u-tools/apps/tar/gnu/fseeko.c

   1 /* -*- buffer-read-only: t -*- vi: set ro: */
   2 /* DO NOT EDIT! GENERATED AUTOMATICALLY! */
   3 /* An fseeko() function that, together with fflush(), is POSIX compliant.
   4    Copyright (C) 2007-2011 Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License along
  17    with this program; if not, write to the Free Software Foundation,
  18    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  19
  20 #include <config.h>
  21
  22 /* Specification.  */
  23 #include <stdio.h>
  24
  25 /* Get off_t and lseek.  */
  26 #include <unistd.h>
  27
  28 #include "stdio-impl.h"
  29
  30 int
  31 fseeko (FILE *fp, off_t offset, int whence)
  32 #undef fseeko
  33 #if !HAVE_FSEEKO
  34 # undef fseek
  35 # define fseeko fseek
  36 #endif
  37 {
  38 #if LSEEK_PIPE_BROKEN
  39   /* mingw gives bogus answers rather than failure on non-seekable files.  */
  40   if (lseek (fileno (fp), 0, SEEK_CUR) == -1)
  41     return EOF;
  42 #endif
  43
  44   /* These tests are based on fpurge.c.  */
  45 #if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
  46   if (fp->_IO_read_end == fp->_IO_read_ptr
  47       && fp->_IO_write_ptr == fp->_IO_write_base
  48       && fp->_IO_save_base == NULL)
  49 #elif defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */
  50 # if defined __SL64 && defined __SCLE /* Cygwin */
  51   if ((fp->_flags & __SL64) == 0)
  52     {
  53       /* Cygwin 1.5.0 through 1.5.24 failed to open stdin in 64-bit
  54          mode; but has an fseeko that requires 64-bit mode.  */
  55       FILE *tmp = fopen ("/dev/null", "r");
  56       if (!tmp)
  57         return -1;
  58       fp->_flags |= __SL64;
  59       fp->_seek64 = tmp->_seek64;
  60       fclose (tmp);
  61     }
  62 # endif
  63   if (fp_->_p == fp_->_bf._base
  64       && fp_->_r == 0
  65       && fp_->_w == ((fp_->_flags & (__SLBF | __SNBF | __SRD)) == 0 /* fully buffered and not currently reading? */
  66                      ? fp_->_bf._size
  67                      : 0)
  68       && fp_ub._base == NULL)
  69 #elif defined __EMX__               /* emx+gcc */
  70   if (fp->_ptr == fp->_buffer
  71       && fp->_rcount == 0
  72       && fp->_wcount == 0
  73       && fp->_ungetc_count == 0)
  74 #elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw, NonStop Kernel */
  75   if (fp_->_ptr == fp_->_base
  76       && (fp_->_ptr == NULL || fp_->_cnt == 0))
  77 #elif defined __UCLIBC__            /* uClibc */
  78   if (((fp->__modeflags & __FLAG_WRITING) == 0
  79        || fp->__bufpos == fp->__bufstart)
  80       && ((fp->__modeflags & (__FLAG_READONLY | __FLAG_READING)) == 0
  81           || fp->__bufpos == fp->__bufread))
  82 #elif defined __QNX__               /* QNX */
  83   if ((fp->_Mode & 0x2000 /* _MWRITE */ ? fp->_Next == fp->_Buf : fp->_Next == fp->_Rend)
  84       && fp->_Rback == fp->_Back + sizeof (fp->_Back)
  85       && fp->_Rsave == NULL)
  86 #elif defined __MINT__              /* Atari FreeMiNT */
  87   if (fp->__bufp == fp->__buffer
  88       && fp->__get_limit == fp->__bufp
  89       && fp->__put_limit == fp->__bufp
  90       && !fp->__pushed_back)
  91 #else
  92   #error "Please port gnulib fseeko.c to your platform! Look at the code in fpurge.c, then report this to bug-gnulib."
  93 #endif
  94     {
  95       /* We get here when an fflush() call immediately preceded this one.  We
  96          know there are no buffers.
  97          POSIX requires us to modify the file descriptor's position.
  98          But we cannot position beyond end of file here.  */
  99       off_t pos =
 100         lseek (fileno (fp),
 101                whence == SEEK_END && offset > 0 ? 0 : offset,
 102                whence);
 103       if (pos == -1)
 104         {
 105 #if defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */
 106           fp_->_flags &= ~__SOFF;
 107 #endif
 108           return -1;
 109         }
 110
 111 #if defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1 /* GNU libc, BeOS, Haiku, Linux libc5 */
 112       fp->_flags &= ~_IO_EOF_SEEN;
 113 #elif defined __sferror || defined __DragonFly__ /* FreeBSD, NetBSD, OpenBSD, DragonFly, MacOS X, Cygwin */
 114 # if defined __CYGWIN__
 115       /* fp_->_offset is typed as an integer.  */
 116       fp_->_offset = pos;
 117 # else
 118       /* fp_->_offset is an fpos_t.  */
 119       {
 120         /* Use a union, since on NetBSD, the compilation flags
 121            determine whether fpos_t is typedef'd to off_t or a struct
 122            containing a single off_t member.  */
 123         union
 124           {
 125             fpos_t f;
 126             off_t o;
 127           } u;
 128         u.o = pos;
 129         fp_->_offset = u.f;
 130       }
 131 # endif
 132       fp_->_flags |= __SOFF;
 133       fp_->_flags &= ~__SEOF;
 134 #elif defined __EMX__               /* emx+gcc */
 135       fp->_flags &= ~_IOEOF;
 136 #elif defined _IOERR                /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, mingw, NonStop Kernel */
 137       fp->_flag &= ~_IOEOF;
 138 #elif defined __MINT__              /* Atari FreeMiNT */
 139       fp->__offset = pos;
 140       fp->__eof = 0;
 141 #endif
 142       /* If we were not requested to position beyond end of file, we're
 143          done.  */
 144       if (!(whence == SEEK_END && offset > 0))
 145         return 0;
 146     }
 147   return fseeko (fp, offset, whence);
 148 }