compiler/arossupport/readword.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Read a big endian word (16bit) from a streamhook
   6     Lang: english
   7 */
   8
   9 #include <proto/dos.h>
  10 #include <stdio.h>
  11 #include <assert.h>
  12
  13 /******************************************************************************
  14
  15     NAME */
  16 #include <aros/bigendianio.h>
  17 #include <proto/alib.h>
  18
  19         BOOL ReadWord (
  20
  21 /*  SYNOPSIS */
  22         struct Hook * hook,
  23         UWORD       * dataptr,
  24         void        * stream)
  25
  26 /*  FUNCTION
  27         Reads one big endian 16bit value from a streamhook.
  28
  29     INPUTS
  30         hook - Streamhook
  31         dataptr - Put the data here
  32         stream - Read from this stream
  33
  34     RESULT
  35         The function returns TRUE on success. On success, the value
  36         read is written into dataptr. On failure, FALSE is returned and the
  37         contents of dataptr are not changed.
  38
  39     NOTES
  40         This function reads big endian values from a streamhook even on
  41         little endian machines.
  42
  43     EXAMPLE
  44
  45     BUGS
  46
  47     SEE ALSO
  48         ReadByte(), ReadWord(), ReadLong(), ReadFloat(), ReadDouble(),
  49         ReadString(), ReadStruct(), WriteByte(), WriteWord(), WriteLong(),
  50         WriteFloat(), WriteDouble(), WriteString(), WriteStruct()
  51
  52     HISTORY
  53
  54 ******************************************************************************/
  55 {
  56     LONG value, c;
  57
  58     struct BEIOM_Read rd = {BEIO_READ};
  59
  60     assert (hook);
  61     assert (stream);
  62     assert (dataptr);
  63
  64     /* High byte */
  65     c = CallHookA (hook, stream, &rd);
  66
  67     if (c == EOF)
  68         return FALSE;
  69
  70     /* Low byte */
  71     value = CallHookA (hook, stream, &rd);
  72
  73     if (value == EOF)
  74         return FALSE;
  75
  76     *dataptr = (c << 8) + value;
  77
  78     return TRUE;
  79 } /* ReadWord */
  80