dirent--文件以及文件夹相关操作(跨平台)

迷南。 2022-07-15 03:46 323阅读 0赞

[windows客户端开发–文件以及文件夹相关操作(windows api)][windows_windows api]  
一文中，主要使用了一些windows api实现文件以及文件夹的相关操作。

c++语言本身不提供文件相关操作，我们也可以使用boost库完成我们想要的功能。

但是为了仅仅一个小功能，引入boost库，似乎有点小题大做吧，那今天就介绍一种“跨平台”的文件操作，dirent。

这里所谓的“跨平台”其实是个伪命题，不是真正意义上的。

let us go!!!

**初识dirent**

是POSIX.1标准定义的unix类目录操作的头文件，包含了许多UNIX系统服务的函数原型，例如opendir函数、readdir函数.

看到上面的描述，你会理解我所说的用引号引起来的“跨平台”了。

在windows平台上同样可以使用：  
[https://github.com/tronkko/dirent/blob/master/include/dirent.h][https_github.com_tronkko_dirent_blob_master_include_dirent.h]

只是简单的包含这个头文件dirent.h就可以了，因为这个文件只有八百多行，在博客的最后面，我将会贴上这个源码。

**熟悉dirent**

dirent结构体：

struct dirent {
            long d_ino;     /* Always zero */
            unsigned short d_reclen;  /* Structure size */
            size_t d_namlen;    /* Length of name without \0 */
            int d_type;   /* File type */
            char d_name[PATH_MAX];     /* File name */
        };
        typedef struct dirent dirent;

DIR：  
A type representing a directory stream.

struct DIR {
            struct dirent ent;
            struct _WDIR *wdirp;
        };
        typedef struct DIR DIR;

一些函数：

int closedir(DIR *);
    DIR *opendir(const char *);
    struct dirent *readdir(DIR *);
    int readdir_r(DIR *, struct dirent *, struct dirent **);
    void rewinddir(DIR *);
    void seekdir(DIR *, long int);
    long int telldir(DIR *);

**使用dirent**

删除文件夹下所有文件：

DIR *foder = opendir(file_path_to_delete.c_str());
        struct dirent *next_file;
        char filepath[256];
    
        while ((next_file = readdir(foder)) != NULL)
        {
            // build the path for each file in the folder
            sprintf(filepath, "%s/%s", course_path.c_str(), next_file->d_name);
            remove(filepath);
        }

**注意：**  
路径要以’/’结尾：

file_path_to_delete += "\/";

判断目录是否存在：

DIR *mydir = NULL;  
        if((mydir= opendir(dir))==NULL)//判断目录 
        {  
          int ret = mkdir(dir, MODE);//创建目录 
          if (ret != 0)  
          {  
              return -1;  
          }  
          printf("%s created sucess!/n", dir);  
        }

判断是文件夹还是文件：

unsigned char isFile =0x8;
    DIR Dir;
    struct dirent *DirEntry;
    Dir = opendir("c:/test/")
    
    while(Dir=readdir(Dir))
    {
       if ( DirEntry->d_type == isFile)
       {
        cout <<"Found a File : " << DirEntry->d_name << endl;
       }
    }

==========================================================华丽的分割线============================================================

//dirent.h

/*
    * dirent.h - dirent API for Microsoft Visual Studio
    *
    * Copyright (C) 2006-2012 Toni Ronkko
    *
    * Permission is hereby granted, free of charge, to any person obtaining
    * a copy of this software and associated documentation files (the
    * ``Software''), to deal in the Software without restriction, including
    * without limitation the rights to use, copy, modify, merge, publish,
    * distribute, sublicense, and/or sell copies of the Software, and to
    * permit persons to whom the Software is furnished to do so, subject to
    * the following conditions:
    *
    * The above copyright notice and this permission notice shall be included
    * in all copies or substantial portions of the Software.
    *
    * THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS
    * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
    * IN NO EVENT SHALL TONI RONKKO BE LIABLE FOR ANY CLAIM, DAMAGES OR
    * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
    * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
    * OTHER DEALINGS IN THE SOFTWARE.
    *
    * $Id: dirent.h,v 1.20 2014/03/19 17:52:23 tronkko Exp $
    */
    #ifndef DIRENT_H
    #define DIRENT_H
    
