c++文件操作

文件操作：

#include <iostream>
#include <string.h>
#include <fstream>
#include <cstdio>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>

// //LINUX下历遍目录 opendir -> readdir -> closedir
// // 打开 ->  读取  -> 关闭

/* Check whether the path identified by 'filename' is a file */
static bool isFile(const std::string& filename) {
    struct stat   buffer;
    return (stat (filename.c_str(), &buffer) == 0 && S_ISREG(buffer.st_mode));
}

/* Check whether the path identified by 'filefodler' is a fodler */
static bool isDirectory(const std::string& filefodler) {
    struct stat   buffer;
    return (stat (filefodler.c_str(), &buffer) == 0 && S_ISDIR(buffer.st_mode));
}

/* Copy the file named by old_name to new_name */
int copyFile(const std::string& old_name, const std::string& new_name)
{
    std::ifstream ifs(old_name, std::ifstream::binary);
    std::ofstream ofs(new_name, std::ifstream::binary| std::ifstream::trunc);
    if(ifs.good() == false)
    {
        return -1;
    }

    ofs << ifs.rdbuf();

    ifs.close();
    ofs.close();
    return 0;
}

/* Copy all files and sub directories in directory to new path */
int copyFileAndDirectory(const std::string& old_path, const std::string& new_path)
{
    int result = 0;
    DIR * p_dir;
    struct dirent * p_dirent;

    if(isDirectory(old_path))
    {
        if(access(new_path.c_str(),0) == -1)
        {
            if(mkdir(new_path.c_str()) < 0)
            {
                std::cout<< "[copyFileAndDirectory] mkdir failed , the errno = " << strerror(errno) << std::endl;
                return -1;
            }
        }

        if((p_dir = opendir(old_path.c_str())) == NULL )
        {
            std::cout << "Usage:cp -r <src_dir> <dat_dir> error: " << strerror(errno) << std::endl;
            return -1;
        }

        while((p_dirent = readdir(p_dir)) != NULL)
        {
            std::string file_name = old_path + "/" + p_dirent->d_name;
            std::string new_file_name = new_path + "/" + p_dirent->d_name;
            // It is a directory
            if(isDirectory(file_name) && (0 != strcmp(p_dirent->d_name, ".")) && (0 != strcmp(p_dirent->d_name, "..")))
            {
                result = copyFileAndDirectory(file_name,new_file_name);
                if(result < 0)
                {
                    return result;
                }
            }
            else if((0 != strcmp(p_dirent->d_name, ".")) && (0 != strcmp(p_dirent->d_name, "..")))
            {
                result = copyFile(file_name, new_file_name);
                if(result < 0)
                {
                    return result;
                }
            }
        }
        closedir(p_dir);
    }
    return result;
}

/* Remove all files and sub directories in directory */
int removeFileAndDirectory(const std::string& path)
{
    int result = 0;
    DIR * p_dir;
    struct dirent * p_dirent;
    if(isDirectory(path))
    {
        if((p_dir = opendir(path.c_str())) == NULL )
        {
            std::cout << "Opendir error: " << strerror(errno) << std::endl;
            return -1;
        }

        while((p_dirent = readdir(p_dir)) != NULL)
        {
            std::string file_name = path + "/" + p_dirent->d_name;
            /* It is a directory */
            if(isDirectory(file_name) && (0 != strcmp(p_dirent->d_name, ".")) && (0 != strcmp(p_dirent->d_name, "..")))
            {
                result = removeFileAndDirectory(file_name);
                if(result < 0)
                {
                    return result;
                }
            }
            /* It is a file */
            else if((0 != strcmp(p_dirent->d_name, ".")) && (0 != strcmp(p_dirent->d_name, "..")))
            {
                result = remove(file_name.c_str());
                if(result < 0)
                {
                    return result;
                }
            }
            else
            {
                /* do nothing */
            }
        }
        closedir(p_dir);
        result = rmdir(path.c_str());
    }
    else if(isFile(path))
    {
        result = remove(path.c_str());
    }
    else
    {
        /* do nothing */
    }
    return result;
}

int main(void)
{
    //参数可以是绝对路径或者相对路径
    std::string src = "./123";
    std::string des = "./1234";
    int result = copyFileAndDirectory(src, des);
    std::cout<< result << std::endl;
    result = removeFileAndDirectory(src);
    std::cout<< result << std::endl;
    return 0;
}

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