关于#c语言#的问题：【测试数据】命令为：16_4D:\a.txtC:\b.txt【运行结果】在C盘根文件夹下创建文件“b.txt”,并将D盘下的文件“a.txt”内容复制到“b.txt”中

编写一个包含带参数的main函数的程序，实现为指定的文本文件创建一个副本文件的命令。
【测试数据】
命令为：16_4 D:\a.txt C:\b.txt

【运行结果】
在C盘根文件夹下创建文件“b.txt”,并将D盘下的文件“a.txt”内容复制到“b.txt”中。

#include
int main(int argc,char *argv[])
{
    FILE  *fp;
    fp=fopen("a.txt","r");
    if(fp== NULL) { 
    
    puts ("Can't open file .");
    exit (1);
    
    
        
}

剩下的就不会了

#include<stdio.h>
int main() {
   char ch;
   FILE *source, *target;
   char source_file[]="D:\\a.txt";
   char target_file[]="C:\\b.txt";
   source = fopen(source_file, "r");
   if (source == NULL) {
      printf("Press any key to exit...\n");
      return -1;
   }
   target = fopen(target_file, "w");
   if (target == NULL) {
      fclose(source);
      printf("Press any key to exit...\n");
      return -1;
   }
   while ((ch = fgetc(source)) != EOF)
      fputc(ch, target);
   printf("File copied successfully.\n");
   fclose(source);
   fclose(target);
   return 0;
}

主函数 
system（"copy c:\abc.txt d:\abc.txt"）;

#include<stdio.h>
int main() {
   char ch;
   FILE *source, *target;
   char source_file[]="D:\\a.txt";
   char target_file[]="C:\\b.txt";
   source = fopen(source_file, "r");
   if (source == NULL) {
      printf("Press any key to exit...\n");
      return -1;
   }
   target = fopen(target_file, "w");
   if (target == NULL) {
      fclose(source);
      printf("Press any key to exit...\n");
      return -1;
   }
   while ((ch = fgetc(source)) != EOF)
      fputc(ch, target);
   printf("File copied successfully.\n");
   fclose(source);
   fclose(target);
   return 0;
}

#include <stdio.h>
#include <string.h>
int main(){
    freopen("D:/a.txt", "r", stdin);
    freopen("C:/b.txt", "w", stdout);
    char str[1024];
    while (gets(str)){
        printf("%s\n", str);
    }
    return 0;
}

#include <stdio.h>
#include <stdlib.h> // For exit()

int main()
{
    FILE *fptr1, *fptr2;
    char filename[100], c;

    printf("Enter the filename to open for reading \n");
    scanf("%s", filename);

    // Open one file for reading
    fptr1 = fopen(filename, "r");
    if (fptr1 == NULL)
    {
        printf("Cannot open file %s \n", filename);
        exit(0);
    }

    printf("Enter the filename to open for writing \n");
    scanf("%s", filename);

    // Open another file for writing
    fptr2 = fopen(filename, "w");
    if (fptr2 == NULL)
    {
        printf("Cannot open file %s \n", filename);
        exit(0);
    }

    // Read contents from file
    c = fgetc(fptr1);
    while (c != EOF)
    {
        fputc(c, fptr2);
        c = fgetc(fptr1);
    }

    printf("\nContents copied to %s", filename);

    fclose(fptr1);
    fclose(fptr2);
    return 0;
}