On Wed, 8 Feb 2023 16:54:41 +0100
Paul Holzinger <pholzing(a)redhat.com> wrote:
Exits codes are very useful for scripts, when the
pasta child execvp()
call fails with ENOENT that parent should also exit with > 0. In short
the parent should always exit with the code from the child to make it
useful in scripts.
It is easy to test with: `pasta -- bash -c "exit 3"; echo $?`
Signed-off-by: Paul Holzinger <pholzing(a)redhat.com>
---
pasta.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/pasta.c b/pasta.c
index 3f6477c..4b18d7e 100644
--- a/pasta.c
+++ b/pasta.c
@@ -64,9 +64,14 @@ void pasta_child_handler(int signal)
if (pasta_child_pid &&
!waitid(P_PID, pasta_child_pid, &infop, WEXITED | WNOHANG)) {
- if (infop.si_pid == pasta_child_pid)
- exit(EXIT_SUCCESS);
- /* Nothing to do, detached PID namespace going away */
+ if (infop.si_pid == pasta_child_pid) {
+ if (infop.si_code == CLD_EXITED)
+ exit(infop.si_status);
+
+ /* else killed by signal, si_status == SIGNUM in this case */
It took me a
while to figure out that SIGNUM is not a constant I wasn't
aware of, just the signal number -- I guess you meant 'signum' from
sigaction() or suchlike?
Maybe you could go with:
/* If killed by a signal, si_status is its number */
+ exit(infop.si_status + 128);
This is a
bit arbitrary -- returning n + 128 is what Bash, zsh, and a
few other shells do, and probably a reasonable convention given that
POSIX says we need to return a value greater than 128. Still I would
mention it:
/* Arbitrary: return signal number + 128 */
or:
/* If killed by a signal, si_status is the number.
* Follow common shell convention of returning it + 128.
*/
+ }
+ /* Nothing to do, detached PID namespace going away */
This should be moved
back into the conditional block (swapping the two
lines above, or moving this comment at the beginning of the block).
Whoops, this
was by accident.
If si_pid is not the child, we need to do other stuff (that is, reap
clones).
> }
>
> waitid(P_ALL, 0, NULL, WEXITED | WNOHANG);