    /*
    * Define architecture flags so we don't need to include windows.h.
    * Avoiding windows.h makes it simpler to use windows sockets in conjunction
    * with dirent.h.
    */
    #if !defined(_68K_) && !defined(_MPPC_) && !defined(_X86_) && !defined(_IA64_) && !defined(_AMD64_) && defined(_M_IX86)
    # define _X86_
    #endif
    #if !defined(_68K_) && !defined(_MPPC_) && !defined(_X86_) && !defined(_IA64_) && !defined(_AMD64_) && defined(_M_AMD64)
    #define _AMD64_
    #endif
    
    #include <stdio.h>
    #include <stdarg.h>
    #include <windef.h>
    #include <winbase.h>
    #include <wchar.h>
    #include <string.h>
    #include <stdlib.h>
    #include <malloc.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <errno.h>
    
    /* Indicates that d_type field is available in dirent structure */
    #define _DIRENT_HAVE_D_TYPE
    
    /* Indicates that d_namlen field is available in dirent structure */
    #define _DIRENT_HAVE_D_NAMLEN
    
    /* Entries missing from MSVC 6.0 */
    #if !defined(FILE_ATTRIBUTE_DEVICE)
    # define FILE_ATTRIBUTE_DEVICE 0x40
    #endif
    
    /* File type and permission flags for stat() */
    #if !defined(S_IFMT)
    # define S_IFMT _S_IFMT /* File type mask */
    #endif
    #if !defined(S_IFDIR)
    # define S_IFDIR _S_IFDIR /* Directory */
    #endif
    #if !defined(S_IFCHR)
    # define S_IFCHR _S_IFCHR /* Character device */
    #endif
    #if !defined(S_IFFIFO)
    # define S_IFFIFO _S_IFFIFO /* Pipe */
    #endif
    #if !defined(S_IFREG)
    # define S_IFREG _S_IFREG /* Regular file */
    #endif
    #if !defined(S_IREAD)
    # define S_IREAD _S_IREAD /* Read permission */
    #endif
    #if !defined(S_IWRITE)
    # define S_IWRITE _S_IWRITE /* Write permission */
    #endif
    #if !defined(S_IEXEC)
    # define S_IEXEC _S_IEXEC /* Execute permission */
    #endif
    #if !defined(S_IFIFO)
    # define S_IFIFO _S_IFIFO /* Pipe */
    #endif
    #if !defined(S_IFBLK)
    # define S_IFBLK 0 /* Block device */
    #endif
    #if !defined(S_IFLNK)
    # define S_IFLNK 0 /* Link */
    #endif
    #if !defined(S_IFSOCK)
    # define S_IFSOCK 0 /* Socket */
    #endif
    
    #if defined(_MSC_VER)
    # define S_IRUSR S_IREAD /* Read user */
    # define S_IWUSR S_IWRITE /* Write user */
    # define S_IXUSR 0 /* Execute user */
    # define S_IRGRP 0 /* Read group */
    # define S_IWGRP 0 /* Write group */
    # define S_IXGRP 0 /* Execute group */
    # define S_IROTH 0 /* Read others */
    # define S_IWOTH 0 /* Write others */
    # define S_IXOTH 0 /* Execute others */
    #endif
    
    /* Maximum length of file name */
    #if !defined(PATH_MAX)
    # define PATH_MAX MAX_PATH
    #endif
    #if !defined(FILENAME_MAX)
    # define FILENAME_MAX MAX_PATH
    #endif
    #if !defined(NAME_MAX)
    # define NAME_MAX FILENAME_MAX
    #endif
    
    /* File type flags for d_type */
    #define DT_UNKNOWN 0
    #define DT_REG S_IFREG
    #define DT_DIR S_IFDIR
    #define DT_FIFO S_IFIFO
    #define DT_SOCK S_IFSOCK
    #define DT_CHR S_IFCHR
    #define DT_BLK S_IFBLK
    #define DT_LNK S_IFLNK
    
