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

/***
*getw.c - read a binary word from a stream
*
*	Copyright (c) 1985-1991, Microsoft Corporation. All rights reserved.
*
*Purpose:
*	defines _getw() - gets a binary integer from a stream
*
*Revision History:
*	09-02-83  RN	initial version
*	11-09-87  JCR	Multi-thread support
*	12-11-87  JCR	Added "_LOAD_DS" to declaration
*	01-13-88  JCR	Removed unnecessary calls to mthread fileno/feof/ferror
*	05-27-88  PHG	Merged DLL and normal versions
*			Fixed bug if EOF occurs in middle of word being read
*	06-15-88  JCR	Near reference to _iob[] entries; improve REG variables
*	08-24-88  GJF	Don't use FP_OFF() macro for the 386
*	08-18-89  GJF	Clean up, now specific to OS/2 2.0 (i.e., 386 flat
*			model). Also fixed copyright and indents.
*	02-15-90  GJF	Fixed copyright
*	03-19-90  GJF	Made calling type _CALLTYPE1, added #include
*			<cruntime.h> and removed #include <register.h>.
*	07-23-90  SBM	Replaced <assertm.h> by <assert.h>
*	08-13-90  SBM	Compiles cleanly with -W3
*	10-02-90  GJF	New-style function declarator.
*	01-21-91  GJF	ANSI naming.
*
*******************************************************************************/

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

/***
*int _getw(stream) - read an int from a stream
*
*Purpose:
*	get n bytes (n=sizeof(int)); OR them together in proper order; high
*	byte first. check for EOF between getc's.
*	this routine should be machine independent.
*
*Entry:
*	FILE *stream - stream to read integer from
*
*Exit:
*	returns the int read from the stream
*	returns EOF if fails (but this is a legit int value, so
*	should test feof() or ferror().
*
*Exceptions:
*
*******************************************************************************/

int _CALLTYPE1 _getw (
	FILE *str
	)
{
	REG1 FILE *stream;
	REG2 int bytecount = sizeof(int);
	int word;
	char *byteptr = (char *)&word;
	int retval;
#ifdef MTHREAD
	int index;
#endif

	assert(str != NULL);

	/* Init stream pointer */
	stream = str;

#ifdef MTHREAD
	index = _iob_index(stream);
#endif
	_lock_str(index);

	while (bytecount--)
		*byteptr++ = (char)_getc_lk(stream);
	retval = ((feof(stream) || ferror(stream)) ? EOF : word);

	_unlock_str(index);
	return(retval);
}