/********************************************************Copyright (C), 2016-2018,FileName: mainAuthor:     woniu201Created:    2018/08/31Description: 文件操作：讀取指定行，刪除指定行，修改指定行********************************************************/#include <iostream>#include <fstream>#include <string>using namespace std;/************************************@ Brief: 讀取指定行數據@ Author: woniu201 @ Created: 2018/08/31@ Return:      ************************************/void ReadLineData(char* fileName, int lineNum, char* data){ ifstream in; in.open(fileName); int line = 1; while (in.getline(data, 1024)) { if (lineNum == line) {  break; } line ++ ; } in.close();}/************************************@ Brief: 字符串轉string類型@ Author: woniu201 @ Created: 2018/08/31@ Return:      ************************************/string CharToStr(char * contentChar){ string tempStr; for (int i=0;contentChar[i]!='/0';i++) { tempStr+=contentChar[i]; } return tempStr;}/************************************@ Brief: 刪除指定行@ Author: woniu201 @ Created: 2018/08/31@ Return:      ************************************/void DelLineData(char* fileName, int lineNum){ ifstream in; in.open(fileName);  string strFileData = ""; int line = 1; char lineData[1024] = {0}; while(in.getline(lineData, sizeof(lineData))) { if (line == lineNum) {  strFileData += "/n"; } else {  strFileData += CharToStr(lineData);  strFileData += "/n"; } line++; } in.close(); //寫入文件 ofstream out; out.open(fileName); out.flush(); out<<strFileData; out.close();}/************************************@ Brief:    修改行數據@ Author: woniu201 @ Created: 2018/08/31@ Return:      ************************************/void ModifyLineData(char* fileName, int lineNum, char* lineData){ ifstream in; in.open(fileName); string strFileData = ""; int line = 1; char tmpLineData[1024] = {0}; while(in.getline(tmpLineData, sizeof(tmpLineData))) { if (line == lineNum) {  strFileData += CharToStr(lineData);  strFileData += "/n"; } else {  strFileData += CharToStr(tmpLineData);  strFileData += "/n"; } line++; } in.close(); //寫入文件 ofstream out; out.open(fileName); out.flush(); out<<strFileData; out.close();}int main(){ char lineData[1024] = {0}; ReadLineData("D://project//cpp//2010//jsondemo//jsondemo//1.json", 21, lineData); cout << lineData << endl; DelLineData("D://project//cpp//2010//jsondemo//jsondemo//1.json", 10); ModifyLineData("D://project//cpp//2010//jsondemo//jsondemo//1.json", 10, "aaaaaaaaaaaaaa"); getchar();}