Question

我正在编写一个分割文件的程序，但是在运行时遇到了一些问题，我不知道如何解决它。
给我一些指导。有时分割为0kb的所有文件有时都有数据。它困惑了我。

#include <stdio.h>
#include <stdlib.h>

void main()
{
    char *fn = new char[250];
    char *nfn = new char[250];
    long int size, n, size_per_pack;
    FILE *f, *ft; //file and temp file

    printf("enter the file you want to split with full path : ");
    scanf("%s", fn);
    printf("enter the number of parts you want to split the file : ");
    scanf("%ld", &n);

    f = fopen(fn, "rb");
    if (f == NULL)
    {
        printf("couldn't open file");
        exit(0);
    }

    fseek(f, 0, 2);
    size = ftell(f);
    printf("the size of the file in bytes is : %ld\n", size);

    size_per_pack = size / n;
    rewind(f);
    int m = 0;
    char *s1 = new char[size_per_pack];
    for (int j = 1; j <= n; j++)
    {
        sprintf(nfn, "%s.%d", fn, j);
        ft = fopen(nfn, "wb");
        fread(s1, 1, size_per_pack, f);
        fwrite(&s1, 1, size_per_pack, ft);
        rewind(ft);
        int present = ftell(f);
        int present2 = ftell(ft);
    }
    delete[]s1; 
    delete[]fn; 
    delete[]nfn;
    _fcloseall();
}

Answer 1

您应该在每次循环迭代后关闭输出文件：

for (int j = 1; j <= n; j++)
    {
        sprintf(nfn, "%s.%d", fn, j);
        ft = fopen(nfn, "wb");
        fread(s1, 1, size_per_pack, f);
        fwrite(s1, 1, size_per_pack, ft);
        fclose(ft);
    }

按代码c拆分文件时出错

1 个答案: