fatherandchildpipe.c

这是linux下的基础C编程代码。都是已经调试成功的

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <limits.h>


int main()
{
	int pipe_fd1[2],pipe_fd2[2],pipe_fd3[2],pipe_fd4[2];

    pid_t child1,child2,child3,child4;
	
	char buf_r1[100],buf_r2[100],buf_r3[100],buf_r4[100];
	char *p_wbuf;
	int r_num;
	char s[100];
	int len;
	int i;

//memset(buf_r1,0,sizeof(buf_r1));
//	memset(buf_r2,0,sizeof(buf_r2));
//	memset(buf_r3,0,sizeof(buf_r3));
//	memset(buf_r4,0,sizeof(buf_r4));

	if(pipe(pipe_fd1)<0)
	{
		printf("creat pipe error");
		return -1;
	}

	if(pipe(pipe_fd2)<0)
	{
		printf("creat pipe error");
		return -1;
	}

	if(pipe(pipe_fd3)<0)
	{
		printf("creat pipe error");
		return -1;
	}

	if(pipe(pipe_fd4)<0)
	{
		printf("creat pipe error");
		return -1;
	}

	if((child1=fork())==0)
	{
		close(pipe_fd1[1]);
		sleep(2);

		while((r_num=read(pipe_fd1[0],buf_r1,PIPE_BUF-1))>0)
		{    
	        printf("child1 %d numbers read from pipe is %s\n",r_num,buf_r1);
        }
	}

	else if((child2=fork())==0)
	{
		close(pipe_fd2[1]);
		sleep(2);

		while((r_num=read(pipe_fd2[0],buf_r2,PIPE_BUF-1))>0)
		{    
	        printf("child2 %d numbers read from pipe is %s\n",r_num,buf_r2);
        }
	}

	else if((child3=fork())==0)
	{
		close(pipe_fd3[1]);
		sleep(2);

	    while((r_num=read(pipe_fd3[0],buf_r3,PIPE_BUF-1))>0)
		{    
	        printf("child3 %d numbers read from pipe is %s\n",r_num,buf_r3);
        }
	}

	else if((child4=fork())==0)
	{
		close(pipe_fd4[1]);
		sleep(2);

		while((r_num=read(pipe_fd4[0],buf_r4,PIPE_BUF-1))>0)
		{    
	        printf("child4 %d numbers read from pipe is %s\n",r_num,buf_r4);
        }
	}

	else
	{ 
		close(pipe_fd1[0]);
		close(pipe_fd2[0]);
		close(pipe_fd3[0]);
		close(pipe_fd4[0]);

		while(1)
		{
			printf("please input data\n");
			scanf("%s",s);
              // printf("data is %s\n",s);
			len=strlen(s);
              //    printf("data len is %d\n",len);
		
		       if(write(pipe_fd1[1],s,len)!=-1)
			   {
		    	    printf("write data to pipe success\n");
			   }

			   if(write(pipe_fd2[1],s,len)!=-1)
			   {
		    	    printf("write data to pipe success\n");
			   }

			   if(write(pipe_fd3[1],s,len)!=-1)
			   {
		    	    printf("write data to pipe success\n");
			   }

			    if(write(pipe_fd4[1],s,len)!=-1)
			   {
		    	    printf("write data to pipe success\n");
			   }
		}
	}
}