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一.dirent.h简介
<dirent.h>
是一个应用程序接口,主要用于文件系统的目录读取操作,主要提供了几个目录数据读取函数,参见 opengroup.org 。
<dirent
.h>
是个unix系统下常见的接口,但 windows 平台的 MSVC 编译器并没有提供这个接口,对于跨平台的项目开发就会带来一些麻烦,如果在 MSVC 下编译时可能因为windows平台缺少这个接口就要为 windows 平台另外写一些代码。
已经有人完成了 windows 平台下 dirent.h 文件编写,github下载地址,源码如下:
/******************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:C/C++ error C1083: Cannot open include file: 'dirent.h': No such file or directory
//@Time:2022/01/06 07:20
//@Motto:不积跬步无以至千里,不积小流无以成江海,程序人生的精彩需要坚持不懈地积累!
/******************************************************************************************/
/*
* Dirent interface for Microsoft Visual Studio
*
* Copyright (C) 1998-2019 Toni Ronkko
* This file is part of dirent. Dirent may be freely distributed
* under the MIT license. For all details and documentation, see
* https://github.com/tronkko/dirent
*/
#ifndef DIRENT_H
#define DIRENT_H
/* Hide warnings about unreferenced local functions */
#if defined(__clang__)
# pragma clang diagnostic ignored "-Wunused-function"
#elif defined(_MSC_VER)
# pragma warning(disable:4505)
#elif defined(__GNUC__)
# pragma GCC diagnostic ignored "-Wunused-function"
#endif
/*
* Include windows.h without Windows Sockets 1.1 to prevent conflicts with
* Windows Sockets 2.0.
*/
#ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#include <stdio.h>
#include <stdarg.h>
#include <wchar.h>
#include <string.h>
#include <stdlib.h>
#include <malloc.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <ctype.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(), general mask */
#if !defined(S_IFMT)
# define S_IFMT _S_IFMT
#endif
/* Directory bit */
#if !defined(S_IFDIR)
# define S_IFDIR _S_IFDIR
#endif
/* Character device bit */
#if !defined(S_IFCHR)
# define S_IFCHR _S_IFCHR
#endif
/* Pipe bit */
#if !defined(S_IFFIFO)
# define S_IFFIFO _S_IFFIFO
#endif
/* Regular file bit */
#if !defined(S_IFREG)
# define S_IFREG _S_IFREG
#endif
/* Read permission */
#if !defined(S_IREAD)
# define S_IREAD _S_IREAD
#endif
/* Write permission */
#if !defined(S_IWRITE)
# define S_IWRITE _S_IWRITE
#endif
/* Execute permission */
#if !defined(S_IEXEC)
# define S_IEXEC _S_IEXEC
#endif
/* Pipe */
#if !defined(S_IFIFO)
# define S_IFIFO _S_IFIFO
#endif
/* Block device */
#if !defined(S_IFBLK)
# define S_IFBLK 0
#endif
/* Link */
#if !defined(S_IFLNK)
# define S_IFLNK 0
#endif
/* Socket */
#if !defined(S_IFSOCK)
# define S_IFSOCK 0
#endif
/* Read user permission */
#if !defined(S_IRUSR)
# define S_IRUSR S_IREAD
#endif
/* Write user permission */
#if !defined(S_IWUSR)
# define S_IWUSR S_IWRITE
#endif
/* Execute user permission */
#if !defined(S_IXUSR)
# define S_IXUSR 0
#endif
/* Read group permission */
#if !defined(S_IRGRP)
# define S_IRGRP 0
#endif
/* Write group permission */
#if !defined(S_IWGRP)
# define S_IWGRP 0
#endif
/* Execute group permission */
#if !defined(S_IXGRP)
# define S_IXGRP 0
#endif
/* Read others permission */
#if !defined(S_IROTH)
# define S_IROTH 0
#endif
/* Write others permission */
#if !defined(S_IWOTH)
# define S_IWOTH 0
#endif
/* Execute others permission */
#if !defined(S_IXOTH)
# define S_IXOTH 0
#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.
