/* Copyright (C) 1991, 1992, 1994, 1996, 1997 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include <errno.h> #include <stdio.h> /* Return the offset in bytes from the beginning of the file of the file position of STREAM. */ long int ftell (stream) FILE *stream; { long int pos; if (!__validfp (stream)) { __set_errno (EINVAL); return -1L; } if (__stdio_check_offset (stream) == EOF) return -1L; /* Start with the file position associated with the beginning of our buffer. */ pos = stream->__target; if (stream->__pushed_back) /* ungetc was just called, so our real buffer pointer is squirreled away in STREAM->__pushback_bufp, not in STREAM->__bufp as normal. Calling ungetc is supposed to decrement the file position. ANSI says the file position is unspecified if you ungetc when the position is zero; -1 seems as good as anything to me. */ pos += stream->__pushback_bufp - stream->__buffer - 1; else pos += stream->__bufp - stream->__buffer; return pos; }