title: How can I have java ant like path pattern matching on ruby?
body: <p>I would like to match patterns on strings like on the following ant documentation. Is there a gem already for this or is this an easy task with regexps?</p>
  
  <hr>
  
  <p>I know Dir.glob already does this but I don't know how to use it without a real filesystem.</p>
  
  <hr>
  
  <pre><code>'*' matches zero or more characters, '?' matches one character.
  
  In general, patterns are considered relative paths, relative to a task dependent base directory (the dir attribute in the case of &lt;fileset&gt;). Only files found below that base directory are considered. So while a pattern like ../foo.java is possible, it will not match anything when applied since the base directory's parent is never scanned for files.
  
  Examples:
  
  *.java  matches  .java, x.java and FooBar.java, but not FooBar.xml (does not end with .java).
  
  ?.java  matches  x.java, A.java, but not .java or xyz.java (both don't have one character before .java).
  
  Combinations of *'s and ?'s are allowed.
  
  Matching is done per-directory. This means that first the first directory in the pattern is matched against the first directory in the path to match. Then the second directory is matched, and so on. For example, when we have the pattern /?abc/*/*.java and the path /xabc/foobar/test.java, the first ?abc is matched with xabc, then * is matched with foobar, and finally *.java is matched with test.java. They all match, so the path matches the pattern.
  
  To make things a bit more flexible, we add one extra feature, which makes it possible to match multiple directory levels. This can be used to match a complete directory tree, or a file anywhere in the directory tree. To do this, ** must be used as the name of a directory. When ** is used as the name of a directory in the pattern, it matches zero or more directories. For example: /test/** matches all files/directories under /test/, such as /test/x.java, or /test/foo/bar/xyz.html, but not /xyz.xml.
  
  There is one "shorthand": if a pattern ends with / or \, then ** is appended. For example, mypackage/test/ is interpreted as if it were mypackage/test/**.
  
  Example patterns:
  **/CVS/*    Matches all files in CVS directories that can be located anywhere in the directory tree.
  Matches:
  
        CVS/Repository
        org/apache/CVS/Entries
        org/apache/jakarta/tools/ant/CVS/Entries
  
  
  But not:
  
        org/apache/CVS/foo/bar/Entries (foo/bar/
        part does not match)
  
  
  org/apache/jakarta/**   Matches all files in the org/apache/jakarta directory tree.
  Matches:
  
        org/apache/jakarta/tools/ant/docs/index.html
        org/apache/jakarta/test.xml
  
  
  But not:
  
        org/apache/xyz.java
  
  
  (jakarta/ part is missing).
  org/apache/**/CVS/*     Matches all files in CVS directories that are located anywhere in the directory tree under org/apache.
  Matches:
  
        org/apache/CVS/Entries
        org/apache/jakarta/tools/ant/CVS/Entries
  
  
  But not:
  
        org/apache/CVS/foo/bar/Entries
  
  
  (foo/bar/ part does not match)
  **/test/**  Matches all files that have a test element in their path, including test as a filename.
  </code></pre>