WebSVN – oidinfo_new_design – Blame – /trunk/regexp.raw.htm

Rev	Author	Line No.	Line
2	daniel-mar	1	<div id="global_content">
		2	<div id="reg_in_regexp">
		3
		4	<table cellspacing="0" cellpadding="0" border="0" width="100%">
		5	<tr>
		6	<td height="6%" valign="top" width="100%">
		7	<span class="page_title">
		8	Regular expressions
		9	</span>
		10	</td>
		11	</tr>
		12	</table><br><a name="introduction"></a>
		13	<table cellspacing="0" cellpadding="0" border="0" width="100%">
		14	<tr>
		15	<td height="8%" valign="middle" width="100%"><span class="section_title">Introduction</span></td>
		16	</tr>
		17	</table>
		18	<table cellspacing="0" cellpadding="0" border="0" width="100%">
		19	<tr>
		20	<td valign="top" width="100%">
		21
		22	<p>
		23	A regular expression is a character sequence that is an abbreviated
13	daniel-mar	24	definition of a set of strings. A string matches a regular
2	daniel-mar	25	expression if it is a member of the set described by the regular expression.
		26	</p>
		27	<p>
		28	A regular expression is allowed to match anywhere within a string,
13	daniel-mar	29	unless the regular expression is explicitly anchored to the beginning (operator <code>^</code>)
		30	or end (operator <code>$</code>) of the string.
2	daniel-mar	31	</p>
		32
		33	</td>
		34
		35
		36
		37	<td width="3%" valign="top"> </td>
		38
		39
		40
		41	<td width="20%"> </td>
		42
		43
		44
		45	</tr>
		46
		47
		48
		49	</table>
		50
		51	<a name="syntax"></a>
		52	<table cellspacing="0" cellpadding="0" border="0" width="100%">
		53
		54
		55
		56	<tr>
		57
		58
		59
		60
		61
		62
		63	<td height="8%" valign="middle" width="100%"><span class="section_title">Syntax</span></td>
		64
		65
		66
		67
		68
		69	</tr>
		70
		71
		72
		73	</table>
		74
		75
		76
		77	<table cellspacing="0" cellpadding="0" border="0" width="100%">
		78
		79
		80
		81	<tr>
		82
		83
		84
		85
		86
		87
		88	<td valign="top" width="100%">
		89	<p>The following character sequences are recognized:</p>
		90	<ul>
		91	<li>
		92	<code class="code">.</code> matches any single character except
		93	newline
		94	</li>
		95	<li>
		96	<code class="code">*</code> (postfix) matches the previous expression
		97	zero, one or several times
		98	</li>
		99	<li>
		100	<code class="code">+</code> (postfix) matches the previous expression
		101	one or several times
		102	<ul>
		103	<li><code>[+]</code> matches a "+" character (escape mechanism)</li>
		104	</ul>
		105	</li>
		106	<li>
		107	<code class="code">?</code> (postfix) matches the previous expression
		108	once or not at all
		109	</li>
		110	<li>
		111	<code class="code">[  ]</code> is a character set
		112	<ul>
		113	<li>
		114	ranges are denoted with a hyphen "<code class="code">-</code>",
		115	as in <code class="code">[a-z]</code>
		116	</li>
		117	<li>
		118	an initial caret "<code class="code">^</code>", as in <code class="code">[^0-9]</code>,
		119	complements the set (i.e., any character, except a lowercase letter from a to z, is accepted)
		120	</li>
		121	<li><code>[[]</code> matches a "[" character (escape mechanism)</li>
		122	<li><code>[]]</code> matches a "]" character (escape mechanism)</li>
		123	</ul>
		124	</li>
		125	<li><code class="code">^</code> matches at beginning of line</li>
		126	<li><code class="code">$</code> matches at end of line</li>
		127	<li><code class="code">\|</code> (infix) alternative between two expressions</li>
		128	<li>
		129	<code class="code">(  )</code> grouping of the enclosed expression
		130	<ul>
		131	<li><code>[(]</code> matches a "(" character (escape mechanism)</li>
		132	<li><code>[)]</code> matches a ")" character (escape mechanism)</li>
		133	</ul>
		134	</li>
		135	<li>
		136	<code class="code">\</code> escapes special characters (<em>i.e.</em>,
		137	<code>^.[$\|*?{'</code>):
		138	<ul>
		139	<li><code>\n</code> matches a newline character</li>
		140	<li><code>\.</code> matches a dot "." character</li>
		141	<li><code>\'</code> matches a quote "<code>'</code>" character</li>
		142	<li>
		143	<code class="code">\</code> cannot be escaped; to search for
		144	a backslash, use <code class="code">.</code> to match any single
		145	character
		146	</li>
		147	</ul>
		148	</li>
		149	</ul>
		150	</td>
		151	<td width="2%" valign="top"> </td>
		152	<td width="20%">  </td>
		153	</tr>
		154	</table>
		155
		156	</div>
		157	<div class="clear"></div>
		158	</div>

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oidinfo_new_design/trunk/regexp.raw.htm – Rev 13