/***
*_open.c - open a stream, with string mode
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines _openfile() - opens a stream, with string arguments for mode
*
*******************************************************************************/
#include <cruntime.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <file2.h>
#include <share.h>
#include <io.h>
#include <dbgint.h>
#include <internal.h>
#include <tchar.h>
#include <sys\stat.h>
#define CMASK 0644 /* rw-r--r-- */
#define P_CMASK 0666 /* different for Posix */
/***
*FILE *_openfile(filename, mode, shflag, stream) - open a file with string
* mode and file sharing flag.
*
*Purpose:
* parse the string, looking for exactly one of {rwa}, at most one '+',
* at most one of {tb}, at most one of {cn}, at most one of {SR}, at most
* one 'T', and at most one 'D'. pass the result on as an int containing
* flags of what was found. open a file with proper mode if permissions
* allow. buffer not allocated until first i/o call is issued. intended
* for use inside library only
*
*Entry:
* char *filename - file to open
* char *mode - mode to use (see above)
* int shflag - file sharing flag
* FILE *stream - stream to use for file
*
*Exit:
* set stream's fields, and causes system file management by system calls
* returns stream or NULL if fails
*
*Exceptions:
*
*******************************************************************************/
FILE * __cdecl __topenfile (
const _TSCHAR *filename,
const _TSCHAR *mode,
int shflag,
FILE *str
)
{
int modeflag = 0;
int streamflag = _commode;
int commodeset = 0;
int scanset = 0;
int whileflag;
int filedes;
FILE *stream;
BOOL encodingFlag = FALSE;
_ASSERTE(filename != NULL);
_ASSERTE(mode != NULL);
_ASSERTE(str != NULL);
/* Parse the user's specification string as set flags in
(1) modeflag - system call flags word
(2) streamflag - stream handle flags word. */
/* Skip leading spaces */
while (*mode == _T(' '))
{
++mode;
}
/* First mode character must be 'r', 'w', or 'a'. */
switch (*mode) {
case _T('r'):
modeflag = _O_RDONLY;
streamflag |= _IOREAD;
break;
case _T('w'):
modeflag = _O_WRONLY | _O_CREAT | _O_TRUNC;
streamflag |= _IOWRT;
break;
case _T('a'):
modeflag = _O_WRONLY | _O_CREAT | _O_APPEND;
streamflag |= _IOWRT;
break;
default:
_VALIDATE_RETURN(("Invalid file open mode",0), EINVAL, NULL);
}
/* There can be up to three more optional mode characters:
(1) A single '+' character,
(2) One of 't' and 'b' and
(3) One of 'c' and 'n'.
*/
whileflag=1;
while(*++mode && whileflag)
switch(*mode) {
case _T(' '):
/* skip spaces */
break;
case _T('+'):
if (modeflag & _O_RDWR)
whileflag=0;
else {
modeflag |= _O_RDWR;
modeflag &= ~(_O_RDONLY | _O_WRONLY);
streamflag |= _IORW;
streamflag &= ~(_IOREAD | _IOWRT);
}
break;
case _T('b'):
if (modeflag & (_O_TEXT | _O_BINARY))
whileflag=0;
else
modeflag |= _O_BINARY;
break;
case _T('t'):
if (modeflag & (_O_TEXT | _O_BINARY))
whileflag=0;
else
modeflag |= _O_TEXT;
break;
case _T('c'):
if (commodeset)
whileflag=0;
else {
commodeset = 1;
streamflag |= _IOCOMMIT;
}
break;
case _T('n'):
if (commodeset)
whileflag=0;
else {
commodeset = 1;
streamflag &= ~_IOCOMMIT;
}
break;
case _T('S'):
if (scanset)
whileflag=0;
else {
scanset = 1;
modeflag |= _O_SEQUENTIAL;
}
break;
case _T('R'):
if (scanset)
whileflag=0;
else {
scanset = 1;
modeflag |= _O_RANDOM;
}
break;
case _T('T'):
if (modeflag & _O_SHORT_LIVED)
whileflag=0;
else
modeflag |= _O_SHORT_LIVED;
break;
case _T('D'):
if (modeflag & _O_TEMPORARY)
whileflag=0;
else
modeflag |= _O_TEMPORARY;
break;
case _T('N'):
modeflag |= _O_NOINHERIT;
break;
case _T(','):
encodingFlag = TRUE;
whileflag = 0;
break;
default:
_VALIDATE_RETURN(("Invalid file open mode",0), EINVAL, NULL);
}
if (encodingFlag)
{
static const _TSCHAR ccsField[] = _T("ccs");
static const _TSCHAR utf8encoding[] = _T("UTF-8");
static const _TSCHAR utf16encoding[] = _T("UTF-16LE");
static const _TSCHAR unicodeencoding[] = _T("UNICODE");
/* Skip spaces */
while (*mode == _T(' '))
{
++mode;
}
/*
* The length that we want to compare is numbers of elements in
* csField -1 since this number also contains NULL terminator
*/
if (_tcsncmp(ccsField, mode, (_countof(ccsField))-1) != 0)
_VALIDATE_RETURN(("Invalid file open mode",0), EINVAL, NULL);
mode += _countof(ccsField)-1;
/* Skip spaces */
while (*mode == _T(' '))
{
++mode;
}
/* Look for '=' */
if (*mode != _T('='))
{
_VALIDATE_RETURN(("Invalid file open mode",0), EINVAL, NULL);
}
++mode;
/* Skip spaces */
while (*mode == _T(' '))
{
++mode;
}
if (_tcsnicmp(mode, utf8encoding, _countof(utf8encoding) - 1) == 0){
mode += _countof(utf8encoding)-1;
modeflag |= _O_U8TEXT;
}
else if (_tcsnicmp(mode, utf16encoding, _countof(utf16encoding) - 1) == 0) {
mode += _countof(utf16encoding)-1;
modeflag |= _O_U16TEXT;
}
else if (_tcsnicmp(mode, unicodeencoding, _countof(unicodeencoding) - 1) == 0) {
mode += _countof(unicodeencoding)-1;
modeflag |= _O_WTEXT;
}
else
_VALIDATE_RETURN(("Invalid file open mode",0), EINVAL, NULL);
}
/* Skip trailing spaces */
while (*mode == _T(' '))
{
++mode;
}
_VALIDATE_RETURN( (*mode == _T('\0')), EINVAL, NULL);
/* Try to open the file. Note that if neither 't' nor 'b' is
specified, _sopen will use the default. */
if (_tsopen_s(&filedes, filename, modeflag, shflag, _S_IREAD | _S_IWRITE) != 0)
return(NULL);
/* Set up the stream data base. */
#ifndef CRTDLL
_cflush++; /* force library pre-termination procedure */
#endif /* CRTDLL */
/* Init pointers */
stream = str;
stream->_flag = streamflag;
stream->_cnt = 0;
stream->_tmpfname = stream->_base = stream->_ptr = NULL;
stream->_file = filedes;
return(stream);
}