fork_descriptor.c

linux下的程序开发（C语言实现）：本程序主要实现linux下进程的管理

#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
int main(int argc,char *argv[])
{
    pid_t pid;
    int fd;
    int i=1;
    int status;
    char *ch1="hello";
    char *ch2="world";
    char *ch3="IN";
    if((fd=open("test.txt",O_RDWR|O_CREAT,0644))==-1)
    {
	perror("parent open");
	exit(EXIT_FAILURE);
    }
    if(write(fd,ch1,strlen(ch1))==-1)
    {	 
	perror("parent write");
	exit(EXIT_FAILURE);
    }
    
    if((pid=fork())==-1)
    {
	perror("fork");
	exit(EXIT_FAILURE);
    }
    else if(pid==0)
    {
	i=2;	
	printf("in child\n");
	printf("i=%d\n",i);
	if(write(fd,ch2,strlen(ch2))==-1)
	    perror("child write");
	return 0;
    }
    else
    {
	sleep(1);
	printf("in parent\n");
	printf("i=%d\n",i);
	if(write(fd,ch3,strlen(ch3))==-1)
	    perror("parent,write");
	wait(&status);
	return 0;
    }
}