文件加解密（二）——使用密码

#define _CRT_SECURE_NO_WARNINGS#define SRC_PATH "C:\\Users\\michael\\Desktop\\yzh.txt"#define CODE_PATH "C:\\Users\\michael\\Desktop\\yzh_code.txt"#define DECODE_PATH "C:\\Users\\michael\\Desktop\\yzh_decode.txt"#include <stdio.h>#include <stdlib.h>#include <string.h>int getFileSize_C(char * file){    int size = -1;    FILE * path;    path = fopen(file, "r");    if (NULL == path)    {        printf("文件打开失败！\n");        return  size; //文件大小不可能为负数    }    else    {        //设置流文件指针的位置,以SEEK_END为起点，偏移量是0,亦即SEEK_END        fseek(path, 0, SEEK_END);        //函数结果：当前文件流指针位置相对于文件起始位置的字节偏移量        size = ftell(path);        fclose(path);        path = NULL;    }    return size;}void code_decode_file_with_psw(char* path, char* newpath,char* psw){    FILE* pRead = fopen(path, "r");    FILE* pWrite = fopen(newpath, "w");    if (pRead == NULL || pWrite == NULL)    {        return;    }    else    {        int ch = 0;        int fileSize = getFileSize_C(path);        int pswLength = strlen(psw);        for (int i = 0; i < fileSize / pswLength; i++)        {            for (int j = 0; j < pswLength; j++)            {                ch = fgetc(pRead);                fputc(ch^psw[j], pWrite);            }        }        for (int k = 0; k <fileSize % pswLength; k++)        {            ch = fgetc(pRead);            fputc(ch^psw[k], pWrite);        }    }    fclose(pRead);    fclose(pWrite);    pRead = NULL;    pWrite = NULL;}void main(){    code_decode_file_with_psw(SRC_PATH, CODE_PATH,"yzh");    code_decode_file_with_psw(CODE_PATH, DECODE_PATH,"yzh");    system("pause");}

说明:文本文件使用密码加密时，不能使用r,w方式打开文件。应该使用rb,wb。