C 命名文件日期

Question

首先:我知道，以前也出现过一些类似的问题，但它对我不起作用。
我需要在 C 中创建一个 .txt 文件，名为“年/月/日_小时:分钟
我的代码是:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
int main(){
int hours, minutes, seconds, day, month, year;
char fileSpec [255];
//TIME for file name
    time_t now;
    time(&now);
    printf("Today is : %s", ctime(&now));
    struct tm *local = localtime(&now);
 
    hours = local->tm_hour;          
    minutes = local->tm_min;         
    seconds = local->tm_sec;         
 
    day = local->tm_mday;            
    month = local->tm_mon + 1;       
    year = local->tm_year + 1900;   
      
    //Time block end

    //create file
    FILE * fPointer;
    snprintf( fileSpec, "%04d_%02d_%02d_%02d:%02d.txt",year,month,day,hours,minutes); //From another post. I do not exactly know the syntax
    fPointer = fopen(fileSpec,"w");
    fprintf(fPointer ,"Date and Time of creation: %d/%d/%d %d:%d:%d\n",day,month,year,hours,minutes,seconds);
}

Sry 我奇怪的格式:/
我还是个初学者。
编辑:整个代码是: https://pastebin.com/78fSRJgx

Answer 1

调用 snprintf 的第二个参数应该是 max。缓冲区大小，您没有给出该参数。更换

snprintf( fileSpec, "%04d_%02d_%02d_%02d:%02d.txt",year,month,day,hours,minutes);

和

snprintf( fileSpec, 255, "%04d_%02d_%02d_%02d:%02d.txt",year,month,day,hours,minutes);

(其中 255 是 snprintf 将写入的字符串的最大长度)似乎应该可以解决您的问题。