#include stdio.h> 
#include unistd.h> 
#include stdlib.h> 
#include string.h> 
 
int pipe_default[2]; 
 
int main() 
{ 
 pid_t pid; 
 char buffer[32]; 
 
 memset(buffer, 0, 32); 
 if(pipe(pipe_default)  0) 
 { 
  printf("Failed to create pipe!\n"); 
  return 0; 
 } 
 
 if(0 == (pid = fork())) 
 { 
  close(pipe_default[1]); 
  sleep(5); 
  if(read(pipe_default[0], buffer, 32) > 0) 
  { 
   printf("Receive data from server, %s!\n", buffer); 
  } 
  close(pipe_default[0]); 
 } 
 else 
 { 
  close(pipe_default[0]); 
  if(-1 != write(pipe_default[1], "hello", strlen("hello"))) 
  { 
   printf("Send data to client, hello!\n"); 
  } 
  close(pipe_default[1]); 
  waitpid(pid, NULL, 0); 
 } 
 
 return 1; 
} 

[test@localhost pipe]$ ./pipe 
Send data to client, hello! 
Receive data from server, hello!