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 #ifdef __UCLIBC_HAS_LFS__
  20 libc_hidden_proto(fseeko64)
  21 #endif
  22 libc_hidden_proto(fseek)
  23
  24 int FSEEK(register FILE *stream, OFFSET_TYPE offset, int whence)
  25 {
  26 #if defined(__UCLIBC_HAS_LFS__) && !defined(__DO_LARGEFILE)
  27
  28         return fseeko64(stream, offset, whence);
  29
  30 #else
  31
  32         __offmax_t pos = offset;
  33         int retval = -1;
  34         __STDIO_AUTO_THREADLOCK_VAR;
  35
  36         if (((unsigned int) whence) > 2) {
  37                 __set_errno(EINVAL);
  38         } else {
  39                 __STDIO_AUTO_THREADLOCK(stream);
  40
  41                 __STDIO_STREAM_VALIDATE(stream);
  42
  43                 if ((!__STDIO_STREAM_IS_WRITING(stream)
  44                           || !__STDIO_COMMIT_WRITE_BUFFER(stream))
  45                         && ((whence != SEEK_CUR)
  46                                  || (__stdio_adjust_position(stream, &pos) >= 0))
  47                         && (__SEEK(stream, &pos, whence) >= 0)
  48                         ) {
  49
  50                         /* Clear reading/writing modes, EOF, and ungots. */
  51                         stream->__modeflags &=
  52                                 ~(__MASK_READING|__FLAG_WRITING|__FLAG_EOF);
  53
  54                         /* Make sure all pointers are reset. */
  55                         __STDIO_STREAM_INIT_BUFREAD_BUFPOS(stream);
  56                         __STDIO_STREAM_DISABLE_GETC(stream);
  57                         __STDIO_STREAM_DISABLE_PUTC(stream);
  58
  59                         /* We reinitialize the mbstate object.  Doing so is
  60                          * implementation defined behavior. */
  61 #ifdef __STDIO_MBSTATE
  62                         __INIT_MBSTATE(&(stream->__state));
  63 #endif
  64 #ifdef __UCLIBC_HAS_WCHAR__
  65                         stream->__ungot_width[0] = 0;
  66 #endif
  67
  68                         retval = 0;
  69                 }
  70
  71                 __STDIO_STREAM_VALIDATE(stream);
  72
  73                 __STDIO_AUTO_THREADUNLOCK(stream);
  74         }
  75
  76         return retval;
  77
  78 #endif
  79 }
  80
  81 #ifdef __DO_LARGEFILE
  82 libc_hidden_def(fseeko64)
  83 #else
  84 libc_hidden_def(fseek)
  85 strong_alias(fseek,fseeko)
  86 #endif