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| <title>ReplaceRegExp Task</title> |
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| <h2><a name="replaceregexp">ReplaceRegExp</a></h2> |
| <h3>Description</h3> |
| <p>ReplaceRegExp is a directory based task for replacing the |
| occurrence of a given regular expression with a substitution pattern |
| in a selected file or set of files.</p> |
| |
| <p>The output file is only written if it differs from the existing |
| file. This prevents spurious rebuilds based on unchanged files which |
| have been regenerated by this task.</p> |
| |
| <p>Similar to <a href="../CoreTypes/mapper.html#regexp-mapper">regexp |
| type mappers</a> this task needs a supporting regular expression |
| library and an implementation of |
| <code>org.apache.tools.ant.util.regexp.Regexp</code>. See details <a href="#implementation">below</a>. </p> |
| |
| <h3>Parameters</h3> |
| <table border="1" cellpadding="2" cellspacing="0"> |
| <tr> |
| <td valign="top"><b>Attribute</b></td> |
| <td valign="top"><b>Description</b></td> |
| <td align="center" valign="top"><b>Required</b></td> |
| </tr> |
| <tr> |
| <td valign="top">file</td> |
| <td valign="top">file for which the regular expression should be replaced.</td> |
| <td align="center">Yes if no nested <fileset> is used</td> |
| </tr> |
| <tr> |
| <td valign="top">match</td> |
| <td valign="top">The regular expression pattern to match in the file(s)</td> |
| <td align="center">Yes, if no nested <regexp> is used</td> |
| </tr> |
| <tr> |
| <td valign="top">replace</td> |
| <td valign="top">The substitution pattern to place in the file(s) in place |
| of the regular expression.</td> |
| <td align="center">Yes, if no nested <substitution> is used</td> |
| </tr> |
| <tr> |
| <td valign="top">flags</td> |
| <td valign="top">The flags to use when matching the regular expression. For more |
| information, consult the Perl5 syntax<br /> |
| g : Global replacement. Replace all occurences found<br /> |
| i : Case Insensitive. Do not consider case in the match<br /> |
| m : Multiline. Treat the string as multiple lines of input, using "^" and "$" as the start or end of any line, respectively, rather than start or end of string.<br /> |
| s : Singleline. Treat the string as a single line of input, using "." to match any character, including a newline, which normally, it would not match.<br /> |
| </td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">byline</td> |
| <td valign="top">Process the file(s) one line at a time, executing the replacement |
| on one line at a time (<i>true/false</i>). This is useful if you |
| want to only replace the first occurence of a regular expression on |
| each line, which is not easy to do when processing the file as a whole. |
| Defaults to <i>false</i>.</td> |
| <td valign="top" align="center">No</td> |
| </tr> |
| <tr> |
| <td valign="top">encoding</td> |
| <td valign="top">The encoding of the file. <em>since Ant 1.6</em></td> |
| <td align="center">No - defaults to default JVM encoding</td> |
| </tr> |
| </table> |
| <h3>Examples</h3> |
| <pre> <replaceregexp file="${src}/build.properties" |
| match="OldProperty=(.*)" |
| replace="NewProperty=\1" |
| byline="true"/> |
| </pre> |
| <p>replaces occurrences of the property name "OldProperty" |
| with "NewProperty" in a properties file, preserving the existing |
| value, in the file <code>${src}/build.properties</code></p> |
| <a name="implementation"/> |
| <h3>Choice of regular expression implementation</h3> |
| <p> |
| Ant comes with |
| wrappers for |
| <a href="http://java.sun.com/j2se/1.4/docs/api/java/util/regex/package-summary.html" target="_top">the java.util.regex package of JDK 1.4</a>, |
| <a href="http://jakarta.apache.org/regexp/" target="_top">jakarta-regexp</a> |