*/
#if !defined(S_ISFIFO)
# define S_ISFIFO(mode) (((mode) & S_IFMT) == S_IFIFO)
#endif
#if !defined(S_ISDIR)
# define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)
#endif
#if !defined(S_ISREG)
# define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG)
#endif
#if !defined(S_ISLNK)
# define S_ISLNK(mode) (((mode) & S_IFMT) == S_IFLNK)
#endif
#if !defined(S_ISSOCK)
# define S_ISSOCK(mode) (((mode) & S_IFMT) == S_IFSOCK)
#endif
#if !defined(S_ISCHR)
# define S_ISCHR(mode) (((mode) & S_IFMT) == S_IFCHR)
#endif
#if !defined(S_ISBLK)
# define S_ISBLK(mode) (((mode) & S_IFMT) == S_IFBLK)
#endif
/* Return the exact length of the file name without zero terminator */
#define _D_EXACT_NAMLEN(p) ((p)->d_namlen)
/* Return the maximum size of a file name */
#define _D_ALLOC_NAMLEN(p) ((PATH_MAX)+1)
#ifdef __cplusplus
extern "C" {
#endif
/* Wide-character version */
struct _wdirent {
/* Always zero */
long d_ino;
/* File position within stream */
long d_off;
/* Structure size */
unsigned short d_reclen;
/* Length of name without \0 */
size_t d_namlen;
/* File type */
int d_type;
/* File name */
wchar_t d_name[PATH_MAX+1];
};
typedef struct _wdirent _wdirent;
struct _WDIR {
/* Current directory entry */
struct _wdirent ent;
/* Private file data */
WIN32_FIND_DATAW data;
/* True if data is valid */
int cached;
/* Win32 search handle */
HANDLE handle;
/* Initial directory name */
wchar_t *patt;
};
typedef struct _WDIR _WDIR;
/* Multi-byte character version */
struct dirent {
/* Always zero */
long d_ino;
/* File position within stream */
long d_off;
/* Structure size */
unsigned short d_reclen;
/* Length of name without \0 */
size_t d_namlen;
/* File type */
int d_type;
/* File name */
char d_name[PATH_MAX+1];
};
typedef struct dirent dirent;
struct DIR {
struct dirent ent;
struct _WDIR *wdirp;
};
typedef struct DIR DIR;
/* Dirent functions */
static DIR *opendir(const char *dirname);
static _WDIR *_wopendir(const wchar_t *dirname);
static struct dirent *readdir(DIR *dirp);
static struct _wdirent *_wreaddir(_WDIR *dirp);
static int readdir_r(
DIR *dirp, struct dirent *entry, struct dirent **result);
static int _wreaddir_r(
_WDIR *dirp, struct _wdirent *entry, struct _wdirent **result);
static int closedir(DIR *dirp);
static int _wclosedir(_WDIR *dirp);
static void rewinddir(DIR* dirp);
static void _wrewinddir(_WDIR* dirp);
static int scandir(const char *dirname, struct dirent ***namelist,
int (*filter)(const struct dirent*),
int (*compare)(const struct dirent**, const struct dirent**));
static int alphasort(const struct dirent **a, const struct dirent **b);
static int versionsort(const struct dirent **a, const struct dirent **b);
static int strverscmp(const char *a, const char *b);
/* For compatibility with Symbian */
#define wdirent _wdirent
#define WDIR _WDIR
#define wopendir _wopendir
#define wreaddir _wreaddir
#define wclosedir _wclosedir
#define wrewinddir _wrewinddir
/* Compatibility with older Microsoft compilers and non-Microsoft compilers */
#if !defined(_MSC_VER) || _MSC_VER < 1400
# define wcstombs_s dirent_wcstombs_s
# define mbstowcs_s dirent_mbstowcs_s
#endif
/* Optimize dirent_set_errno() away on modern Microsoft compilers */
#if defined(_MSC_VER) && _MSC_VER >= 1400
# define dirent_set_errno _set_errno
#endif
/* Internal utility functions */
static WIN32_FIND_DATAW *dirent_first(_WDIR *dirp);
static WIN32_FIND_DATAW *dirent_next(_WDIR *dirp);
#if !defined(_MSC_VER) || _MSC_VER < 1400
static int dirent_mbstowcs_s(
size_t *pReturnValue, wchar_t *wcstr, size_t sizeInWords,
const char *mbstr, size_t count);
#endif
#if !defined(_MSC_VER) || _MSC_VER < 1400
static int dirent_wcstombs_s(
size_t *pReturnValue, char *mbstr, size_t sizeInBytes,
const wchar_t *wcstr, size_t count);
#endif
#if !defined(_MSC_VER) || _MSC_VER < 1400
static void dirent_set_errno(int error);
#endif
/*
* 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)
{
wchar_t *p;
/* Must have directory name */
if (dirname == NULL || dirname[0] == '\0') {
dirent_set_errno(ENOENT);
return NULL;
}
/* Allocate new _WDIR structure */
_WDIR *dirp = (_WDIR*) malloc(sizeof(struct _WDIR));
if (!dirp)
return NULL;
/* Reset _WDIR structure */
dirp->handle = INVALID_HANDLE_VALUE;
dirp->patt = NULL;
dirp->cached = 0;
/*
* Compute the length of full path plus zero terminator
*
* Note that on WinRT there's no way to convert relative paths
* into absolute paths, so just assume it is an absolute path.
