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- <div class="titlepage"><div><div><h3 class="title">
- <a name="boost_regex.syntax.basic_syntax"></a><a class="link" href="basic_syntax.html" title="POSIX Basic Regular Expression Syntax">POSIX Basic Regular
- Expression Syntax</a>
- </h3></div></div></div>
- <h4>
- <a name="boost_regex.syntax.basic_syntax.h0"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.synopsis"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.synopsis">Synopsis</a>
- </h4>
- <p>
- The POSIX-Basic regular expression syntax is used by the Unix utility <code class="computeroutput"><span class="identifier">sed</span></code>, and variations are used by <code class="computeroutput"><span class="identifier">grep</span></code> and <code class="computeroutput"><span class="identifier">emacs</span></code>.
- You can construct POSIX basic regular expressions in Boost.Regex by passing
- the flag <code class="computeroutput"><span class="identifier">basic</span></code> to the regex
- constructor (see <a class="link" href="../ref/syntax_option_type.html" title="syntax_option_type"><code class="computeroutput"><span class="identifier">syntax_option_type</span></code></a>), for example:
- </p>
- <pre class="programlisting"><span class="comment">// e1 is a case sensitive POSIX-Basic expression:</span>
- <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">e1</span><span class="special">(</span><span class="identifier">my_expression</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span><span class="special">::</span><span class="identifier">basic</span><span class="special">);</span>
- <span class="comment">// e2 a case insensitive POSIX-Basic expression:</span>
- <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">e2</span><span class="special">(</span><span class="identifier">my_expression</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span><span class="special">::</span><span class="identifier">basic</span><span class="special">|</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span><span class="special">::</span><span class="identifier">icase</span><span class="special">);</span>
- </pre>
- <a name="boost_regex.posix_basic"></a><h4>
- <a name="boost_regex.syntax.basic_syntax.h1"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.posix_basic_syntax"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.posix_basic_syntax">POSIX
- Basic Syntax</a>
- </h4>
- <p>
- In POSIX-Basic regular expressions, all characters are match themselves except
- for the following special characters:
- </p>
- <pre class="programlisting">.[\*^$</pre>
- <h5>
- <a name="boost_regex.syntax.basic_syntax.h2"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.wildcard"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.wildcard">Wildcard:</a>
- </h5>
- <p>
- The single character '.' when used outside of a character set will match
- any single character except:
- </p>
- <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
- <li class="listitem">
- The NULL character when the flag <code class="computeroutput"><span class="identifier">match_no_dot_null</span></code>
- is passed to the matching algorithms.
- </li>
- <li class="listitem">
- The newline character when the flag <code class="computeroutput"><span class="identifier">match_not_dot_newline</span></code>
- is passed to the matching algorithms.
- </li>
- </ul></div>
- <h5>
- <a name="boost_regex.syntax.basic_syntax.h3"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.anchors"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.anchors">Anchors:</a>
- </h5>
- <p>
- A '^' character shall match the start of a line when used as the first character
- of an expression, or the first character of a sub-expression.
- </p>
- <p>
- A '$' character shall match the end of a line when used as the last character
- of an expression, or the last character of a sub-expression.
- </p>
- <h5>
- <a name="boost_regex.syntax.basic_syntax.h4"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.marked_sub_expressions"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.marked_sub_expressions">Marked sub-expressions:</a>
- </h5>
- <p>
- A section beginning <code class="computeroutput"><span class="special">\(</span></code> and ending
- <code class="computeroutput"><span class="special">\)</span></code> acts as a marked sub-expression.
- Whatever matched the sub-expression is split out in a separate field by the
- matching algorithms. Marked sub-expressions can also repeated, or referred-to
- by a back-reference.
- </p>
- <h5>
- <a name="boost_regex.syntax.basic_syntax.h5"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.repeats"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.repeats">Repeats:</a>
- </h5>
- <p>
- Any atom (a single character, a marked sub-expression, or a character class)
- can be repeated with the * operator.
