C - 在文件的第二行写入

Question

我正在用 C 语言做 Hangman 游戏，但我在其中一个 txt 文件上遇到了问题。我试图在文件的第二行附加“num_letters”。我猜每次我的代码都会在新行上打印。是否有一种“轻量级”方法可以跳过第一行并附加到第二行？

  void write_stats(int tries, int num_letters)
{
    FILE *stats;
    stats = fopen("C:\\Users\\rjmal\\Documents\\CLION PROJECTS\\JogoDaForca\\stats.txt", "a");
    fprintf(stats," %d",tries);
    fprintf(stats,"\n %d",num_letters);
    fclose(stats);
}

Answer 1

给你:

/* Compiles with: gcc main.c -o test -pedantic -Wall -Wextra */
#include <stdio.h>

int write_stats(const int tries, const int num_letters, FILE* file) {
  if (!file)
    return -1;
  const int written = fprintf(file, "%d\n%d", tries, num_letters);
  if (written < 0)
    return -1;
  return 0;
}

int read_stats(int* tries, int* num_letters, FILE* file) {
  if (!file)
    return -1;

  if (fscanf(file, "%d\n%d", tries, num_letters) != 2)
    return -1;
  return 0;
}

int main() {
  /* writing stats */
  FILE* w_stats = fopen("stats.dat", "w");
  if (!w_stats) {
    fprintf(stderr, "Could not open the file specified!\n");
    return 1;
  }
  if (write_stats(3, 8, w_stats) != 0) {
    fprintf(stderr, "Problem occoured while writing stats!\n");
    fclose(w_stats);
    return 1;
  }
  fclose(w_stats);

  /* reading the stats */
  FILE* r_stats = fopen("stats.dat", "r");
  if (!r_stats) {
    fprintf(stderr, "Could not open the file specified!\n");
    return 1;
  }
  int tries, num_letters;
  if (read_stats(&tries, &num_letters, r_stats) != 0) {
    fprintf(stderr, "Problem occoured while reading stats!\n");
    fclose(r_stats);
    return 1;
  }
  fclose(r_stats);
  printf("tries: %d, num_letters: %d\n", tries, num_letters);

  return 0;
}

希望这是有道理的，我认为这不需要任何进一步的解释，因为代码本身就解释了它。但是，如果您想澄清一些事情，请随时询问。