1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2008 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 30 Sfoff_t sftell(Sfio_t* f) 31 #else 32 Sfoff_t sftell(f) 33 Sfio_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