http://www.perlmonks.org?node_id=181423

Fastolfe has asked for the wisdom of the Perl Monks concerning the following question:

I am attempting to use File::Find to recurse down a dated directory structure and yell when it finds a certain (the "latest") path/filename within that structure (at the 'year', 'month' or 'day' level).

Running this script with an argument of /path/content, for example, should recurse down a directory tree and print out:

2002/07/14/path/content
if it's able to locate path/content (with any file extension) within the 2002/07/14 directory.

The trick here is that I need the testing done such that the most recent dates are checked first (year 2002 tested before 2001, month 12 checked before 11). The File::Find::Unix man page would seem to indicate that all I need to do is specify a 'preprocess' function to do my sorting. My preprocess function is not getting called and I'm at a loss as to why. The script I'm using appears below (it's small).

use strict; use File::Find; use File::Spec; my $search = File::Spec->canonpath("/".shift()); 1 while $search =~ s!/[^/]+/\.\./?!/!; $search =~ s!^/!!; find({ wanted => \&wanted, preprocess => \&preprocess, # this should do it follow => 1, }, "."); sub wanted { return unless -d; print "testing $File::Find::name\n"; # see these fine if (glob("$_/${search}.*")) { print "$File::Find::name/$search\n"; exit; } } sub preprocess { print "pre-processing @_\n"; # never see this return sort { $b <=> $a } grep { /^\d+$/ } @_; }
Output:
[fastolfe@home test]$ ./resolve-name /path/content testing . testing ./2001 testing ./2001/05 testing ./2001/05/30 ./2001/05/30/path/content
Unfortunately the one it found was actually the oldest, which might imply that it's following a standard ascending sort that one typically sees on Unix.