my @plf_files = {"files.plf","orphans.plf"};creates a single element array containing a reference to a hash, because you used { } (called a 'composer'). You probably meant:
my @plf_files = ('files.plf','orphans.plf');

[download]

Your subroutine tests the same thing several times, try this:
sub recursion
{
    my $plf = shift;
    open my $fh, '<', $plf or die "could not open '$plf' $!";
    
    foreach (my $line = <$fh>){
        if($line =~ /(\w+\.plf)$/)
        {
            $match_plf_name = $1;
            next if $match_plf_name eq $plf;   
            push @recursive_plfs ,$match_plf_name;
            recursion($match_plf_name);
        }
    }
}

[download]
You will notice that I don't use $DATA for filehandle name. This is because there is a reserved filehandle called DATA, so $DATA would be confusing. You will also notice that there is not a grep in sight. The capturing parentheses group is saved into $1.

Finally, notice also the 'next' statement as an insurance against infinite recursion.

In reply to Re^3: Recursive search by cdarke
in thread Recursive search by perl_mystery

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