+(defun getenv (var)
+ "Return the value of the environment variable."
+ #+allegro (sys::getenv (string var))
+ #+clisp (ext:getenv (string var))
+ #+(or cmu scl)
+ (cdr (assoc (string var) ext:*environment-list* :test #'equalp
+ :key #'string))
+ #+lispworks (lw:environment-variable (string var))
+ #+mcl (ccl::getenv var)
+ #+sbcl (sb-ext:posix-getenv var))