usr/src/lib/libc/gen/alarm.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)alarm.c     5.3 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

/*
 * Backwards compatible alarm.
 */
#include <sys/time.h>

alarm(secs)
        int secs;
{
        struct itimerval it, oitv;
        register struct itimerval *itp = &it;

        timerclear(&itp->it_interval);
        itp->it_value.tv_sec = secs;
        itp->it_value.tv_usec = 0;
        if (setitimer(ITIMER_REAL, itp, &oitv) < 0)
                return (-1);
        if (oitv.it_value.tv_usec)
                oitv.it_value.tv_sec++;
        return (oitv.it_value.tv_sec);
}