如何从我的C或c++代码中确定目录中的文件列表?

我不允许在程序中执行ls命令并解析结果。


当前回答

这对我很有用。如果我不记得出处,我很抱歉。它可能来自一个手册页。

#include <ftw.h>

int AnalizeDirectoryElement (const char *fpath, 
                            const struct stat *sb,
                            int tflag, 
                            struct FTW *ftwbuf) {

  if (tflag == FTW_F) {
    std::string strFileName(fpath);

    DoSomethingWith(strFileName);
  }
  return 0; 
}

void WalkDirectoryTree (const char * pchFileName) {

  int nFlags = 0;

  if (nftw(pchFileName, AnalizeDirectoryElement, 20, nFlags) == -1) {
    perror("nftw");
  }
}

int main() {
  WalkDirectoryTree("some_dir/");
}

其他回答

由于目录下的文件和子目录一般存储在树状结构中,一种直观的方法是使用DFS算法递归遍历每个目录。 下面是一个在windows操作系统中使用io.h中的基本文件函数的例子。您可以在其他平台上替换这些功能。我想表达的是,DFS的基本思想完美地满足了这个问题。

#include<io.h>
#include<iostream.h>
#include<string>
using namespace std;

void TraverseFilesUsingDFS(const string& folder_path){
   _finddata_t file_info;
   string any_file_pattern = folder_path + "\\*";
   intptr_t handle = _findfirst(any_file_pattern.c_str(),&file_info);
   //If folder_path exsist, using any_file_pattern will find at least two files "." and "..", 
   //of which "." means current dir and ".." means parent dir
   if (handle == -1){
       cerr << "folder path not exist: " << folder_path << endl;
       exit(-1);
   }
   //iteratively check each file or sub_directory in current folder
   do{
       string file_name=file_info.name; //from char array to string
       //check whtether it is a sub direcotry or a file
       if (file_info.attrib & _A_SUBDIR){
            if (file_name != "." && file_name != ".."){
               string sub_folder_path = folder_path + "\\" + file_name;                
               TraverseFilesUsingDFS(sub_folder_path);
               cout << "a sub_folder path: " << sub_folder_path << endl;
            }
       }
       else
            cout << "file name: " << file_name << endl;
    } while (_findnext(handle, &file_info) == 0);
    //
    _findclose(handle);
}

基于上面的答案

#include <vector>
#include <string>
#include <algorithm>

#ifdef _WIN32
#include <windows.h>
std::vector<std::string> files_in_directory(std::string path)
{
    std::vector<std::string> files;

    // check directory exists
    char fullpath[MAX_PATH];
    GetFullPathName(path.c_str(), MAX_PATH, fullpath, 0);
    std::string fp(fullpath);
    if (GetFileAttributes(fp.c_str()) != FILE_ATTRIBUTE_DIRECTORY)
        return files;

    // get file names
    WIN32_FIND_DATA findfiledata;
    HANDLE hFind = FindFirstFile((LPCSTR)(fp + "\\*").c_str(), &findfiledata);
    if (hFind != INVALID_HANDLE_VALUE)
    {
        do 
        {
            files.push_back(findfiledata.cFileName);
        } 
        while (FindNextFile(hFind, &findfiledata));
        FindClose(hFind);
    }

    // delete current and parent directories
    files.erase(std::find(files.begin(), files.end(), "."));
    files.erase(std::find(files.begin(), files.end(), ".."));

    // sort in alphabetical order
    std::sort(files.begin(), files.end());

    return files;
}
#else
#include <dirent.h>
std::vector<std::string> files_in_directory(std::string directory)
{
    std::vector<std::string> files;

    // open directory
    DIR *dir;
    dir = opendir(directory.c_str());
    if (dir == NULL)
        return files;

    // get file names
    struct dirent *ent;
    while ((ent = readdir(dir)) != NULL)
        files.push_back(ent->d_name);
    closedir(dir);

