perlfunc
root
<P>
find - traverse a file tree
<P>
finddepth - traverse a directory structure depth-first
<P>
<HR>
<P>
<PRE> use <A HREF="File::Find">File::Find</A>;
find(\&wanted, '/foo','/bar');
sub wanted { ... }
</PRE>
<P>
<PRE> use <A HREF="File::Find">File::Find</A>;
finddepth(\&wanted, '/foo','/bar');
sub wanted { ... }
</PRE>
<P>
<P>
The first argument to
<CODE>find()</CODE> is either a hash
reference describing the operations to be performed for each file, or a
code reference. If it is a hash reference, then the value for the key <CODE>wanted</CODE> should be a code reference. This code reference is called <EM>the wanted()
function</EM> below.
<P>
Currently the only other supported key for the above hash is
<CODE>bydepth</CODE>, in presense of which the walk over directories is performed depth-first. Entry point
<CODE>finddepth()</CODE> is a shortcut for specifying
<CODE>{ bydepth =</CODE> 1}> in the first argument of
<CODE>find().</CODE>
<P>
The
<CODE>wanted()</CODE> function does
whatever verifications you want. $File::Find::dir contains the current
directory name, and <CODE>$_</CODE> the current filename within that
directory. $File::Find::name contains
<CODE>"$File::Find::dir/$_"</CODE>. You are
<CODE>chdir()'d</CODE> to
$File::Find::dir when the function is called. The function may set
$File::Find::prune to prune the tree.
<P>
File::Find assumes that you don't alter the <CODE>$_</CODE> variable. If
you do then make sure you return it to its original value before exiting
your function.
<P>
This library is useful for the <CODE>find2perl</CODE> tool, which when fed,
<P>
<PRE> find2perl / -name .nfs\* -mtime +7 \
-exec rm -f {} \; -o -fstype nfs -prune
</PRE>
<P>
produces something like:
<P>
<PRE> sub wanted {
/^\.nfs.*$/ &&
(($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_)) &&
int(-M _) > 7 &&
unlink($_)
||
($nlink || (($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_))) &&
$dev < 0 &&
($<A HREF="File::Find::prune">File::Find::prune</A> = 1);
}
</PRE>
<P>
Set the variable $File::Find::dont_use_nlink if you're using
<FONT SIZE=-1>AFS,</FONT> since
<FONT SIZE=-1>AFS</FONT> cheats.
<P>
<CODE>finddepth</CODE> is just like <CODE>find</CODE>, except that it does a depth-first search.
<P>
Here's another interesting wanted function. It will find all symlinks that
don't resolve:
<P>
<PRE> sub wanted {
-l && !-e && print "bogus link: $<A HREF="File::Find::name">File::Find::name</A>\n";
}
</PRE>
<P>
<HR>
<H1><A NAME="BUGS">BUGS</A></H1>
<P>
There is no way to make find or finddepth follow symlinks.
<HR>