wait - wait for a process to terminate
integer function wait (status)
Wait causes its caller to be suspended until a signal is received or
one of its child processes terminates. If any child has terminated
since the last wait, return is immediate; if there are no children,
return is immediate with an error code.
If the returned value is positive, it is the process ID of the child
and status is its termination status (see wait(2)). If the returned
value is negative, it is the negation of a system error code.
wait(2), signal(3F), kill(3F), perror(3F)
4th Berkeley Distribution 13 June 1983 WAIT(3F)