File Find -- using a module - Robert's Perl Tutorial

File::Find -- using a module

An example of a module included with Perl is File::Find. There are several modules under the File::Find section, such as File::Basetree, File::Compare and File::Stat.

This is an example of how File::Find can be used:

use File::Find;

$dir1='/some/dir/with/lots/of/files';
$dir2='/another/directory/';

find(\&wanted, $dir1,$dir2);

sub wanted {
	print "Found it $File::Find::dir/$_\n" if /^[a-d]/i;

}

The first line is the most important. The use function loads the File::Find module. Now, all the power and functionality of File::Find is available for use. Such as the find function. This accepts two basic parameters:

The name of a subroutine, usually wanted which defines what you want to do with the list of files being returned. The filename will be in $_.
A list of directories to be searched. Subdirectories will also be searched.

The subroutine wanted simply prints the directory the file was found in if the filename begins with a,b,c or d. Make your own regex to suit. The line $File::Find::dir means the $dir variable in the module $File::Find. This is explained further in the next section.

Note -- the \&wanted parameter is a reference to a subroutine. Essentially, this means that the code in File::Find knows where to find the &wanted subroutine. It is basically like shortcuts under Windows 9x and NT4, instead of actual files (but the UNIX Perl people would slaughter me for that, so be quiet).