*/
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
/* Desktop */
DWORD n = GetFullPathNameW(dirname, 0, NULL, NULL);
#else
/* WinRT */
size_t n = wcslen(dirname);
#endif
/* Allocate room for absolute directory name and search pattern */
dirp->patt = (wchar_t*) malloc(sizeof(wchar_t) * n + 16);
if (dirp->patt == NULL)
goto exit_closedir;
/*
* 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().
*
* Note that on WinRT there's no way to convert relative paths
* into absolute paths, so just assume it is an absolute path.
*/
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
/* Desktop */
n = GetFullPathNameW(dirname, n, dirp->patt, NULL);
if (n <= 0)
goto exit_closedir;
#else
/* WinRT */
wcsncpy_s(dirp->patt, n+1, dirname, n);
#endif
/* Append search pattern \* to the directory name */
p = dirp->patt + n;
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))
goto exit_closedir;
/* Success */
return dirp;
/* Failure */
exit_closedir:
_wclosedir(dirp);
return NULL;
}
/*
* Read next directory entry.
*
* Returns pointer to static directory entry which may be overwritten by
* subsequent calls to _wreaddir().
*/
static struct _wdirent *_wreaddir(_WDIR *dirp)
{
/*
* Read directory entry to buffer. We can safely ignore the return
* value as entry will be set to NULL in case of error.
*/
struct _wdirent *entry;
(void) _wreaddir_r(dirp, &dirp->ent, &entry);
/* Return pointer to statically allocated directory entry */
return entry;
}
/*
* Read next directory entry.
*
* Returns zero on success. If end of directory stream is reached, then sets
* result to NULL and returns zero.
*/
static int _wreaddir_r(
_WDIR *dirp, struct _wdirent *entry, struct _wdirent **result)
{
/* Read next directory entry */
WIN32_FIND_DATAW *datap = dirent_next(dirp);
if (!datap) {
/* Return NULL to indicate end of directory */
*result = NULL;
return /*OK*/0;
}
/*
* 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.
*/
size_t n = 0;
while (n < PATH_MAX && datap->cFileName[n] != 0) {
entry->d_name[n] = datap->cFileName[n];
n++;
}
entry->d_name[n] = 0;
/* Length of file name excluding zero terminator */
entry->d_namlen = n;
/* File type */
DWORD attr = datap->dwFileAttributes;
if ((attr & FILE_ATTRIBUTE_DEVICE) != 0)
entry->d_type = DT_CHR;
else if ((attr & FILE_ATTRIBUTE_DIRECTORY) != 0)
entry->d_type = DT_DIR;
else
entry->d_type = DT_REG;
/* Reset dummy fields */
entry->d_ino = 0;
entry->d_off = 0;
entry->d_reclen = sizeof(struct _wdirent);
/* Set result address */
*result = entry;
return /*OK*/0;
}
/*
* 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)
{
if (!dirp) {
dirent_set_errno(EBADF);
return /*failure*/-1;
}
/* Release search handle */
if (dirp->handle != INVALID_HANDLE_VALUE)
FindClose(dirp->handle);
/* Release search pattern */
free(dirp->patt);
/* Release directory structure */
free(dirp);
return /*success*/0;
}
/*
* Rewind directory stream such that _wreaddir() returns the very first
* file name again.
