usr/src/lib/libc/port/stdio/ftello.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 /*
  33  * Return file offset.
  34  * Coordinates with buffering.
  35  */
  36
  37 #include <sys/feature_tests.h>
  38
  39 #if !defined(_LP64)
  40 #pragma weak _ftello64 = ftello64
  41 #endif
  42 #pragma weak _ftello = ftello
  43
  44 #include "lint.h"
  45 #include "file64.h"
  46 #include "mtlib.h"
  47 #include <sys/types.h>
  48 #include <unistd.h>
  49 #include <stdio.h>
  50 #include <thread.h>
  51 #include <synch.h>
  52 #include <errno.h>
  53 #include <limits.h>
  54 #include <fcntl.h>
  55 #include <stddef.h>
  56 #include "stdiom.h"
  57
  58 #if !defined(_LP64)
  59
  60 off64_t
  61 ftello64(FILE *iop)
  62 {
  63         ptrdiff_t adjust;
  64         off64_t tres;
  65         rmutex_t *lk;
  66
  67         FLOCKFILE(lk, iop);
  68         if (iop->_cnt < 0)
  69                 iop->_cnt = 0;
  70         if (iop->_flag & _IOREAD)
  71                 adjust = (ptrdiff_t)-iop->_cnt;
  72         else if (iop->_flag & (_IOWRT | _IORW)) {
  73                 adjust = 0;
  74                 if (((iop->_flag & (_IOWRT | _IONBF)) == _IOWRT) &&
  75                     (iop->_base != 0))
  76                         adjust = iop->_ptr - iop->_base;
  77         } else {
  78                 errno = EBADF;  /* file descriptor refers to no open file */
  79                 FUNLOCKFILE(lk);
  80                 return ((off64_t)EOF);
  81         }
  82         tres = lseek64(FILENO(iop), 0, SEEK_CUR);
  83         if (tres >= 0)
  84                 tres += (off64_t)adjust;
  85         FUNLOCKFILE(lk);
  86         return (tres);
  87 }
  88
  89 #endif  /* _LP64 */
  90
  91 off_t
  92 ftello(FILE *iop)
  93 {
  94         return ((off_t)ftell(iop));
  95 }