NAME¶
wait - check child process status
SYNTAX¶
#include <wait.h>
int
wait_nohang(&
wstat);
int
wait_stop(&
wstat);
int
wait_stopnohang(&
wstat);
int
wait_pid(&
wstat,
pid);
int
wait_exitcode(
wstat);
int
wait_crashed(
wstat);
int
wait_stopped(
wstat);
int
wait_stopsig(
wstat);
int
pid;
int
wstat;
DESCRIPTION¶
wait_nohang looks for zombies (child processes that have exited). If it
sees a zombie, it eliminates the zombie, puts the zombie's exit status into
wstat, and returns the zombie's process ID. If there are several
zombies,
wait_nohang picks one. If there are children but no zombies,
wait_nohang returns 0. If there are no children,
wait_nohang
returns -1, setting
errno appropriately.
wait_stopnohang is similar to
wait_nohang, but it also looks for
children that have stopped.
wait_stop is similar to
wait_stopnohang, but if there are children
it will pause waiting for one of them to stop or exit.
wait_pid waits for child process
pid to exit. It eliminates any
zombie that shows up in the meantime, discarding the exit status.
wait_stop and
wait_pid retry upon
error_intr.
STATUS PARSING¶
If the child stopped,
wait_stopped is nonzero;
wait_stopsig is the
signal that caused the child to stop.
If the child exited by crashing,
wait_stopped is zero;
wait_crashed is nonzero.
If the child exited normally,
wait_stopped is zero;
wait_crashed
is zero; and
wait_exitcode is the child's exit code.
SEE ALSO¶
wait(2),
error(3)