topic Re: using wait command on completed jobs in Operating System - HP-UX

using wait command on completed jobs

Chris Baugh — Thu, 22 Mar 2001 13:15:32 GMT

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?

Re: using wait command on completed jobs

unixdaddy — Thu, 22 Mar 2001 13:23:49 GMT

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.

Re: using wait command on completed jobs

unixdaddy — Thu, 22 Mar 2001 13:25:40 GMT

That should read echo $?

Re: using wait command on completed jobs

John Palmer — Thu, 22 Mar 2001 14:03:51 GMT

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