newlib-cygwin/winsup/mingw/mingwex/dirent.c

456 lines
11 KiB
C

/*
* dirent.c
* This file has no copyright assigned and is placed in the Public Domain.
* This file is a part of the mingw-runtime package.
* No warranty is given; refer to the file DISCLAIMER within the package.
*
* Derived from DIRLIB.C by Matt J. Weinstein
* This note appears in the DIRLIB.H
* DIRLIB.H by M. J. Weinstein Released to public domain 1-Jan-89
*
* Updated by Jeremy Bettis <jeremy@hksys.com>
* Significantly revised and rewinddir, seekdir and telldir added by Colin
* Peters <colin@fu.is.saga-u.ac.jp>
*
*/
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <io.h>
#include <direct.h>
#include <dirent.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h> /* for GetFileAttributes */
#include <tchar.h>
#define SUFFIX _T("*")
#define SLASH _T("\\")
union __dirstream_t
{
/* Actual (private) declaration for opaque data type "DIR". */
/* dirent struct to return from dir (NOTE: this makes this thread
* safe as long as only one thread uses a particular DIR struct at
* a time) */
struct dirent dd_dir;
struct __dirstream_private_t
{
/* Three padding fields, matching the head of dd_dir...
*/
long dd_ino; /* Always zero. */
unsigned short dd_reclen; /* Always zero. */
unsigned short dd_namlen; /* Length of name in d_name. */
/* ...to keep the start of this disk transfer area for this dir
* aligned at the offset of the dd_dir.d_type field
*/
struct _finddata_t dd_dta;
/* _findnext handle */
intptr_t dd_handle;
/* Status of search:
* (type is now int -- was short in older versions).
* 0 = not started yet (next entry to read is first entry)
* -1 = off the end
* positive = 0 based index of next entry
*/
int dd_stat;
/* given path for dir with search pattern (struct is extended) */
char dd_name[1];
} dd_private;
};
union __wdirstream_t
{
/* Actual (private) declaration for opaque data type "_WDIR". */
/* dirent struct to return from dir (NOTE: this makes this thread
* safe as long as only one thread uses a particular DIR struct at
* a time) */
struct _wdirent dd_dir;
struct __wdirstream_private_t
{
/* Three padding fields, matching the head of dd_dir...
*/
long dd_ino; /* Always zero. */
unsigned short dd_reclen; /* Always zero. */
unsigned short dd_namlen; /* Length of name in d_name. */
/* ...to keep the start of this disk transfer area for this dir
* aligned at the offset of the dd_dir.d_type field
*/
struct _wfinddata_t dd_dta;
/* _findnext handle */
intptr_t dd_handle;
/* Status of search:
* 0 = not started yet (next entry to read is first entry)
* -1 = off the end
* positive = 0 based index of next entry
*/
int dd_stat;
/* given path for dir with search pattern (struct is extended) */
wchar_t dd_name[1];
} dd_private;
};
/* We map the BSD d_type field in the returned dirent structure
* from the Microsoft _finddata_t dd_dta.attrib bits, which are:
*
* _A_NORMAL (0x0000) normal file: best fit for DT_REG
* _A_RDONLY (0x0001) read-only: no BSD d_type equivalent
* _A_HIDDEN (0x0002) hidden entity: no BSD equivalent
* _A_SYSTEM (0x0004) system entity: no BSD equivalent
* _A_VOLID (0x0008) volume label: no BSD equivalent
* _A_SUBDIR (0x0010) directory: best fit for DT_DIR
* _A_ARCH (0x0020) "dirty": no BSD equivalent
*
* Of these, _A_RDONLY, _A_HIDDEN, _A_SYSTEM, and _A_ARCH are
* modifier bits, rather than true entity type specifiers; we
* will ignore them in the mapping, by applying this mask:
*/
#define DT_IGNORED (_A_RDONLY | _A_HIDDEN | _A_SYSTEM | _A_ARCH)
/* Helper for opendir(). */
static inline unsigned _tGetFileAttributes (const _TCHAR * tPath)
{
#ifdef _UNICODE
/* GetFileAttributesW does not work on W9x, so convert to ANSI */
if (_osver & 0x8000)
{
char aPath [MAX_PATH];
WideCharToMultiByte (CP_ACP, 0, tPath, -1, aPath, MAX_PATH, NULL,
NULL);
return GetFileAttributesA (aPath);
}
return GetFileAttributesW (tPath);
#else
return GetFileAttributesA (tPath);
#endif
}
/*
* opendir
*
* Returns a pointer to a DIR structure appropriately filled in to begin
* searching a directory.
