abort.c

UNIX编程高级环境（第二版）的信号部分的程序源码

#include <sys/signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

void
abort(void)            /* POSIX-style abort() function */
{
    sigset_t            mask;
    struct sigaction    action;

        /* caller can't ignore SIGABRT, if so reset to default */
    sigaction(SIGABRT, NULL, &action);
    if (action.sa_handler == SIG_IGN) {
        action.sa_handler = SIG_DFL;
        sigaction(SIGABRT, &action, NULL);
    }

    if (action.sa_handler == SIG_DFL)
        fflush(NULL);            /* flush all open stdio streams */

        /* caller can't block SIGABRT; make sure it's unblocked */
    sigfillset(&mask);
    sigdelset(&mask, SIGABRT);    /* mask has only SIGABRT turned off */
    sigprocmask(SIG_SETMASK, &mask, NULL);

    kill(getpid(), SIGABRT);    /* send the signal */

        /* if we're here, process caught SIGABRT and returned */
    fflush(NULL);                /* flush all open stdio streams */

    action.sa_handler = SIG_DFL;
    sigaction(SIGABRT, &action, NULL);    /* reset disposition to default */
    sigprocmask(SIG_SETMASK, &mask, NULL);    /* just in case ... */

    kill(getpid(), SIGABRT);                /* and one more time */

    exit(1);    /* this should never be executed ... */
}