    /* Macros for converting between st_mode and d_type */
    #define IFTODT(mode) ((mode) & S_IFMT)
    #define DTTOIF(type) (type)
    
    /*
    * File type macros.  Note that block devices, sockets and links cannot be
    * distinguished on Windows and the macros S_ISBLK, S_ISSOCK and S_ISLNK are
    * only defined for compatibility.  These macros should always return false
    * on Windows.
    */
    #define S_ISFIFO(mode) (((mode) & S_IFMT) == S_IFIFO)
    #define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
    #define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG)
    #define S_ISLNK(mode) (((mode) & S_IFMT) == S_IFLNK)
    #define S_ISSOCK(mode) (((mode) & S_IFMT) == S_IFSOCK)
    #define S_ISCHR(mode) (((mode) & S_IFMT) == S_IFCHR)
    #define S_ISBLK(mode) (((mode) & S_IFMT) == S_IFBLK)
    
    /* Return the exact length of d_namlen without zero terminator */
    #define _D_EXACT_NAMLEN(p) ((p)->d_namlen)
    
    /* Return number of bytes needed to store d_namlen */
    #define _D_ALLOC_NAMLEN(p) (PATH_MAX)
    
    
    #ifdef __cplusplus
    extern "C" {
    #endif
    
    
        /* Wide-character version */
        struct _wdirent {
            long d_ino;                                 /* Always zero */
            unsigned short d_reclen;                    /* Structure size */
            size_t d_namlen;                            /* Length of name without \0 */
            int d_type;                                 /* File type */
            wchar_t d_name[PATH_MAX];                   /* File name */
        };
        typedef struct _wdirent _wdirent;
    
        struct _WDIR {
            struct _wdirent ent;                        /* Current directory entry */
            WIN32_FIND_DATAW data;                      /* Private file data */
            int cached;                                 /* True if data is valid */
            HANDLE handle;                              /* Win32 search handle */
            wchar_t *patt;                              /* Initial directory name */
        };
        typedef struct _WDIR _WDIR;
    
        static _WDIR *_wopendir(const wchar_t *dirname);
        static struct _wdirent *_wreaddir(_WDIR *dirp);
        static int _wclosedir(_WDIR *dirp);
        static void _wrewinddir(_WDIR* dirp);
    
    
        /* For compatibility with Symbian */
    #define wdirent _wdirent
    #define WDIR _WDIR
    #define wopendir _wopendir
    #define wreaddir _wreaddir
    #define wclosedir _wclosedir
    #define wrewinddir _wrewinddir
    
    
        /* Multi-byte character versions */
        struct dirent {
            long d_ino;                                 /* Always zero */
            unsigned short d_reclen;                    /* Structure size */
            size_t d_namlen;                            /* Length of name without \0 */
            int d_type;                                 /* File type */
            char d_name[PATH_MAX];                      /* File name */
        };
        typedef struct dirent dirent;
    
        struct DIR {
            struct dirent ent;
            struct _WDIR *wdirp;
        };
        typedef struct DIR DIR;
    
        static DIR *opendir(const char *dirname);
        static struct dirent *readdir(DIR *dirp);
        static int closedir(DIR *dirp);
        static void rewinddir(DIR* dirp);
    
    
        /* Internal utility functions */
        static WIN32_FIND_DATAW *dirent_first(_WDIR *dirp);
        static WIN32_FIND_DATAW *dirent_next(_WDIR *dirp);
    
        static int dirent_mbstowcs_s(
            size_t *pReturnValue,
            wchar_t *wcstr,
            size_t sizeInWords,
            const char *mbstr,
            size_t count);
    
        static int dirent_wcstombs_s(
            size_t *pReturnValue,
            char *mbstr,
            size_t sizeInBytes,
            const wchar_t *wcstr,
            size_t count);
    
        static void dirent_set_errno(int error);
    
