-i</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">--no-ignore-case</samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dno_002dignore_002dcase"></a> -<p>Do not ignore case distinctions in patterns and input data. This is +<dt><a id="index-_002d_002dno_002dignore_002dcase"></a><span><samp class="option">--no-ignore-case</samp><a class="copiable-link" href="#index-_002d_002dno_002dignore_002dcase"> ¶</a></span></dt> +<dd><p>Do not ignore case distinctions in patterns and input data. This is the default. This option is useful for passing to shell scripts that already use <samp class="option">-i</samp>, in order to cancel its effects because the two options override each other. </p> </dd> -<dt><samp class="option">-v</samp></dt> -<dt><samp class="option">--invert-match</samp></dt> -<dd><a class="index-entry-id" id="index-_002dv"></a> -<a class="index-entry-id" id="index-_002d_002dinvert_002dmatch"></a> +<dt><a class="index-entry-id" id="index-_002d_002dinvert_002dmatch"></a> <a class="index-entry-id" id="index-invert-matching"></a> <a class="index-entry-id" id="index-print-non_002dmatching-lines"></a> -<p>Invert the sense of matching, to select non-matching lines. +<a id="index-_002dv"></a><span><samp class="option">-v</samp><a class="copiable-link" href="#index-_002dv"> ¶</a></span></dt> +<dt><samp class="option">--invert-match</samp></dt> +<dd><p>Invert the sense of matching, to select non-matching lines. (<samp class="option">-v</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">-w</samp></dt> -<dt><samp class="option">--word-regexp</samp></dt> -<dd><a class="index-entry-id" id="index-_002dw"></a> -<a class="index-entry-id" id="index-_002d_002dword_002dregexp"></a> +<dt><a class="index-entry-id" id="index-_002d_002dword_002dregexp"></a> <a class="index-entry-id" id="index-matching-whole-words"></a> -<p>Select only those lines containing matches that form whole words. +<a id="index-_002dw"></a><span><samp class="option">-w</samp><a class="copiable-link" href="#index-_002dw"> ¶</a></span></dt> +<dt><samp class="option">--word-regexp</samp></dt> +<dd><p>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. @@ -355,12 +349,11 @@ word constituent. See <a class="xref" href="#Special-Backslash-Expressions">Special Backslash Expressions</a>. </p> </dd> -<dt><samp class="option">-x</samp></dt> -<dt><samp class="option">--line-regexp</samp></dt> -<dd><a class="index-entry-id" id="index-_002dx"></a> -<a class="index-entry-id" id="index-_002d_002dline_002dregexp"></a> +<dt><a class="index-entry-id" id="index-_002d_002dline_002dregexp"></a> <a class="index-entry-id" id="index-match-the-whole-line"></a> -<p>Select only those matches that exactly match the whole line. +<a id="index-_002dx"></a><span><samp class="option">-x</samp><a class="copiable-link" href="#index-_002dx"> ¶</a></span></dt> +<dt><samp class="option">--line-regexp</samp></dt> +<dd><p>Select only those matches that exactly match the whole line. For regular expression patterns, this is like parenthesizing each pattern and then surrounding it with ‘<samp class="samp">^</samp>’ and ‘<samp class="samp">$</samp>’. (<samp class="option">-x</samp> is specified by POSIX.) @@ -378,24 +371,22 @@ <h4 class="subsection" id="General-Output-Control-1"><span>2.1.3 General Output Control<a class="copiable-link" href="#General-Output-Control-1"> ¶</a></span></h4> <dl class="table"> -<dt><samp class="option">-c</samp></dt> -<dt><samp class="option">--count</samp></dt> -<dd><a class="index-entry-id" id="index-_002dc"></a> -<a class="index-entry-id" id="index-_002d_002dcount"></a> +<dt><a class="index-entry-id" id="index-_002d_002dcount"></a> <a class="index-entry-id" id="index-counting-lines"></a> -<p>Suppress normal output; +<a id="index-_002dc"></a><span><samp class="option">-c</samp><a class="copiable-link" href="#index-_002dc"> ¶</a></span></dt> +<dt><samp class="option">--count</samp></dt> +<dd><p>Suppress normal output; instead print a count of matching lines for each input file. With the <samp class="option">-v</samp> (<samp class="option">--invert-match</samp>) option, count non-matching lines. (<samp class="option">-c</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">--color[=<var class="var">WHEN</var>]</samp></dt> -<dt><samp class="option">--colour[=<var class="var">WHEN</var>]</samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dcolor"></a> -<a class="index-entry-id" id="index-_002d_002dcolour"></a> +<dt><a class="index-entry-id" id="index-_002d_002dcolour"></a> <a class="index-entry-id" id="index-highlight_002c-color_002c-colour"></a> -<p>Surround matched non-empty strings, matching lines, context lines, +<a id="index-_002d_002dcolor"></a><span><samp class="option">--color[=<var class="var">WHEN</var>]</samp><a class="copiable-link" href="#index-_002d_002dcolor"> ¶</a></span></dt> +<dt><samp class="option">--colour[=<var class="var">WHEN</var>]</samp></dt> +<dd><p>Surround 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. @@ -413,34 +404,31 @@ if no <samp class="option">--color</samp> option is given, the default is <samp class="option">--color=never</samp>. </p> </dd> -<dt><samp class="option">-L</samp></dt> -<dt><samp class="option">--files-without-match</samp></dt> -<dd><a class="index-entry-id" id="index-_002dL"></a> -<a class="index-entry-id" id="index-_002d_002dfiles_002dwithout_002dmatch"></a> +<dt><a class="index-entry-id" id="index-_002d_002dfiles_002dwithout_002dmatch"></a> <a class="index-entry-id" id="index-files-which-don_0027t-match"></a> -<p>Suppress normal output; +<a id="index-_002dL"></a><span><samp class="option">-L</samp><a class="copiable-link" href="#index-_002dL"> ¶</a></span></dt> +<dt><samp class="option">--files-without-match</samp></dt> +<dd><p>Suppress normal output; instead print the name of each input file from which no output would normally have been printed. </p> </dd> -<dt><samp class="option">-l</samp></dt> -<dt><samp class="option">--files-with-matches</samp></dt> -<dd><a class="index-entry-id" id="index-_002dl"></a> -<a class="index-entry-id" id="index-_002d_002dfiles_002dwith_002dmatches"></a> +<dt><a class="index-entry-id" id="index-_002d_002dfiles_002dwith_002dmatches"></a> <a class="index-entry-id" id="index-names-of-matching-files"></a> -<p>Suppress normal output; +<a id="index-_002dl"></a><span><samp class="option">-l</samp><a class="copiable-link" href="#index-_002dl"> ¶</a></span></dt> +<dt><samp class="option">--files-with-matches</samp></dt> +<dd><p>Suppress normal output; instead print the name of each input file from which output would normally have been printed. Scanning each input file stops upon first match. (<samp class="option">-l</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">-m <var class="var">num</var></samp></dt> -<dt><samp class="option">--max-count=<var class="var">num</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002dm"></a> -<a class="index-entry-id" id="index-_002d_002dmax_002dcount"></a> +<dt><a class="index-entry-id" id="index-_002d_002dmax_002dcount"></a> <a class="index-entry-id" id="index-max_002dcount"></a> -<p>Stop after the first <var class="var">num</var> selected lines. +<a id="index-_002dm"></a><span><samp class="option">-m <var class="var">num</var></samp><a class="copiable-link" href="#index-_002dm"> ¶</a></span></dt> +<dt><samp class="option">--max-count=<var class="var">num</var></samp></dt> +<dd><p>Stop after the first <var class="var">num</var> selected lines. If <var class="var">num</var> is zero, <code class="command">grep</code> stops right away without reading input. A <var class="var">num</var> of −1 is treated as infinity and <code class="command">grep</code> does not stop; this is the default. @@ -481,25 +469,23 @@ <code class="command">grep</code> stops after outputting <var class="var">num</var> non-matching lines. </p> </dd> -<dt><samp class="option">-o</samp></dt> -<dt><samp class="option">--only-matching</samp></dt> -<dd><a class="index-entry-id" id="index-_002do"></a> -<a class="index-entry-id" id="index-_002d_002donly_002dmatching"></a> +<dt><a class="index-entry-id" id="index-_002d_002donly_002dmatching"></a> <a class="index-entry-id" id="index-only-matching"></a> -<p>Print only the matched non-empty parts of matching lines, +<a id="index-_002do"></a><span><samp class="option">-o</samp><a class="copiable-link" href="#index-_002do"> ¶</a></span></dt> +<dt><samp class="option">--only-matching</samp></dt> +<dd><p>Print only the matched non-empty parts of matching lines, with each such part on a separate output line. Output lines use the same delimiters as input, and delimiters are null bytes if <samp class="option">-z</samp> (<samp class="option">--null-data</samp>) is also used (see <a class="pxref" href="#Other-Options">Other Options</a>). </p> </dd> -<dt><samp class="option">-q</samp></dt> -<dt><samp class="option">--quiet</samp></dt> -<dt><samp class="option">--silent</samp></dt> -<dd><a class="index-entry-id" id="index-_002dq"></a> -<a class="index-entry-id" id="index-_002d_002dquiet"></a> +<dt><a class="index-entry-id" id="index-_002d_002dquiet"></a> <a class="index-entry-id" id="index-_002d_002dsilent"></a> <a class="index-entry-id" id="index-quiet_002c-silent"></a> -<p>Quiet; do not