libc/stdio/fseeko.c

   1 /* Copyright (C) 2004       Manuel Novoa III    <mjn3@codepoet.org>
   2  *
   3  * GNU Library General Public License (LGPL) version 2 or later.
   4  *
   5  * Dedicated to Toni.  See uClibc/DEDICATION.mjn3 for details.
   6  */
   7
   8 #include "_stdio.h"
   9
  10 #if SEEK_SET != 0 || SEEK_CUR != 1 || SEEK_END != 2
  11 # error Assumption violated -- values of SEEK_SET, SEEK_CUR, SEEK_END
  12 #endif
  13
  14 #ifndef __DO_LARGEFILE
  15 # define FSEEK         fseek
  16 # define OFFSET_TYPE   long int
  17 #endif
  18
  19 int FSEEK(register FILE *stream, OFFSET_TYPE offset, int whence)
  20 {
  21 #if !defined(__DO_LARGEFILE)
  22
  23         return fseeko64(stream, offset, whence);
  24
  25 #else
  26
  27         __offmax_t pos = offset;
  28         int retval = -1;
  29         __STDIO_AUTO_THREADLOCK_VAR;
  30
  31         if (((unsigned int) whence) > 2) {
  32                 __set_errno(EINVAL);
  33         } else {
  34                 __STDIO_AUTO_THREADLOCK(stream);
  35
  36                 __STDIO_STREAM_VALIDATE(stream);
  37
  38                 if ((!__STDIO_STREAM_IS_WRITING(stream)
  39                           || !__STDIO_COMMIT_WRITE_BUFFER(stream))
  40                         && ((whence != SEEK_CUR)
  41                                  || (__stdio_adjust_position(stream, &pos) >= 0))
  42                         && (__SEEK(stream, &pos, whence) >= 0)
  43                         ) {
  44
  45                         /* Clear reading/writing modes, EOF, and ungots. */
  46                         stream->__modeflags &=
  47                                 ~(__MASK_READING|__FLAG_WRITING|__FLAG_EOF);
  48
  49                         /* Make sure all pointers are reset. */
  50                         __STDIO_STREAM_INIT_BUFREAD_BUFPOS(stream);
  51                         __STDIO_STREAM_DISABLE_GETC(stream);
  52                         __STDIO_STREAM_DISABLE_PUTC(stream);
  53
  54                         /* We reinitialize the mbstate object.  Doing so is
  55                          * implementation defined behavior. */
  56 #ifdef __STDIO_MBSTATE
  57                         __INIT_MBSTATE(&(stream->__state));
  58 #endif
  59 #ifdef __UCLIBC_HAS_WCHAR__
  60                         stream->__ungot_width[0] = 0;
  61 #endif
  62
  63                         retval = 0;
  64                 }
  65
  66                 __STDIO_STREAM_VALIDATE(stream);
  67
  68                 __STDIO_AUTO_THREADUNLOCK(stream);
  69         }
  70
  71         return retval;
  72
  73 #endif
  74 }
  75
  76 #ifdef __DO_LARGEFILE
  77 libc_hidden_def(fseeko64)
  78 #else
  79 libc_hidden_def(fseek)
  80 strong_alias_untyped(fseek,fseeko)
  81 #endif