xref: /titanic_41/usr/src/lib/libast/common/sfio/sfgetu.c (revision 40db2e2b777b79f3dd0d6d9629593a07f86b9c0a)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                      by AT&T Knowledge Ventures                      *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #include	"sfhdr.h"
23 
24 /*	Read an unsigned long value coded in a portable format.
25 **
26 **	Written by Kiem-Phong Vo
27 */
28 
29 #if __STD_C
30 Sfulong_t sfgetu(reg Sfio_t* f)
31 #else
32 Sfulong_t sfgetu(f)
33 reg Sfio_t*	f;
34 #endif
35 {
36 	Sfulong_t	v;
37 	reg uchar	*s, *ends, c;
38 	reg int		p;
39 
40 	SFMTXSTART(f, (Sfulong_t)(-1));
41 
42 	if(f->mode != SF_READ && _sfmode(f,SF_READ,0) < 0)
43 		SFMTXRETURN(f, (Sfulong_t)(-1));
44 
45 	SFLOCK(f,0);
46 
47 	for(v = 0;;)
48 	{	if(SFRPEEK(f,s,p) <= 0)
49 		{	f->flags |= SF_ERROR;
50 			v = (Sfulong_t)(-1);
51 			goto done;
52 		}
53 		for(ends = s+p; s < ends;)
54 		{	c = *s++;
55 			v = (v << SF_UBITS) | SFUVALUE(c);
56 			if(!(c&SF_MORE))
57 			{	f->next = s;
58 				goto done;
59 			}
60 		}
61 		f->next = s;
62 	}
63 done:
64 	SFOPEN(f,0);
65 	SFMTXRETURN(f, v);
66 }
67