waitpid

Wait for the termination of arbitrary processes. See also: wait. More information: https://manned.org/waitpid.1.

• Sleep until all processes whose PIDs have been specified have exited:

waitpid {{pid1 pid2 ...}}

• Sleep for at most n seconds:

waitpid --timeout {{n}} {{pid1 pid2 ...}}

• Do not error if specified PIDs have already exited:

waitpid --exited {{pid1 pid2 ...}}

• Sleep until n of the specified processes have exited:

waitpid --count {{n}} {{pid1 pid2 ...}}

• Display help:

waitpid -h