linux fork()º¯Êýѧϰ

#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
int main()
{
    pid_t pid;
    static int n = 0;
    printf("fork!\n"); /*printf("fork!")*/
    switch (pid = fork())
    {
        case -1:
        {
            /* ÕâÀïpidΪ-1£¬forkº¯Êýʧ°Ü */
            /* һЩ¿ÉÄܵÄÔ­ÒòÊÇ */
            /* ½ø³ÌÊý»òÐéÄâÄÚ´æÓþ¡ */
            perror("The fork failed!");
            break;
        }
        case 0:
        {
            /* pidΪ0£¬×Ó½ø³Ì */
            printf("[child]i am child!\n");
            printf("[child]getpid=[%d]\n", getpid() );
            printf("[child]pid=[%d]\n", pid );
            break;
        }
        default:
        {
            /* pid´óÓÚ0£¬¸¸½ø³Ì */
            printf("[parent]i am parent!\n" );
            printf("[parent]getpid=[%d]\n",getpid() );
            printf("[paren