- </p>
- <p>
- For example <code class="computeroutput"><span class="identifier">a</span><span class="special">*</span></code>
- will match any number of letter a's repeated zero or more times (an atom
- repeated zero times matches an empty string), so the expression <code class="computeroutput"><span class="identifier">a</span><span class="special">*</span><span class="identifier">b</span></code>
- will match any of the following:
- </p>
- <pre class="programlisting">b
- ab
- aaaaaaaab
- </pre>
- <p>
- An atom can also be repeated with a bounded repeat:
- </p>
- <p>
- <code class="computeroutput"><span class="identifier">a</span><span class="special">\{</span><span class="identifier">n</span><span class="special">\}</span></code> Matches
- 'a' repeated exactly n times.
- </p>
- <p>
- <code class="computeroutput"><span class="identifier">a</span><span class="special">\{</span><span class="identifier">n</span><span class="special">,\}</span></code> Matches
- 'a' repeated n or more times.
- </p>
- <p>
- <code class="computeroutput"><span class="identifier">a</span><span class="special">\{</span><span class="identifier">n</span><span class="special">,</span> <span class="identifier">m</span><span class="special">\}</span></code> Matches 'a' repeated between n and m times
- inclusive.
- </p>
- <p>
- For example:
- </p>
- <pre class="programlisting">^a{2,3}$</pre>
- <p>
- Will match either of:
- </p>
- <pre class="programlisting">aa
- aaa
- </pre>
- <p>
- But neither of:
- </p>
- <pre class="programlisting">a
- aaaa
- </pre>
- <p>
- It is an error to use a repeat operator, if the preceding construct can not
- be repeated, for example:
- </p>
- <pre class="programlisting">a(*)</pre>
- <p>
- Will raise an error, as there is nothing for the * operator to be applied
- to.
- </p>
- <h5>
- <a name="boost_regex.syntax.basic_syntax.h6"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.back_references"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.back_references">Back
- references:</a>
- </h5>
- <p>
- An escape character followed by a digit <span class="emphasis"><em>n</em></span>, where <span class="emphasis"><em>n</em></span>
- is in the range 1-9, matches the same string that was matched by sub-expression
- <span class="emphasis"><em>n</em></span>. For example the expression:
- </p>
- <pre class="programlisting">^\(a*\)[^a]*\1$</pre>
- <p>
- Will match the string:
- </p>
- <pre class="programlisting">aaabbaaa</pre>
- <p>
- But not the string:
- </p>
- <pre class="programlisting">aaabba</pre>
- <h5>
- <a name="boost_regex.syntax.basic_syntax.h7"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.character_sets"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.character_sets">Character
- sets:</a>
- </h5>
- <p>
- A character set is a bracket-expression starting with [ and ending with ],
- it defines a set of characters, and matches any single character that is
- a member of that set.
- </p>
- <p>
- A bracket expression may contain any combination of the following:
- </p>
- <h6>
- <a name="boost_regex.syntax.basic_syntax.h8"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.single_characters"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.single_characters">Single
- characters:</a>
- </h6>
- <p>
- For example <code class="computeroutput"><span class="special">[</span><span class="identifier">abc</span><span class="special">]</span></code>, will match any of the characters 'a', 'b',
- or 'c'.
- </p>
- <h6>
- <a name="boost_regex.syntax.basic_syntax.h9"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.character_ranges"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.character_ranges">Character
- ranges:</a>
- </h6>
- <p>
- For example <code class="computeroutput"><span class="special">[</span><span class="identifier">a</span><span class="special">-</span><span class="identifier">c</span><span class="special">]</span></code>
- will match any single character in the range 'a' to 'c'. By default, for
- POSIX-Basic regular expressions, a character <span class="emphasis"><em>x</em></span> is within
- the range <span class="emphasis"><em>y</em></span> to <span class="emphasis"><em>z</em></span>, if it collates
- within that range; this results in locale specific behavior. This behavior
- can be turned off by unsetting the <code class="computeroutput"><span class="identifier">collate</span></code>
- option flag when constructing the regular expression - in which case whether
- a character appears within a range is determined by comparing the code points
- of the characters only.
- </p>
- <h6>
- <a name="boost_regex.syntax.basic_syntax.h10"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.negation"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.negation">Negation:</a>
- </h6>
- <p>
- If the bracket-expression begins with the ^ character, then it matches the
- complement of the characters it contains, for example <code class="computeroutput"><span class="special">[^</span><span class="identifier">a</span><span class="special">-</span><span class="identifier">c</span><span class="special">]</span></code> matches any character that is not in the
- range a-c.
