File::Find

use File::Find; # Print out all directories below current one. find sub {
 print "$File::Find::name\n" if -d }, "."; # Compute total space used by all files in listed directories. @dirs = @ARGV ? @ARGV : ('.'); my $sum = 0; find sub {
 $sum += -s }, @dirs;
print "@dirs contained $sum bytes\n"; # Alter default behavior to go through symlinks # and visit subdirectories first. find {
 wanted => \&myfunc, follow => 1, bydepth => 1 }, ".";

The File::Find module's find function recursively descends directories. Its first argument should be a reference to a function, and all following arguments should be directories. The function is called on each filename from the listed directories. Within that function, the $_ variable is set to the basename of the current filename visited, and the process's current working directory is by default set to that directory. The package variable $File::Find::name is the full pathname of the visited filename. An alternative calling convention takes as its first argument a reference to a hash containing option specifications, including "wanted", "bydepth", "follow", "follow_fast", "follow_skip", "no_chdir", "untaint", "untaint_pattern", and "untaint_skip", as fully explained in the online documentation. This module is also used by the standard find2perl(1) translator program that comes with Perl.