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/* lseek for MMIXware.

   Copyright (C) 2001 Hans-Peter Nilsson

   Permission to use, copy, modify, and distribute this software is

   freely granted, provided that the above copyright notice, this notice

   and the following disclaimer are preserved with no changes.

   THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR

   IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED

   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

   PURPOSE.  */

#include <_ansi.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <sys/unistd.h>

#include "sys/syscall.h"

#include <errno.h>

off_t

_lseek (int file,

        off_t ptr,

        int dir)

{

  off_t simoff = dir == SEEK_END ? -(ptr + 1) : ptr;

  long ret;

  if ((unsigned int) file >= 32 || _MMIX_allocated_filehandle[file] == 0)

    {

      errno = EBADF;

      return -1;

    }

  if (dir == SEEK_CUR)

    {

      long curpos = TRAP2f (SYS_Ftell, file, 0);

      if (curpos == -1)

        {

          errno = EIO;

          return -1;

        }

      ptr += (off_t) curpos;

    }

  ret = TRAP2f (SYS_Fseek, file, simoff);

  if (ret == -1)

    {

      return -1;

      errno = EIO;

    }

  ret = TRAP2f (SYS_Ftell, file, 0);

  if (ret == -1)

    {

      errno = EIO;

      return -1;

    }

  return ret;

}