*/
_TDIR *
_topendir (const _TCHAR *szPath)
{
_TDIR *nd;
unsigned int rc;
_TCHAR szFullPath[MAX_PATH];
errno = 0;
if (!szPath)
{
errno = EFAULT;
return (_TDIR *) 0;
}
if (szPath[0] == _T('\0'))
{
errno = ENOTDIR;
return (_TDIR *) 0;
}
/* Attempt to determine if the given path really is a directory. */
rc = _tGetFileAttributes (szPath);
if (rc == (unsigned int)-1)
{
/* call GetLastError for more error info */
errno = ENOENT;
return (_TDIR *) 0;
}
if (!(rc & FILE_ATTRIBUTE_DIRECTORY))
{
/* Error, entry exists but not a directory. */
errno = ENOTDIR;
return (_TDIR *) 0;
}
/* Make an absolute pathname. */
_tfullpath (szFullPath, szPath, MAX_PATH);
/* Allocate enough space to store DIR structure and the complete
* directory path given. */
nd = (_TDIR *) malloc (sizeof (_TDIR) + (_tcslen (szFullPath)
+ _tcslen (SLASH)
+ _tcslen (SUFFIX) + 1)
* sizeof (_TCHAR));
if (!nd)
{
/* Error, out of memory. */
errno = ENOMEM;
return (_TDIR *) 0;
}
/* Create the search expression. */
_tcscpy (nd->dd_private.dd_name, szFullPath);
/* Add on a slash if the path does not end with one. */
if (nd->dd_private.dd_name[0] != _T('\0')
&& _tcsrchr (nd->dd_private.dd_name, _T('/')) != nd->dd_private.dd_name
+ _tcslen (nd->dd_private.dd_name) - 1
&& _tcsrchr (nd->dd_private.dd_name, _T('\\')) != nd->dd_private.dd_name
+ _tcslen (nd->dd_private.dd_name) - 1)
{
_tcscat (nd->dd_private.dd_name, SLASH);
}
/* Add on the search pattern */
_tcscat (nd->dd_private.dd_name, SUFFIX);
/* Initialize handle to -1 so that a premature closedir doesn't try
* to call _findclose on it. */
nd->dd_private.dd_handle = -1;
/* Initialize the status. */
nd->dd_private.dd_stat = 0;
/* Initialize the dirent structure. ino and reclen are invalid under
* Win32, and name simply points at the appropriate part of the
* findfirst_t structure. */
nd->dd_dir.d_ino = 0;
nd->dd_dir.d_reclen = 0;
nd->dd_dir.d_namlen = 0;
memset (nd->dd_dir.d_name, 0, FILENAME_MAX);
return nd;
}
/*
* readdir
*
* Return a pointer to a dirent structure filled with the information on the
* next entry in the directory.
*/
struct _tdirent *
_treaddir (_TDIR * dirp)
{
errno = 0;
/* Check for valid DIR struct. */
if (!dirp)
{
errno = EFAULT;
return (struct _tdirent *) 0;
}
if (dirp->dd_private.dd_stat < 0)
{
/* We have already returned all files in the directory
* (or the structure has an invalid dd_stat). */
return (struct _tdirent *) 0;
}
else if (dirp->dd_private.dd_stat == 0)
{
/* We haven't started the search yet. */
/* Start the search */
dirp->dd_private.dd_handle = _tfindfirst (dirp->dd_private.dd_name, &(dirp->dd_private.dd_dta));
if (dirp->dd_private.dd_handle == -1)
{
/* Whoops! Seems there are no files in that
* directory. */
dirp->dd_private.dd_stat = -1;
}
else
{
dirp->dd_private.dd_stat = 1;
}
}
else
{
/* Get the next search entry. */
if (_tfindnext (dirp->dd_private.dd_handle, &(dirp->dd_private.dd_dta)))
{
/* We are off the end or otherwise error.
