codingStyleIdioms/3_RAII/c++_example1.cpp - master - githubmirror/CPlusPlusThings

codingStyleIdioms/3_RAII/c++_example1.cpp
68 строк2 KB
Francis
Update c++_example1.cpp
10 апр 2022, 12:35
10 апр 2022, 12:3503ee450
//
// Created by light on 19-12-12.
//
#include <iostream>
#include <vector>
#include <cstring>
#include <fstream>

using namespace std;
vector<string> read_lines_from_file(string &file_name) {
    vector<string> lines;
    string line;

    ifstream file_handle (file_name.c_str());
    //  file_handle.peek()!=EOF 解决多读一行问题
    while (file_handle.good() && !file_handle.eof() && file_handle.peek()!=EOF) {
        getline(file_handle, line);
        lines.push_back(line);
    }

    file_handle.close();

    return lines;
}
vector<string> * read_lines_from_file1(string &file_name) {
    vector<string> * lines;
    string line;

    ifstream file_handle (file_name.c_str());
    //  file_handle.peek()!=EOF
    while (file_handle.good() && !file_handle.eof() && file_handle.peek()!=EOF) {
        getline(file_handle, line);
        lines->push_back(line);
    }

    file_handle.close();

    return lines;
}
vector<string> * read_lines_from_file1_1(string &file_name) {
    vector<string> * lines=new vector<string>;
    string line;

    ifstream file_handle (file_name.c_str());
    while (file_handle.good() && !file_handle.eof() &&  file_handle.peek()!=EOF) {
        getline(file_handle, line);
        lines->push_back(line);
    }

    file_handle.close();

    return lines;
}
int main() {
    // get file name from the first argument
    string file_name ("/home/light/CLionProjects/Morden_C++/CMakeLists.txt");
    int count = read_lines_from_file(file_name).size();
    cout << "File " << file_name << " contains " << count << " lines.";

    cout<<endl;
//    string file_name1 ("/home/light/CLionProjects/Morden_C++/CMakeLists.txt");
//    int count1 = read_lines_from_file1(file_name1)->size();
//    cout << "File " << file_name << " contains " << count1 << " lines.";
    string file_name1 ("/home/light/CLionProjects/Morden_C++/CMakeLists.txt");
    int count1 = read_lines_from_file1_1(file_name1)->size();
    cout << "File " << file_name << " contains " << count1 << " lines.";
    return 0;
}