Executing a shell command from Common Lisp

Question

How can i execute a shell (bash) command within a Common Lisp program and assign the output to a variable?

Answer 1

I tried out some answers but it was not straightforward. This is what worked easily:

(ql:quickload "external-program")
;; run shell command e.g. "ls -l" and capture the output into string *output*
(defparameter *output* 
              (with-output-to-string (out) 
                (external-program:run "ls" '("-l")  ; command with parameters as list of strings
                                      :output out)))
;; and after that, you can write functions to parse the output ...

This is from Edi Weitz's book Common Lisp Recipes which belongs to the shelve of any serious Lisp programmer, in my view...