use IO::Dir;

my @cmds;
my @paths = split /\:/, $ENV{PATH};

foreach my $path (@paths) {
	tie my %dir, 'IO::Dir', $path;

	foreach my $file (keys %dir) {
		if (-f -x $file) {
			push @cmds, $file;
		}
	}

	undef %dir;
}

foreach my $cmd (@cmds) {
	print $cmd . "\n";
}