use File::Spec;

use strict;

my $dir = '/foo/bar';

my $filesdir = File::Spec->catdir($dir, 'files');

my $file = '';

opendir my $dh, $filesdir or die "Can't opendir, $filesdir: $!";
while (readdir $dh) {
    if (/\.txt$/) {
        $file = $_;
        last;
    }
}

print $file . "\n";
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