write anything to standard output. +<a id="index-_002dq"></a><span><samp class="option">-q</samp><a class="copiable-link" href="#index-_002dq"> ¶</a></span></dt> +<dt><samp class="option">--quiet</samp></dt> +<dt><samp class="option">--silent</samp></dt> +<dd><p>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 <samp class="option">-s</samp> or <samp class="option">--no-messages</samp> option. @@ -509,12 +495,11 @@ (<samp class="option">-q</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">-s</samp></dt> -<dt><samp class="option">--no-messages</samp></dt> -<dd><a class="index-entry-id" id="index-_002ds"></a> -<a class="index-entry-id" id="index-_002d_002dno_002dmessages"></a> +<dt><a class="index-entry-id" id="index-_002d_002dno_002dmessages"></a> <a class="index-entry-id" id="index-suppress-error-messages"></a> -<p>Suppress error messages about nonexistent or unreadable files. +<a id="index-_002ds"></a><span><samp class="option">-s</samp><a class="copiable-link" href="#index-_002ds"> ¶</a></span></dt> +<dt><samp class="option">--no-messages</samp></dt> +<dd><p>Suppress error messages about nonexistent or unreadable files. (<samp class="option">-s</samp> is specified by POSIX.) </p> </dd> @@ -534,40 +519,36 @@ regardless of the order in which these options were specified. </p> <dl class="table"> -<dt><samp class="option">-b</samp></dt> -<dt><samp class="option">--byte-offset</samp></dt> -<dd><a class="index-entry-id" id="index-_002db"></a> -<a class="index-entry-id" id="index-_002d_002dbyte_002doffset"></a> +<dt><a class="index-entry-id" id="index-_002d_002dbyte_002doffset"></a> <a class="index-entry-id" id="index-byte-offset"></a> -<p>Print the 0-based byte offset within the input file +<a id="index-_002db"></a><span><samp class="option">-b</samp><a class="copiable-link" href="#index-_002db"> ¶</a></span></dt> +<dt><samp class="option">--byte-offset</samp></dt> +<dd><p>Print the 0-based byte offset within the input file before each line of output. If <samp class="option">-o</samp> (<samp class="option">--only-matching</samp>) is specified, print the offset of the matching part itself. </p> </dd> -<dt><samp class="option">-H</samp></dt> -<dt><samp class="option">--with-filename</samp></dt> -<dd><a class="index-entry-id" id="index-_002dH"></a> -<a class="index-entry-id" id="index-_002d_002dwith_002dfilename"></a> +<dt><a class="index-entry-id" id="index-_002d_002dwith_002dfilename"></a> <a class="index-entry-id" id="index-with-filename-prefix"></a> -<p>Print the file name for each match. +<a id="index-_002dH"></a><span><samp class="option">-H</samp><a class="copiable-link" href="#index-_002dH"> ¶</a></span></dt> +<dt><samp class="option">--with-filename</samp></dt> +<dd><p>Print the file name for each match. This is the default when there is more than one file to search. </p> </dd> -<dt><samp class="option">-h</samp></dt> -<dt><samp class="option">--no-filename</samp></dt> -<dd><a class="index-entry-id" id="index-_002dh"></a> -<a class="index-entry-id" id="index-_002d_002dno_002dfilename"></a> +<dt><a class="index-entry-id" id="index-_002d_002dno_002dfilename"></a> <a class="index-entry-id" id="index-no-filename-prefix"></a> -<p>Suppress the prefixing of file names on output. +<a id="index-_002dh"></a><span><samp class="option">-h</samp><a class="copiable-link" href="#index-_002dh"> ¶</a></span></dt> +<dt><samp class="option">--no-filename</samp></dt> +<dd><p>Suppress the prefixing of file names on output. This is the default when there is only one file (or only standard input) to search. </p> </dd> -<dt><samp class="option">--label=<var class="var">LABEL</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dlabel"></a> -<a class="index-entry-id" id="index-changing-name-of-standard-input"></a> -<p>Display input actually coming from standard input +<dt><a class="index-entry-id" id="index-changing-name-of-standard-input"></a> +<a id="index-_002d_002dlabel"></a><span><samp class="option">--label=<var class="var">LABEL</var></samp><a class="copiable-link" href="#index-_002d_002dlabel"> ¶</a></span></dt> +<dd><p>Display input actually coming from standard input as input coming from file <var class="var">LABEL</var>. This can be useful for commands that transform a file’s contents before searching; e.g.: @@ -577,21 +558,19 @@ </pre></div> </dd> -<dt><samp class="option">-n</samp></dt> -<dt><samp class="option">--line-number</samp></dt> -<dd><a class="index-entry-id" id="index-_002dn"></a> -<a class="index-entry-id" id="index-_002d_002dline_002dnumber"></a> +<dt><a class="index-entry-id" id="index-_002d_002dline_002dnumber"></a> <a class="index-entry-id" id="index-line-numbering"></a> -<p>Prefix each line of output with the 1-based line number within its input file. +<a id="index-_002dn"></a><span><samp class="option">-n</samp><a class="copiable-link" href="#index-_002dn"> ¶</a></span></dt> +<dt><samp class="option">--line-number</samp></dt> +<dd><p>Prefix each line of output with the 1-based line number within its input file. (<samp class="option">-n</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">-T</samp></dt> -<dt><samp class="option">--initial-tab</samp></dt> -<dd><a class="index-entry-id" id="index-_002dT"></a> -<a class="index-entry-id" id="index-_002d_002dinitial_002dtab"></a> +<dt><a class="index-entry-id" id="index-_002d_002dinitial_002dtab"></a> <a class="index-entry-id" id="index-tab_002daligned-content-lines"></a> -<p>Make sure that the first character of actual line content lies on a tab stop, +<a id="index-_002dT"></a><span><samp class="option">-T</samp><a class="copiable-link" href="#index-_002dT"> ¶</a></span></dt> +<dt><samp class="option">--initial-tab</samp></dt> +<dd><p>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: <samp class="option">-H</samp>, <samp class="option">-n</samp>, and <samp class="option">-b</samp>. @@ -599,12 +578,11 @@ so that lines from a single file all start at the same column. </p> </dd> -<dt><samp class="option">-Z</samp></dt> -<dt><samp class="option">--null</samp></dt> -<dd><a class="index-entry-id" id="index-_002dZ"></a> -<a class="index-entry-id" id="index-_002d_002dnull"></a> +<dt><a class="index-entry-id" id="index-_002d_002dnull"></a> <a class="index-entry-id" id="index-zero_002dterminated-file-names"></a> -<p>Output a zero byte (the ASCII NUL character) +<a id="index-_002dZ"></a><span><samp class="option">-Z</samp><a class="copiable-link" href="#index-_002dZ"> ¶</a></span></dt> +<dt><samp class="option">--null</samp></dt> +<dd><p>Output a zero byte (the ASCII NUL character) instead of the character that normally follows a file name. For example, ‘<samp class="samp">grep -lZ</samp>’ outputs a zero byte after each file name @@ -637,45 +615,40 @@ these options have no effect and a warning is given upon their use. </p> <dl class="table"> -<dt><samp class="option">-A <var class="var">num</var></samp></dt> -<dt><samp class="option">--after-context=<var class="var">num</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002dA"></a> -<a class="index-entry-id" id="index-_002d_002dafter_002dcontext"></a> +<dt><a class="index-entry-id" id="index-_002d_002dafter_002dcontext"></a> <a class="index-entry-id" id="index-after-context"></a> <a class="index-entry-id" id="index-context-lines_002c-after-match"></a> -<p>Print <var class="var">num</var> lines of trailing context after matching lines. +<a id="index-_002dA"></a><span><samp class="option">-A <var class="var">num</var></samp><a class="copiable-link" href="#index-_002dA"> ¶</a></span></dt> +<dt><samp class="option">--after-context=<var class="var">num</var></samp></dt> +<dd><p>Print <var class="var">num</var> lines of trailing context after matching lines. </p> </dd> -<dt><samp class="option">-B <var class="var">num</var></samp></dt> -<dt><samp class="option">--before-context=<var class="var">num</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002dB"></a> -<a class="index-entry-id" id="index-_002d_002dbefore_002dcontext"></a> +<dt><a class="index-entry-id" id="index-_002d_002dbefore_002dcontext"></a> <a class="index-entry-id" id="index-before-context"></a> <a class="index-entry-id" id="index-context-lines_002c-before-match"></a> -<p>Print <var class="var">num</var> lines of leading context before matching lines. +<a id="index-_002dB"></a><span><samp class="option">-B <var class="var">num</var></samp><a class="copiable-link" href="#index-_002dB"> ¶</a></span></dt> +<dt><samp class="option">--before-context=<var class="var">num</var></samp></dt> +<dd><p>Print <var class="var">num</var> lines of leading context before matching lines. </p> </dd> -<dt><samp class="option">-C <var class="var">num</var></samp></dt> -<dt><samp class="option">-<var class="var">num</var></samp></dt> -<dt><samp class="option">--context=<var class="var">num</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002dC"></a> -<a class="index-entry-id" id="index-_002d_002dcontext"></a> +<dt><a class="index-entry-id" id="index-_002d_002dcontext"></a> <a class="index-entry-id" id="index-_002dnum"></a> <a class="index-entry-id" id="index-context-lines-2"></a> -<p>Print <var class="var">num</var> lines of leading and trailing output context. +<a id="index-_002dC"></a><span><samp class="option">-C <var