C++文本的读写操作

￡神魔★判官ぃ 2022-06-01 00:41 258阅读 0赞

#include "stdafx.h"
    #include <fstream>
    #include <iostream>
    #include <iomanip> 
    #include<string>
    using namespace std;
    void ByCharRead(char filename[256])
    {
        fstream ByCharFile;
        char c;
        ByCharFile.open(filename, ios::in); //ios::in表示读
        while (!ByCharFile.eof())
        {
            ByCharFile >> c;
            cout << c << endl;
        }
        ByCharFile.close();
    }
    
    void ByLineRead(char filename[256])
    {
        char buffer[256];
        fstream outFile;
        outFile.open(filename, ios::in); //ios::in表示读
        cout << filename << "--- all file is as follows:---" << endl;
        while (!outFile.eof())   //eof表示到文件尾
        {
            outFile.getline(buffer, 256, '\n');//getline(char *,int,char) 表示该行字符达到256个或遇到换行就结束 
            cout << buffer << endl; //控制台输出文本
        }
        outFile.close();
    }
    
    void WriteFile(char filename[256])
    {
        ofstream inFile;
        /*ios::trunc表示在打开文件前将文件清空,由于是写入,文件不存在则创建*/
        inFile.open(filename, ios::trunc);
    
        int i;
        char a = 'a';
        for (i = 1; i <= 26; i++)//将26个数字及英文字母写入文件 
        {
            inFile << setw(2) << i << "\t" << a << "\n";
            a++;
        }
        inFile.close();//关闭文件 
    }
    int main()
    {
        char filenameinput[256] = "F:\\program_work\\c_work\\HelloWord\\a.txt";
        cout << endl << "逐个字符的读取文件：testByChar() " << endl << endl;
        ByCharRead(filenameinput);
        cout << endl << "将文件每行内容存储到字符串中，再输出字符串 ：testByLine()" << endl << endl;
        ByLineRead(filenameinput);
        cout << endl << "文本写入：" << endl << endl;
        char filenameoutput[256] = "F:\\program_work\\c_work\\HelloWord\\b.txt";
        WriteFile(filenameoutput);
    }