text: #include <sys/stat.h>
  #include <errno.h>
  #include <fcntl.h>
  #include <unistd.h>
  #include <stdio.h>
  #include "test.h"
  
  // ============================================================================
  // Helper function
  // ============================================================================
  
  static int create_file(const char *file_path) {
      int fd;
      int flags = O_RDONLY | O_CREAT | O_TRUNC;
      int mode = 00444;
  
      fd = open(file_path, flags, mode);
      if (fd < 0) {
          THROW_ERROR("failed to create a file");
      }
      close(fd);
      return 0;
  }
  
  static int remove_file(const char *file_path) {
      int ret;
  
      ret = unlink(file_path);
      if (ret < 0) {
          THROW_ERROR("failed to unlink the created file");
      }
      return 0;
  }
  
  // ============================================================================
  // Test cases for stat
  // ============================================================================
  
  static int __test_chmod(const char *file_path) {
      struct stat stat_buf;
      mode_t mode = 00664;
      int ret;
  
      ret = chmod(file_path, mode);
      if (ret < 0) {
          THROW_ERROR("failed to chmod file");
      }
      ret = stat(file_path, &stat_buf);
      if (ret < 0) {
          THROW_ERROR("failed to stat file");
      }
      if ((stat_buf.st_mode & 07777) != mode) {
          THROW_ERROR("check chmod result failed");
      }
      return 0;
  }
  
  static int __test_fchmod(const char *file_path) {
      struct stat stat_buf;
      mode_t mode = 00664;
      int fd, ret;
  
      fd = open(file_path, O_RDONLY);
      if (fd < 0) {
          THROW_ERROR("failed to open file");
      }
      ret = fchmod(fd, mode);
      if (ret < 0) {
          close(fd);
          THROW_ERROR("failed to fchmod file");
      }
      close(fd);
      ret = stat(file_path, &stat_buf);
      if (ret < 0) {
          THROW_ERROR("failed to stat file");
      }
      if ((stat_buf.st_mode & 07777) != mode) {
          THROW_ERROR("check fchmod result failed");
      }
      return 0;
  }
  
  typedef int(*test_chmod_func_t)(const char *);
  
  static int test_chmod_framework(test_chmod_func_t fn) {
      const char *file_path = "/root/test_filesystem_chmod.txt";
  
      if (create_file(file_path) < 0) {
          return -1;
      }
      if (fn(file_path) < 0) {
          return -1;
      }
      if (remove_file(file_path) < 0) {
          return -1;
      }
      return 0;
  }
  
  static int test_chmod() {
      return test_chmod_framework(__test_chmod);
  }
  
  static int test_fchmod() {
      return test_chmod_framework(__test_fchmod);
  }
  
  // ============================================================================
  // Test suite main
  // ============================================================================
  
  static test_case_t test_cases[] = {
      TEST_CASE(test_chmod),
      TEST_CASE(test_fchmod),
  };
  
  int main(int argc, const char *argv[]) {
      return test_suite_run(test_cases, ARRAY_SIZE(test_cases));
  }
  