class="var">num</var></samp><a class="copiable-link" href="#index-_002dC"> ¶</a></span></dt> +<dt><samp class="option">-<var class="var">num</var></samp></dt> +<dt><samp class="option">--context=<var class="var">num</var></samp></dt> +<dd><p>Print <var class="var">num</var> lines of leading and trailing output context. </p> </dd> -<dt><samp class="option">--group-separator=<var class="var">string</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dgroup_002dseparator"></a> -<a class="index-entry-id" id="index-group-separator"></a> -<p>When <samp class="option">-A</samp>, <samp class="option">-B</samp> or <samp class="option">-C</samp> are in use, -print <var class="var">string</var> instead of <samp class="option">--</samp> between groups of lines. +<dt><a class="index-entry-id" id="index-group-separator"></a> +<a id="index-_002d_002dgroup_002dseparator"></a><span><samp class="option">--group-separator=<var class="var">string</var></samp><a class="copiable-link" href="#index-_002d_002dgroup_002dseparator"> ¶</a></span></dt> +<dd><p>When <samp class="option">-A</samp>, <samp class="option">-B</samp> or <samp class="option">-C</samp> are in use, +print <var class="var">string</var> instead of ‘<samp class="samp">--</samp>’ between groups of lines. </p> </dd> -<dt><samp class="option">--no-group-separator</samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dgroup_002dseparator-1"></a> -<a class="index-entry-id" id="index-group-separator-1"></a> -<p>When <samp class="option">-A</samp>, <samp class="option">-B</samp> or <samp class="option">-C</samp> are in use, +<dt><a class="index-entry-id" id="index-group-separator-1"></a> +<a id="index-_002d_002dgroup_002dseparator-1"></a><span><samp class="option">--no-group-separator</samp><a class="copiable-link" href="#index-_002d_002dgroup_002dseparator-1"> ¶</a></span></dt> +<dd><p>When <samp class="option">-A</samp>, <samp class="option">-B</samp> or <samp class="option">-C</samp> are in use, do not print a separator between groups of lines. </p> </dd> @@ -718,20 +691,18 @@ <h4 class="subsection" id="File-and-Directory-Selection-1"><span>2.1.6 File and Directory Selection<a class="copiable-link" href="#File-and-Directory-Selection-1"> ¶</a></span></h4> <dl class="table"> -<dt><samp class="option">-a</samp></dt> -<dt><samp class="option">--text</samp></dt> -<dd><a class="index-entry-id" id="index-_002da"></a> -<a class="index-entry-id" id="index-_002d_002dtext"></a> +<dt><a class="index-entry-id" id="index-_002d_002dtext"></a> <a class="index-entry-id" id="index-suppress-binary-data"></a> <a class="index-entry-id" id="index-binary-files"></a> -<p>Process a binary file as if it were text; +<a id="index-_002da"></a><span><samp class="option">-a</samp><a class="copiable-link" href="#index-_002da"> ¶</a></span></dt> +<dt><samp class="option">--text</samp></dt> +<dd><p>Process a binary file as if it were text; this is equivalent to the ‘<samp class="samp">--binary-files=text</samp>’ option. </p> </dd> -<dt><samp class="option">--binary-files=<var class="var">type</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dbinary_002dfiles"></a> -<a class="index-entry-id" id="index-binary-files-1"></a> -<p>If a file’s data or metadata +<dt><a class="index-entry-id" id="index-binary-files-1"></a> +<a id="index-_002d_002dbinary_002dfiles"></a><span><samp class="option">--binary-files=<var class="var">type</var></samp><a class="copiable-link" href="#index-_002d_002dbinary_002dfiles"> ¶</a></span></dt> +<dd><p>If a file’s data or metadata indicate that the file contains binary data, assume that the file is of type <var class="var">type</var>. Non-text bytes indicate binary data; these are either output bytes that are @@ -745,9 +716,11 @@ with a message to standard error saying that a binary file matches. </p> <p>If <var class="var">type</var> is ‘<samp class="samp">without-match</samp>’, -when <code class="command">grep</code> discovers null input binary data -it assumes that the rest of the file does not match; +when <code class="command">grep</code> discovers null binary data in an input file +it assumes that any unprocessed input does not match; this is equivalent to the <samp class="option">-I</samp> option. +In this case the region of unprocessed input starts no later than the +null binary data, and continues to end of file. </p> <p>If <var class="var">type</var> is ‘<samp class="samp">text</samp>’, <code class="command">grep</code> processes binary data as if it were text; @@ -763,6 +736,16 @@ <var class="var">type</var> is ‘<samp class="samp">binary</samp>’ the pattern ‘<samp class="samp">.</samp>’ (period) might not match a null byte. </p> +<p>The heuristic that <code class="command">grep</code> uses to intuit whether input is +binary is specific to <code class="command">grep</code> and may well be unsuitable for +other applications, as it depends on command-line options, on locale, +and on hardware and operating system characteristics such as system +page size and input buffering. For example, if the input consists of +a matching text line followed by nonmatching data that contains a null +byte, <code class="command">grep</code> might either output the matching line or treat +the file as binary, depending on whether the unprocessed input happens +to include the matching text line. +</p> <p><em class="emph">Warning:</em> The <samp class="option">-a</samp> (<samp class="option">--binary-files=text</samp>) option 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 @@ -772,12 +755,11 @@ even if the matches are unsafe for direct display. </p> </dd> -<dt><samp class="option">-D <var class="var">action</var></samp></dt> -<dt><samp class="option">--devices=<var class="var">action</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002dD"></a> -<a class="index-entry-id" id="index-_002d_002ddevices"></a> +<dt><a class="index-entry-id" id="index-_002d_002ddevices"></a> <a class="index-entry-id" id="index-device-search"></a> -<p>If an input file is a device, FIFO, or socket, use <var class="var">action</var> to process it. +<a id="index-_002dD"></a><span><samp class="option">-D <var class="var">action</var></samp><a class="copiable-link" href="#index-_002dD"> ¶</a></span></dt> +<dt><samp class="option">--devices=<var class="var">action</var></samp></dt> +<dd><p>If an input file is a device, FIFO, or socket, use <var class="var">action</var> to process it. If <var class="var">action</var> is ‘<samp class="samp">read</samp>’, all devices are read just as if they were ordinary files. If <var class="var">action</var> is ‘<samp class="samp">skip</samp>’, @@ -789,13 +771,12 @@ This option has no effect on a file that is read via standard input. </p> </dd> -<dt><samp class="option">-d <var class="var">action</var></samp></dt> -<dt><samp class="option">--directories=<var class="var">action</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002dd"></a> -<a class="index-entry-id" id="index-_002d_002ddirectories"></a> +<dt><a class="index-entry-id" id="index-_002d_002ddirectories"></a> <a class="index-entry-id" id="index-directory-search"></a> <a class="index-entry-id" id="index-symbolic-links"></a> -<p>If an input file is a directory, use <var class="var">action</var> to process it. +<a id="index-_002dd"></a><span><samp class="option">-d <var class="var">action</var></samp><a class="copiable-link" href="#index-_002dd"> ¶</a></span></dt> +<dt><samp class="option">--directories=<var class="var">action</var></samp></dt> +<dd><p>If an input file is a directory, use <var class="var">action</var> to process it. By default, <var class="var">action</var> is ‘<samp class="samp">read</samp>’, which means that directories are read just as if they were ordinary files (some operating systems and file systems disallow this, @@ -808,34 +789,31 @@ this is equivalent to the <samp class="option">-r</samp> option. </p> </dd> -<dt><samp class="option">--exclude=<var class="var">glob</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dexclude"></a> -<a class="index-entry-id" id="index-exclude-files"></a> +<dt><a class="index-entry-id" id="index-exclude-files"></a> <a class="index-entry-id" id="index-searching-directory-trees"></a> -<p>Skip any command-line file with a name suffix that matches the pattern +<a id="index-_002d_002dexclude"></a><span><samp class="option">--exclude=<var class="var">glob</var></samp><a class="copiable-link" href="#index-_002d_002dexclude"> ¶</a></span></dt> +<dd><p>Skip any command-line file with a name suffix that matches the pattern <var class="var">glob</var>, using wildcard matching; a name suffix is either the whole name, or a trailing part that starts with a non-slash character immediately after a slash (‘<samp class="samp">/</samp>’) in the name. When searching recursively, skip any subfile whose base name matches <var class="var">glob</var>; the base name is the part after the last slash. A pattern can use -‘<samp class="samp">*</samp>’, ‘<samp class="samp">?</samp>’, and ‘<samp class="samp">[</samp>’...‘<samp class="samp">]</samp>’ as wildcards, +‘<samp class="samp">*</samp>’, ‘<samp class="samp">?