linux c++ 拷贝文件

#include <iostream>
#include <fstream>

bool copyFile(const std::string& source, const std::string& destination) {
    std::ifstream src(source, std::ios::binary);
    if (!src) {
        std::cerr << "无法打开源文件: " << source << std::endl;
        return false;
    }

    std::ofstream dest(destination, std::ios::binary);
    if (!dest) {
        std::cerr << "无法打开目标文件: " << destination << std::endl;
        return false;
    }

    dest << src.rdbuf();
    return true;
}

int main() {
    std::string source = "source.txt";
    std::string destination = "destination.txt";
    if (copyFile(source, destination)) {
        std::cout << "文件拷贝成功！" << std::endl;
    } else {
        std::cout << "文件拷贝失败！" << std::endl;
    }
    return 0;
}

#include <iostream>
#include <fcntl.h>
#include <unistd.h>
#include <cstring>

bool copyFile(const std::string& source, const std::string& destination) {
    int srcFd = open(source.c_str(), O_RDONLY);
    if (srcFd == -1) {
        std::cerr << "无法打开源文件: " << source << std::endl;
        return false;
    }

    int destFd = open(destination.c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0644);
    if (destFd == -1) {
        std::cerr << "无法打开目标文件: " << destination << std::endl;
        close(srcFd);
        return false;
    }

    char buffer[4096];
    ssize_t bytesRead;
    while ((bytesRead = read(srcFd, buffer, sizeof(buffer))) > 0) {
        if (write(destFd, buffer, bytesRead) != bytesRead) {
            std::cerr << "写入错误" << std::endl;
            close(srcFd);
            close(destFd);
            return false;
        }
    }

    if (bytesRead == -1) {
        std::cerr << "读取错误" << std::endl;
    }

    close(srcFd);
    close(destFd);
    return bytesRead != -1;
}

int main() {
    std::string source = "source.txt";
    std::string destination = "destination.txt";
    if (copyFile(source, destination)) {
        std::cout << "文件拷贝成功！" << std::endl;
    } else {
        std::cout << "文件拷贝失败！" << std::endl;
    }
    return 0;
}

#include <iostream>
#include <fcntl.h>
#include <unistd.h>
#include <sys/sendfile.h>
#include <sys/stat.h>

bool copyFile(const std::string& source, const std::string& destination) {
    int srcFd = open(source.c_str(), O_RDONLY);
    if (srcFd == -1) {
        std::cerr << "无法打开源文件: " << source << std::endl;
        return false;
    }

    struct stat fileStat;
    if (fstat(srcFd, &fileStat) == -1) {
        std::cerr << "无法获取源文件状态" << std::endl;
        close(srcFd);
        return false;
    }

    int destFd = open(destination.c_str(), O_WRONLY | O_CREAT | O_TRUNC, fileStat.st_mode);
    if (destFd == -1) {
        std::cerr << "无法打开目标文件: " << destination << std::endl;
        close(srcFd);
        return false;
    }

    off_t offset = 0;
    ssize_t bytesSent = sendfile(destFd, srcFd, &offset, fileStat.st_size);
    if (bytesSent == -1) {
        std::cerr << "发送文件错误" << std::endl;
    }

    close(srcFd);
    close(destFd);
    return bytesSent != -1;
}

int main() {
    std::string source = "source.txt";
    std::string destination = "destination.txt";
    if (copyFile(source, destination)) {
        std::cout << "文件拷贝成功！" << std::endl;
    } else {
        std::cout << "文件拷贝失败！" << std::endl;
    }
    return 0;
}