1/***********************************************************************
2*                                                                      *
3*               This software is part of the ast package               *
4*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5*                      and is licensed under the                       *
6*                  Common Public License, Version 1.0                  *
7*                    by AT&T Intellectual Property                     *
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/*	Tell the current location in a given stream
25**
26**	Written by Kiem-Phong Vo.
27*/
28
29#if __STD_C
30Sfoff_t sftell(Sfio_t* f)
31#else
32Sfoff_t sftell(f)
33Sfio_t	*f;
34#endif
35{
36	reg int	mode;
37	Sfoff_t	p;
38	SFMTXDECL(f);
39
40	SFMTXENTER(f, (Sfoff_t)(-1));
41
42	/* set the stream to the right mode */
43	if((mode = f->mode&SF_RDWR) != (int)f->mode && _sfmode(f,mode,0) < 0)
44		SFMTXRETURN(f, (Sfoff_t)(-1));
45
46	/* throw away ungetc data */
47	if(f->disc == _Sfudisc)
48		(void)sfclose((*_Sfstack)(f,NIL(Sfio_t*)));
49
50	if(f->flags&SF_STRING)
51		SFMTXRETURN(f, (Sfoff_t)(f->next-f->data));
52
53	/* let sfseek() handle the hard case */
54	if(f->extent >= 0 && (f->flags&(SF_SHARE|SF_APPENDWR)) )
55		p = sfseek(f,(Sfoff_t)0,SEEK_CUR);
56	else	p = f->here + ((f->mode&SF_WRITE) ? f->next-f->data : f->next-f->endb);
57
58	SFMTXRETURN(f,p);
59}
60