We all know the regular expression character classes, right? There are 12 standard classes:
[:alnum:] [:digit:] [:punct:] [:alpha:] [:graph:] [:space:] [:blank:] [:lower:] [:upper:] [:cntrl:] [:print:] [:xdigit:]But have you seen a visual representation of what these classes match? Probably not. Therefore I created a visualization that illustrates which part of the ASCII set each character class matches.
» Peteris Krumins | catonmat.net