Increase the scope of @dirlist:

use File::Find;

my @dirlist;

sub wanted {
   return unless -d $_;
   push(@dirlist, $File::Find::name);
}

find(\&wanted, shift(@ARGV));

# Use @dirlist here
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Closures come in useful if you'd wish to avoid using a global:

use File::Find;

sub find_dirs {
   my @dirlist;
   find(sub {
      return unless -d $_;
      push(@dirlist, $File::Find::name);
   }, @_);
   return @dirlist;
}

{
   # Not a global.
   my @dirlist = find_dirs(shift(@ARGV));

   # Use @dirlist here
}
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Yet another way. This one uses dynamically scoped variables:

use File::Find;

sub wanted {
   return unless -d $_;
   push(@File::Find::matches, $File::Find::name);
}

sub find_it {
   local *File::Find::matches;
   find(@_);
   return @File::Find::matches;
}

{
   # Not a global.
   my @dirlist = find_it(\&wanted, shift(@ARGV));

   # Use @dirlist here
}
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Update: Added 2nd snippet.
Update: Added 3rd snippet.

{
  my @dirlist;

  sub wanted {
    return unless -d $_;
    push(@dirlist,$File::Find::name);
    return(@dirlist);
  }
}
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That's really the same thing as just having the file be the enclosing scope. It would be different if this were for a subroutine that returned the list.

sub get_dirlist {
  my $dir_to_scan = shift;

  my @dirlist;
  my $wanted = sub {    
    return unless -d $_;
    push(@dirlist,$File::Find::name);
  } 

  find( $wanted, $dir_to_scan );

  return @dirlist;
}
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The anonymous subroutine attached to $wanted is compiled only once, but gets a fresh copy of @dirlist for each invokation. Contrast that to this, which would continue to add to @dirlist each time the get_dirlist function was called and return a longer and longer array each time:

my @dirlist;

sub wanted {    
  return unless -d $_;
  push(@dirlist,$File::Find::name);
} 

sub get_dirlist {
  my $dir_to_scan = shift;
  find( \&wanted, $dir_to_scan );
  return @dirlist;
}
[download]

-xdg

Code written by xdg and posted on PerlMonks is public domain. It is provided as is with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.

use File::Find;

# set up closure here
my @dirlist;
sub wanted {
    return unless -d $_;
    push(@dirlist,$File::Find::name);
}


# call the sub to fill @dirlist
find(\&wanted, shift(@ARGV));

# use results here
print "$_\n" for @dirlist;
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@dirlist is visible within the sub, and the push will work as normal. A "closure" essentially boils down to using a lexical ("my") variable from outside a subroutine inside a subroutine. See the Closure on Closures tutorial.

use strict;
use warnings;

use File::Find;

main();
exit;

sub main {
{
    dostuff($_) foreach findit(shift(@ARGV));
}

sub findit {
    my @dirlist;
    find(sub {
        return unless -d $_;
        push(@dirlist, $File::Find::name);
    }, @_);
    return @dirlist;
}

sub dostuff {
    my ($dir) = @_;
    print "$dir\n"
}
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This is nothing more than applying my original node.

I don't think you get how the 'wanted' function works. It is run once for each file and directory in the tree you're searching.

If you don't want a global array to store these results, you have two choices: you can either make the wanted function do the work on each file, or you can change the structure of your program. The former might look like:

sub main {
    findit();
    # dostuff($_) for @dirlist;
}

sub findit {
    find(\&wanted, shift(@ARGV));
}

sub wanted {
    return unless -d $_;
    # push(@dirlist,$File::Find::name);
    dostuff($File::Find::name);
}

sub dostuff {
    print "$_\n"
}
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I commented out the lines in your code, so you can more easily see the change.

The latter solution might look something like this:

sub main {
   my @dirlist;
   find( 
      sub { 
         return unless -d $_;
         push(@dirlist,$File::Find::name);
      }, 
      (shift @ARGV) 
   );

   dostuff($_) for @dirlist;
}

sub dostuff {
   print "$_\n";
}
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I highly recommend the first approach -- it seems silly, in most cases, to build a list of files and then act on it when you can act on each file as you find it.

use strict;
use File::Find;
sub main;
my @dirlist;

main();
exit;


sub main {
    findit();
    dostuff($_) for @dirlist;
}

sub findit {
    find(\&wanted, shift(@ARGV));
}

sub wanted {
    return unless -d $_;
    push(@dirlist,$File::Find::name);
}

sub dostuff {
    print "$_\n"
}
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Have you considered passing and returning data to/from these subs?

use strict;
use File::Find;

main();
exit;


sub main {
    dostuff($_) for findit( @ARGV );
}

sub findit {
    my( $root ) = @_;
    my @dirlist;
    find( sub { -d $_ or push @dirlist, $File::Find::name; }, $root );
    @dirlist
}

sub dostuff {
    print "$_\n"
}
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It should be noted that the above uses a closure, which is one way to "eliminate" global variables without unduly restricting access to them.

We're building the house of the future together.

You don't need to separate your variable declarations from your sub declarations. You can declare @dirlist just before the first subroutine that uses it. The declaration line will never be executed (because you exit before it gets to the declaration, so don't try to initialize it — you'd need to do that in a BEGIN block) but will be visible to the subs below it because the declaration is handled at compile time.

For tighter scoping, you can enclose it in a block with the subs that use it (main and wanted in your example code).

ikegami's solution shows you how to do multiple finds that don't all write to the same array. That is one of the main things closures are useful for.

---

Caution: Contents may have been coded under pressure.

Try File::Find::Rule. Your example would translate as something like (untested):

use File::Find::Rule;
dostuff($_) for  File::Find::Rule->file->in( @ARGV );
[download]