    // delete current and parent directories
    files.erase(std::find(files.begin(), files.end(), "."));
    files.erase(std::find(files.begin(), files.end(), ".."));

    // sort in alphabetical order
    std::sort(files.begin(), files.end());

    return files;
}
#endif  // _WIN32

不幸的是,c++标准并没有定义这样处理文件和文件夹的标准方法。

由于没有跨平台的方法,最好的跨平台方法是使用boost文件系统模块之类的库。

跨平台提升方法:

The following function, given a directory path and a file name, recursively searches the directory and its sub-directories for the file name, returning a bool, and if successful, the path to the file that was found. bool find_file(const path & dir_path, // in this directory, const std::string & file_name, // search for this name, path & path_found) // placing path here if found { if (!exists(dir_path)) return false; directory_iterator end_itr; // default construction yields past-the-end for (directory_iterator itr(dir_path); itr != end_itr; ++itr) { if (is_directory(itr->status())) { if (find_file(itr->path(), file_name, path_found)) return true; } else if (itr->leaf() == file_name) // see below { path_found = itr->path(); return true; } } return false; }

来源来自上面提到的boost页面。

对于Unix/Linux系统:

您可以使用opendir / readdir / closedir。

在目录中搜索条目“name”的示例代码如下: Len = strlen(name); Dirp = opendir("."); ((dp = readdir(dirp)) != NULL) 如果(dp - > d_namlen = = len & & !比较字符串(dp - > d_name,名字)){ (空白)closedir (dirp); 返回发现; } (空白)closedir (dirp); 返回NOT_FOUND;

来自上述手册页的源代码。

对于基于windows的系统:

你可以使用Win32 API的FindFirstFile / FindNextFile / FindClose函数。

The following C++ example shows you a minimal use of FindFirstFile. #include <windows.h> #include <tchar.h> #include <stdio.h> void _tmain(int argc, TCHAR *argv[]) { WIN32_FIND_DATA FindFileData; HANDLE hFind; if( argc != 2 ) { _tprintf(TEXT("Usage: %s [target_file]\n"), argv[0]); return; } _tprintf (TEXT("Target file is %s\n"), argv[1]); hFind = FindFirstFile(argv[1], &FindFileData); if (hFind == INVALID_HANDLE_VALUE) { printf ("FindFirstFile failed (%d)\n", GetLastError()); return; } else { _tprintf (TEXT("The first file found is %s\n"), FindFileData.cFileName); FindClose(hFind); } }

来自上述msdn页面的源代码。

2017年更新:

在c++ 17中,现在有一种官方的方法来列出文件系统中的文件:std::filesystem。下面是Shreevardhan给出的一个很好的答案:

# include <字符串> # include < iostream > # include <文件> 命名空间fs = std::filesystem; int main () { Std::string path = "/path/to/directory"; For (const auto & entry: fs::directory_iterator(path)) Std::cout << entry.path() << Std::endl; }

旧的回答:

在小而简单的任务中,我不使用boost,我使用direct .h。它可以作为UNIX中的标准标头使用,也可以通过Toni Ronkko创建的兼容层用于Windows。

DIR *dir;
struct dirent *ent;
if ((dir = opendir ("c:\\src\\")) != NULL) {
  /* print all the files and directories within directory */
  while ((ent = readdir (dir)) != NULL) {
    printf ("%s\n", ent->d_name);
  }
  closedir (dir);
} else {
  /* could not open directory */
  perror ("");
  return EXIT_FAILURE;
}

它只是一个小的头文件,做了大部分你需要的简单的事情,而不使用像boost这样的基于模板的大方法(无意冒犯,我喜欢boost!)

#include <string>
#include <iostream>
#include <filesystem>
namespace fs = std::filesystem;

int main() {
    std::string path = "/path/to/directory";
    for (const auto & entry : fs::directory_iterator(path))
        std::cout << entry.path() << std::endl;
}