- </p>
- <h6>
- <a name="boost_regex.syntax.basic_syntax.h11"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.character_classes"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.character_classes">Character
- classes:</a>
- </h6>
- <p>
- An expression of the form <code class="computeroutput"><span class="special">[[:</span><span class="identifier">name</span><span class="special">:]]</span></code>
- matches the named character class "name", for example <code class="computeroutput"><span class="special">[[:</span><span class="identifier">lower</span><span class="special">:]]</span></code> matches any lower case character. See
- <a class="link" href="character_classes.html" title="Character Class Names">character class names</a>.
- </p>
- <h6>
- <a name="boost_regex.syntax.basic_syntax.h12"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.collating_elements"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.collating_elements">Collating
- Elements:</a>
- </h6>
- <p>
- An expression of the form <code class="computeroutput"><span class="special">[[.</span><span class="identifier">col</span><span class="special">.]</span></code> matches
- the collating element <span class="emphasis"><em>col</em></span>. A collating element is any
- single character, or any sequence of characters that collates as a single
- unit. Collating elements may also be used as the end point of a range, for
- example: <code class="computeroutput"><span class="special">[[.</span><span class="identifier">ae</span><span class="special">.]-</span><span class="identifier">c</span><span class="special">]</span></code>
- matches the character sequence "ae", plus any single character
- in the range "ae"-c, assuming that "ae" is treated as
- a single collating element in the current locale.
- </p>
- <p>
- Collating elements may be used in place of escapes (which are not normally
- allowed inside character sets), for example <code class="computeroutput"><span class="special">[[.^.]</span><span class="identifier">abc</span><span class="special">]</span></code> would
- match either one of the characters 'abc^'.
- </p>
- <p>
- As an extension, a collating element may also be specified via its symbolic
- name, for example:
- </p>
- <pre class="programlisting">[[.NUL.]]</pre>
- <p>
- matches a 'NUL' character. See <a class="link" href="collating_names.html" title="Collating Names">collating
- element names</a>.
- </p>
- <h6>
- <a name="boost_regex.syntax.basic_syntax.h13"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.equivalence_classes"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.equivalence_classes">Equivalence
- classes:</a>
- </h6>
- <p>
- An expression of the form <code class="computeroutput"><span class="special">[[=</span><span class="identifier">col</span><span class="special">=]]</span></code>,
- matches any character or collating element whose primary sort key is the
- same as that for collating element <span class="emphasis"><em>col</em></span>, as with collating
- elements the name <span class="emphasis"><em>col</em></span> may be a <a class="link" href="collating_names.html" title="Collating Names">collating
- symbolic name</a>. A primary sort key is one that ignores case, accentation,
- or locale-specific tailorings; so for example <code class="computeroutput"><span class="special">[[=</span><span class="identifier">a</span><span class="special">=]]</span></code> matches
- any of the characters: a, À, Á, Â, Ã, Ä, Å, A, à, á, â, ã, ä and å. Unfortunately implementation
- of this is reliant on the platform's collation and localisation support;
- this feature can not be relied upon to work portably across all platforms,
- or even all locales on one platform.
- </p>
- <h6>
- <a name="boost_regex.syntax.basic_syntax.h14"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.combinations"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.combinations">Combinations:</a>
- </h6>
- <p>
- All of the above can be combined in one character set declaration, for example:
- <code class="computeroutput"><span class="special">[[:</span><span class="identifier">digit</span><span class="special">:]</span><span class="identifier">a</span><span class="special">-</span><span class="identifier">c</span><span class="special">[.</span><span class="identifier">NUL</span><span class="special">.]].</span></code>
- </p>
- <h5>
- <a name="boost_regex.syntax.basic_syntax.h15"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.escapes"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.escapes">Escapes</a>
- </h5>
- <p>
- With the exception of the escape sequences \{, \}, \(, and \), which are
- documented above, an escape followed by any character matches that character.
