regexp and emacs

You can test your regular expression in emacs by activating the mode regexp-builder.

 Note: the regexp-builder by default will use the lisp syntax, to use the one that emacs use in replace-regexp command you need to change the syntax mode using the command reb-change-syntax, use the value string.

 Another nice way to test your regexp is in this website http://gskinner.com/RegExr/