$gw="abcdefgh";
if ( ( my $a = $gw ) =~ m/abc/ig){
    print pos( $a ), ": abc\n";
}
if ( ( my $b = $gw ) =~ m/cde/ig){
    print pos( $b ), ": cde\n";
}
if ( ( my $c = $gw ) =~ m/defgh/ig){
    print pos( $c ), ": defgh\n";
}
if ( ( my $d = $gw ) =~ m/gh/ig){
    print pos( $d ), ": gh\n";
}
if ( ( my $e = $gw ) =~ m/fg/ig){
    print pos( $e ), ": fg\n";
}

##</code><code>##

3: abc
5: cde
8: defgh
8: gh
7: fg