>perl -wMstrict -le
"my $string = 'foo bart bare';
 ;;
 if ($string =~ m{bar}g) { print qq{found bar at offset $-[0]}; }
 print 'string pos is ', defined(pos $string) ? pos $string : 'UNDEF';
 ;;
 if ($string =~ m{foo}g) { print qq{found foo at offset $-[0]}; }
 print 'string pos is ', defined(pos $string) ? pos $string : 'UNDEF';
 ;;
 if ($string =~ m{bar}g) { print qq{found bar at offset $-[0]}; }
 print 'string pos is ', defined(pos $string) ? pos $string : 'UNDEF';
"
found bar at offset 4
string pos is 7
string pos is UNDEF
found bar at offset 4
string pos is 7