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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> |
| <a name="boost_regex.syntax.basic_syntax.synopsis"></a><h4> |
| <a name="id920126"></a> |
| <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><p> |
| </p> |
| <a name="boost_regex.syntax.basic_syntax.posix_basic_syntax"></a><h4> |
| <a name="id920322"></a> |
| <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">.[\*^$</pre> |
| <a name="boost_regex.syntax.basic_syntax.wildcard_"></a><h5> |
| <a name="id920344"></a> |
| <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.wildcard_">Wildcard:</a> |
| </h5> |
| <p> |
| The single character '.' when used outside of a character set will match |
| any single character except: |
| </p> |
| <div class="itemizedlist"><ul type="disc"> |
| <li> |
| The NULL character when the flag <code class="computeroutput"><span class="identifier">match_no_dot_null</span></code> |
| is passed to the matching algorithms. |
| </li> |
| <li> |
| The newline character when the flag <code class="computeroutput"><span class="identifier">match_not_dot_newline</span></code> |
| is passed to the matching algorithms. |
| </li> |
| </ul></div> |
| <a name="boost_regex.syntax.basic_syntax.anchors_"></a><h5> |
| <a name="id920395"></a> |
| <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.anchors_">Anchors:</a> |
| </h5> |
| <p> |
| A '^' character shall match the start of a line when used as the first character |
| of an expression, or the first character of a sub-expression. |
| </p> |
| <p> |
| A '$' 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> |
| <a name="boost_regex.syntax.basic_syntax.marked_sub_expressions_"></a><h5> |
| <a name="id920416"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.repeats_"></a><h5> |
| <a name="id920447"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.back_references_"></a><h5> |
| <a name="id920611"></a> |
| <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">^\(a*\).*\1$</pre> |
| <p> |
| Will match the string: |
| </p> |
| <pre class="programlisting">aaabbaaa</pre> |
| <p> |
| But not the string: |
| </p> |
| <pre class="programlisting">aaabba</pre> |
| <a name="boost_regex.syntax.basic_syntax.character_sets_"></a><h5> |
| <a name="id920660"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.single_characters_"></a><h6> |
| <a name="id920681"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.character_ranges_"></a><h6> |
| <a name="id920712"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.negation_"></a><h6> |
| <a name="id920768"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.character_classes_"></a><h6> |
| <a name="id920807"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.collating_elements_"></a><h6> |
| <a name="id920858"></a> |
| <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 rangle "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> |
| <a name="boost_regex.syntax.basic_syntax.equivalence_classes_"></a><h6> |
| <a name="id920950"></a> |
| <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.equivalence_classes_">Equivalence |
| classes:</a> |
| </h6> |
| <p> |
| An expression of theform <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> |
| <a name="boost_regex.syntax.basic_syntax.combinations_"></a><h6> |
| <a name="id921007"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.escapes"></a><h5> |
| <a name="id921060"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.what_gets_matched"></a><h4> |
| <a name="id921094"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.variations"></a><h4> |
| <a name="id921115"></a> |
| <a class="link" href="basic_syntax.html#boost_regex.syntax.basic_syntax.variations">Variations</a> |
| </h4> |
| <a name="boost_regex.grep_syntax"></a><p> |
| </p> |
| <a name="boost_regex.syntax.basic_syntax.grep"></a><h5> |
| <a name="id921136"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.emacs"></a><h5> |
| <a name="id921230"></a> |
| <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> |
| <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> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.options"></a><h4> |
| <a name="id921671"></a> |
| <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> |
| <a name="boost_regex.syntax.basic_syntax.references"></a><h4> |
| <a name="id921778"></a> |
| <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 -2010 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> |
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