There are various different regular expression libraries available for Lisp. A nice overview can be found at CLiki. I had a look at the Portable Perl-compatible regular expressions for Common Lisp (CL-PPCRE). Installation is very easy using Quicklisp. After installation you can add the library to your image as follows.
Then you can use the library in your code. Let’s define a very simple function to extract some text from a given string.
(:use :common-lisp :cl-ppcre)
(defun print-match ()
(let ((a 0) (b 0))
(setf (values a b) (cl-ppcre:scan-to-strings ” ([a-z]+) ” “My text string.”))
(print (aref b 0))))