io操作（代码）

#define _CRT_SECURE_NO_WARNINGS#include "stdlib.h"#include "stdio.h"#include "string.h"//读取文本文件/*void main(){char *path = "E:\\ndk\\08_08_C_05\\files\\friends.txt";//打开FILE *fp = fopen(path,"r");if (fp == NULL){printf("文件打开失败...");return;}//读取char buff[50]; //缓冲while (fgets(buff,50,fp)){printf("%s",buff);}//关闭fclose(fp);system("pause");getchar();}*///写入文本文件/*void main(){char *path = "E:\\ndk\\08_08_C_05\\files\\friends_new.txt";//打开FILE *fp = fopen(path, "w");char *text = "[e-mail],程华才,学清路 8\n号科技财富中心 A";fputs(text,fp);//关闭流fclose(fp);getchar();}*///计算机的文件存储在物理上都是二进制//文本文件和二进制之分，其实是一个逻辑之分//C读写文本文件与二进制文件的差别仅仅体现在回车换行符//写文本时，每遇到一个'\n'，会将其转换成'\r\n'(回车换行)//读文本时，每遇到一个'\r\n'，会将其转换成'\n'//文件复制/*void main(){char *read_path = "E:\\ndk\\08_08_C_05\\files\\liuyan.png";char *write_path = "E:\\ndk\\08_08_C_05\\files\\liuyan_new.png";//读的文件 b字符表示操作二进制文件binaryFILE *read_fp = fopen(read_path, "rb");//写的文件FILE *write_fp = fopen(write_path, "wb");//复制int buff[50]; //缓冲区域int len = 0; //每次读到的数据长度while ((len = fread(buff, sizeof(int), 50, read_fp)) != 0){//将读到的内容写入新的文件fwrite(buff,sizeof(int),len,write_fp);}//关闭流fclose(read_fp);fclose(write_fp);getchar();}*///获取文件的大小/*void main(){char *read_path = "E:\\ndk\\08_08_C_05\\files\\liuyan.png";FILE *fp = fopen(read_path, "r");//重新定位文件指针//SEEK_END文件末尾，0偏移量fseek(fp,0,SEEK_END);//返回当前的文件指针，相对于文件开头的位移量long filesize = ftell(fp);printf("%d\n",filesize);getchar();}*///练习：文本文件加解密/*//异或//规则：1^1=0, 0^0=0, 1^0=1, 0^1=1 同为0，不同为1//加密void crpypt(char normal_path[],char crypt_path[]){//打开文件FILE *normal_fp = fopen(normal_path, "r");FILE *crypt_fp = fopen(crypt_path, "w");//一次读取一个字符int ch;while ((ch = fgetc(normal_fp)) != EOF){ //End of File//写入（异或运算）fputc(ch ^ 9,crypt_fp);}//关闭fclose(crypt_fp);fclose(normal_fp);}//解密void decrpypt(char crypt_path[], char decrypt_path[]){//打开文件FILE *normal_fp = fopen(crypt_path, "r");FILE *crypt_fp = fopen(decrypt_path, "w");//一次读取一个字符int ch;while ((ch = fgetc(normal_fp)) != EOF){ //End of File//写入（异或运算）fputc(ch ^ 9, crypt_fp);}//关闭fclose(crypt_fp);fclose(normal_fp);}void main(){char *normal_path = "E:\\08_08_C_05\\files\\friends.txt";char *crypt_path = "E:\\ndk\\08_08_C_05\\files\\friends_crypt.txt";char *decrypt_path = "E:\\ndk\\08_08_C_05\\files\\friends_decrypt.txt";//crpypt(normal_path, crypt_path);//解密decrpypt(crypt_path, decrypt_path);getchar();}*///二进制文件加解密//读取二进制文件中的数据时，一个一个字符读取//密码：ilovely/*void crpypt(char normal_path[], char crypt_path[],char password[]){//打开文件FILE *normal_fp = fopen(normal_path, "rb");FILE *crypt_fp = fopen(crypt_path, "wb");//一次读取一个字符int ch;int i = 0; //循环使用密码中的字母进行异或运算int pwd_len = strlen(password); //密码的长度while ((ch = fgetc(normal_fp)) != EOF){ //End of File//写入（异或运算）fputc(ch ^ password[i % pwd_len], crypt_fp);i++;}//关闭fclose(crypt_fp);fclose(normal_fp);}//解密void decrpypt(char crypt_path[], char decrypt_path[],char password[]){//打开文件FILE *normal_fp = fopen(crypt_path, "rb");FILE *crypt_fp = fopen(decrypt_path, "wb");//一次读取一个字符int ch;int i = 0; //循环使用密码中的字母进行异或运算int pwd_len = strlen(password); //密码的长度while ((ch = fgetc(normal_fp)) != EOF){ //End of File//写入（异或运算）fputc(ch ^ password[i % pwd_len], crypt_fp);i++;}//关闭fclose(crypt_fp);fclose(normal_fp);}void main(){char *normal_path = "E:\\08_08_C_05\\files\\liuyan.png";char *crypt_path = "E:\\ndk\\08_08_C_05\\files\\liuyan_crypt.png";char *decrypt_path = "E:\\ndk\\08_08_C_05\\files\\liuyan_decrypt.png";//crpypt(normal_path, crypt_path,"iloveqq");//解密decrpypt(crypt_path, decrypt_path,"iloveqq");getchar();}*/