我一直试图在星期一的实验室之前对FIFO和这种低级别的I / O有所了解,但我发现这种情况并不是很明白。
该计划应该:
服务器:
客户端:
服务器
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
int main(int argc, char* argv[])
{
int s2c, c2s, i;
char fifo_name1[] = "/tmp/fifo1";
char fifo_name2[] = "/tmp/fifo2";
char msg[80], buf[10];
struct stat st;
// if no fifos, create 'em
if (stat(fifo_name1, &st) != 0)
mkfifo(fifo_name1, 0666);
if (stat(fifo_name2, &st) != 0)
mkfifo(fifo_name2, 0666);
s2c= open(fifo_name1, O_WRONLY);
c2s= open(fifo_name2, O_RDONLY);
// start sending messages, with 5s interval
for (i=0; i<5; i++)
{
printf("Message #%d \n", i);
strcat(msg, "Message #");
strcat(msg, itoa(i, buf, 10));
strcat(msg, "\0");
write(s2c, msg, strlen(msg)+1);
sleep(5);
}
// delete fifos
unlink(fifo_name1);
unlink(fifo_name2);
printf("server exit successfully");
return EXIT_SUCCESS;
}
客户端
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
int main(int argc, char* argv[])
{
int c2s, s2c, c=0;
char buf[10];
char fifo_name1[] = "/tmp/fifo1";
char fifo_name2[] = "/tmp/fifo2";
s2c= open(fifo_name1, O_RDONLY);
c2s= open(fifo_name2, O_WRONLY);
// receive messages
while (1)
{
if (read(s2c, &buf, sizeof(char)*10) > 0)
{
printf("%s \n", buf);
c=0;
}
sleep(1);
c++;
if (c>6)
break;
}
printf("client exit successfully");
return EXIT_SUCCESS;
}
答案 0 :(得分:4)
strcat(msg, "Message #");
总是追加到msg
中已经存在的字符串的末尾,并且在循环期间永远不会重置字符串。将其替换为strcpy(msg, "Message #");
以从头开始每条新消息。