1/*********************************************************************** 2* * 3* This software is part of the ast package * 4* Copyright (c) 1985-2010 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