"
 COPYRIGHT (c) 1989-92 by Claus Gittinger
	      All Rights Reserved

 This software is furnished under a license and may be used
 only in accordance with the terms of that license and with the
 inclusion of the above copyright notice.   This software may not
 be provided or otherwise made available to, or used by, any
 other person.  No title to or ownership of the software is
 hereby transferred.
"

ExternalStream subclass:#NonPositionableExternalStream
       instanceVariableNames:'typeIfStandard'
       classVariableNames:''
       poolDictionaries:''
       category:'Streams-External'
!

NonPositionableExternalStream comment:'

COPYRIGHT (c) 1989-92 by Claus Gittinger
	      All Rights Reserved

this one stands all non-positionable external streams; there are
terminal streams, pipe streams etc.

$Header: /cvs/stx/stx/libbasic/NonPositionableExternalStream.st,v 1.3 1993-10-13 00:16:43 claus Exp $
'!

%{
#include <stdio.h>
%}

!NonPositionableExternalStream class methodsFor:'instance creation'!

forStdin
    ^ self basicNew initializeForStdin
!

forStdout
    ^ self basicNew initializeForStdout
!

forStderr
    ^ self basicNew initializeForStderr
! !

!NonPositionableExternalStream methodsFor:'private'!

initializeForStdin
    mode := #readonly.
    typeIfStandard := #Stdin.
%{
    _INST(filePointer) = MKOBJ(stdin);
%}
!

initializeForStdout
    mode := #readwrite.
    unBuffered := true.
    typeIfStandard := #Stdout.
%{
    _INST(filePointer) = MKOBJ(stdout);
%}
!

initializeForStderr
    mode := #readwrite.
    unBuffered := true.
    typeIfStandard := #Stderr.
%{
    _INST(filePointer) = MKOBJ(stderr);
%}
!

reOpen
    "if I am one of the standard streams, reopen is easy"

'reopen NPExtStr' printNewline.
    (typeIfStandard == #Stdin) ifTrue:[
	^ self initializeForStdin
    ].
    (typeIfStandard == #Stdout) ifTrue:[
	^ self initializeForStdout
    ].
    (typeIfStandard == #Stderr) ifTrue:[
	^ self initializeForStderr
    ].
    ^ super reOpen
! !

!NonPositionableExternalStream methodsFor:'error handling'!

errorNotPositionable
    ^ self error:'positioning not allowd'
! !

!NonPositionableExternalStream methodsFor:'positioning'!

position
    ^ 0
!

position:anInteger
    self errorNotPositionable
! !