</samp>’, and ‘<samp class="samp">[</samp>’…‘<samp class="samp">]</samp>’ as wildcards, and <code class="code">\</code> to quote a wildcard or backslash character literally. </p> </dd> -<dt><samp class="option">--exclude-from=<var class="var">file</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dexclude_002dfrom"></a> -<a class="index-entry-id" id="index-exclude-files-1"></a> +<dt><a class="index-entry-id" id="index-exclude-files-1"></a> <a class="index-entry-id" id="index-searching-directory-trees-1"></a> -<p>Skip files whose name matches any of the patterns +<a id="index-_002d_002dexclude_002dfrom"></a><span><samp class="option">--exclude-from=<var class="var">file</var></samp><a class="copiable-link" href="#index-_002d_002dexclude_002dfrom"> ¶</a></span></dt> +<dd><p>Skip files whose name matches any of the patterns read from <var class="var">file</var> (using wildcard matching as described under <samp class="option">--exclude</samp>). </p> </dd> -<dt><samp class="option">--exclude-dir=<var class="var">glob</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dexclude_002ddir"></a> -<a class="index-entry-id" id="index-exclude-directories"></a> -<p>Skip any command-line directory with a name suffix that matches the +<dt><a class="index-entry-id" id="index-exclude-directories"></a> +<a id="index-_002d_002dexclude_002ddir"></a><span><samp class="option">--exclude-dir=<var class="var">glob</var></samp><a class="copiable-link" href="#index-_002d_002dexclude_002ddir"> ¶</a></span></dt> +<dd><p>Skip any command-line directory with a name suffix that matches the pattern <var class="var">glob</var>. When searching recursively, skip any subdirectory whose base name matches <var class="var">glob</var>. Ignore any redundant trailing slashes in <var class="var">glob</var>. @@ -846,11 +824,10 @@ this is equivalent to the ‘<samp class="samp">--binary-files=without-match</samp>’ option. </p> </dd> -<dt><samp class="option">--include=<var class="var">glob</var></samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dinclude"></a> -<a class="index-entry-id" id="index-include-files"></a> +<dt><a class="index-entry-id" id="index-include-files"></a> <a class="index-entry-id" id="index-searching-directory-trees-2"></a> -<p>Search only files whose name matches <var class="var">glob</var>, +<a id="index-_002d_002dinclude"></a><span><samp class="option">--include=<var class="var">glob</var></samp><a class="copiable-link" href="#index-_002d_002dinclude"> ¶</a></span></dt> +<dd><p>Search only files whose name matches <var class="var">glob</var>, using wildcard matching as described under <samp class="option">--exclude</samp>. If contradictory <samp class="option">--include</samp> and <samp class="option">--exclude</samp> options are given, the last matching one wins. If no <samp class="option">--include</samp> or @@ -858,14 +835,13 @@ such option is <samp class="option">--include</samp>. </p> </dd> -<dt><samp class="option">-r</samp></dt> -<dt><samp class="option">--recursive</samp></dt> -<dd><a class="index-entry-id" id="index-_002dr"></a> -<a class="index-entry-id" id="index-_002d_002drecursive"></a> +<dt><a class="index-entry-id" id="index-_002d_002drecursive"></a> <a class="index-entry-id" id="index-recursive-search"></a> <a class="index-entry-id" id="index-searching-directory-trees-3"></a> <a class="index-entry-id" id="index-symbolic-links-1"></a> -<p>For each directory operand, +<a id="index-_002dr"></a><span><samp class="option">-r</samp><a class="copiable-link" href="#index-_002dr"> ¶</a></span></dt> +<dt><samp class="option">--recursive</samp></dt> +<dd><p>For each directory operand, read and process all files in that directory, recursively. Follow symbolic links on the command line, but skip symlinks that are encountered recursively. @@ -873,14 +849,13 @@ This is the same as the ‘<samp class="samp">--directories=recurse</samp>’ option. </p> </dd> -<dt><samp class="option">-R</samp></dt> -<dt><samp class="option">--dereference-recursive</samp></dt> -<dd><a class="index-entry-id" id="index-_002dR"></a> -<a class="index-entry-id" id="index-_002d_002ddereference_002drecursive"></a> +<dt><a class="index-entry-id" id="index-_002d_002ddereference_002drecursive"></a> <a class="index-entry-id" id="index-recursive-search-1"></a> <a class="index-entry-id" id="index-searching-directory-trees-4"></a> <a class="index-entry-id" id="index-symbolic-links-2"></a> -<p>For each directory operand, read and process all files in that +<a id="index-_002dR"></a><span><samp class="option">-R</samp><a class="copiable-link" href="#index-_002dR"> ¶</a></span></dt> +<dt><samp class="option">--dereference-recursive</samp></dt> +<dd><p>For each directory operand, read and process all files in that directory, recursively, following all symbolic links. </p> </dd> @@ -896,32 +871,29 @@ <h4 class="subsection" id="Other-Options-1"><span>2.1.7 Other Options<a class="copiable-link" href="#Other-Options-1"> ¶</a></span></h4> <dl class="table"> -<dt><samp class="option">--</samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002d"></a> -<a class="index-entry-id" id="index-option-delimiter"></a> -<p>Delimit the option list. Later arguments, if any, are treated as -operands even if they begin with ‘<samp class="samp">-</samp>’. For example, ‘<samp class="samp">grep PAT -- --file1 file2</samp>’ searches for the pattern PAT in the files named <samp class="file">-file1</samp> -and <samp class="file">file2</samp>. +<dt><a class="index-entry-id" id="index-option-delimiter"></a> +<a id="index-_002d_002d"></a><span><samp class="option">--</samp><a class="copiable-link" href="#index-_002d_002d"> ¶</a></span></dt> +<dd><p>Delimit the option list. Any later argument is not treated as an +option even if it begins with ‘<samp class="samp">-</samp>’. For example, +‘<samp class="samp">grep -- -PAT -file1 file2</samp>’ searches for the pattern ‘<samp class="samp">-PAT</samp>’ +in the files named <samp class="file">-file1</samp> and <samp class="file">file2</samp>. </p> </dd> -<dt><samp class="option">--line-buffered</samp></dt> -<dd><a class="index-entry-id" id="index-_002d_002dline_002dbuffered"></a> -<a class="index-entry-id" id="index-line-buffering"></a> -<p>Use line buffering for standard output, regardless of output device. +<dt><a class="index-entry-id" id="index-line-buffering"></a> +<a id="index-_002d_002dline_002dbuffered"></a><span><samp class="option">--line-buffered</samp><a class="copiable-link" href="#index-_002d_002dline_002dbuffered"> ¶</a></span></dt> +<dd><p>Use line buffering for standard output, regardless of output device. By default, standard output is line buffered for interactive devices, and is fully buffered otherwise. With full buffering, the output buffer is flushed when full; with line buffering, the buffer is also flushed after every output line. The buffer size is system dependent. </p> </dd> -<dt><samp class="option">-U</samp></dt> -<dt><samp class="option">--binary</samp></dt> -<dd><a class="index-entry-id" id="index-_002dU"></a> -<a class="index-entry-id" id="index-_002d_002dbinary"></a> +<dt><a class="index-entry-id" id="index-_002d_002dbinary"></a> <a class="index-entry-id" id="index-MS_002dWindows-binary-I_002fO"></a> <a class="index-entry-id" id="index-binary-I_002fO"></a> -<p>On platforms that distinguish between text and binary I/O, +<a id="index-_002dU"></a><span><samp class="option">-U</samp><a class="copiable-link" href="#index-_002dU"> ¶</a></span></dt> +<dt><samp class="option">--binary</samp></dt> +<dd><p>On platforms that distinguish between text and binary I/O, use the latter when reading and writing files other than the user’s terminal, so that all input bytes are read and written as-is. This overrides the default behavior where <code class="command">grep</code> @@ -942,12 +914,11 @@ which do not distinguish text from binary I/O. </p> </dd> -<dt><samp class="option">-z</samp></dt> -<dt><samp class="option">--null-data</samp></dt> -<dd><a class="index-entry-id" id="index-_002dz"></a> -<a class="index-entry-id" id="index-_002d_002dnull_002ddata"></a> +<dt><a class="index-entry-id" id="index-_002d_002dnull_002ddata"></a> <a class="index-entry-id" id="index-zero_002dterminated-lines"></a> -<p>Treat input and output data as sequences of lines, each terminated by +<a id="index-_002dz"></a><span><samp class="option">-z</samp><a class="copiable-link" href="#index-_002dz"> ¶</a></span></dt> +<dt><samp class="option">--null-data</samp></dt> +<dd><p>Treat input and output data as sequences of lines, each terminated by a zero byte (the ASCII NUL character) instead of a newline. Like the <samp class="option">-Z</samp> or <samp class="option">--null</samp> option, this option can be used with commands like @@ -998,20 +969,18 @@ <p>The following environment variables affect the behavior of <code class="command">grep</code>. </p> <dl class="table"> -<dt><code class="env">GREP_COLOR</code></dt> -<dd><a class="index-entry-id" id="index-GREP_005fCOLOR-environment-variable"></a> -<a class="index-entry-id" id="index-highlight-markers"></a> -<p>This obsolescent variable interacts with <code class="env">GREP_COLORS</code> +<dt><a class="index-entry-id" id="index-highlight-markers"></a> +<a id="index-GREP_005fCOLOR-environment-variable"></a><span><code class="env">GREP_COLOR</code><a class="copiable-link" href="#index-GREP_005fCOLOR-environment-variable"> ¶</a></span></dt> +<dd><p>This