scsh name Posix ctype Alternate ----------------------------------------- lower-case lower upper-case upper alphabetic alpha numeric digit num alphanumeric alnum alphanum punctuation punct graphic graph blank (Gnu extension) whitespace space white ("space" is potentially confusing.) printing print control cntrl hex-digit xdigit hex ascii ascii (Gnu extension) SRE ::= ... <char-class> ... <char-class> ::= <char> | any | nonl | <class-name> | (in <char-class-arg> ...) | (not-in <char-class-arg> ...) | (and <char-class-arg> ...) | (diff <char-class-arg> ...) | (- <char-or-string> ...) | ,<cset-exp> <char-class-arg> ::= <char-class> | <string> (diff <arg1> <arg2> ...) = (and <arg1> (not-in <arg2> ...)) ~!@#$%^&*-_+=|:<>?/ in (: ...) sequence (and ...) (or ...) (not ...) (diff ...) (* ...) (+ ...) (- ...) (in ...) ; union (not-in ...) ; complement-of-union (and ...) ; intersection (diff ...) ; diff (+ ...) ; union (~ ...) ; complement-of-union (& ...) ; intersection (- ...) ; diff (in ...) ; union (~ ...) ; complement-of-union (& ...) ; intersection (- ...) ; diff