How can I match everything that is after the last occurrence of some char in a perl regular expression?

Question

For example, return the part of the string that is after the last x in axxxghdfx445 (should return 445).

Answer 1

the first answer is a good one, but when talking about "something that does not contain"... i like to use the regex that "matches" it

my($substr) = $string =~ /.*x([^x]*)$/;

very usefull in some case