        /*
        * Open directory stream DIRNAME for read and return a pointer to the
        * internal working area that is used to retrieve individual directory
        * entries.
        */
        static _WDIR*
            _wopendir(
            const wchar_t *dirname)
        {
            _WDIR *dirp = NULL;
            int error;
    
            /* Must have directory name */
            if (dirname == NULL || dirname[0] == '\0') {
                dirent_set_errno(ENOENT);
     return NULL;
            }
    
            /* Allocate new _WDIR structure */
            dirp = (_WDIR*)malloc(sizeof(struct _WDIR));
            if (dirp != NULL) {
                DWORD n;
    
                /* Reset _WDIR structure */
                dirp->handle = INVALID_HANDLE_VALUE;
                dirp->patt = NULL;
                dirp->cached = 0;
    
                /* Compute the length of full path plus zero terminator */
                n = GetFullPathNameW(dirname, 0, NULL, NULL);
    
                /* Allocate room for absolute directory name and search pattern */
                dirp->patt = (wchar_t*)malloc(sizeof(wchar_t) * n + 16);
                if (dirp->patt) {
    
                    /*
                    * Convert relative directory name to an absolute one.  This
                    * allows rewinddir() to function correctly even when current
                    * working directory is changed between opendir() and rewinddir().
                    */
                    n = GetFullPathNameW(dirname, n, dirp->patt, NULL);
                    if (n > 0) {
                        wchar_t *p;
    
                        /* Append search pattern \* to the directory name */
                        p = dirp->patt + n;
                        if (dirp->patt < p) {
                            switch (p[-1]) {
                            case '\\':
                            case '/':
                            case ':':
                                /* Directory ends in path separator, e.g. c:\temp\ */
                                /*NOP*/;
                                break;
    
                            default:
                                /* Directory name doesn't end in path separator */
                                *p++ = '\\';
                            }
                        }
                        *p++ = '*';
                        *p = '\0';
    
                        /* Open directory stream and retrieve the first entry */
                        if (dirent_first(dirp)) {
                            /* Directory stream opened successfully */
                            error = 0;
                        }
                        else {
                            /* Cannot retrieve first entry */
                            error = 1;
                            dirent_set_errno(ENOENT);
                        }
    
                    }
                    else {
                        /* Cannot retrieve full path name */
                        dirent_set_errno(ENOENT);
                        error = 1;
                    }
    
                }
                else {
                    /* Cannot allocate memory for search pattern */
                    error = 1;
                }
    
            }
            else {
                /* Cannot allocate _WDIR structure */
                error = 1;
            }
    
            /* Clean up in case of error */
            if (error  &&  dirp) {
                _wclosedir(dirp);
                dirp = NULL;
            }
     return dirp;
        }
    
        /*
        * Read next directory entry.  The directory entry is returned in dirent
        * structure in the d_name field.  Individual directory entries returned by
        * this function include regular files, sub-directories, pseudo-directories
        * "." and ".." as well as volume labels, hidden files and system files.
        */
        static struct _wdirent*
            _wreaddir(
            _WDIR *dirp)
        {
            WIN32_FIND_DATAW *datap;
            struct _wdirent *entp;
    
            /* Read next directory entry */
            datap = dirent_next(dirp);
            if (datap) {
                size_t n;
                DWORD attr;
    
                /* Pointer to directory entry to return */
                entp = &dirp->ent;
    
                /*
                * Copy file name as wide-character string.  If the file name is too
                * long to fit in to the destination buffer, then truncate file name
                * to PATH_MAX characters and zero-terminate the buffer.
                */
                n = 0;
                while (n + 1 < PATH_MAX  &&  datap->cFileName[n] != 0) {
                    entp->d_name[n] = datap->cFileName[n];
                    n++;
                }
                dirp->ent.d_name[n] = 0;
    
                /* Length of file name excluding zero terminator */
                entp->d_namlen = n;
    
