When I use exec or ! to run a shell command, I want to get strings containing the contents of stdout and stderr (even if empty) as well as the exit code of the program.
I could direct the output in the command like so:
(! "ls 2>/tmp/err >/tmp/out")
And then just read those files but that seems horribly crufty.
Now exec gives me stdout but I still want exit code and stderr.
Is there a better way to see what is happening with the programs I run?
Old post but it's worth a reply as I was also looking for a solution.
process and waitpid can be used. An example returning stdout/stderr
combined and the return code of the command:
(define (exec2 cmd)
(let ((pid) (out_r) (out_w) (output) (data))
(map set '(out_r out_w) (pipe))
(setq pid (process cmd 0 out_w))
(close out_w)
(while (read out_r data 1024)
(extend output data))
(list output (>> ((wait-pid pid) 1) 8))))
Examples of the execution of a successful and a failed command:
> (exec2 "/bin/echo pouet")
("pouetn" 0)
> (exec2 "/bin/ls /root")
("/bin/ls: cannot open directory /root: Permission deniedn" 2)
It depends on the platform of course. With bash and similar, you could also have
That will nicely parse and deliver the output (stdout and stderr) as a list of lines, with the addition of the return code as an additional string element at the end.