WAIT(II) 8/5/73 WAIT(II)
NAME
wait - wait for process to die
SYNOPSIS
(wait = 7.)
sys wait
wait(status)
int *status;
DESCRIPTION
Wait causes its caller to delay until one of its child
processes terminates. If any child has died since the last
wait, return is immediate; if there are no children, return
is immediate with the error bit set (resp. with a value of
-1 returned). In the case of several children several wait
calls are needed to learn of all the deaths.
If no error is indicated on return, the r1 high byte (resp.
the high byte stored into status ) contains the low byte of
the child process r0 (resp. the argument of exit ) when it
terminated. The r1 (resp. status ) low byte contains the
termination status of the process. See signal (II) for a
list of termination statuses (signals); 0 status indicates
normal termination. If the 0200 bit of the termination
status is set, a core image of the process was produced by
the system.
If the parent process terminates without waiting on its
children, the initialization process (process ID = 1)
inherits the children.
SEE ALSO
exit (II), fork (II), signal (II)
DIAGNOSTICS
The error bit (c-bit) is set if there are no children not
previously waited for. From C, a returned value of -1
indicates an error.