C++遍历文件夹函数

#include <iostream>
#include <fstream>
#include <string.h>
#include <vector>
#include <sys/io.h>
#include <dirent.h>
#include <stdlib.h>
#include <sys/stat.h>
#include "tools.hpp"

//遍历文件夹
void showAllFiles(const char * dir_name,vector<string> &files )
{
    // check the parameter !
    if( NULL == dir_name )
    {
        cout<<" dir_name is null ! "<<endl;
        return;
    }
 
    // check if dir_name is a valid dir
    struct stat s;
    lstat( dir_name , &s );
    if( ! S_ISDIR( s.st_mode ) )
    {
        cout<<"dir_name is not a valid directory !"<<endl;
        return;
    }
    
    struct dirent * filename;    // return value for readdir()
     DIR * dir;                   // return value for opendir()
    dir = opendir( dir_name );
    if( NULL == dir )
    {
        cout<<"Can not open dir "<<dir_name<<endl;
        return;
    }
    cout<<"Successfully opened the dir !"<<endl;
    
    /* read all the files in the dir ~ */
    while( ( filename = readdir(dir) ) != NULL )
    {
        // get rid of "." and ".."
        if( strcmp( filename->d_name , "." ) == 0 || 
            strcmp( filename->d_name , "..") == 0    )
            continue;
        files.push_back(filename->d_name);
    }
}