wait1.c

UNIX编程高级环境（第二版）的进程部分的程序源码

#include    <sys/types.h>
#include    <sys/wait.h>
#include    "ourhdr.h"

int
main(void)
{
    pid_t    pid;
    int        status;

    if ( (pid = fork()) < 0)
        err_sys("fork error");
    else if (pid == 0)        /* child */
        exit(7);

    if (wait(&status) != pid)        /* wait for child */
        err_sys("wait error");
    pr_exit(status);                /* and print its status */

    if ( (pid = fork()) < 0)
        err_sys("fork error");
    else if (pid == 0)        /* child */
        abort();            /* generates SIGABRT */

    if (wait(&status) != pid)        /* wait for child */
        err_sys("wait error");
    pr_exit(status);                /* and print its status */

    if ( (pid = fork()) < 0)
        err_sys("fork error");
    else if (pid == 0)        /* child */
        status /= 0;        /* divide by 0 generates SIGFPE */

    if (wait(&status) != pid)        /* wait for child */
        err_sys("wait error");
    pr_exit(status);                /* and print its status */

    if ( (pid = fork()) < 0)
        err_sys("fork error");
    else if (pid == 0){        /* child */
		printf("pid is %d\n", getpid());
        sleep(30);        /* divide by 0 generates SIGFPE */
		exit(0);
	}

    if (wait(&status) != pid)        /* wait for child */
        err_sys("wait error");
    pr_exit(status);                /* and print its status */

    exit(0);
}