using wait command on completed jobs

[Chris Baugh]

If the wait command is issued on a process ID, where the process ID relates to a job that has completed, and hence the process ID is no longer in existance, is it safe to assume that the returncode from the wait command would be 127?

[unixdaddy]

I would say yes. Try it by issuing a wait against a non-existent pid and then issue the $? straight afterwards it should return 127.

[unixdaddy]

That should read echo $?

[John Palmer]

From some experiments on both HP-UX 11.00 and 10.20, it appears that two waits of the form:
wait
will successfully return the return code from
A third wait returns 127.
Note this is when has been issued by the shell with &
Thus it is only safe to assume a response of 127 on the third (and subsequent calls to wait).

However if you use the format
wait
where is %1 for instance (or %% for the last job issued) then only the first wait returns the valid return code for the job. All subsequent waits of this form return 1.

Regards,
John