How to flush a named pipe (FIFO) after reading from it?

[Mr_Miguel]

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

int main() {
  mkfifo("test",0777);
  int i = open("test",O_RDONLY);
  char* msg = malloc(PIPE_BUF*sizeof(char));
  while(1) {
    read(i,msg,PIPE_BUF);
    printf("%s\n",msg);
  }
  return 0;
}

I build this small program on Ubuntu Linux and successfully compiled it with gcc and executed it. However, if I execute the following command:

echo "This is a sample test" > test

the program keeps printing "This is a sample test" indefinitely. But what I want is to change the program so that it blocks each time it reads, until a new message arrives.

How do I do it? Thank you in advance.

[quzah]

You could always try checking the return value of read. Then do something appropriate.


Quzah.