/*******************************************************************
*                                                                  *
*             This software is part of the ast package             *
*                Copyright (c) 1985-2004 AT&T Corp.                *
*        and it may only be used by you under license from         *
*                       AT&T Corp. ("AT&T")                        *
*         A copy of the Source Code Agreement is available         *
*                at the AT&T Internet web site URL                 *
*                                                                  *
*       http://www.research.att.com/sw/license/ast-open.html       *
*                                                                  *
*    If you have copied or used this software without agreeing     *
*        to the terms of the license you are infringing on         *
*           the license and copyright and are violating            *
*               AT&T's intellectual property rights.               *
*                                                                  *
*            Information and Software Systems Research             *
*                        AT&T Labs Research                        *
*                         Florham Park NJ                          *
*                                                                  *
*               Glenn Fowler <gsf@research.att.com>                *
*                David Korn <dgk@research.att.com>                 *
*                 Phong Vo <kpv@research.att.com>                  *
*                                                                  *
*******************************************************************/
#include	"sfhdr.h"

/*	Read an unsigned long value coded portably for a given range.
**
**	Written by Kiem-Phong Vo
*/

#if __STD_C
Sfulong_t sfgetm(reg Sfio_t* f, Sfulong_t m)
#else
Sfulong_t sfgetm(f, m)
reg Sfio_t*	f;
Sfulong_t	m;
#endif
{
	Sfulong_t	v;
	reg uchar	*s, *ends, c;
	reg int		p;

	SFMTXSTART(f, (Sfulong_t)(-1));

	if(f->mode != SF_READ && _sfmode(f,SF_READ,0) < 0)
		SFMTXRETURN(f, (Sfulong_t)(-1));

	SFLOCK(f,0);

	for(v = 0;; )
	{	if(SFRPEEK(f,s,p) <= 0)
		{	f->flags |= SF_ERROR;
			v = (Sfulong_t)(-1);
			goto done;
		}
		for(ends = s+p; s < ends;)
		{	c = *s++;
			v = (v << SF_BBITS) | SFBVALUE(c);
			if((m >>= SF_BBITS) <= 0)
			{	f->next = s;
				goto done;
			}
		}
		f->next = s;
	}
done:
	SFOPEN(f,0);
	SFMTXRETURN(f, v);
}
