linux 管道通信

下面举linux下有名管道通信的代码。

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fifo_read.c

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#include<errno.h>
#include<stdio.h>
#include<memory.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#define FIFO "myfifo"

int main(void)
{
int fd;
int num;
char buff[100];
if(access(FIFO,F_OK) == -1)
{
mkfifo(FIFO,0777);
}
fd = open(FIFO,O_RDONLY|O_NONBLOCK);
if(fd < 0)
{
printf("open fifo error:%s\n",strerror(errno));
}
printf("open fifo fd=%d\n",fd);
while(1)
{
num=0;
memset(buff,'\0',100);
num=read(fd,buff,100);
if(num<0)
{
printf("read fifo:%s\n",strerror(errno));
}
else if(num==0)
{
printf("no data to read.\n");
}
else
{
printf("read [%d] bytes in fifo,it is [%s].\n",num,buff);
}
sleep(1);
}
return 0;
}

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fifo_write.c

==========

#include<stdio.h>
#include<fcntl.h>
#include<memory.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#define FIFO "myfifo"

int main(void)
{
int fd;
char buff[100];
int num =0;
if(access(FIFO,F_OK)== -1)
{
mkfifo(FIFO,0777);
}
fd = open(FIFO,O_WRONLY);
if(fd < 0)
{
printf("open fifo error!\n");
}
printf("open file fd=%d\n",fd);
while(1)
{
memset(buff,'\0',100);
num=0;
printf("please write less than 100 letters:\n");
scanf("%s",buff);
num= write(fd,buff,strlen(buff));
printf("[%d] letters is written,it is [%s]\n",num,buff);
sleep(1);
}
return 0;
}