p6-1.c

来自「UNIX程序设计教程」· C语言 代码 · 共 30 行

#include <unistd.h>
#include <stdio.h>
#include "err_exit.h"
int global = 5;
int main(void)
{
        pid_t pid;
        char *string = "these are values before fork:";
        int local = 10;
        printf(" before fork*** ");
        if ((pid = fork()) < 0)  /* fork调用失败 */  
                err_exit("fork");
        if (pid == 0){            /* 子进程 */
            printf("My pid is %d. %s\n "
                    " variable pid=%d\n global=%d\n local=%d\n ",
                      getpid(),string, pid, global, local);
            string = "I am child.";
                global ++;
        } 
    else {           /* 父进程 */
            printf("My pid is %d. %s\n"
                       " variable pid=%d\n global=%d\n local=%d\n ",
                     getpid(),      string, pid, global, local);
        string = "I am parent.";
                local++;
    }
        printf("%s\n   Now, global=%d, local=%d\n", string, global, local);
    exit(EXIT_SUCCESS);
}