*/
static void _wrewinddir(_WDIR* dirp)
{
if (!dirp)
return;
/* Release existing search handle */
if (dirp->handle != INVALID_HANDLE_VALUE)
FindClose(dirp->handle);
/* Open new search handle */
dirent_first(dirp);
}
/* Get first directory entry */
static WIN32_FIND_DATAW *dirent_first(_WDIR *dirp)
{
if (!dirp)
return NULL;
/* Open directory and retrieve the first entry */
dirp->handle = FindFirstFileExW(
dirp->patt, FindExInfoStandard, &dirp->data,
FindExSearchNameMatch, NULL, 0);
if (dirp->handle == INVALID_HANDLE_VALUE)
goto error;
/* A directory entry is now waiting in memory */
dirp->cached = 1;
return &dirp->data;
error:
/* Failed to open directory: no directory entry in memory */
dirp->cached = 0;
/* Set error code */
DWORD errorcode = GetLastError();
switch (errorcode) {
case ERROR_ACCESS_DENIED:
/* No read access to directory */
dirent_set_errno(EACCES);
break;
case ERROR_DIRECTORY:
/* Directory name is invalid */
dirent_set_errno(ENOTDIR);
break;
case ERROR_PATH_NOT_FOUND:
default:
/* Cannot find the file */
dirent_set_errno(ENOENT);
}
return NULL;
}
/* Get next directory entry */
static WIN32_FIND_DATAW *dirent_next(_WDIR *dirp)
{
/* Is the next directory entry already in cache? */
if (dirp->cached) {
/* Yes, a valid directory entry found in memory */
dirp->cached = 0;
return &dirp->data;
}
/* No directory entry in cache */
if (dirp->handle == INVALID_HANDLE_VALUE)
return NULL;
/* Read the next directory entry from stream */
if (FindNextFileW(dirp->handle, &dirp->data) == FALSE)
goto exit_close;
/* Success */
return &dirp->data;
/* Failure */
exit_close:
FindClose(dirp->handle);
dirp->handle = INVALID_HANDLE_VALUE;
return NULL;
}
/* Open directory stream using plain old C-string */
static DIR *opendir(const char *dirname)
{
/* Must have directory name */
if (dirname == NULL || dirname[0] == '\0') {
dirent_set_errno(ENOENT);
return NULL;
}
/* Allocate memory for DIR structure */
struct DIR *dirp = (DIR*) malloc(sizeof(struct DIR));
if (!dirp)
return NULL;
/* Convert directory name to wide-character string */
wchar_t wname[PATH_MAX + 1];
size_t n;
int error = mbstowcs_s(&n, wname, PATH_MAX + 1, dirname, PATH_MAX+1);
if (error)
goto exit_failure;
/* Open directory stream using wide-character name */
dirp->wdirp = _wopendir(wname);
if (!dirp->wdirp)
goto exit_failure;
/* Success */
return dirp;
/* Failure */
exit_failure:
free(dirp);
return NULL;
}
/* Read next directory entry */
static struct dirent *readdir(DIR *dirp)
{
/*
* Read directory entry to buffer. We can safely ignore the return
* value as entry will be set to NULL in case of error.
*/
struct dirent *entry;
(void) readdir_r(dirp, &dirp->ent, &entry);
/* Return pointer to statically allocated directory entry */
return entry;
}
/*
* Read next directory entry into called-allocated buffer.
*
* Returns zero on success. If the end of directory stream is reached, then
* sets result to NULL and returns zero.