obsolescent variable interacts with <code class="env">GREP_COLORS</code> confusingly, and <code class="command">grep</code> warns if it is set and is not overridden by <code class="env">GREP_COLORS</code>. Instead of ‘<samp class="samp">GREP_COLOR='<var class="var">color</var>'</samp>’, you can use ‘<samp class="samp">GREP_COLORS='mt=<var class="var">color</var>'</samp>’. </p> </dd> -<dt><code class="env">GREP_COLORS</code></dt> -<dd><a class="index-entry-id" id="index-GREP_005fCOLORS-environment-variable"></a> -<a class="index-entry-id" id="index-highlight-markers-1"></a> -<p>This variable controls how the <samp class="option">--color</samp> option highlights output. +<dt><a class="index-entry-id" id="index-highlight-markers-1"></a> +<a id="index-GREP_005fCOLORS-environment-variable"></a><span><code class="env">GREP_COLORS</code><a class="copiable-link" href="#index-GREP_005fCOLORS-environment-variable"> ¶</a></span></dt> +<dd><p>This variable controls how the <samp class="option">--color</samp> option highlights output. Its value is a colon-separated list of <code class="code">terminfo</code> capabilities that defaults to ‘<samp class="samp">ms=01;31:mc=01;31:sl=:cx=:fn=35:ln=32:bn=32:se=36</samp>’ with the ‘<samp class="samp">rv</samp>’ and ‘<samp class="samp">ne</samp>’ boolean capabilities omitted (i.e., false). @@ -1031,7 +1000,7 @@ These substring values are integers in decimal representation and can be concatenated with semicolons. <code class="command">grep</code> takes care of assembling the result -into a complete SGR sequence (‘<samp class="samp">\33[</samp>’...‘<samp class="samp">m</samp>’). +into a complete SGR sequence (‘<samp class="samp">\33[</samp>’…‘<samp class="samp">m</samp>’). Common values to concatenate include ‘<samp class="samp">1</samp>’ for bold, ‘<samp class="samp">4</samp>’ for underline, @@ -1051,9 +1020,8 @@ <p>Supported capabilities are as follows. </p> <dl class="table"> -<dt><code class="code">sl=</code></dt> -<dd><a class="index-entry-id" id="index-sl-GREP_005fCOLORS-capability"></a> -<p>SGR substring for whole selected lines +<dt><a id="index-sl-GREP_005fCOLORS-capability"></a><span><code class="code">sl=</code><a class="copiable-link" href="#index-sl-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>SGR substring for whole selected lines (i.e., matching lines when the <samp class="option">-v</samp> command-line option is omitted, or non-matching lines when <samp class="option">-v</samp> is specified). @@ -1063,9 +1031,8 @@ The default is empty (i.e., the terminal’s default color pair). </p> </dd> -<dt><code class="code">cx=</code></dt> -<dd><a class="index-entry-id" id="index-cx-GREP_005fCOLORS-capability"></a> -<p>SGR substring for whole context lines +<dt><a id="index-cx-GREP_005fCOLORS-capability"></a><span><code class="code">cx=</code><a class="copiable-link" href="#index-cx-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>SGR substring for whole context lines (i.e., non-matching lines when the <samp class="option">-v</samp> command-line option is omitted, or matching lines when <samp class="option">-v</samp> is specified). @@ -1075,17 +1042,15 @@ The default is empty (i.e., the terminal’s default color pair). </p> </dd> -<dt><code class="code">rv</code></dt> -<dd><a class="index-entry-id" id="index-rv-GREP_005fCOLORS-capability"></a> -<p>Boolean value that reverses (swaps) the meanings of +<dt><a id="index-rv-GREP_005fCOLORS-capability"></a><span><code class="code">rv</code><a class="copiable-link" href="#index-rv-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>Boolean value that reverses (swaps) the meanings of the ‘<samp class="samp">sl=</samp>’ and ‘<samp class="samp">cx=</samp>’ capabilities when the <samp class="option">-v</samp> command-line option is specified. The default is false (i.e., the capability is omitted). </p> </dd> -<dt><code class="code">mt=01;31</code></dt> -<dd><a class="index-entry-id" id="index-mt-GREP_005fCOLORS-capability"></a> -<p>SGR substring for matching non-empty text in any matching line +<dt><a id="index-mt-GREP_005fCOLORS-capability"></a><span><code class="code">mt=01;31</code><a class="copiable-link" href="#index-mt-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>SGR substring for matching non-empty text in any matching line (i.e., a selected line when the <samp class="option">-v</samp> command-line option is omitted, or a context line when <samp class="option">-v</samp> is specified). @@ -1094,45 +1059,39 @@ The default is a bold red text foreground over the current line background. </p> </dd> -<dt><code class="code">ms=01;31</code></dt> -<dd><a class="index-entry-id" id="index-ms-GREP_005fCOLORS-capability"></a> -<p>SGR substring for matching non-empty text in a selected line. +<dt><a id="index-ms-GREP_005fCOLORS-capability"></a><span><code class="code">ms=01;31</code><a class="copiable-link" href="#index-ms-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>SGR substring for matching non-empty text in a selected line. (This is used only when the <samp class="option">-v</samp> command-line option is omitted.) The effect of the ‘<samp class="samp">sl=</samp>’ (or ‘<samp class="samp">cx=</samp>’ if ‘<samp class="samp">rv</samp>’) capability remains active when this takes effect. The default is a bold red text foreground over the current line background. </p> </dd> -<dt><code class="code">mc=01;31</code></dt> -<dd><a class="index-entry-id" id="index-mc-GREP_005fCOLORS-capability"></a> -<p>SGR substring for matching non-empty text in a context line. +<dt><a id="index-mc-GREP_005fCOLORS-capability"></a><span><code class="code">mc=01;31</code><a class="copiable-link" href="#index-mc-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>SGR substring for matching non-empty text in a context line. (This is used only when the <samp class="option">-v</samp> command-line option is specified.) The effect of the ‘<samp class="samp">cx=</samp>’ (or ‘<samp class="samp">sl=</samp>’ if ‘<samp class="samp">rv</samp>’) capability remains active when this takes effect. The default is a bold red text foreground over the current line background. </p> </dd> -<dt><code class="code">fn=35</code></dt> -<dd><a class="index-entry-id" id="index-fn-GREP_005fCOLORS-capability"></a> -<p>SGR substring for file names prefixing any content line. +<dt><a id="index-fn-GREP_005fCOLORS-capability"></a><span><code class="code">fn=35</code><a class="copiable-link" href="#index-fn-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>SGR substring for file names prefixing any content line. The default is a magenta text foreground over the terminal’s default background. </p> </dd> -<dt><code class="code">ln=32</code></dt> -<dd><a class="index-entry-id" id="index-ln-GREP_005fCOLORS-capability"></a> -<p>SGR substring for line numbers prefixing any content line. +<dt><a id="index-ln-GREP_005fCOLORS-capability"></a><span><code class="code">ln=32</code><a class="copiable-link" href="#index-ln-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>SGR substring for line numbers prefixing any content line. The default is a green text foreground over the terminal’s default background. </p> </dd> -<dt><code class="code">bn=32</code></dt> -<dd><a class="index-entry-id" id="index-bn-GREP_005fCOLORS-capability"></a> -<p>SGR substring for byte offsets prefixing any content line. +<dt><a id="index-bn-GREP_005fCOLORS-capability"></a><span><code class="code">bn=32</code><a class="copiable-link" href="#index-bn-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>SGR substring for byte offsets prefixing any content line. The default is a green text foreground over the terminal’s default background. </p> </dd> -<dt><code class="code">se=36</code></dt> -<dd><a class="index-entry-id" id="index-fn-GREP_005fCOLORS-capability-1"></a> -<p>SGR substring for separators that are inserted +<dt><a id="index-fn-GREP_005fCOLORS-capability-1"></a><span><code class="code">se=36</code><a class="copiable-link" href="#index-fn-GREP_005fCOLORS-capability-1"> ¶</a></span></dt> +<dd><p>SGR substring for separators that are inserted between selected line fields (‘<samp class="samp">:</samp>’), between context line fields (‘<samp class="samp">-</samp>’), and between groups of adjacent lines @@ -1140,9 +1099,8 @@ The default is a cyan text foreground over the terminal’s default background. </p> </dd> -<dt><code class="code">ne</code></dt> -<dd><a class="index-entry-id" id="index-ne-GREP_005fCOLORS-capability"></a> -<p>Boolean value that prevents clearing to the end of line +<dt><a id="index-ne-GREP_005fCOLORS-capability"></a><span><code class="code">ne</code><a class="copiable-link" href="#index-ne-GREP_005fCOLORS-capability"> ¶</a></span></dt> +<dd><p>Boolean value that prevents clearing to the end of line using Erase in Line (EL) to Right (‘<samp class="samp">\33[K</samp>’) each time a colorized item ends. This is needed on terminals on which EL is not supported. @@ -1155,60 +1113,56 @@ </p></dd> </dl> -<p>Note that boolean capabilities have no ‘<samp class="samp">=</samp>’... part. +<p>Note that boolean capabilities have no ‘<samp class="samp">=</samp>’… part. They are omitted (i.e., false) by default and become true when