If I'm reading your description correctly, you are passing over the list of files two or three times (possibly doing steps 1 & 2 in one pass). Step 3 also does a linear search over the file names, which is going to go quadratic in terms of processing.

Maybe try to get all the info in one pass, store the details in a hash structure, and then iterate over that hash. That will take care of the need for exact matches and avoid linear searches.

use strict;
use warnings;

#  I assume the actual code will obtain this list using
#  glob or similar
my @allfiles = qw /
baz.txt
baz.epub
baz.doc
baz.pdf
bar.epub
boo.epub
boo.txt
/;

my %by_ext;
#  %by_fbase is actually redundant below,
#  but is maybe useful for other things
#  so I have left it in
my %by_fbase;  

foreach my $file (@allfiles) {
    #  should use a proper filename parser here
    #  like File::Basename, but a split will serve
    #  for the purposes of an example.
    my ($name, $ext) = split /\./, $file;
    
    $by_ext{$ext}{$name} = $file;
    $by_fbase{$name}{$ext} = $file;
}

foreach my $name (keys %by_fbase) {
    #print "$name\n";
    no autovivification;
    #  could use exists in this check if you want to avoid autoviv,
    #  but file names should evaluate to true if they have
    #  an extension, even if the name part evaluates to false
    if ($by_fbase{$name}{pdf} && $by_fbase{$name}{epub}) {
        #  do stuff
        print "$name has epub and pdf extensions: "
          . "$by_fbase{$name}{epub} $by_fbase{$name}{pdf}\n";
        #  now do stuff like moving files since you can iterate over
        #  the values of the relevant subhash
        foreach my $file (values %{$by_fbase{$name}}) {
            print "now do something to $file\n";
        }
        
    }
}

[download]
That code prints: 
baz has epub and pdf extensions: baz.epub baz.pdf
now do something to baz.epub
now do something to baz.doc
now do something to baz.txt
now do something to baz.pdf

[download]

Update: Edited incomplete comment starting with "now do stuff"

In reply to Re: Duplicates in Directories by swl
in thread Duplicates in Directories by kel

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