rom/dos/waitforchar.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Waits for a character to arrive at a filehandle.
   6     Lang: English
   7 */
   8 #include <proto/exec.h>
   9 #include "dos_intern.h"
  10
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <proto/dos.h>
  15 #include <exec/types.h>
  16
  17         AROS_LH2(LONG, WaitForChar,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(BPTR, file, D1),
  21         AROS_LHA(LONG, timeout, D2),
  22
  23 /*  LOCATION */
  24         struct DosLibrary *, DOSBase, 34, Dos)
  25
  26 /*  FUNCTION
  27         Wait for a character to arrive at a filehandle. The filehandle
  28         can be either a console handle, or a regular file. For a regular
  29         file most filesystems will return a character immediately, but
  30         sometimes (for example a network handler) the character may not
  31         have arrived.
  32
  33     INPUTS
  34         file            - File to wait for a character on.
  35         timeout         - Number of microseconds to wait for the character
  36                           to arrive. A value of 0 says to wait indefinately.
  37     RESULT
  38         != 0    if a character arrived before the timeout expired
  39         == 0    if no character arrived
  40
  41     NOTES
  42         Many filesystems do not implement this function.
  43
  44     EXAMPLE
  45
  46     BUGS
  47
  48     SEE ALSO
  49
  50     INTERNALS
  51
  52 *****************************************************************************/
  53 {
  54     AROS_LIBFUNC_INIT
  55
  56     struct FileHandle *fh = (struct FileHandle *)BADDR(file);
  57
  58     /* Get pointer to I/O request. Use stackspace for now. */
  59     struct IOFileSys iofs;
  60
  61     /* NULL-pointers are okay. */
  62     if(file == NULL)
  63         return 0;
  64
  65     /* Prepare I/O request. */
  66     InitIOFS(&iofs, FSA_WAIT_CHAR, DOSBase);
  67
  68     iofs.IOFS.io_Device = fh->fh_Device;
  69     iofs.IOFS.io_Unit   = fh->fh_Unit;
  70
  71     iofs.io_Union.io_WAIT_CHAR.io_Timeout = timeout;
  72
  73     /* Send the request. */
  74     DosDoIO(&iofs.IOFS);
  75
  76     SetIoErr(iofs.io_DosError);
  77
  78     if(iofs.io_DosError == 0)
  79         return iofs.io_Union.io_WAIT_CHAR.io_Success;
  80     else
  81         return DOSFALSE;
  82
  83     AROS_LIBFUNC_EXIT
  84 } /* WaitForChar */