递归文件夹扫描在c ++ [英] recursive folder scanning in c++

问题描述

您好
我想扫描目录树并列出每个目录中的所有文件和文件夹。我创建了一个程序，从网络摄像头下载图像并将其保存在本地。此程序根据下载图片的时间创建文件树。我现在想要扫描这些文件夹并将图像上传到网络服务器，但我不知道如何扫描目录来找到图像。
如果任何人可以发布一些示例代码，这将是非常有帮助的。

编辑：我在嵌入式linux系统且不想使用boost

解决方案

请参阅 man ftw 。我还在此示例中使用了 fnmatch 。

  #include< ftw.h> 
 #include< fnmatch.h> 
 
 static const char * filters [] = {
* .jpg，* .jpeg，* .gif，* .png
}; 
 
静态int回调（const char * fpath，const struct stat * sb，int typeflag）{
 / *如果是文件* / 
 if（typeflag == FTW_F） {
 int i; 
 / *每个过滤器，* / 
 for（i = 0; i  / *如果文件名匹配过滤器，* / 
 if（fnmatch（filters [i]，fpath，FNM_CASEFOLD）== 0）{
 / * do something * / 
 printf（found image：％s \\\
，fpath）; 
 break; 
} 
} 
} 
 
 / *告诉ftw继续* / 
 return 0; 
} 
 
 int main（）{
 ftw（。，callback，16）; 
} 
  

（甚至没有经过编译测试， p>

这比处理 DIRENT s简单得多，可以递归遍历。

---

为了更好地控制遍历，还有 fts 。在此示例中，除非明确传递到程序作为起点，否则将跳过点文件（以。开头的文件和目录）。

  #include< fts.h> 
 #include< string.h> 
 
 int main（int argc，char ** argv）{
 char * dot [] = {。，0}; 
 char ** paths = argc> 1？ argv + 1：dot; 
 
 FTS * tree = fts_open（paths，FTS_NOCHDIR，0）; 
 if（！tree）{
 perror（fts_open）; 
 return 1; 
} 
 
 FTSENT * node; 
 while（（node = fts_read（tree）））{
 if（node-> fts_level> 0&& node-> fts_name [0] =='。'）
 fts_set（tree，node，FTS_SKIP）; 
 else if（node-> fts_info& FTS_F）{
 printf（获得在深度％d处命名为％s的文件，
可通过％s从当前目录
或通过从原始开始目录\\\
，
 node-> fts_name，node-> fts_level，
 node-> fts_accpath，node-> fts_path） ; 
 / *如果fts_open没有给出FTS_NOCHDIR，
 * fts可以改变程序的当前工作目录* / 
} 
} 
 if（errno）{
 perror（fts_read）; 
 return 1; 
} 
 
 if（fts_close（tree））{
 perror（fts_close）; 
 return 1; 
} 
 
 return 0; 
} 
  

同样，它既不经过编译测试也不经过运行测试， 'd提及它。

Hi I want to scan a directory tree and list all files and folders inside each directory. I created a program that downloads images from a webcamera and saves them locally. This program creates a filetree based on the time the picture is downloaded. I now want to scan these folders and upload the images to a webserver but I´m not sure how I can scan the directories to find the images. If anyone could post some sample code it would be very helpful.

edit: I´m running this on an embedded linux system and don´t want to use boost

解决方案

See man ftw for a simple "file tree walk". I also used fnmatch in this example.

#include <ftw.h>
#include <fnmatch.h>

static const char *filters[] = {
    "*.jpg", "*.jpeg", "*.gif", "*.png"
};

static int callback(const char *fpath, const struct stat *sb, int typeflag) {
    /* if it's a file */
    if (typeflag == FTW_F) {
        int i;
        /* for each filter, */
        for (i = 0; i < sizeof(filters) / sizeof(filters[0]); i++) {
            /* if the filename matches the filter, */
            if (fnmatch(filters[i], fpath, FNM_CASEFOLD) == 0) {
                /* do something */
                printf("found image: %s\n", fpath);
                break;
            }
        }
    }

    /* tell ftw to continue */
    return 0;
}

int main() {
    ftw(".", callback, 16);
}

(Not even compile-tested, but you get the idea.)

This is much simpler than dealing with DIRENTs and recursive traversal yourself.

---

For greater control over traversal, there's also fts. In this example, dot-files (files and directories with names starting with ".") are skipped, unless explicitly passed to the program as a starting point.

#include <fts.h>
#include <string.h>

int main(int argc, char **argv) {
    char *dot[] = {".", 0};
    char **paths = argc > 1 ? argv + 1 : dot;

    FTS *tree = fts_open(paths, FTS_NOCHDIR, 0);
    if (!tree) {
        perror("fts_open");
        return 1;
    }

    FTSENT *node;
    while ((node = fts_read(tree))) {
        if (node->fts_level > 0 && node->fts_name[0] == '.')
            fts_set(tree, node, FTS_SKIP);
        else if (node->fts_info & FTS_F) {
            printf("got file named %s at depth %d, "
                "accessible via %s from the current directory "
                "or via %s from the original starting directory\n",
                node->fts_name, node->fts_level,
                node->fts_accpath, node->fts_path);
            /* if fts_open is not given FTS_NOCHDIR,
             * fts may change the program's current working directory */
        }
    }
    if (errno) {
        perror("fts_read");
        return 1;
    }

    if (fts_close(tree)) {
        perror("fts_close");
        return 1;
    }

    return 0;
}

Again, it's neither compile-tested nor run-tested, but I thought I'd mention it.

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