进程间通信——管道通信

远行的心

　　pipe管道通信


#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>
#include<sys/types.h>
int main(){
pid_t childpid;
int fd[2];
pipe(fd);
char writebuf[]="this if from centos";
char readbuf[100];
if((childpid=fork())==-1){
perror("fork error");
exit(1);
}
printf("after fork %d\n",childpid);
if(childpid==0){
close(fd[0]);//读管道
write(fd[1],writebuf,(strlen(writebuf)+1));
printf("this is father\n");
printf("childpid in if is %d\n",childpid);
exit(0);
}
else{
close(fd[1]);//写管道
printf("childpid in else %d \n",childpid);
read(fd[0],readbuf,100);
printf("childpid in else %d \n",childpid);
printf("received string:%s\n",readbuf);
}
return 0;}
　　执行效果如下，这个我也搞得不是很清楚，自己看运行结果吧，那些打印语句就是我故意写上去，看看运行结果的

[iyunv@bogon bp]# ./a.out
after fork 85552
childpid in else 85552
after fork 0
this is father
childpid in if is 0
childpid in else 85552
received string:this if from centos