Finally,I think I know why ,am pushing $_\n to array,a new line,that is the reason it's not matching

But I have one question,in the below code which ever is present first push or print is working,the second line is not coming into picture,is there a way I can push to array and print to a file at the same time?

open(my $FOLDERS, '+>', "dirs.log") or die $!;

find(sub {
    push @folders, "$_" if -d $File::Find::name && !$seen{$_}++;
    print $FOLDERS "$_\n" if -d $File::Find::name && !$seen{$_}++;
}, $cwd);
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Just use the block form of if otherwise the %seen hash is being checked twice, and only the first statement would pass.

find(sub {
    if (-d $File::Find::name && !$seen{$_}++) {
        push @folders, "$_" ;
        print $FOLDERS "$_\n";
    }
}, $cwd);
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