#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

void preprocess_line(char *s)
{
  int i;

  for (i = 0; s[i] != '\0'; i++) {
    if (s[i] <= 'z' && s[i] >= 'a') s[i] += ('A'-'a');
  }
}

void postprocess_line(char *s)
{
  int i;
  char buf[500];

  if (strlen(s) > 490) return;
  sprintf(buf, "Output: %s", s);
  strcpy(s, buf);
  return;
}

main()
{
  char line[500];
  int p1[2], p2[2];
  FILE *fin, *fout;

  pipe(p1);
  pipe(p2);

  if (fork() == 0) {
    dup2(p1[0], 0);
    dup2(p2[1], 1);
    close(p1[0]);
    close(p1[1]);
    close(p2[0]);
    close(p2[1]);
    execl("./chpmnk", "chpmnk", NULL);
    perror("execl chpmnk");
    exit(1);
  } 

  close(p1[0]);
  close(p2[1]);
  fin = fdopen(p2[0], "r");
  fout = fdopen(p1[1], "w");
  
  while (fgets(line, 500, stdin) != NULL) {

    preprocess_line(line);
    fputs(line, fout);
    fflush(fout);

    if (fgets(line, 500, fin) == NULL) {
      fprintf(stderr, "Alvin, Simon and Theodore messed up again.\n");
      exit(1);
    }
 
    postprocess_line(line);
    fputs(line, stdout);
  }
  exit(0);
}