windows-nt/Source/XPSP1/NT/base/crts/crtw32/dos/access.c
2020-09-26 16:20:57 +08:00

87 lines
2.8 KiB
C

/***
*access.c - access function
*
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* This file has the _access() function which checks on file accessability.
*
*Revision History:
* 06-06-89 PHG Module created, based on asm version
* 11-10-89 JCR Replaced DOS32QUERYFILEMODE with DOS32QUERYPATHINFO
* 03-07-90 GJF Made calling type _CALLTYPE2 (for now), added #include
* <cruntime.h>, fixed copyright and fixed compiler
* warnings. Also, cleaned up the formatting a bit.
* 03-30-90 GJF Now _CALLTYPE1.
* 07-24-90 SBM Removed '32' from API names
* 09-27-90 GJF New-style function declarator.
* 12-04-90 SRW Changed to include <oscalls.h> instead of <doscalls.h>
* 12-06-90 SRW Added _CRUISER_ and _WIN32 conditionals.
* 01-16-91 GJF ANSI naming.
* 04-09-91 PNT Added _MAC_ conditional
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
* 12-07-93 CFW Rip out Cruiser, enable wide char.
* 02-08-95 JWM Spliced _WIN32 & Mac versions.
* 07-01-96 GJF Replaced defined(_WIN32) with !defined(_MAC). Also,
* detab-ed and cleaned up the format a bit.
* 05-17-99 PML Remove all Macintosh support.
*
*******************************************************************************/
#include <cruntime.h>
#include <io.h>
#include <oscalls.h>
#include <stdlib.h>
#include <errno.h>
#include <msdos.h>
#include <internal.h>
#include <tchar.h>
/***
*int _access(path, amode) - check whether file can be accessed under mode
*
*Purpose:
* Checks to see if the specified file exists and can be accessed
* in the given mode.
*
*Entry:
* _TSCHAR *path - pathname
* int amode - access mode
* (0 = exist only, 2 = write, 4 = read, 6 = read/write)
*
*Exit:
* returns 0 if file has given mode
* returns -1 and sets errno if file does not have given mode or
* does not exist
*
*Exceptions:
*
*******************************************************************************/
int __cdecl _taccess (
const _TSCHAR *path,
int amode
)
{
DWORD attr;
attr = GetFileAttributes((LPTSTR)path);
if (attr == 0xffffffff) {
/* error occured -- map error code and return */
_dosmaperr(GetLastError());
return -1;
}
/* no error; see if returned premission settings OK */
if ( (attr & FILE_ATTRIBUTE_READONLY) && (amode & 2) ) {
/* no write permission on file, return error */
errno = EACCES;
_doserrno = E_access;
return -1;
}
else
/* file exists and has requested permission setting */
return 0;
}