*/
static int readdir_r(
DIR *dirp, struct dirent *entry, struct dirent **result)
{
/* Read next directory entry */
WIN32_FIND_DATAW *datap = dirent_next(dirp->wdirp);
if (!datap) {
/* No more directory entries */
*result = NULL;
return /*OK*/0;
}
/* Attempt to convert file name to multi-byte string */
size_t n;
int error = wcstombs_s(
&n, entry->d_name, PATH_MAX + 1,
datap->cFileName, PATH_MAX + 1);
/*
* If the file name cannot be represented by a multi-byte string, then
* attempt to use old 8+3 file name. This allows the program to
* access files 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 = wcstombs_s(
&n, entry->d_name, PATH_MAX + 1,
datap->cAlternateFileName, PATH_MAX + 1);
}
if (!error) {
/* Length of file name excluding zero terminator */
entry->d_namlen = n - 1;
/* File attributes */
DWORD attr = datap->dwFileAttributes;
if ((attr & FILE_ATTRIBUTE_DEVICE) != 0)
entry->d_type = DT_CHR;
else if ((attr & FILE_ATTRIBUTE_DIRECTORY) != 0)
entry->d_type = DT_DIR;
else
entry->d_type = DT_REG;
/* Reset dummy fields */
entry->d_ino = 0;
entry->d_off = 0;
entry->d_reclen = sizeof(struct dirent);
} else {
/*
* Cannot convert file name to multi-byte string so construct
* an erroneous directory entry and return that. Note that
* we cannot return NULL as that would stop the processing
* of directory entries completely.
*/
entry->d_name[0] = '?';
entry->d_name[1] = '\0';
entry->d_namlen = 1;
entry->d_type = DT_UNKNOWN;
entry->d_ino = 0;
entry->d_off = -1;
entry->d_reclen = 0;
}
/* Return pointer to directory entry */
*result = entry;
return /*OK*/0;
}
/* Close directory stream */
static int closedir(DIR *dirp)
{
int ok;
if (!dirp)
goto exit_failure;
/* Close wide-character directory stream */
ok = _wclosedir(dirp->wdirp);
dirp->wdirp = NULL;
/* Release multi-byte character version */
free(dirp);
return ok;
exit_failure:
/* Invalid directory stream */
dirent_set_errno(EBADF);
return /*failure*/-1;
}
/* Rewind directory stream to beginning */
static void rewinddir(DIR* dirp)
{
if (!dirp)
return;
/* Rewind wide-character string directory stream */
_wrewinddir(dirp->wdirp);
}
/* Scan directory for entries */
static int scandir(
const char *dirname, struct dirent ***namelist,
int (*filter)(const struct dirent*),
int (*compare)(const struct dirent**, const struct dirent**))
{
int result;
/* Open directory stream */
DIR *dir = opendir(dirname);
if (!dir) {
/* Cannot open directory */
return /*Error*/ -1;
}
/* Read directory entries to memory */
struct dirent *tmp = NULL;
struct dirent **files = NULL;
size_t size = 0;
size_t allocated = 0;
while (1) {
/* Allocate room for a temporary directory entry */
if (!tmp) {
tmp = (struct dirent*) malloc(sizeof(struct dirent));
if (!tmp)
goto exit_failure;
}
/* Read directory entry to temporary area */
struct dirent *entry;
if (readdir_r(dir, tmp, &entry) != /*OK*/0)
goto exit_failure;
/* Stop if we already read the last directory entry */
if (entry == NULL)
goto exit_success;
/* Determine whether to include the entry in results */
if (filter && !filter(tmp))
continue;
/* Enlarge pointer table to make room for another pointer */
if (size >= allocated) {
/* Compute number of entries in the new table */
size_t num_entries = size * 2 + 16;
/* Allocate new pointer table or enlarge existing */
void *p = realloc(files, sizeof(void*) * num_entries);
if (!p)
goto exit_failure;
/* Got the memory */
files = (dirent**) p;
allocated = num_entries;
}
/* Store the temporary entry to ptr table */
files[size++] = tmp;
tmp = NULL;
}
exit_failure:
