term% cat index.txt WAIT(2) System Calls Manual WAIT(2)
NAME
wait - wait for a process to exit
SYNOPSIS
#include <u.h>
#include <libc.h>
int wait(Waitmsg *w)
DESCRIPTION
Wait causes a process to wait for any child process (see fork(2)) to
exit. It returns the pid of a child that has exited and fills in w
with more information about the child. W points to a Waitmsg, which
has this structure:
typedef
struct Waitmsg
{
char pid[12]; /* of loved one */
char time[3*12]; /* of loved one & descendants */
char msg[ERRLEN];
} Waitmsg;
Pid is the child's process id. The time array contains the time the
child and its descendants spent in user code, the time spent in system
calls, and the child's elapsed real time, all in units of milliseconds.
All integers in a Waitmsg are formatted as right-justified textual num‐
bers in 11-byte fields followed by a blank. Msg contains the message
that the child specified in exits(2). For a normal exit, msg[0] is
zero, otherwise msg is prefixed by the process name, a blank, the
process id, and a colon.
If there are no more children to wait for, wait returns immediately,
with return value -1.
SOURCE
/sys/src/libc/9syscall
SEE ALSO
fork(2), exits(2), the wait file in proc(3)
DIAGNOSTICS
Sets errstr.
WAIT(2)