【转】vs2005下的dirent.h
http://www.analogcn.com/Article/wz3/200802/20080202211037.html
dirent.h是gcc下的一个头文件，而在VS2005中是没有的。这个文件中封装了几个对目录进行操作函数：
static DIR *opendir (const char *dirname);
static struct dirent *readdir (DIR *dirp);
static int closedir (DIR *dirp);
对于在linux->windows之间进行程序移植来讲常常会造成一些困扰，在网上仔细搜了一下，发现原来已经有位好同志写了相应的移植代码，如下所示：
typedef struct dirent {
/* name of current directory entry (a multi-byte character string) */
char d_name[MAX_PATH + 1];
/* file attributes */
WIN32_FIND_DATA data;
} dirent;
typedef struct DIR {
/* current directory entry */
dirent current;
/* is there an un-processed entry in current? */
int cached;
/* file search handle */
HANDLE search_handle;
/* search pattern (3 = zero terminator + pattern "\\*") */
TCHAR patt[MAX_PATH + 3];
} DIR;
static DIR *opendir (const char *dirname);
static struct dirent *readdir (DIR *dirp);
static int closedir (DIR *dirp);
/* use the new safe string functions introduced in Visual Studio 2005 */
#if defined(_MSC_VER) && _MSC_VER >= 1400
# define STRNCPY(dest,src,size) strncpy_s((dest),(size),(src),_TRUNCATE)
#else
# define STRNCPY(dest,src,size) strncpy((dest),(src),(size))
#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 DIR*
opendir(
const char *dirname)
{
DIR *dirp;
assert (dirname != NULL);
assert (strlen (dirname) < MAX_PATH);
/* construct new DIR structure */
dirp = (DIR*) malloc (sizeof (struct DIR));
if (dirp != NULL) {
TCHAR *p;
/* prepare search pattern */
#ifdef _UNICODE
/* convert directory name to wide character string */
MultiByteToWideChar(
CP_ACP, /* code page */
0, /* conversion flags */
dirname, /* mb-string to convert */
-1, /* length of mb-string */
dirp->patt, /* wc-string to produce */
MAX_PATH); /* max length of wc-string */
dirp->patt[MAX_PATH] = '\0';
/* append search pattern to directory name */
p = wcschr (dirp->patt, '\0');
if (dirp->patt < p && *(p-1) != '\\' && *(p-1) != ':') {
*p++ = '\\';
}
*p++ = '*';
*p = '\0';
#else /* !_UNICODE */
/* take directory name... */
STRNCPY (dirp->patt, dirname, sizeof(dirp->patt));
dirp->patt[MAX_PATH] = '\0';
/* ... and append search pattern to it */
p = strchr (dirp->patt, '\0');
if (dirp->patt < p && *(p-1) != '\\' && *(p-1) != ':') {
*p++ = '\\';
}
*p++ = '*';
*p = '\0';
#endif /* !_UNICODE */
/* open stream and retrieve first file */
dirp->search_handle = FindFirstFile (dirp->patt, &dirp->current.data);
if (dirp->search_handle == INVALID_HANDLE_VALUE) {
/* invalid search pattern? */
free (dirp);
return NULL;
}
/* there is an un-processed directory entry in memory now */
dirp->cached = 1;
}
return dirp;
}
/*
* Read a directory entry, and return a pointer to a dirent structure
* containing the name of the entry in d_name field. Individual directory
* entries returned by this very function include regular files,
* sub-directories, pseudo-directories "." and "..", but also volume labels,
* hidden files and system files may be returned.
*/
static struct dirent *
readdir(
DIR *dirp)
{
assert (dirp != NULL);
if (dirp->search_handle == INVALID_HANDLE_VALUE) {
/* directory stream was opened/rewound incorrectly or it ended normally */
return NULL;
}
/* get next directory entry */
if (dirp->cached != 0) {
/* a valid directory entry already in memory */
dirp->cached = 0;
} else {
/* read next directory entry from disk */
if (FindNextFile (dirp->search_handle, &dirp->current.data) == FALSE) {
/* the very last file has been processed or an error occured */
FindClose (dirp->search_handle);
dirp->search_handle = INVALID_HANDLE_VALUE;
return NULL;
}
}
/* copy directory entry to d_name */
#ifdef _UNICODE
/* convert entry name to multibyte */
WideCharToMultiByte(
CP_ACP, /* code page */
0, /* conversion flags */
dirp->current.data.cFileName, /* wc-string to convert */
-1, /* length of wc-string */
dirp->current.d_name, /* mb-string to produce */
MAX_PATH, /* max length of mb-string */
NULL, /* use sys default character */
NULL); /* don't care */
dirp->current.d_name[MAX_PATH] = '\0';
#else /* !_UNICODE */
/* copy as a multibyte character string */
STRNCPY (dirp->current.d_name, dirp->current.data.cFileName, sizeof(dirp->current.d_name));
dirp->current.d_name[MAX_PATH] = '\0';
#endif /* !_UNICODE */
return &dirp->current;
}
/*
* Close directory stream opened by opendir() function. Close of the
* directory stream invalidates the DIR structure as well as any previously
* read directory entry.
*/
static int
closedir(
DIR *dirp)
{
assert (dirp != NULL);
/* release search handle */
if (dirp->search_handle != INVALID_HANDLE_VALUE) {
FindClose (dirp->search_handle);
dirp->search_handle = INVALID_HANDLE_VALUE;
}
/* release directory handle */
free (dirp);
return 0;
}
此文件可从http://www.softagalleria.net/dirent/index.en.html下载得到，直接将它放在VS2005的include目录就OK 了！
