lib/libc/stdio/fseek.c

   1 /*      $NetBSD: fseek.c,v 1.24 2014/11/16 20:32:52 christos Exp $      */
   2
   3 /*-
   4  * Copyright (c) 2005 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by David Laight.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 __RCSID("$NetBSD: fseek.c,v 1.24 2014/11/16 20:32:52 christos Exp $");
  35 #endif /* LIBC_SCCS and not lint */
  36
  37 #include <sys/types.h>
  38 #include <sys/stat.h>
  39
  40 #include "namespace.h"
  41 #include <assert.h>
  42 #include <errno.h>
  43 #include <fcntl.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include "reentrant.h"
  47 #include "local.h"
  48
  49 /*
  50  * Seek the given file to the given offset.
  51  * Zero extend the offset if SEEK_SET to allow access to 4GB files
  52  */
  53 int
  54 fseek(FILE *fp, long l_offset, int whence)
  55 {
  56         off_t offset;
  57
  58 #if 0
  59         /* This is a bad idea because makes fseek(fp, -6, SEEK_SET) work... */
  60         if (whence == SEEK_SET)
  61                 offset = (unsigned long)l_offset;
  62         else
  63 #endif
  64                 offset = l_offset;
  65         return fseeko(fp, offset, whence);
  66 }