C++ 文件读写操作

依赖gcc、 cmake

1. 代码编写

main.cpp

#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

const static string fileName = "data.txt";

int save()
{
    fstream file(fileName, ios::out);
    if (!file.is_open()) 
    {
        cout << "open file " << fileName << " fail." << endl;
        return -1;
    }
    
    for (int i=0; i<10; i++)
    {
        file <<"line:" << i<< " Hello world!" << endl;
    }

    file.close();
    return 0;
}

int load(vector<string>& data)
{
    fstream file(fileName, ios::in);
    if (!file.is_open()) 
    {
        cout << "open file " << fileName << " fail." << endl;
        return -1;
    }
    while(!file.eof())
    {
        string strLine;
        getline(file, strLine);
        data.push_back(strLine);
    }

    file.close();
    return 0;
}

int main()
{
    vector<string> data;
    data.clear();

    save();
    load(data);

    for (int i = 0; i < data.size(); i++)
    {
        cout << data[i] << endl;
    }

    return 0;
}

2. cmake 编写

CMakeLists.txt

project(test)

cmake_minimum_required(VERSION 2.8)
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_BUILD_TYPE "Debug")

include_directories(
    ${PROJECT_SOURCE_DIR})

aux_source_directory(./ SRC_LIST)

add_executable(${PROJECT_NAME} ${SRC_LIST})
target_link_libraries(${PROJECT_NAME}
    -ldl -lm -lpthread -lrt)

3. 测试运行

cd test
mkdir build
cd build
cmake ..
make
./test