pipe_fork.c

Linux网络编程。程序创建一个管道

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int glob = 0;
int var = 0;


int i=0;
int main()
{
    int fd[2];
	int size=0;
	const char final_chars[]="123456";
	char buff[BUFSIZ+1];//BUFSIZ=8192
	pid_t pid;

	memset(buff, '\0', sizeof(buff));
	
	if (pipe(fd)==0){
		pid=fork();
		printf("pid=[%d]   ", pid);
		if (pid==0){ // son 
			i=3;
			printf("son start \n");
			//close(fd[1]);//close write port
			size=read(fd[0], buff, BUFSIZ);
			printf("size is : [%d]   \n", size);
			printf("read chars is : [%s]\n", buff);
			printf("i=%d  \n",i);
			int j;
			for(j=0;j<4;j++)
			{
				var++;
				printf("var=%d \n",var);
			}
			printf("son end!  \n");
		}
		else if (pid==-1){  
			printf ("fork failure\n");
			exit(EXIT_FAILURE);
		}
		else{ // father
		printf("i=%d  \n",i);
			//close(fd[0]);//close read port
			size=write(fd[1], final_chars, strlen(final_chars));
			printf ("wrote %d chars  \n", size);
			int j;
			for(j=0;j<5;j++)
			{
				glob++;
				printf("glob=%d \n",glob);
			}
			wait(0);
			printf("father end   \n");
		}
	}
	else{
		exit(EXIT_FAILURE);
	}

}