xref: /titanic_44/usr/src/lib/libast/common/sfio/sftell.c (revision 3e14f97f673e8a630f076077de35afdd43dc1587)
1da2e3ebdSchin /***********************************************************************
2da2e3ebdSchin *                                                                      *
3da2e3ebdSchin *               This software is part of the ast package               *
4*3e14f97fSRoger A. Faulkner *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
5da2e3ebdSchin *                      and is licensed under the                       *
6da2e3ebdSchin *                  Common Public License, Version 1.0                  *
77c2fbfb3SApril Chin *                    by AT&T Intellectual Property                     *
8da2e3ebdSchin *                                                                      *
9da2e3ebdSchin *                A copy of the License is available at                 *
10da2e3ebdSchin *            http://www.opensource.org/licenses/cpl1.0.txt             *
11da2e3ebdSchin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12da2e3ebdSchin *                                                                      *
13da2e3ebdSchin *              Information and Software Systems Research               *
14da2e3ebdSchin *                            AT&T Research                             *
15da2e3ebdSchin *                           Florham Park NJ                            *
16da2e3ebdSchin *                                                                      *
17da2e3ebdSchin *                 Glenn Fowler <gsf@research.att.com>                  *
18da2e3ebdSchin *                  David Korn <dgk@research.att.com>                   *
19da2e3ebdSchin *                   Phong Vo <kpv@research.att.com>                    *
20da2e3ebdSchin *                                                                      *
21da2e3ebdSchin ***********************************************************************/
22da2e3ebdSchin #include	"sfhdr.h"
23da2e3ebdSchin 
24da2e3ebdSchin /*	Tell the current location in a given stream
25da2e3ebdSchin **
26da2e3ebdSchin **	Written by Kiem-Phong Vo.
27da2e3ebdSchin */
28da2e3ebdSchin 
29da2e3ebdSchin #if __STD_C
sftell(Sfio_t * f)307c2fbfb3SApril Chin Sfoff_t sftell(Sfio_t* f)
31da2e3ebdSchin #else
32da2e3ebdSchin Sfoff_t sftell(f)
337c2fbfb3SApril Chin Sfio_t	*f;
34da2e3ebdSchin #endif
35da2e3ebdSchin {
36da2e3ebdSchin 	reg int	mode;
37da2e3ebdSchin 	Sfoff_t	p;
387c2fbfb3SApril Chin 	SFMTXDECL(f);
39da2e3ebdSchin 
407c2fbfb3SApril Chin 	SFMTXENTER(f, (Sfoff_t)(-1));
41da2e3ebdSchin 
42da2e3ebdSchin 	/* set the stream to the right mode */
43da2e3ebdSchin 	if((mode = f->mode&SF_RDWR) != (int)f->mode && _sfmode(f,mode,0) < 0)
44da2e3ebdSchin 		SFMTXRETURN(f, (Sfoff_t)(-1));
45da2e3ebdSchin 
46da2e3ebdSchin 	/* throw away ungetc data */
47da2e3ebdSchin 	if(f->disc == _Sfudisc)
48da2e3ebdSchin 		(void)sfclose((*_Sfstack)(f,NIL(Sfio_t*)));
49da2e3ebdSchin 
50da2e3ebdSchin 	if(f->flags&SF_STRING)
51da2e3ebdSchin 		SFMTXRETURN(f, (Sfoff_t)(f->next-f->data));
52da2e3ebdSchin 
53da2e3ebdSchin 	/* let sfseek() handle the hard case */
54da2e3ebdSchin 	if(f->extent >= 0 && (f->flags&(SF_SHARE|SF_APPENDWR)) )
55da2e3ebdSchin 		p = sfseek(f,(Sfoff_t)0,SEEK_CUR);
56da2e3ebdSchin 	else	p = f->here + ((f->mode&SF_WRITE) ? f->next-f->data : f->next-f->endb);
57da2e3ebdSchin 
58da2e3ebdSchin 	SFMTXRETURN(f,p);
59da2e3ebdSchin }
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