alarm(S-osr5)
alarm --
set a process alarm clock
Syntax
cc . . . -lc
#include <unistd.h>
unsigned int alarm(unsigned int seconds);
Description
The alarm function causes the system to send the calling
process a SIGALRM signal after the number of
real time seconds has elapsed. If seconds is zero (0),
a pending alarm request, if any, is cancelled. Processor
scheduling delays may prevent the process from handling the
signal as soon as it is generated.
Refer to
signal(M)
for more information on SIGALRM.
alarm requests are not stacked;
successive calls reset the alarm clock of the calling process.
The
fork(S-osr5)
system call sets the alarm clock
of a child process to 0.
A process created by the
exec(S-osr5)
family of calls inherits the time
left on the old process's alarm clock.
See also
exec(S-osr5),
fork(S-osr5),
getitimer(S-osr5),
signal(M),
sigaction(S-osr5)
Diagnostics
The alarm function is always successful and no return
value is reserved to indicate an error. This function returns
the amount of time, in seconds, remaining before the system is
scheduled to generate the SIGALRM signal from the
previous call to alarm, or zero if there was no
previous alarm request.
Standards conformance
alarm is conformant with:
X/Open Portability Guide, Issue 3, 1989
;
IEEE POSIX Std 1003.1-1990 System Application Program Interface (API) [C Language] (ISO/IEC 9945-1)
;
and
NIST FIPS 151-1
.
© 2005 System Services (S-osr5)
SCO OpenServer Release 6.0.0 -- 02 June 2005