Why I hate File::Find and how I (hope I) fixed it

[mirod]

OK, so every time someone here asks how to walk a directory tree and process files we all religiously (!) chant the File::Find mantra.

The truth is that I have always hated File::Find. It just feels old.

My main gripe is that the wanted function, which is called for each file found, does not accept arguments. So if I really need arguments, which happens quite often, then I have to use good ole globals. This is definitely _not_ what I'd call good coding practice. Plus how do I put this code in a module?

So here is my solution, using closures to generate various functions from a single "template" one. The interesting part is really the make_wanted function, that takes a code reference and a list of arguments, and generates a function (with takes no arguments) that will call the code reference with the arguments (which will have the value they had when make_wanted was called):

#!/bin/perl -w
use strict;
use File::Find;

# create various wnated functions
my $wanted= make_wanted( \&wanted_1, 'toto', 'tata');
find( $wanted, '.');
print "\n";

$wanted= make_wanted( \&wanted_1, 'foo',  'bar', 'baz');
find( $wanted, '.');
print "\n";

$wanted= make_wanted( \&wanted_2, 'toto', 'tata');
find( $wanted, '.');
print "\n";

$wanted= make_wanted( \&wanted_2, 'foo',  'bar', 'baz');
find( $wanted, '.');
print "\n";

# a regular function, can access its arguments and the File::Find vari
+ables

sub wanted_1
  { my @args= @_;
    print "wanted_1( ", join( ', ', @args), ") on $_\n" if( m/\.xml$/)
+;
  }

sub wanted_2
  { my @args= @_;
    print "wanted_2( ", join( ', ', @args), ") on $_\n" if( m/\.txt$/)
+;
  }

# the closure generator
# creates a function that calls the function passed as first argument
# passing it the arguments make_wanted is called with

sub make_wanted
  { my $wanted= shift;                      # get the "real" wanted fu
+nction
    my @args= @_;                           # "freeze" the arguments
    my $sub= sub { $wanted->( @args);  };   # generate the anon sub
    return $sub;                            # return it
  }