#include <errno.h>
#include <fcntl.h>  
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/wait.h>
#define BUFSIZE 256
#define FIFO_PERM  (S_IRUSR | S_IWUSR)

int dofifochild(const char *fifoname, const char *idstring);
int dofifoparent(const char *fifoname);

int main (int argc, char *argv[]) {
   pid_t childpid; 

   if (argc != 2) {                           /* command line has pipe name */
      fprintf(stderr, "Usage: %s pipename\n", argv[0]);
      return 1; 
   }
   if (mkfifo(argv[1], FIFO_PERM) == -1) {           /* create a named pipe */
      if (errno != EEXIST) {
         fprintf(stderr, "[%ld]:failed to create named pipe %s: %s\n", 
              (long)getpid(), argv[1], strerror(errno));
         return 1; 
      }
   }
   if ((childpid = fork()) == -1){
      perror("Failed to fork");
      return 1;
   } 
   if (childpid == 0)                                   /* The child writes */
      return dofifochild(argv[1], "this was written by the child");
   else
      return dofifoparent(argv[1]);
}