specified. </p> </dd> -<dt><code class="env">LC_ALL</code></dt> -<dt><code class="env">LC_COLLATE</code></dt> -<dt><code class="env">LANG</code></dt> -<dd><a class="index-entry-id" id="index-LC_005fALL-environment-variable-1"></a> -<a class="index-entry-id" id="index-LC_005fCOLLATE-environment-variable"></a> +<dt><a class="index-entry-id" id="index-LC_005fCOLLATE-environment-variable"></a> <a class="index-entry-id" id="index-LANG-environment-variable-1"></a> <a class="index-entry-id" id="index-character-type"></a> <a class="index-entry-id" id="index-national-language-support"></a> <a class="index-entry-id" id="index-NLS"></a> -<p>These variables specify the locale for the <code class="env">LC_COLLATE</code> category, +<a id="index-LC_005fALL-environment-variable-1"></a><span><code class="env">LC_ALL</code><a class="copiable-link" href="#index-LC_005fALL-environment-variable-1"> ¶</a></span></dt> +<dt><code class="env">LC_COLLATE</code></dt> +<dt><code class="env">LANG</code></dt> +<dd><p>These variables specify the locale for the <code class="env">LC_COLLATE</code> category, which might affect how range expressions like ‘<samp class="samp">a-z</samp>’ are interpreted. </p> </dd> -<dt><code class="env">LC_ALL</code></dt> -<dt><code class="env">LC_CTYPE</code></dt> -<dt><code class="env">LANG</code></dt> -<dd><a class="index-entry-id" id="index-LC_005fALL-environment-variable-2"></a> -<a class="index-entry-id" id="index-LC_005fCTYPE-environment-variable"></a> +<dt><a class="index-entry-id" id="index-LC_005fCTYPE-environment-variable"></a> <a class="index-entry-id" id="index-LANG-environment-variable-2"></a> <a class="index-entry-id" id="index-encoding-error"></a> <a class="index-entry-id" id="index-null-character"></a> -<p>These variables specify the locale for the <code class="env">LC_CTYPE</code> category, +<a id="index-LC_005fALL-environment-variable-2"></a><span><code class="env">LC_ALL</code><a class="copiable-link" href="#index-LC_005fALL-environment-variable-2"> ¶</a></span></dt> +<dt><code class="env">LC_CTYPE</code></dt> +<dt><code class="env">LANG</code></dt> +<dd><p>These variables specify the locale for the <code class="env">LC_CTYPE</code> category, which determines the type of characters, e.g., which characters are whitespace. This category also determines the character encoding. See <a class="xref" href="#Character-Encoding">Character Encoding</a>. </p> </dd> -<dt><code class="env">LANGUAGE</code></dt> -<dt><code class="env">LC_ALL</code></dt> -<dt><code class="env">LC_MESSAGES</code></dt> -<dt><code class="env">LANG</code></dt> -<dd><a class="index-entry-id" id="index-LANGUAGE-environment-variable-1"></a> -<a class="index-entry-id" id="index-LC_005fALL-environment-variable-3"></a> +<dt><a class="index-entry-id" id="index-LC_005fALL-environment-variable-3"></a> <a class="index-entry-id" id="index-LC_005fMESSAGES-environment-variable-1"></a> <a class="index-entry-id" id="index-LANG-environment-variable-3"></a> <a class="index-entry-id" id="index-language-of-messages"></a> <a class="index-entry-id" id="index-message-language"></a> <a class="index-entry-id" id="index-national-language-support-1"></a> <a class="index-entry-id" id="index-translation-of-message-language"></a> -<p>These variables specify the locale for the <code class="env">LC_MESSAGES</code> category, +<a id="index-LANGUAGE-environment-variable-1"></a><span><code class="env">LANGUAGE</code><a class="copiable-link" href="#index-LANGUAGE-environment-variable-1"> ¶</a></span></dt> +<dt><code class="env">LC_ALL</code></dt> +<dt><code class="env">LC_MESSAGES</code></dt> +<dt><code class="env">LANG</code></dt> +<dd><p>These variables specify the locale for the <code class="env">LC_MESSAGES</code> category, which determines the language that <code class="command">grep</code> uses for messages. The default ‘<samp class="samp">C</samp>’ locale uses American English messages. </p> </dd> -<dt><code class="env">POSIXLY_CORRECT</code></dt> -<dd><a class="index-entry-id" id="index-POSIXLY_005fCORRECT-environment-variable"></a> -<p>If set, <code class="command">grep</code> behaves as POSIX requires; otherwise, +<dt><a id="index-POSIXLY_005fCORRECT-environment-variable"></a><span><code class="env">POSIXLY_CORRECT</code><a class="copiable-link" href="#index-POSIXLY_005fCORRECT-environment-variable"> ¶</a></span></dt> +<dd><p>If set, <code class="command">grep</code> behaves as POSIX requires; otherwise, <code class="command">grep</code> behaves more like other GNU programs. POSIX requires that options that @@ -1218,9 +1172,8 @@ and are treated as options. </p> </dd> -<dt><code class="env">TERM</code></dt> -<dd><a class="index-entry-id" id="index-TERM-environment-variable"></a> -<p>This variable specifies the output terminal type, which can affect +<dt><a id="index-TERM-environment-variable"></a><span><code class="env">TERM</code><a class="copiable-link" href="#index-TERM-environment-variable"> ¶</a></span></dt> +<dd><p>This variable specifies the output terminal type, which can affect what the <samp class="option">--color</samp> option does. See <a class="xref" href="#General-Output-Control">General Output Control</a>. </p> </dd> @@ -1281,54 +1234,77 @@ controlled by the following options. </p> <dl class="table"> -<dt><samp class="option">-G</samp></dt> -<dt><samp class="option">--basic-regexp</samp></dt> -<dd><a class="index-entry-id" id="index-_002dG"></a> -<a class="index-entry-id" id="index-_002d_002dbasic_002dregexp"></a> +<dt><a class="index-entry-id" id="index-_002d_002dbasic_002dregexp"></a> <a class="index-entry-id" id="index-matching-basic-regular-expressions"></a> -<p>Interpret patterns as basic regular expressions (BREs). +<a id="index-_002dG"></a><span><samp class="option">-G</samp><a class="copiable-link" href="#index-_002dG"> ¶</a></span></dt> +<dt><samp class="option">--basic-regexp</samp></dt> +<dd><p>Interpret patterns as basic regular expressions (BREs). This is the default. </p> </dd> -<dt><samp class="option">-E</samp></dt> -<dt><samp class="option">--extended-regexp</samp></dt> -<dd><a class="index-entry-id" id="index-_002dE"></a> -<a class="index-entry-id" id="index-_002d_002dextended_002dregexp"></a> +<dt><a class="index-entry-id" id="index-_002d_002dextended_002dregexp"></a> <a class="index-entry-id" id="index-matching-extended-regular-expressions"></a> -<p>Interpret patterns as extended regular expressions (EREs). +<a id="index-_002dE"></a><span><samp class="option">-E</samp><a class="copiable-link" href="#index-_002dE"> ¶</a></span></dt> +<dt><samp class="option">--extended-regexp</samp></dt> +<dd><p>Interpret patterns as extended regular expressions (EREs). (<samp class="option">-E</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">-F</samp></dt> -<dt><samp class="option">--fixed-strings</samp></dt> -<dd><a class="index-entry-id" id="index-_002dF"></a> -<a class="index-entry-id" id="index-_002d_002dfixed_002dstrings"></a> +<dt><a class="index-entry-id" id="index-_002d_002dfixed_002dstrings"></a> <a class="index-entry-id" id="index-matching-fixed-strings"></a> -<p>Interpret patterns as fixed strings, not regular expressions. +<a id="index-_002dF"></a><span><samp class="option">-F</samp><a class="copiable-link" href="#index-_002dF"> ¶</a></span></dt> +<dt><samp class="option">--fixed-strings</samp></dt> +<dd><p>Interpret patterns as fixed strings, not regular expressions. (<samp class="option">-F</samp> is specified by POSIX.) </p> </dd> -<dt><samp class="option">-P</samp></dt> -<dt><samp class="option">--perl-regexp</samp></dt> -<dd><a class="index-entry-id" id="index-_002dP"></a> -<a class="index-entry-id" id="index-_002d_002dperl_002dregexp"></a> +<dt><a class="index-entry-id" id="index-_002d_002dperl_002dregexp"></a> <a class="index-entry-id" id="index-matching-Perl_002dcompatible-regular-expressions"></a> -<p>Interpret patterns as Perl-compatible regular expressions (PCREs). -PCRE support is here to stay, but consider this option experimental when -combined with the <samp class="option">-z</samp> (<samp class="option">--null-data</samp>) option, and note that -‘<samp class="samp">grep -P</samp>’ may warn of unimplemented features. -See <a class="xref" href="#Other-Options">Other Options</a>. +<a id="index-_002dP"></a><span><samp class="option">-P</samp><a class="copiable-link" href="#index-_002dP"> ¶</a></span></dt> +<dt><samp class="option">--perl-regexp</samp></dt> +<dd><p>Interpret patterns as Perl-compatible regular expressions (PCREs). </p> <p>For documentation, refer to <a class="url" href="https://www.pcre.org/";>https://www.pcre.org/</a>, with these caveats: </p><ul class="itemize mark-bullet"> -<li>‘<samp class="samp">\d</samp>’ matches only the ten ASCII digits -(and ‘<samp class="samp">\D</samp>’ matches the complement), regardless of locale. -Use ‘<samp class="samp">\p{Nd}</samp>’ to also match non-ASCII digits. -(The behavior of ‘<samp class="samp">\d</samp>’ and ‘<samp class="samp">\D</samp>’ is unspecified after -in-regexp directives like ‘<samp class="samp">(?aD)</samp>’.) +<li>In a UTF-8 locale, Perl treats data as UTF-8 only under certain +conditions, e.g., if <code class="command">perl</code> is invoked with the <samp class="option">-C</samp> +option or the <code