Commands Reference, Volume 1

bterm command

Purpose

Emulates terminals in bidirectional (BIDI) mode.

Syntax

bterm [ -maps Map ] [ -help ] [ -keywords ] [ -nobidi ] [ -symmetric ] [ -autopush ] [ -or Orientation ] [ -text TextType ] [ -nss NumShape ] [ -csd CharShape ] [ -tail ] [ -nonulls ]

The bterm command emulates the IBM 3151, VT220, HFT and other terminals. It operates in BIDI mode on ASCII terminals. This command creates a BIDI shell that can run any BIDI application. You cannot initiate the bterm command recursively from within itself.

The maps that determine the keyboard mapping and the symmetric swapping of characters are specified by the -maps flag. You can specify other BIDI behaviors using the flags available to the bterm command or by setting them in the defaults files. Such behaviors include the default text mode, the default screen orientation, the default mode of Arabic character shaping, the default shape of numerals, whether the Symmetric Swapping mode is enabled and whether the Autopush mode is enabled or not. The behaviors specified with flags take precedence over the behaviors set in the defaults files.

The default files are searched in the following order:

The .Bidi-defaults file is searched for in your home directory.
If the file is not found, the bterm command searches for the BTerm resource file in the /usr/lib/nls/bidi/$LANG/app-defaults file.

Flags

-autopush	Enables the Autopush mode in visual text mode.
-csd CharShape	Specifies the shape of Arabic characters. The CharShape variable can be one of the following options: automatic isolated (visual text mode only) initial (visual text mode only) middle (visual text mode only) final (visual text mode only) passthru The default is automatic shaping.
-help	Lists the available parameters and their syntax.
-keywords	Lists the keywords available in defaults file.
-maps Map	Specifies the map used for keyboard mapping and symmetric swapping of characters. Each language has a different map, and the available options for the Map variable are in the /usr/lib/nls/bidi/maps directory. You must specify the environment variable BIDIPATH as follows: export BIDIPATH=/usr/lib/nls/bidi
-nobidi	Disables the BIDI mode.
-nonulls	Initializes the screen with spaces instead of nulls.
-nss NumShape	Specifies the shape of the numerals. Specify one of the following options for the NumShape variable: bilingual hindi arabic passthru The default is bilingual.
-or Orientation	Specifies screen orientation. The Orientation variable can be either LTR or RTL. The default is LTR.
-symmetric	Enables the Symmetric Swapping mode.
-tail	Writes the "seen," "sheen," "sad," and "dad" characters of the Arabic language in two cells instead of one cell.
-text TextType	Specifies the type of data stream. The TextType variable can be either implicit or visual. The default is implicit.

Key Combinations

To change the BIDI settings using key combinations, press the Ctrl+X key sequence to enter a BIDI command mode. Any key you type after this key sequence is interpreted as a BIDI command. Invalid keys sound a beep and exit the BIDI command mode. The following keys are valid BIDI commands:

Key	Purpose
r	Reverses the screen orientation.
n	Sets the language keyboard layer to National.
l	Sets the language keyboard layer to Latin.
a	Toggles the automatic shaping variable option of the Arabic characters (valid also for Implicit mode).
t	Displays the status.
space	Enters a required space (RSP).

For implicit mode only :

Key	Purpose
c	Toggles the column heading mode.

For visual mode only :

Key	Purpose
s	Initiates the Push mode.
e	Terminates the End Push mode.
p	Toggles the Autopush mode.
f	Shapes Arabic characters in their final forms.
i	Shapes Arabic characters in their initial forms.
b	Shapes Arabic characters in the Passthru mode.
o	Shapes Arabic characters in their isolated forms.
m	Shapes Arabic characters in their middle forms.

.Bidi-defaults Keywords

Use the following keywords to set the defaults for the bterm command.

.Bidi-defaults Keywords
Keywords	Value	Effect
fScrRev	on	Screen reverse function key is enabled.
	off	Screen reverse function key is disabled.
fRTL	on	RTL keyboard layer function key is enabled.
	off	RTL keyboard layer function key is disabled.
fLTR	on	LTR keyboard layer function key is enabled.
	off	LTR keyboard layer function key is disabled.
fPush	on	Push function key is enabled.
	off	Push function key is disabled.
fEndPush	on	End Push function key is enabled.
	off	End Push function key is disabled.
fAutoPush	on	AutoPush function key is enabled.
	off	AutoPush function key is disabled.
fASD	on	Automatic Shape Determination function key is enabled.
	off	Automatic Shape Determination function key is disabled.
fShapeIS	on	Isolated Shape function key is enabled.
	off	Isolated Shape function key is disabled.
fShapeIN	on	Initial Shape function key is enabled.
	off	Initial Shape function key is disabled.
fShapeM	on	Middle Shape function key is enabled.
	off	Middle Shape function key is disabled.
fShapeF	on	Final Shape function key is enabled.
	off	Final Shape function key is disabled.
textType	implicit	Type of data stream is set to Implicit.
	visual	Type of data stream is set to Visual.
orientation	LTR	Left-to-right default screen orientation.
	RTL	Right-to-left default screen orientation.
symmetric	on	Symmetric Swapping enabled.
	off	Symmetric Swapping disabled.
numShape	bilingual	Numeral shaping is set to bilingual.
	hindi	Numerals are represented in Hindi.
	arabic	Numerals are represented in Arabic/Hebrew.
	passthru	Numerals are represented in passthru.
charShape	automatic	Arabic characters are shaped automatically.
	passthru	Arabic characters are displayed in passthru mode.
	isolated	Arabic characters are displayed in isolated mode.
	initial	Arabic characters are displayed in initial mode.
	final	Arabic characters are displayed in final mode.
	middle	Arabic characters are displayed in middle mode.
maps		Specifies the page code directory to be used for Keyboard. layering, input, output and symmetric character swapping.
expandTail	on	Writes "seen"-like characters and their tails on two cells.
	off	Writes "seen"-like characters and their tails on one cell.
nobidi	on	Activates BIDI mode.
	off	Turn off BIDI mode.
noNulls	on	Replaces nulls by spaces.
	off	Leaves nulls as null, no replacement of spaces.

Related Information

The aixterm command, the telnet, tn, or tn3270 command.

Bidirectionality and Arabic Character Shaping Overview AIX 5L Version 5.1 General Programming Concepts: Writing and Debugging Programs.