                /* File type */
                attr = datap->dwFileAttributes;
                if ((attr & FILE_ATTRIBUTE_DEVICE) != 0) {
                    entp->d_type = DT_CHR;
                }
                else if ((attr & FILE_ATTRIBUTE_DIRECTORY) != 0) {
                    entp->d_type = DT_DIR;
                }
                else {
                    entp->d_type = DT_REG;
                }
    
                /* Reset dummy fields */
                entp->d_ino = 0;
                entp->d_reclen = sizeof(struct _wdirent);
    
            }
            else {
    
                /* Last directory entry read */
                entp = NULL;
    
            }
     return entp;
        }
    
        /*
        * Close directory stream opened by opendir() function.  This invalidates the
        * DIR structure as well as any directory entry read previously by
        * _wreaddir().
        */
        static int
            _wclosedir(
            _WDIR *dirp)
        {
            int ok;
            if (dirp) {
    
                /* Release search handle */
                if (dirp->handle != INVALID_HANDLE_VALUE) {
                    FindClose(dirp->handle);
                    dirp->handle = INVALID_HANDLE_VALUE;
                }
    
                /* Release search pattern */
                if (dirp->patt) {
                    free(dirp->patt);
                    dirp->patt = NULL;
                }
    
                /* Release directory structure */
                free(dirp);
                ok = /*success*/0;
    
            }
            else {
                /* Invalid directory stream */
                dirent_set_errno(EBADF);
                ok = /*failure*/-1;
            }
     return ok;
        }
    
        /*
        * Rewind directory stream such that _wreaddir() returns the very first
        * file name again.
        */
        static void
            _wrewinddir(
            _WDIR* dirp)
        {
            if (dirp) {
                /* Release existing search handle */
                if (dirp->handle != INVALID_HANDLE_VALUE) {
                    FindClose(dirp->handle);
                }
    
                /* Open new search handle */
                dirent_first(dirp);
            }
        }
    
        /* Get first directory entry (internal) */
        static WIN32_FIND_DATAW*
            dirent_first(
            _WDIR *dirp)
        {
            WIN32_FIND_DATAW *datap;
    
            /* Open directory and retrieve the first entry */
            dirp->handle = FindFirstFileW(dirp->patt, &dirp->data);
            if (dirp->handle != INVALID_HANDLE_VALUE) {
    
                /* a directory entry is now waiting in memory */
                datap = &dirp->data;
                dirp->cached = 1;
    
            }
            else {
    
                /* Failed to re-open directory: no directory entry in memory */
                dirp->cached = 0;
                datap = NULL;
    
            }
     return datap;
        }
    
        /* Get next directory entry (internal) */
        static WIN32_FIND_DATAW*
            dirent_next(
            _WDIR *dirp)
        {
            WIN32_FIND_DATAW *p;
    
            /* Get next directory entry */
            if (dirp->cached != 0) {
    
                /* A valid directory entry already in memory */
                p = &dirp->data;
                dirp->cached = 0;
    
            }
            else if (dirp->handle != INVALID_HANDLE_VALUE) {
    
                /* Get the next directory entry from stream */
                if (FindNextFileW(dirp->handle, &dirp->data) != FALSE) {
                    /* Got a file */
                    p = &dirp->data;
                }
                else {
                    /* The very last entry has been processed or an error occured */
                    FindClose(dirp->handle);
                    dirp->handle = INVALID_HANDLE_VALUE;
                    p = NULL;
                }
    
            }
            else {
    
                /* End of directory stream reached */
                p = NULL;
    
            }
     return p;
        }
    
        /*
        * Open directory stream using plain old C-string.
        */
        static DIR*
            opendir(
            const char *dirname)
        {
            struct DIR *dirp;
            int error;
    
            /* Must have directory name */
            if (dirname == NULL || dirname[0] == '\0') {
                dirent_set_errno(ENOENT);
     return NULL;
            }
    
            /* Allocate memory for DIR structure */
            dirp = (DIR*)malloc(sizeof(struct DIR));
            if (dirp) {
                wchar_t wname[PATH_MAX];
                size_t n;
    
                /* Convert directory name to wide-character string */
                error = dirent_mbstowcs_s(&n, wname, PATH_MAX, dirname, PATH_MAX);
                if (!error) {
    
