process.c

基于ARM9嵌入式开发板LINUX环境下的程序代码

/*
****************************************Copyright (c)**************************************************
**                               Guangzhou Zhiyuan Electronic Co.,LTD.
**                                     graduate school
**                                 http://www.zyinside.com
**
**------------------------------------- File Info ------------------------------------------------------
** File name:           process.c
** Last modified Date:  2005-12-30
** Last Version:        1.0
** Descriptions:        Demo multi-process program.
**------------------------------------------------------------------------------------------------------
** Created by:          Chenxibing
** Created date:        2005-12-30
** Version:             1.0
** Descriptions:        Preliminary version.
**
**------------------------------------------------------------------------------------------------------
** Modified by:
** Modified date:
** Version:
** Descriptions:
**
********************************************************************************************************
*/
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
/*
*******************************************************************************************************
** Function name: mprocess()
** Descriptions	: Demo for fork usage.
** Input	: NONE
** Output	: NONE
** Created by	: Chenxibing
** Created Date	: 2005-12-30
**-----------------------------------------------------------------------------------------------------
** Modified by	:
** Modified Date: 
**-----------------------------------------------------------------------------------------------------
*******************************************************************************************************
*/
int main(int argc, char **argv)
{
    int val, stat;
    pid_t child;

    printf("\nTry to create new process.\n");
    child = fork();

    switch(child)
    {
        case -1:  // fault
        	perror("fork.\n");
        	exit(EXIT_FAILURE);
        case 0:    // child process
        	printf("This is child.\n");
		printf("\tchild pid is %d\n", getpid());
		printf("\tchild ppid is %d\n", getppid());
        	exit(EXIT_SUCCESS);

        default:  // father process
		waitpid(child, &stat, 0);
        	printf("This is parent.\n");
		printf("\tparent pid is %d\n", getpid());
		printf("\tparent ppid is %d\n", getppid());
		printf("\tchild exited with %d\n", stat);
    }

    exit(EXIT_SUCCESS);
}