/* Release allocated file entries */
for (size_t i = 0; i < size; i++) {
free(files[i]);
}
/* Release the pointer table */
free(files);
files = NULL;
/* Exit with error code */
result = /*error*/ -1;
goto exit_status;
exit_success:
/* Sort directory entries */
qsort(files, size, sizeof(void*),
(int (*) (const void*, const void*)) compare);
/* Pass pointer table to caller */
if (namelist)
*namelist = files;
/* Return the number of directory entries read */
result = (int) size;
exit_status:
/* Release temporary directory entry, if we had one */
free(tmp);
/* Close directory stream */
closedir(dir);
return result;
}
/* Alphabetical sorting */
static int alphasort(const struct dirent **a, const struct dirent **b)
{
return strcoll((*a)->d_name, (*b)->d_name);
}
/* Sort versions */
static int versionsort(const struct dirent **a, const struct dirent **b)
{
return strverscmp((*a)->d_name, (*b)->d_name);
}
/* Compare strings */
static int strverscmp(const char *a, const char *b)
{
size_t i = 0;
size_t j;
/* Find first difference */
while (a[i] == b[i]) {
if (a[i] == '\0') {
/* No difference */
return 0;
}
++i;
}
/* Count backwards and find the leftmost digit */
j = i;
while (j > 0 && isdigit(a[j-1])) {
--j;
}
/* Determine mode of comparison */
if (a[j] == '0' || b[j] == '0') {
/* Find the next non-zero digit */
while (a[j] == '0' && a[j] == b[j]) {
j++;
}
/* String with more digits is smaller, e.g 002 < 01 */
if (isdigit(a[j])) {
if (!isdigit(b[j])) {
return -1;
}
} else if (isdigit(b[j])) {
return 1;
}
} else if (isdigit(a[j]) && isdigit(b[j])) {
/* Numeric comparison */
size_t k1 = j;
size_t k2 = j;
/* Compute number of digits in each string */
while (isdigit(a[k1])) {
k1++;
}
while (isdigit(b[k2])) {
k2++;
}
/* Number with more digits is bigger, e.g 999 < 1000 */
if (k1 < k2)
return -1;
else if (k1 > k2)
return 1;
}
/* Alphabetical comparison */
return (int) ((unsigned char) a[i]) - ((unsigned char) b[i]);
}
/* Convert multi-byte string to wide character string */
#if !defined(_MSC_VER) || _MSC_VER < 1400
static int dirent_mbstowcs_s(
size_t *pReturnValue, wchar_t *wcstr,
size_t sizeInWords, const char *mbstr, size_t count)
{
/* Older Visual Studio or non-Microsoft compiler */
size_t n = mbstowcs(wcstr, mbstr, sizeInWords);
if (wcstr && n >= count)
return /*error*/ 1;
/* Zero-terminate output buffer */
if (wcstr && sizeInWords) {
if (n >= sizeInWords)
n = sizeInWords - 1;
wcstr[n] = 0;
}
/* Length of multi-byte string with zero terminator */
if (pReturnValue) {
*pReturnValue = n + 1;
}
/* Success */
return 0;
}
#endif
/* Convert wide-character string to multi-byte string */
#if !defined(_MSC_VER) || _MSC_VER < 1400
static int dirent_wcstombs_s(
size_t *pReturnValue, char *mbstr,
size_t sizeInBytes, const wchar_t *wcstr, size_t count)
{
/* Older Visual Studio or non-Microsoft compiler */
size_t n = wcstombs(mbstr, wcstr, sizeInBytes);
if (mbstr && n >= count)
return /*error*/1;
/* Zero-terminate output buffer */
if (mbstr && sizeInBytes) {
if (n >= sizeInBytes) {
n = sizeInBytes - 1;
}
mbstr[n] = '\0';
}
/* Length of resulting multi-bytes string WITH zero-terminator */
if (pReturnValue) {
*pReturnValue = n + 1;
}
/* Success */
return 0;
}
#endif
/* Set errno variable */
#if !defined(_MSC_VER) || _MSC_VER < 1400
static void dirent_set_errno(int error)
{
/* Non-Microsoft compiler or older Microsoft compiler */
errno = error;
}
#endif
#ifdef __cplusplus
}
#endif
#endif /*DIRENT_H*/
使用方法:直接在 windows 的 visual studio 中新建 dirent.h ,将上面源码复制粘贴,然后将文件添加到工程中即可;
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