#include <stdio.h>
#include <stdlib.h>
void copyfile(char *src, char *dst)
{
    if (strcmp(src, dst) == 0)//防止源文件与目标文件同名
    {
        printf("Destination file name and source file name can't be the same!");
        exit(1);
    }
    FILE *fsrc = fopen(src, "rb"); //一定要“rb”否则复制的文件有时会不能使用
    FILE *fdst = fopen(dst, "wb"); //一定要“wb”否则复制的文件有时会不能使用
    int buflen = 1024;
    char *buf;
    buf = (char *)malloc(buflen * sizeof(char));
    int nread = 0;

    while ((nread = fread(buf, 1, buflen, fsrc)) > 0) //最好把读文件的代码放这里
    {
        fwrite(buf, nread, 1, fdst);
    }
    free(buf);
    buf = NULL;
    fclose(fsrc);
    fsrc = NULL;
    fclose(fdst);
    fdst = NULL;
}
int main(int argc, char const *argv[])
{
    if (argv[1] == NULL || argv[2] == NULL)
    {
        printf("usage: myCp.exe fileSrc fileDst");
    }
    else
    {
        copyfile(argv[1], argv[2]);
    }

    return 0;
}