sleep1.c

UNIX编程高级环境（第二版）的信号部分的程序源码

#include    <signal.h>
#include    <unistd.h>

static void
sig_alrm(int signo)
{
    return;    /* nothing to do, just return to wake up the pause */
}

unsigned int
sleep1(unsigned int nsecs)
{
    if (signal(SIGALRM, sig_alrm) == SIG_ERR)
        return(nsecs);
    alarm(nsecs);        /* start the timer */
    pause();            /* next caught signal wakes us up */
    return( alarm(0) );    /* turn off timer, return unslept time */
}