                    /* Open directory stream using wide-character name */
                    dirp->wdirp = _wopendir(wname);
                    if (dirp->wdirp) {
                        /* Directory stream opened */
                        error = 0;
                    }
                    else {
                        /* Failed to open directory stream */
                        error = 1;
                    }
    
                }
                else {
                    /*
                    * Cannot convert file name to wide-character string.  This
                    * occurs if the string contains invalid multi-byte sequences or
                    * the output buffer is too small to contain the resulting
                    * string.
                    */
                    error = 1;
                }
    
            }
            else {
                /* Cannot allocate DIR structure */
                error = 1;
            }
    
            /* Clean up in case of error */
            if (error  &&  dirp) {
                free(dirp);
                dirp = NULL;
            }
     return dirp;
        }
    
        /*
        * Read next directory entry.
        *
        * When working with text consoles, please note that file names returned by
        * readdir() are represented in the default ANSI code page while any output to
        * console is typically formatted on another code page.  Thus, non-ASCII
        * characters in file names will not usually display correctly on console.  The
        * problem can be fixed in two ways: (1) change the character set of console
        * to 1252 using chcp utility and use Lucida Console font, or (2) use
        * _cprintf function when writing to console.  The _cprinf() will re-encode
        * ANSI strings to the console code page so many non-ASCII characters will
        * display correcly.
        */
        static struct dirent*
            readdir(
            DIR *dirp)
        {
            WIN32_FIND_DATAW *datap;
            struct dirent *entp;
    
            /* Read next directory entry */
            datap = dirent_next(dirp->wdirp);
            if (datap) {
                size_t n;
                int error;
    
                /* Attempt to convert file name to multi-byte string */
                error = dirent_wcstombs_s(
                    &n, dirp->ent.d_name, PATH_MAX, datap->cFileName, PATH_MAX);
    
                /*
                * If the file name cannot be represented by a multi-byte string,
                * then attempt to use old 8+3 file name.  This allows traditional
                * Unix-code to access some file names despite of unicode
                * characters, although file names may seem unfamiliar to the user.
                *
                * Be ware that the code below cannot come up with a short file
                * name unless the file system provides one.  At least
                * VirtualBox shared folders fail to do this.
                */
                if (error  &&  datap->cAlternateFileName[0] != '\0') {
                    error = dirent_wcstombs_s(
                        &n, dirp->ent.d_name, PATH_MAX,
                        datap->cAlternateFileName, PATH_MAX);
                }
    
                if (!error) {
                    DWORD attr;
    
                    /* Initialize directory entry for return */
                    entp = &dirp->ent;
    
                    /* Length of file name excluding zero terminator */
                    entp->d_namlen = n - 1;
    
                    /* File attributes */
                    attr = datap->dwFileAttributes;
                    if ((attr & FILE_ATTRIBUTE_DEVICE) != 0) {
                        entp->d_type = DT_CHR;
                    }
                    else if ((attr & FILE_ATTRIBUTE_DIRECTORY) != 0) {
                        entp->d_type = DT_DIR;
                    }
                    else {
                        entp->d_type = DT_REG;
                    }
    
                    /* Reset dummy fields */
                    entp->d_ino = 0;
                    entp->d_reclen = sizeof(struct dirent);
    
                }
                else {
                    /*
                    * Cannot convert file name to multi-byte string so construct
                    * an errornous directory entry and return that.  Note that
                    * we cannot return NULL as that would stop the processing
                    * of directory entries completely.
                    */
                    entp = &dirp->ent;
                    entp->d_name[0] = '?';
                    entp->d_name[1] = '\0';
                    entp->d_namlen = 1;
                    entp->d_type = DT_UNKNOWN;
                    entp->d_ino = 0;
                    entp->d_reclen = 0;
                }
    
            }
            else {
                /* No more directory entries */
                entp = NULL;
            }
     return entp;
        }
    