_findnext sets errno to ENOENT if no more file
Undo this. */
DWORD winerr = GetLastError ();
if (winerr == ERROR_NO_MORE_FILES)
errno = 0;
_findclose (dirp->dd_private.dd_handle);
dirp->dd_private.dd_handle = -1;
dirp->dd_private.dd_stat = -1;
}
else
{
/* Update the status to indicate the correct
* number. */
dirp->dd_private.dd_stat++;
}
}
if (dirp->dd_private.dd_stat > 0)
{
/* Successfully got an entry. Everything about the file is
* already appropriately filled in except the length of the
* file name...
*/
dirp->dd_dir.d_namlen = _tcslen (dirp->dd_dir.d_name);
/*
* ...and the attributes returned in the dd_dta.attrib field;
* these require adjustment to their BSD equivalents, which are
* returned via the union with the dd_dir.d_type field:
*/
switch( dirp->dd_dir.d_type &= ~DT_IGNORED )
{
case DT_REG:
case DT_DIR:
/* After stripping out the modifier bits in DT_IGNORED,
* (which we ALWAYS ignore), this pair require no further
* adjustment...
*/
break;
default:
/* ...while nothing else has an appropriate equivalent
* in the BSD d_type identification model.
*/
dirp->dd_dir.d_type = DT_UNKNOWN;
}
return &dirp->dd_dir;
}
return (struct _tdirent *) 0;
}
/*
* closedir
*
* Frees up resources allocated by opendir.
*/
int
_tclosedir (_TDIR * dirp)
{
int rc;
errno = 0;
rc = 0;
if (!dirp)
{
errno = EFAULT;
return -1;
}
if (dirp->dd_private.dd_handle != -1)
{
rc = _findclose (dirp->dd_private.dd_handle);
}
/* Delete the dir structure. */
free (dirp);
return rc;
}
/*
* rewinddir
*
* Return to the beginning of the directory "stream". We simply call findclose
* and then reset things like an opendir.
*/
void
_trewinddir (_TDIR * dirp)
{
errno = 0;
if (!dirp)
{
errno = EFAULT;
return;
}
if (dirp->dd_private.dd_handle != -1)
{
_findclose (dirp->dd_private.dd_handle);
}
dirp->dd_private.dd_handle = -1;
dirp->dd_private.dd_stat = 0;
}
/*
* telldir
*
* Returns the "position" in the "directory stream" which can be used with
* seekdir to go back to an old entry. We simply return the value in stat.
*/
long
_ttelldir (_TDIR * dirp)
{
errno = 0;
if (!dirp)
{
errno = EFAULT;
return -1;
}
return dirp->dd_private.dd_stat;
}
/*
* seekdir
*
* Seek to an entry previously returned by telldir. We rewind the directory
* and call readdir repeatedly until either dd_stat is the position number
* or -1 (off the end). This is not perfect, in that the directory may
* have changed while we weren't looking. But that is probably the case with
* any such system.
*/
void
_tseekdir (_TDIR * dirp, long lPos)
{
errno = 0;
if (!dirp)
{
errno = EFAULT;
return;
}
if (lPos < -1)
{
/* Seeking to an invalid position. */
errno = EINVAL;
return;
}
else if (lPos == -1)
{
/* Seek past end. */
if (dirp->dd_private.dd_handle != -1)
{
_findclose (dirp->dd_private.dd_handle);
}
dirp->dd_private.dd_handle = -1;
dirp->dd_private.dd_stat = -1;
}
else
{
/* Rewind and read forward to the appropriate index. */
_trewinddir (dirp);
while ((dirp->dd_private.dd_stat < lPos) && _treaddir (dirp))
;
}
}