使用 fwrite 复制文本文件，结果是垃圾？ C

Question

我正在尝试将文本文件复制到新文件。我在想，如果我想做得聪明，我只需复制所有二进制文件，这样副本将与第一个副本相同。然而，我最终在新文档中得到了奇怪的字符。

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

int main(int argc, char * argv[])
{
    FILE * fporgi, * fpcopy;


    if((fporgi = fopen(argv[1], "rb")) == NULL){
            //Error checking
        fprintf(stdout, "Error occurred trying to open file :%s", argv[1]);
        exit(EXIT_FAILURE);
    }
    if((fpcopy = fopen(argv[2], "wb")) == NULL){
        fprintf(stdout, "Error occurred trying to open file :%s", argv[2]);
        exit(EXIT_FAILURE);
    }

    long bytes;

    fseek(fporgi, 0L, SEEK_END); 
    bytes = ftell(fporgi);
    fprintf(stdout, "\n%ld\n", bytes);

    unsigned char buffer[bytes]; 
    fprintf(stdout, "\n%u\n", sizeof(buffer));
    fread(buffer, sizeof(buffer), 1, fporgi); 
    fwrite(buffer, sizeof(buffer), 1, fpcopy);

    fclose(fporgi);
    fclose(fpcopy);

    return 0;
}

例如，如果原始文件包含“hej svej”，则新文件将包含:“(œÌuR0@NUL”

Answer 1

读取长度后，您需要返回到文件的开头:

fseek(fporgi, 0L, SEEK_END); 
bytes = ftell(fporgi);
fprintf(stdout, "\n%ld\n", bytes);
fseek(fporgi, 0L, SEEK_SET);