Question about use of uiop:launch-program

[rpgoldman]

py4cl/src/python-process.lisp

Lines 17 to 34 in 601ed20

 (defun python-start (&optional (command *python-command*)) 
   "Start a new python subprocess 
 This sets the global variable *python* to the process handle, 
 in addition to returning it. 
 COMMAND is a string with the python executable to launch e.g. \"python\" 
 By default this is is set to *PYTHON-COMMAND* 
 " 
   (setf *python* 
         (uiop:launch-program 
          (concatenate 'string 
                       "exec " 
                       command  ; Run python executable 
                       " " 
                       ;; Path *base-pathname* is defined in py4cl.asd 
                       ;; Calculate full path to python script 
                       (namestring (merge-pathnames #p"py4cl.py" py4cl/config:*base-directory*))) 
          :input :stream :output :stream)) 
   (incf *current-python-process-id*)) 

Is there some reason for using the shell + exec instead of just using the binary directly? This would be something like the following:

(uiop:launch-program
              (list command 
                      ;; Calculate full path to python script
                      (namestring (merge-pathnames #p"py4cl.py" py4cl/config:*base-directory*)) 
              :input :stream :output :stream))

I would guess that using the shell might introduce some oddities depending on the user's configuration.

Thanks!

[Shubhamkar Ayare]

I ended up removing exec in this context in py4cl2 very early on, so I too am curious about if it was important.