- This can be used to make the special characters
- </p>
- <pre class="programlisting">.[\*^$</pre>
- <p>
- "ordinary". Note that the escape character loses its special meaning
- inside a character set, so <code class="computeroutput"><span class="special">[\^]</span></code>
- will match either a literal '\' or a '^'.
- </p>
- <h4>
- <a name="boost_regex.syntax.basic_syntax.h16"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.what_gets_matched"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.what_gets_matched">What
- Gets Matched</a>
- </h4>
- <p>
- When there is more that one way to match a regular expression, the "best"
- possible match is obtained using the <a class="link" href="leftmost_longest_rule.html" title="The Leftmost Longest Rule">leftmost-longest
- rule</a>.
- </p>
- <h4>
- <a name="boost_regex.syntax.basic_syntax.h17"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.variations"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.variations">Variations</a>
- </h4>
- <a name="boost_regex.grep_syntax"></a><h5>
- <a name="boost_regex.syntax.basic_syntax.h18"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.grep"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.grep">Grep</a>
- </h5>
- <p>
- When an expression is compiled with the flag <code class="computeroutput"><span class="identifier">grep</span></code>
- set, then the expression is treated as a newline separated list of <a class="link" href="basic_syntax.html#boost_regex.posix_basic">POSIX-Basic expressions</a>, a match
- is found if any of the expressions in the list match, for example:
- </p>
- <pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span> <span class="identifier">e</span><span class="special">(</span><span class="string">"abc\ndef"</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">regex</span><span class="special">::</span><span class="identifier">grep</span><span class="special">);</span>
- </pre>
- <p>
- will match either of the <a class="link" href="basic_syntax.html#boost_regex.posix_basic">POSIX-Basic
- expressions</a> "abc" or "def".
- </p>
- <p>
- As its name suggests, this behavior is consistent with the Unix utility grep.
- </p>
- <h5>
- <a name="boost_regex.syntax.basic_syntax.h19"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.emacs"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.emacs">emacs</a>
- </h5>
- <p>
- In addition to the <a class="link" href="basic_syntax.html#boost_regex.posix_basic">POSIX-Basic features</a>
- the following characters are also special:
- </p>
- <div class="informaltable"><table class="table">
- <colgroup>
- <col>
- <col>
- </colgroup>
- <thead><tr>
- <th>
- <p>
- Character
- </p>
- </th>
- <th>
- <p>
- Description
- </p>
- </th>
- </tr></thead>
- <tbody>
- <tr>
- <td>
- <p>
- +
- </p>
- </td>
- <td>
- <p>
- repeats the preceding atom one or more times.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- ?
- </p>
- </td>
- <td>
- <p>
- repeats the preceding atom zero or one times.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
- ?
- </li></ul></div>
- </td>
- <td>
- <p>
- A non-greedy version of *.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- +?
- </p>
- </td>
- <td>
- <p>
- A non-greedy version of +.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- ??
- </p>
- </td>
- <td>
- <p>
- A non-greedy version of ?.
- </p>
- </td>
- </tr>
- </tbody>
- </table></div>
- <p>
- And the following escape sequences are also recognised:
- </p>
- <div class="informaltable"><table class="table">
- <colgroup>
- <col>
- <col>
- </colgroup>
- <thead><tr>
- <th>
- <p>
- Escape
- </p>
- </th>
- <th>
- <p>
- Description
- </p>
- </th>
- </tr></thead>
- <tbody>
- <tr>
- <td>
- <p>
- \|
- </p>
- </td>
- <td>
- <p>
- specifies an alternative.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \(?: ... )
- </p>
- </td>
- <td>
- <p>
- is a non-marking grouping construct - allows you to lexically group
- something without spitting out an extra sub-expression.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \w
- </p>
- </td>
- <td>
- <p>
- matches any word character.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \W
- </p>
- </td>
- <td>
- <p>
- matches any non-word character.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \sx
- </p>
- </td>
- <td>
- <p>
- matches any character in the syntax group x, the following emacs
- groupings are supported: 's', ' ', '_', 'w', '.', ')', '(', '"',
- '\'', '>' and '<'. Refer to the emacs docs for details.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \Sx
- </p>
- </td>
- <td>
- <p>
- matches any character not in the syntax grouping x.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \c and \C
- </p>
- </td>
- <td>
- <p>
- These are not supported.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \`
- </p>
- </td>
- <td>
- <p>
- matches zero characters only at the start of a buffer (or string
- being matched).
