#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my @files;
my $path = shift || '.';
print Dumper traverse($path);

sub traverse {
    my ($path) = @_;

    return if not -d $path;
    opendir my $dh, $path or die;
    while (my $sub = readdir $dh) {
        next if $sub eq '.' or $sub eq '..';
	push @files, "$path/$sub"
	    if ("$path/$sub" =~ /(?:\btest\b|\banotherSample\b|\bsample\b)/);
	traverse("$path/$sub");
    }
    close $dh;
    return \@files;
}

__DATA__

$ perl file.pl
$VAR1 = [
          './test.pl~',
          './sample.c',
          './test.txt~',
          './testDir/anotherSample.c',
          './test.pl',
          './test.txt'
        ];