gistfile1.c

int main(void) {
  int pfd[2];      /* Pipe’s file descriptors. */
  pid_t child_pid; /* Child’s process id. */
  /* Set up pipe. */
  if (pipe(pfd) == -1) {
    fprintf(stderr, "Call to pipe failed.\n");
    exit(1);
  }
  /* FILE *out = fdopen(pfd[1], "a"); */

  /* Fork a child process and let it execute the grep command. */
  if ((child_pid = fork()) == 0) {
    /* The child process. First, redirect its stdout to pipe. */
    if (dup2(pfd[1], STDOUT_FILENO) == -1) {
      fprintf(stderr, "dup2 in child failed.\n");
      exit(1);
    }
    if (dup2(pfd[0], STDIN_FILENO) == -1) {
      fprintf(stderr, "dup2 in child failed.\n");
      exit(1);
    }
    /* Now that redirection of stdout to pipe has been accomplished, */
    /* remove the file descriptors for the pipe from the child’s */
    /* file descriptor table. */
    if (close(pfd[0]) == -1) { /* Failed to close read end of pipe. */
      fprintf(stderr, "Couldn’t close read end of pipe in child\n");
      exit(1);
    }
    if (close(pfd[1]) == -1) { /* Failed to close write end of pipe. */
      fprintf(stderr, "Couldn’t close write end of pipe in child\n");
      exit(1);
    }

    /* Exec the grep command. */
    execlp("cat", "cat",
           "/home/yyoncho/Sources/nim/jsonrpc/test/fixtures/message.txt", NULL);
    /* If the following statement is reached, execlp must have failed. */
    /* close(int __fd) */
    /* fprintf(stderr, "Call to execlp in child failed.\n"); */
    exit(1);
  } /* End of child. */
  else {
    /* The parent process. Make sure that fork worked. */
    if (child_pid == (pid_t)-1) {
      fprintf(stderr, "The call to fork failed.\n");
      exit(1);
    }

    printf("XX");

    char *line;
    size_t len;

    FILE *in = fdopen(pfd[0], "r");

    /* FILE *fp = pfd[0]; */

    int header_len = strlen("Content-Length:");

    printf("XX");
    while ((getline(&line, &len, in) != -1)) {
      char *end;
      if (!strncmp(line, "Content-Length:", header_len)) {
        size_t message_lenght = strtol(line + header_len, &end, 36);

        char *buf = (char *)malloc(message_lenght);
        /* printf(">> message_lenght = %d\n", message_lenght); */

        // skip new lines after the header
        while ((getline(&line, &len, in) != -1) && (strcmp(line, "\r\n") != 0))
          ;

        /* read(; */
        int res = fread(buf, 8, 1, in);

        printf(">> res = |%d|\n", res);
        printf(">> buf = |%s|\n", buf);

        int c = fgetc(in);
        printf(">>>>>>> XXXXX\n");

        if (c == EOF) {
          break;
        } else {
          printf(">>>>>>> %d\n", c);
          ungetc(c, in);
        }

        /* free(buf); */
      }
    }

    /* pclose(in); */
  } /* End of parent. */
  return 0;
} /* End of main. */