path: root/private/crt32/stdio/fopen.c

/***
*fopen.c - open a file
*
*	Copyright (c) 1985-1991, Microsoft Corporation. All rights reserved.
*
*Purpose:
*	defines fopen() and _fsopen() - open a file as a stream and open a file
*	with a specified sharing mode as a stream
*
*Revision History:
*	09-02-83  RN	initial version
*	04-13-87  JCR	added const to declarations
*	11-01-87  JCR	Multi-thread support
*	12-11-87  JCR	Added "_LOAD_DS" to declaration
*	05-31-88  PHG	Merged DLL and normal versions
*	11-14-88  GJF	Added _fsopen().
*	02-15-90  GJF	Fixed copyright and indents
*	03-19-90  GJF	Replaced _LOAD_DS with _CALLTYPE1, added #include
*			<cruntime.h> and removed #include <register.h>.
*	07-23-90  SBM	Replaced <assertm.h> by <assert.h>
*	10-02-90  GJF	New-style function declarators.
*	01-21-91  GJF	ANSI naming.
*	03-26-92  DJM	POSIX support
*
*******************************************************************************/

#include <cruntime.h>
#include <stdio.h>
#include <share.h>
#include <assert.h>
#include <internal.h>
#include <os2dll.h>
#include <file2.h>

/***
*FILE *_fsopen(file, mode, shflag) - open a file
*
*Purpose:
*	Opens the file specified as a stream.  mode determines file mode:
*	"r": read	"w": write	"a": append
*	"r+": read/write		"w+": open empty for read/write
*	"a+": read/append
*	Append "t" or "b" for text and binary mode. shflag determines the
*	sharing mode. Values are the same as for sopen().
*
*Entry:
*	char *file - file name to open
*	char *mode - mode of file access
*
*Exit:
*	returns pointer to stream
*	returns NULL if fails
*
*Exceptions:
*
*******************************************************************************/

FILE * _CALLTYPE1 _fsopen (
	const char *file,
	const char *mode
#ifndef _POSIX_
	,int shflag
#endif
	)
{
	REG1 FILE *stream;
	REG2 FILE *retval;

	assert(file != NULL);
	assert(*file != '\0');
	assert(mode != NULL);
	assert(*mode != '\0');

	/* Get a free stream */
	/* [NOTE: _getstream() returns a locked stream.] */

	if ((stream = _getstream()) == NULL)
		return(NULL);

	/* open the stream */
#ifdef _POSIX_
	retval = _openfile(file,mode, stream);
#else
	retval = _openfile(file,mode,shflag,stream);
#endif

	/* unlock stream and return. */
	_unlock_str(_iob_index(stream));
	return(retval);
}


/***
*FILE *fopen(file, mode) - open a file
*
*Purpose:
*	Opens the file specified as a stream.  mode determines file mode:
*	"r": read	"w": write	"a": append
*	"r+": read/write		"w+": open empty for read/write
*	"a+": read/append
*	Append "t" or "b" for text and binary mode
*
*Entry:
*	char *file - file name to open
*	char *mode - mode of file access
*
*Exit:
*	returns pointer to stream
*	returns NULL if fails
*
*Exceptions:
*
*******************************************************************************/

FILE * _CALLTYPE1 fopen (
	const char *file,
	const char *mode
	)
{
#ifdef _POSIX_
	return( _fsopen(file, mode) );
#else
	return( _fsopen(file, mode, _SH_DENYNO) );
#endif
}