class="env">PERL_UNICODE</code> environment variable set appropriately. +Similarly, <code class="command">pcre2grep</code> treats data as UTF-8 only if +invoked with <samp class="option">-u</samp> or <samp class="option">-U</samp>. +In contrast, in a UTF-8 locale <code class="command">grep</code> and <code class="command">git grep</code> +always treat data as UTF-8. + +</li><li>In Perl and <code class="command">git grep -P</code>, ‘<samp class="samp">\d</samp>’ matches all Unicode digits, +even if they are not ASCII. +For example, ‘<samp class="samp">\d</samp>’ matches +“Ù£” +(U+0663 ARABIC-INDIC DIGIT THREE). +In contrast, in ‘<samp class="samp">grep -P</samp>’, ‘<samp class="samp">\d</samp>’ matches only +the ten ASCII digits, regardless of locale. +In <code class="command">pcre2grep</code>, ‘<samp class="samp">\d</samp>’ ordinarily behaves like Perl and +<code class="command">git grep -P</code>, but when given the <samp class="option">--posix-digit</samp> option +it behaves like ‘<samp class="samp">grep -P</samp>’. +(On all platforms, ‘<samp class="samp">\D</samp>’ matches the complement of ‘<samp class="samp">\d</samp>’.) + +</li><li>The pattern ‘<samp class="samp">[[:digit:]]</samp>’ matches all Unicode digits +in Perl, ‘<samp class="samp">grep -P</samp>’, <code class="command">git grep -P</code>, and <code class="command">pcre2grep</code>, +so you can use it +to get the effect of Perl’s ‘<samp class="samp">\d</samp>’ on all these platforms. +In other words, in Perl and <code class="command">git grep -P</code>, +‘<samp class="samp">\d</samp>’ is equivalent to ‘<samp class="samp">[[:digit:]]</samp>’, +whereas in ‘<samp class="samp">grep -P</samp>’, ‘<samp class="samp">\d</samp>’ is equivalent to ‘<samp class="samp">[0-9]</samp>’, +and <code class="command">pcre2grep</code> ordinarily follows Perl but +when given <samp class="option">--posix-digit</samp> it follows ‘<samp class="samp">grep -P</samp>’. + +<p>(On all these platforms, ‘<samp class="samp">[[:digit:]]</samp>’ is equivalent to ‘<samp class="samp">\p{Nd}</samp>’ +and to ‘<samp class="samp">\p{General_Category: Decimal_Number}</samp>’.) +</p> +</li><li>If <code class="command">grep</code> is built with PCRE2 version 10.43 (2024) or later, +‘<samp class="samp">(?aD)</samp>’ causes ‘<samp class="samp">\d</samp>’ to behave like ‘<samp class="samp">[0-9]</samp>’ and +‘<samp class="samp">(?-aD)</samp>’ causes it to behave like ‘<samp class="samp">[[:digit:]]</samp>’. </li><li>Although PCRE tracks the syntax and semantics of Perl’s regular -expressions, the match is not always exact. For example, Perl +expressions, the match is not always exact. Perl evolves and a Perl installation may predate or postdate the PCRE2 installation on the same host, or their Unicode versions may differ, or Perl and PCRE2 may disagree about an obscure construct. @@ -1419,54 +1395,47 @@ are called <em class="dfn">interval expressions</em>. </p> <dl class="table"> -<dt>‘<samp class="samp">?</samp>’</dt> -<dd><a class="index-entry-id" id="index-_003f"></a> -<a class="index-entry-id" id="index-question-mark"></a> +<dt><a class="index-entry-id" id="index-question-mark"></a> <a class="index-entry-id" id="index-match-expression-at-most-once"></a> -<p>The preceding item is optional and is matched at most once. +<a id="index-_003f"></a><span>‘<samp class="samp">?</samp>’<a class="copiable-link" href="#index-_003f"> ¶</a></span></dt> +<dd><p>The preceding item is optional and is matched at most once. </p> </dd> -<dt>‘<samp class="samp">*</samp>’</dt> -<dd><a class="index-entry-id" id="index-_002a"></a> -<a class="index-entry-id" id="index-asterisk"></a> +<dt><a class="index-entry-id" id="index-asterisk"></a> <a class="index-entry-id" id="index-match-expression-zero-or-more-times"></a> -<p>The preceding item is matched zero or more times. +<a id="index-_002a"></a><span>‘<samp class="samp">*</samp>’<a class="copiable-link" href="#index-_002a"> ¶</a></span></dt> +<dd><p>The preceding item is matched zero or more times. </p> </dd> -<dt>‘<samp class="samp">+</samp>’</dt> -<dd><a class="index-entry-id" id="index-_002b"></a> -<a class="index-entry-id" id="index-plus-sign"></a> +<dt><a class="index-entry-id" id="index-plus-sign"></a> <a class="index-entry-id" id="index-match-expression-one-or-more-times"></a> -<p>The preceding item is matched one or more times. +<a id="index-_002b"></a><span>‘<samp class="samp">+</samp>’<a class="copiable-link" href="#index-_002b"> ¶</a></span></dt> +<dd><p>The preceding item is matched one or more times. </p> </dd> -<dt>‘<samp class="samp">{<var class="var">n</var>}</samp>’</dt> -<dd><a class="index-entry-id" id="index-_007bn_007d"></a> -<a class="index-entry-id" id="index-braces_002c-one-argument"></a> +<dt><a class="index-entry-id" id="index-braces_002c-one-argument"></a> <a class="index-entry-id" id="index-match-expression-n-times"></a> -<p>The preceding item is matched exactly <var class="var">n</var> times. +<a id="index-_007bn_007d"></a><span>‘<samp class="samp">{<var class="var">n</var>}</samp>’<a class="copiable-link" href="#index-_007bn_007d"> ¶</a></span></dt> +<dd><p>The preceding item is matched exactly <var class="var">n</var> times. </p> </dd> -<dt>‘<samp class="samp">{<var class="var">n</var>,}</samp>’</dt> -<dd><a class="index-entry-id" id="index-_007bn_002c_007d"></a> -<a class="index-entry-id" id="index-braces_002c-second-argument-omitted"></a> +<dt><a class="index-entry-id" id="index-braces_002c-second-argument-omitted"></a> <a class="index-entry-id" id="index-match-expression-n-or-more-times"></a> -<p>The preceding item is matched <var class="var">n</var> or more times. +<a id="index-_007bn_002c_007d"></a><span>‘<samp class="samp">{<var class="var">n</var>,}</samp>’<a class="copiable-link" href="#index-_007bn_002c_007d"> ¶</a></span></dt> +<dd><p>The preceding item is matched <var class="var">n</var> or more times. </p> </dd> -<dt>‘<samp class="samp">{,<var class="var">m</var>}</samp>’</dt> -<dd><a class="index-entry-id" id="index-_007b_002cm_007d"></a> -<a class="index-entry-id" id="index-braces_002c-first-argument-omitted"></a> +<dt><a class="index-entry-id" id="index-braces_002c-first-argument-omitted"></a> <a class="index-entry-id" id="index-match-expression-at-most-m-times"></a> -<p>The preceding item is matched at most <var class="var">m</var> times. +<a id="index-_007b_002cm_007d"></a><span>‘<samp class="samp">{,<var class="var">m</var>}</samp>’<a class="copiable-link" href="#index-_007b_002cm_007d"> ¶</a></span></dt> +<dd><p>The preceding item is matched at most <var class="var">m</var> times. This is a GNU extension. </p> </dd> -<dt>‘<samp class="samp">{<var class="var">n</var>,<var class="var">m</var>}</samp>’</dt> -<dd><a class="index-entry-id" id="index-_007bn_002cm_007d"></a> -<a class="index-entry-id" id="index-braces_002c-two-arguments"></a> +<dt><a class="index-entry-id" id="index-braces_002c-two-arguments"></a> <a class="index-entry-id" id="index-match-expression-from-n-to-m-times"></a> -<p>The preceding item is matched at least <var class="var">n</var> times, but not more than +<a id="index-_007bn_002cm_007d"></a><span>‘<samp class="samp">{<var class="var">n</var>,<var class="var">m</var>}</samp>’<a class="copiable-link" href="#index-_007bn_002cm_007d"> ¶</a></span></dt> +<dd><p>The preceding item is matched at least <var class="var">n</var> times, but not more than <var class="var">m</var> times. </p> </dd> @@ -1518,13 +1487,13 @@ <a class="index-entry-id" id="index-range-expression"></a> <p>Within a bracket expression, a <em class="dfn">range expression</em> consists of two characters separated by a hyphen. -It matches any single character that -sorts between the two characters, inclusive. -In the default C locale, the sorting sequence is the native character -order; for example, ‘<samp class="samp">[a-d]</samp>’ is equivalent to ‘<samp class="samp">[abcd]</samp>’. -In other locales, the sorting sequence is not specified, and -‘<samp class="samp">[a-d]</samp>’ might be equivalent to ‘<samp class="samp">[abcd]</samp>’ or to -‘<samp class="samp">[aBbCcDd]</samp>’, or it might fail to match any character, or the set of +In the default C locale, it matches any single character that appears +between the two characters in ASCII order, inclusive. +For example, ‘<samp class="samp">[a-d]</samp>’ is equivalent to ‘<samp class="samp">[abcd]</samp>’. +In other locales the behavior is unspecified: +‘<samp class="samp">[a-d]</samp>’ might be equivalent to +‘<samp class="samp">[abcd]</samp>’ or ‘<samp class="samp">[aBbCcDd]</samp>’ or some other bracket expression, +or it might fail to match any character, or the set of characters that it matches might be erratic, or it might be invalid. To obtain the traditional interpretation of bracket expressions, you can use the ‘<samp class="samp">C</samp>’ locale by setting the @@ -1539,98 +1508,86 @@ <a class="index-entry-id" id="index-classes-of-characters"></a> <a class="index-entry-id" id="index-character-classes"></a> <dl class="table"> -<dt>‘<samp class="samp">[:alnum:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-alnum-character-class"></a> -<a class="index-entry-id" id="index-alphanumeric-characters"></a> -<p>Alphanumeric characters: +<dt><a