unsigned
int
alarm(
unsigned int seconds
)
The
alarm()
function sets a timer to deliver the signal
SIGALRM
to the calling process
seconds
after the call to
alarm().
If an alarm has already been set with
alarm(
)
but has not been delivered, another call to
alarm(
)
will supersede the prior call.
The request
alarm(
0
)
voids the current
alarm and the signal SIGALRM will not be delivered.
The maximum number of
seconds
allowed
is 2147483647.
The return value of
alarm()
is the amount of time left on the timer from a previous call to
alarm(
).
If no alarm is currently set, the return value is 0.
If there is an error setting the timer,
alarm(
)
returns ((unsigned int) -1).
)
function conforms to
ISO/IEC 9945-1:1990 (``POSIX.1'') .
)
function appeared in
Version 7 AT&T UNIX
.