        /*
        * Close directory stream.
        */
        static int
            closedir(
            DIR *dirp)
        {
            int ok;
            if (dirp) {
    
                /* Close wide-character directory stream */
                ok = _wclosedir(dirp->wdirp);
                dirp->wdirp = NULL;
    
                /* Release multi-byte character version */
                free(dirp);
    
            }
            else {
    
                /* Invalid directory stream */
                dirent_set_errno(EBADF);
                ok = /*failure*/-1;
    
            }
     return ok;
        }
    
        /*
        * Rewind directory stream to beginning.
        */
        static void
            rewinddir(
            DIR* dirp)
        {
            /* Rewind wide-character string directory stream */
            _wrewinddir(dirp->wdirp);
        }
    
        /* Convert multi-byte string to wide character string */
        static int
            dirent_mbstowcs_s(
            size_t *pReturnValue,
            wchar_t *wcstr,
            size_t sizeInWords,
            const char *mbstr,
            size_t count)
        {
            int error;
    
    #if defined(_MSC_VER) && _MSC_VER >= 1400
    
            /* Microsoft Visual Studio 2005 or later */
            error = mbstowcs_s(pReturnValue, wcstr, sizeInWords, mbstr, count);
    
    #else
    
            /* Older Visual Studio or non-Microsoft compiler */
            size_t n;
    
            /* Convert to wide-character string (or count characters) */
            n = mbstowcs(wcstr, mbstr, sizeInWords);
            if (!wcstr || n < count) {
    
                /* Zero-terminate output buffer */
                if (wcstr  &&  sizeInWords) {
                    if (n >= sizeInWords) {
                        n = sizeInWords - 1;
                    }
                    wcstr[n] = 0;
                }
    
                /* Length of resuting multi-byte string WITH zero terminator */
                if (pReturnValue) {
                    *pReturnValue = n + 1;
                }
    
                /* Success */
                error = 0;
    
            }
            else {
    
                /* Could not convert string */
                error = 1;
    
            }
    
    #endif
     return error;
        }
    
        /* Convert wide-character string to multi-byte string */
        static int
            dirent_wcstombs_s(
            size_t *pReturnValue,
            char *mbstr,
            size_t sizeInBytes, /* max size of mbstr */
            const wchar_t *wcstr,
            size_t count)
        {
            int error;
    
    #if defined(_MSC_VER) && _MSC_VER >= 1400
    
            /* Microsoft Visual Studio 2005 or later */
            error = wcstombs_s(pReturnValue, mbstr, sizeInBytes, wcstr, count);
    
    #else
    
            /* Older Visual Studio or non-Microsoft compiler */
            size_t n;
    
            /* Convert to multi-byte string (or count the number of bytes needed) */
            n = wcstombs(mbstr, wcstr, sizeInBytes);
            if (!mbstr || n < count) {
    
                /* Zero-terminate output buffer */
                if (mbstr  &&  sizeInBytes) {
                    if (n >= sizeInBytes) {
                        n = sizeInBytes - 1;
                    }
                    mbstr[n] = '\0';
                }
    
                /* Lenght of resulting multi-bytes string WITH zero-terminator */
                if (pReturnValue) {
                    *pReturnValue = n + 1;
                }
    
                /* Success */
                error = 0;
    
            }
            else {
    
                /* Cannot convert string */
                error = 1;
    
            }
    
    #endif
     return error;
        }
    
        /* Set errno variable */
        static void
            dirent_set_errno(
            int error)
        {
    #if defined(_MSC_VER) && _MSC_VER >= 1400
    
            /* Microsoft Visual Studio 2005 and later */
            _set_errno(error);
    
    #else
    
            /* Non-Microsoft compiler or older Microsoft compiler */
            errno = error;
    
    #endif
        }
    
    
    #ifdef __cplusplus
    }
    #endif
    #endif /*DIRENT_H*/

[windows_windows api]: http://blog.csdn.net/wangshubo1989/article/details/52993466
[https_github.com_tronkko_dirent_blob_master_include_dirent.h]: https://github.com/tronkko/dirent/blob/master/include/dirent.h