class="index-entry-id" id="index-alphanumeric-characters"></a> +<a id="index-alnum-character-class"></a><span>‘<samp class="samp">[:alnum:]</samp>’<a class="copiable-link" href="#index-alnum-character-class"> ¶</a></span></dt> +<dd><p>Alphanumeric characters: ‘<samp class="samp">[:alpha:]</samp>’ and ‘<samp class="samp">[:digit:]</samp>’; in the ‘<samp class="samp">C</samp>’ locale and ASCII character encoding, this is the same as ‘<samp class="samp">[0-9A-Za-z]</samp>’. </p> </dd> -<dt>‘<samp class="samp">[:alpha:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-alpha-character-class"></a> -<a class="index-entry-id" id="index-alphabetic-characters"></a> -<p>Alphabetic characters: +<dt><a class="index-entry-id" id="index-alphabetic-characters"></a> +<a id="index-alpha-character-class"></a><span>‘<samp class="samp">[:alpha:]</samp>’<a class="copiable-link" href="#index-alpha-character-class"> ¶</a></span></dt> +<dd><p>Alphabetic characters: ‘<samp class="samp">[:lower:]</samp>’ and ‘<samp class="samp">[:upper:]</samp>’; in the ‘<samp class="samp">C</samp>’ locale and ASCII character encoding, this is the same as ‘<samp class="samp">[A-Za-z]</samp>’. </p> </dd> -<dt>‘<samp class="samp">[:blank:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-blank-character-class"></a> -<a class="index-entry-id" id="index-blank-characters"></a> -<p>Blank characters: +<dt><a class="index-entry-id" id="index-blank-characters"></a> +<a id="index-blank-character-class"></a><span>‘<samp class="samp">[:blank:]</samp>’<a class="copiable-link" href="#index-blank-character-class"> ¶</a></span></dt> +<dd><p>Blank characters: space and tab. </p> </dd> -<dt>‘<samp class="samp">[:cntrl:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-cntrl-character-class"></a> -<a class="index-entry-id" id="index-control-characters"></a> -<p>Control characters. +<dt><a class="index-entry-id" id="index-control-characters"></a> +<a id="index-cntrl-character-class"></a><span>‘<samp class="samp">[:cntrl:]</samp>’<a class="copiable-link" href="#index-cntrl-character-class"> ¶</a></span></dt> +<dd><p>Control characters. In ASCII, these characters have octal codes 000 through 037, and 177 (DEL). In other character sets, these are the equivalent characters, if any. </p> </dd> -<dt>‘<samp class="samp">[:digit:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-digit-character-class"></a> -<a class="index-entry-id" id="index-digit-characters"></a> +<dt><a class="index-entry-id" id="index-digit-characters"></a> <a class="index-entry-id" id="index-numeric-characters"></a> -<p>Digits: <code class="code">0 1 2 3 4 5 6 7 8 9</code>. +<a id="index-digit-character-class"></a><span>‘<samp class="samp">[:digit:]</samp>’<a class="copiable-link" href="#index-digit-character-class"> ¶</a></span></dt> +<dd><p>Digits: <code class="code">0 1 2 3 4 5 6 7 8 9</code>. </p> </dd> -<dt>‘<samp class="samp">[:graph:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-graph-character-class"></a> -<a class="index-entry-id" id="index-graphic-characters"></a> -<p>Graphical characters: +<dt><a class="index-entry-id" id="index-graphic-characters"></a> +<a id="index-graph-character-class"></a><span>‘<samp class="samp">[:graph:]</samp>’<a class="copiable-link" href="#index-graph-character-class"> ¶</a></span></dt> +<dd><p>Graphical characters: ‘<samp class="samp">[:alnum:]</samp>’ and ‘<samp class="samp">[:punct:]</samp>’. </p> </dd> -<dt>‘<samp class="samp">[:lower:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-lower-character-class"></a> -<a class="index-entry-id" id="index-lower_002dcase-letters"></a> -<p>Lower-case letters; in the ‘<samp class="samp">C</samp>’ locale and ASCII character +<dt><a class="index-entry-id" id="index-lower_002dcase-letters"></a> +<a id="index-lower-character-class"></a><span>‘<samp class="samp">[:lower:]</samp>’<a class="copiable-link" href="#index-lower-character-class"> ¶</a></span></dt> +<dd><p>Lower-case letters; in the ‘<samp class="samp">C</samp>’ locale and ASCII character encoding, this is <code class="code">a b c d e f g h i j k l m n o p q r s t u v w x y z</code>. </p> </dd> -<dt>‘<samp class="samp">[:print:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-print-character-class"></a> -<a class="index-entry-id" id="index-printable-characters"></a> -<p>Printable characters: +<dt><a class="index-entry-id" id="index-printable-characters"></a> +<a id="index-print-character-class"></a><span>‘<samp class="samp">[:print:]</samp>’<a class="copiable-link" href="#index-print-character-class"> ¶</a></span></dt> +<dd><p>Printable characters: ‘<samp class="samp">[:alnum:]</samp>’, ‘<samp class="samp">[:punct:]</samp>’, and space. </p> </dd> -<dt>‘<samp class="samp">[:punct:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-punct-character-class"></a> -<a class="index-entry-id" id="index-punctuation-characters"></a> -<p>Punctuation characters; in the ‘<samp class="samp">C</samp>’ locale and ASCII character +<dt><a class="index-entry-id" id="index-punctuation-characters"></a> +<a id="index-punct-character-class"></a><span>‘<samp class="samp">[:punct:]</samp>’<a class="copiable-link" href="#index-punct-character-class"> ¶</a></span></dt> +<dd><p>Punctuation characters; in the ‘<samp class="samp">C</samp>’ locale and ASCII character encoding, this is <code class="code">! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~</code>. </p> </dd> -<dt>‘<samp class="samp">[:space:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-space-character-class"></a> -<a class="index-entry-id" id="index-space-characters"></a> +<dt><a class="index-entry-id" id="index-space-characters"></a> <a class="index-entry-id" id="index-whitespace-characters"></a> -<p>Space characters: in the ‘<samp class="samp">C</samp>’ locale, this is +<a id="index-space-character-class"></a><span>‘<samp class="samp">[:space:]</samp>’<a class="copiable-link" href="#index-space-character-class"> ¶</a></span></dt> +<dd><p>Space characters: in the ‘<samp class="samp">C</samp>’ locale, this is tab, newline, vertical tab, form feed, carriage return, and space. See <a class="xref" href="#Usage">Usage</a>, for more discussion of matching newlines. </p> </dd> -<dt>‘<samp class="samp">[:upper:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-upper-character-class"></a> -<a class="index-entry-id" id="index-upper_002dcase-letters"></a> -<p>Upper-case letters: in the ‘<samp class="samp">C</samp>’ locale and ASCII character +<dt><a class="index-entry-id" id="index-upper_002dcase-letters"></a> +<a id="index-upper-character-class"></a><span>‘<samp class="samp">[:upper:]</samp>’<a class="copiable-link" href="#index-upper-character-class"> ¶</a></span></dt> +<dd><p>Upper-case letters: in the ‘<samp class="samp">C</samp>’ locale and ASCII character encoding, this is <code class="code">A B C D E F G H I J K L M N O P Q R S T U V W X Y Z</code>. </p> </dd> -<dt>‘<samp class="samp">[:xdigit:]</samp>’</dt> -<dd><a class="index-entry-id" id="index-xdigit-character-class"></a> -<a class="index-entry-id" id="index-xdigit-class"></a> +<dt><a class="index-entry-id" id="index-xdigit-class"></a> <a class="index-entry-id" id="index-hexadecimal-digits"></a> -<p>Hexadecimal digits: +<a id="index-xdigit-character-class"></a><span>‘<samp class="samp">[:xdigit:]</samp>’<a class="copiable-link" href="#index-xdigit-character-class"> ¶</a></span></dt> +<dd><p>Hexadecimal digits: <code class="code">0 1 2 3 4 5 6 7 8 9 A B C D E F a b c d e f</code>. </p> </dd> @@ -1960,8 +1917,9 @@ locales ‘<samp class="samp">[a-z]</samp>’ might match some characters that are not lowercase letters, or might not match some lowercase letters, or might be invalid. With GNU <code class="command">grep</code> it is not documented whether -these range expressions use native code points, or use the collating -sequence specified by the <code class="env">LC_COLLATE</code> category, or have some +these range expressions use native code points, or use the collation +sequence specified by the <code class="env">LC_COLLATE</code> category, or use the +collation ordering used by <code class="command">sort</code> and <code class="code">strcoll</code>, or have some other interpretation. Outside the POSIX locale, it is portable to use ‘<samp class="samp">[[:lower:]]</samp>’ to match a lower-case letter, or ‘<samp class="samp">[abcdefghijklmnopqrstuvwxyz]</samp>’ to match an ASCII lower-case @@ -2229,7 +2187,7 @@ <code class="command">grep</code> does not have any limit on the length of a line except the available memory. </p> -</li><li> Why does <code class="command">grep</code> report “Binary file matches”? +</li><li> Why does <code class="command">grep</code> report “binary file matches”? <p>If <code class="command">grep</code> listed all matching “lines” from a binary file, it would probably generate output that is not useful, and it might even @@ -2584,8 +2542,8 @@ </div> <div class="display"> -<pre class="display-preformatted">Copyright © 2000–2002, 2007–2008, 2023 Free Software Foundation, -Inc. +<pre class="display-preformatted">Copyright © 2000–2002, 2007–2008, 2023–2025 Free Software +Foundation, Inc. <a class="uref" href="https://fsf.org/";>https://fsf.org/</a> Everyone is permitted to copy and distribute verbatim copies
