为何程序通过命名管道传递值却输出内存地址而非目标值？

我在使用命名管道实现父子进程间数值传递时遇到问题，测试传入值22，却持续得到类似整数内存地址的无效结果。以下是我的C语言代码及运行输出：

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

void fib(int n) {
  int fib1;
  int fib2;
  int fd;
  int sum;

  char * myfifo = "/home/user/Desktop";
  mkfifo("myfifo", 0666);

  if (mkfifo("myfifo", 0666) < 0 && errno != EEXIST) {
    perror("mkfifo failure");
    exit(1);
  }

  if ((fd = open("myfifo", O_WRONLY)) < 0) {
    perror("open failure");
    exit(2);
  }

  if (n == 0 || n == 1) {
    fib1 = 22;

    write(fd, &fib1, sizeof(fib1)); // write fib(n) into the pipe/shared memory/shared queue

    close(fd);
    return;
  } else {
    int pid = fork();
    if (pid == 0) {
      // child
      fib(n - 1);
      exit(0);
    } else {
      waitpid(pid, NULL, 0); // parent
      fib(n - 2);
      read(fd, &fib1, sizeof(fib1)); // read fib(n - 1) & fib(n - 2) from the pipe/shared memory/shared queue
      read(fd, &fib2, sizeof(fib2)); // read fib(n - 1) & fib(n - 2) from the pipe/shared memory/shared queue
      printf("Value 1: %d\n", fib1);
      printf("Value 2: %d\n", fib2);
      sum = fib1 + fib2;
      printf("Sum: %d\n", sum);
      write(fd, &sum, sizeof(sum)); // write fib(n) back into the pipe/shared memory/shared queue

    }

    return;
  }
  printf("Sum: %d", sum);
}

int main() {
  int value;
  printf("Enter number to be calculated: ");
  scanf("%d", &value);
  fib(value);
  return 0;
}

运行输出：

Enter number to be calculated: 3
Value 1: -140833897
Value 2: 0
Sum: -140833897
Value 1: 0
Value 2: 0
Sum: 0

内容的提问来源于stack exchange，提问作者Michael