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \'
- </p>
- </td>
- <td>
- <p>
- matches zero characters only at the end of a buffer (or string
- being matched).
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \b
- </p>
- </td>
- <td>
- <p>
- matches zero characters at a word boundary.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \B
- </p>
- </td>
- <td>
- <p>
- matches zero characters, not at a word boundary.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \<
- </p>
- </td>
- <td>
- <p>
- matches zero characters only at the start of a word.
- </p>
- </td>
- </tr>
- <tr>
- <td>
- <p>
- \>
- </p>
- </td>
- <td>
- <p>
- matches zero characters only at the end of a word.
- </p>
- </td>
- </tr>
- </tbody>
- </table></div>
- <p>
- Finally, you should note that emacs style regular expressions are matched
- according to the <a class="link" href="perl_syntax.html#boost_regex.syntax.perl_syntax.what_gets_matched">Perl
- "depth first search" rules</a>. Emacs expressions are matched
- this way because they contain Perl-like extensions, that do not interact
- well with the <a class="link" href="leftmost_longest_rule.html" title="The Leftmost Longest Rule">POSIX-style
- leftmost-longest rule</a>.
- </p>
- <h4>
- <a name="boost_regex.syntax.basic_syntax.h20"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.options"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.options">Options</a>
- </h4>
- <p>
- There are a <a class="link" href="../ref/syntax_option_type/syntax_option_type_basic.html" title="Options for POSIX Basic Regular Expressions">variety
- of flags</a> that may be combined with the <code class="computeroutput"><span class="identifier">basic</span></code>
- and <code class="computeroutput"><span class="identifier">grep</span></code> options when constructing
- the regular expression, in particular note that the <a class="link" href="../ref/syntax_option_type/syntax_option_type_basic.html" title="Options for POSIX Basic Regular Expressions"><code class="computeroutput"><span class="identifier">newline_alt</span></code>, <code class="computeroutput"><span class="identifier">no_char_classes</span></code>,
- <code class="computeroutput"><span class="identifier">no</span><span class="special">-</span><span class="identifier">intervals</span></code>, <code class="computeroutput"><span class="identifier">bk_plus_qm</span></code>
- and <code class="computeroutput"><span class="identifier">bk_plus_vbar</span></code></a> options
- all alter the syntax, while the <a class="link" href="../ref/syntax_option_type/syntax_option_type_basic.html" title="Options for POSIX Basic Regular Expressions"><code class="computeroutput"><span class="identifier">collate</span></code> and <code class="computeroutput"><span class="identifier">icase</span></code>
- options</a> modify how the case and locale sensitivity are to be applied.
- </p>
- <h4>
- <a name="boost_regex.syntax.basic_syntax.h21"></a>
- <span class="phrase"><a name="boost_regex.syntax.basic_syntax.references"></a></span><a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.references">References</a>
- </h4>
- <p>
- <a href="http://www.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap09.html" target="_top">IEEE
- Std 1003.1-2001, Portable Operating System Interface (POSIX ), Base Definitions
- and Headers, Section 9, Regular Expressions (FWD.1).</a>
- </p>
- <p>
- <a href="http://www.opengroup.org/onlinepubs/000095399/utilities/grep.html" target="_top">IEEE
- Std 1003.1-2001, Portable Operating System Interface (POSIX ), Shells and
- Utilities, Section 4, Utilities, grep (FWD.1).</a>
- </p>
- <p>
- <a href="http://www.gnu.org/software/emacs/" target="_top">Emacs Version 21.3.</a>
- </p>
- </div>
- <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
- <td align="left"></td>
- <td align="right"><div class="copyright-footer">Copyright © 1998-2013 John Maddock<p>
- Distributed under the Boost Software License, Version 1.0. (See accompanying
- file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
- </p>
- </div></td>
- </tr></table>
- <hr>
- <div class="spirit-nav">
- <a accesskey="p" href="basic_extended.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../syntax.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="character_classes.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
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