| and <a href="http://jakarta.apache.org/oro/" target="_top">jakarta-ORO</a>, |
| See <a href="../install.html#librarydependencies">installation dependencies</a> |
| concerning the supporting libraries.</p> |
| <p> |
| The system property <code>ant.regexp.regexpimpl</code> governs which regular expression implementation will be chosen. |
| Possible values for this property are : |
| <ul> |
| <li> |
| org.apache.tools.ant.util.regexp.Jdk14RegexpRegexp |
| </li> |
| <li> |
| org.apache.tools.ant.util.regexp.JakartaOroRegexp |
| </li> |
| <li> |
| org.apache.tools.ant.util.regexp.JakartaRegexpRegexp |
| </li> |
| </ul> |
| It can also be another implementation of the interface <code>org.apache.tools.ant.util.regexp.Regexp</code>. |
| If <code>ant.regexp.regexpimpl</code> is not defined, ant checks in the order Jdk14Regexp, JakartaOroRegexp, |
| JakartaRegexp for the availability of the corresponding library. The first of these 3 which is found will be used.</p> |
| <p> |
| There are cross-platform issues for matches related to line terminator. |
| For example if you use $ to anchor your regular expression on the end of a line |
| the results might be very different depending on both your platform and the regular |
| expression library you use. It is 'highly recommended' that you test your pattern on |
| both Unix and Windows platforms before you rely on it. |
| <ul> |
| <li>Jakarta Oro defines a line terminator as '\n' and is consistent with Perl.</li> |
| <li>Jakarta RegExp uses a system-dependant line terminator.</li> |
| <li>JDK 1.4 uses '\n', '\r\n', '\u0085', '\u2028', '\u2029' as a default |
| but is configured in the wrapper to use only '\n' (UNIX_LINE)</li> |
| </ul> |
| <em>We <b>strongly</b> recommend that you use Jakarta Oro.</em> |
| </p> |
| <h3>Parameters specified as nested elements</h3> |
| <p>This task supports a nested <a href="../CoreTypes/fileset.html">FileSet</a> |
| element.</p> |
| <p>This task supports a nested <i>Regexp</i> element to specify |
| the regular expression. You can use this element to refer to a previously |
| defined regular expression datatype instance.</p> |
| <blockquote> |
| <regexp id="id" pattern="alpha(.+)beta"/><br /> |
| <regexp refid="id"/> |
| </blockquote> |
| <p>This task supports a nested <i>Substitution</i> element to specify |
| the substitution pattern. You can use this element to refer to a previously |
| defined substitution pattern datatype instance.</p> |
| <blockquote> |
| <substitution id="id" expression="beta\1alpha"/><br /> |
| <substitution refid="id"/> |
| </blockquote> |
| <h3>Examples</h3> |
| <blockquote> |
| <pre> |
| <replaceregexp byline="true"> |
| <regexp pattern="OldProperty=(.*)"/> |
| <substitution expression="NewProperty=\1"/> |
| <fileset dir="."> |
| <includes="*.properties"/> |
| </fileset> |
| </replaceregexp> |
| </pre></blockquote> |
| <p>replaces occurrences of the property name "OldProperty" |
| with "NewProperty" in a properties file, preserving the existing |
| value, in all files ending in <code>.properties</code> in the current directory</p> |
| |
| <blockquote> |
| <pre><replaceregexp match="\s+" replace=" " flags="g" byline="true"> |
| <fileset dir="${html.dir}" includes="**/*.html" /> |
| </replaceregexp> |
| </pre></blockquote> |
| <p>replaces all whitespaces (blanks, tabs, etc) by one blank remaining the |
| line separator. So with input |
| |
| <blockquote> |
| <pre> |
| <html> <body> |
| <<TAB>><h1> T E S T </h1> <<TAB>> |
| <<TAB>> </body></html> |
| </pre></blockquote> |
| would converted to |
| <pre> |
| <html> <body> |
| <h1> T E S T </h1> </body></html> |
| </pre> |
| </p> |
| <hr/> |
| <p align="center">Copyright © 2001-2003 Apache Software Foundation. All rights |
| Reserved.</p> |
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