136 lines
3.4 KiB
C
136 lines
3.4 KiB
C
|
/***
|
||
|
|
*access.c - access function
|
||
|
|
*
|
||
|
|
* Copyright (c) Microsoft Corporation. All rights reserved.
|
||
|
|
*
|
||
|
|
*Purpose:
|
||
|
|
* This file has the _access() function which checks on file accessability.
|
||
|
|
*
|
||
|
|
*******************************************************************************/
|
||
|
|
|
||
|
|
#include <cruntime.h>
|
||
|
|
#include <io.h>
|
||
|
|
#include <oscalls.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <errno.h>
|
||
|
|
#include <msdos.h>
|
||
|
|
#include <internal.h>
|
||
|
|
#include <tchar.h>
|
||
|
|
#include <malloc.h>
|
||
|
|
#include <dbgint.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
|
||
|
|
)
|
||
|
|
{
|
||
|
|
errno_t e;
|
||
|
|
e = _taccess_s(path,amode);
|
||
|
|
|
||
|
|
return e ? -1 : 0 ;
|
||
|
|
}
|
||
|
|
|
||
|
|
/***
|
||
|
|
*errno_t _access_s(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 errno_t for any other errors
|
||
|
|
*
|
||
|
|
*Exceptions:
|
||
|
|
*
|
||
|
|
*******************************************************************************/
|
||
|
|
#ifndef _UNICODE
|
||
|
|
|
||
|
|
errno_t __cdecl _access_s (
|
||
|
|
const char *path,
|
||
|
|
int amode
|
||
|
|
)
|
||
|
|
{
|
||
|
|
wchar_t* pathw = NULL;
|
||
|
|
errno_t retval;
|
||
|
|
|
||
|
|
if (path)
|
||
|
|
{
|
||
|
|
if (!__copy_path_to_wide_string(path, &pathw))
|
||
|
|
return errno;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* call the wide-char variant */
|
||
|
|
retval = _waccess_s(pathw, amode);
|
||
|
|
|
||
|
|
_free_crt(pathw); /* _free_crt leaves errno alone if everything completes as expected */
|
||
|
|
|
||
|
|
return retval;
|
||
|
|
}
|
||
|
|
|
||
|
|
#else /* _UNICODE */
|
||
|
|
|
||
|
|
errno_t __cdecl _waccess_s (
|
||
|
|
const wchar_t *path,
|
||
|
|
int amode
|
||
|
|
)
|
||
|
|
{
|
||
|
|
|
||
|
|
WIN32_FILE_ATTRIBUTE_DATA attr_data;
|
||
|
|
|
||
|
|
_VALIDATE_CLEAR_OSSERR_RETURN_ERRCODE( (path != NULL), EINVAL);
|
||
|
|
_VALIDATE_CLEAR_OSSERR_RETURN_ERRCODE( ((amode & (~6)) == 0), EINVAL);
|
||
|
|
|
||
|
|
if (!GetFileAttributesExW(path, GetFileExInfoStandard, (void*) &attr_data)) {
|
||
|
|
/* error occured -- map error code and return */
|
||
|
|
_dosmaperr(GetLastError());
|
||
|
|
return errno;
|
||
|
|
}
|
||
|
|
|
||
|
|
if(attr_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
|
||
|
|
{
|
||
|
|
/* All directories have read & write access */
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* no error; see if returned premission settings OK */
|
||
|
|
if ( (attr_data.dwFileAttributes & FILE_ATTRIBUTE_READONLY) && (amode & 2) ) {
|
||
|
|
/* no write permission on file, return error */
|
||
|
|
_doserrno = E_access;
|
||
|
|
errno = EACCES;
|
||
|
|
return errno;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
/* file exists and has requested permission setting */
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* _UNICODE */
|