Dear Monks,

I have a couple of questions about the usage of File::Next and some basic anonymous subroutine concepts I don't understand. Here's what works for me so far.

 
use strict;
use warnings;
use File::Next;

my $find_this = sub {
    my ($starting_points, $target) = @_;
    my $ref_sub = File::Next::files( "$starting_points" );
    while ( my @files = $ref_sub->()  ) {
    return @files if $files[1] =~ $target;
    }
};

my @files = &$find_this( "/tmp/dir1",  "file3.txt" );
print "@files\n";
[download]

__output__

$ ./file_next.pl
/tmp/dir1/dir3 file3.txt /tmp/dir1/dir3/file3.txt
[download]

My questions:

The docs for File::Next state that the first parameter to any of the iterator factory functions may be a hashref of options and gives an example like this:

For the three iterators,  the \%options are optional.
files( [ \%options,  ] @starting_points )])
[download]

I understand they're optional but what are examples of something I would use there for \%options?

I think I only half understand what this line is doing:
while ( my @files = $ref_sub->()  ) {
What I see is the reference $ref_sub being assigned to @files for each file down the directory tree and while that condition is true do something. This works fine but am I supposed to put something in the parens after $ref_sub->(HERE) ?

Is there a way that I can put my anonymous subroutines down in the bottom of my file out of the way like I do with regular subroutines and then put the line where I call it somewhere higher above?

Thank-you again for any advice.

UPDATE:
I finally realized I didn't need to make everything anonymous subroutines to avoid getting "Variable $x will not stay shared" errors and instead I could have subroutines within subroutines by passing data and return values into and out of the subroutines keeping the data local to the subroutine instead of making it global.
FWIW about the File::Next question, here's what I ended up using

 
sub findfile {
        my ($target, $starting_points ) = @_;
        my $file = File::Next::files( { file_filter => sub { /$target$
+/ } }, "$starting_points" );
                while ( my @files = $file->() )  {
                        return $files[0], $files[1], $files[2]; #direc
+tory, filename, full path and name
        }
}
[download]

Thanks for the feedback that you provided on this. It was very useful.