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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<head>
<meta content="text/html; charset=ISO-8859-1" http-equiv="content-type">
<title>Regular Expression Summary</title>
</head>
<body>
<h3>Regular Expression Help</h3>
<br>
<b>The following match as stated</b>:<br><br>
<table style="text-align: left; width: 80%;" border="0" cellpadding="5" cellspacing="2">
<tbody>
<tr>
<td style="white-space: nowrap; vertical-align: middle;">
<table style="text-align: left; width: 100%;" border="0" cellpadding="2" cellspacing="2">
<tbody>
<tr>
<td style="vertical-align: middle; white-space: nowrap; width: 50px;"> .</td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">any single character </td>
</tr>
<tr>
<td style="vertical-align: middle; white-space: nowrap; width: 50px;"> $</td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">end of a line </td>
</tr>
<tr>
<td style="width: 50px;" nowrap="nowrap" valign="middle">\< </td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">start of a word </td>
</tr>
<tr>
<td style="width: 50px;" nowrap="nowrap" valign="middle">\b </td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">either edge of a word </td>
</tr>
<tr>
<td nowrap="nowrap" valign="middle"></td>
<td nowrap="nowrap" valign="middle"></td>
</tr>
<tr>
<td style="white-space: nowrap; vertical-align: middle;">[asd]</td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">a, s <i>or</i> d </td>
</tr>
<tr>
<td style="width: 50px;" nowrap="nowrap" valign="middle">[^a-zA-Z]</td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">Anything <i>except</i> a letter (the ^ negates)</td>
</tr>
</tbody>
</table>
</td>
<td style="vertical-align: middle; white-space: nowrap; width: 50%;">
<table style="text-align: left; width: 100%;" border="0" cellpadding="2" cellspacing="2">
<tbody>
<tr>
<td nowrap="nowrap" valign="middle"></td>
<td nowrap="nowrap" valign="middle"></td>
</tr>
<tr>
<td style="white-space: nowrap; vertical-align: middle;"> ^</td>
<td nowrap="nowrap" valign="middle">beginning of a line </td>
</tr>
<tr>
<td nowrap="nowrap" valign="middle">\></td>
<td nowrap="nowrap" valign="middle">end of a word </td>
</tr>
<tr>
<td nowrap="nowrap" valign="middle">\B </td>
<td nowrap="nowrap" valign="middle">empty string <i>not</i> at the edge of a word </td>
</tr>
<tr>
<td nowrap="nowrap" valign="middle"></td>
<td nowrap="nowrap" valign="middle"></td>
</tr>
<tr>
<td nowrap="nowrap" valign="middle">[a-d 0-9]</td>
<td nowrap="nowrap" valign="middle">abcd0123456789 <i>or</i> space </td>
</tr>
<tr>
<td nowrap="nowrap" valign="middle"></td>
<td nowrap="nowrap" valign="middle"></td>
</tr>
</tbody>
</table>
</td>
</tr>
</tbody>
</table>
<br><br><br>
<b>Repetition Operators</b>:<br><br>
<table style="text-align: left;" border="0" cellpadding="2" cellspacing="2">
<tbody>
<tr>
<td style="vertical-align: middle; width: 50px;">? </td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">The preceding item will be matched zero or one times </td>
</tr>
<tr>
<td style="vertical-align: middle; width: 50px;">* </td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">The preceding item will be matched zero or more times </td>
</tr>
<tr>
<td style="width: 50px;" nowrap="nowrap" valign="middle">+ </td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">The preceding item will be matched one or more times </td>
</tr>
<tr>
<td style="width: 50px;" nowrap="nowrap" valign="middle">{n} </td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">The preceding item will be matched exactly n times </td>
</tr>
<tr>
<td nowrap="nowrap" valign="middle">{n,}</td>
<td nowrap="nowrap" valign="middle">The preceding item will be matched n or more times</td>
</tr>
<tr>
<td style="vertical-align: middle;">{n,m} </td>
<td style="width: 347px;" nowrap="nowrap" valign="middle">The preceding item will be matched from n to m times </td>
</tr>
</tbody>
</table>
<br><br><br>
<b>Shortcuts</b>:<br><br>
[:alpha:] [:lower:] [:upper:] [:digit:] [:alnum:] [:punct:] [:blank:]
[:cntrl:] [:graph:] [:print:] [:space:] [:xdigit:]<br><br>
[:blank:] means space or tab. [:space:] means space tab CR FF NL or VT<br>
[:print:] means [:alnum:], [:punct:] or [:space:]<br>
[:xdigit:] means a hexadecimal digit, i.e. [0-9A-Fa-f]<br><br>
Note that these shortcuts still need to be in brackets. Yes, really! e.g. [[:punct:]e] matches
punctuation or 'e'<br><br>
\w is a synonym for [[:alnum:]] \W is a synonym for [^[:alnum]]<br>
( ) do their usual precedence thing. | is the OR operator e.g. d(i|o)g matches dig or dog<br><br><br>
For less concise information, including about backreferences, see man grep. If then you are still insufficiently
confused, try man 7 regex.
</body>
</html>
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