elinks/doc/terminals.txt

The Terminal Setup
------------------

ELinks uses neither (n)curses nor termcap/terminfo, so unless you are using
a terminal that is known by ELinks and have a built-in configuration (see below
for a list), it might be required that you do a little configuring of how your
terminal should be handled.  The easiest way to do this is by using the Terminal
Options dialog located in the Setup submenu of the Main menu.

It is possible to have configurations for multiple terminals as long as the TERM
environment variable -- used to distinguish terminals from one another -- is set
to something different for each terminal.  So be sure to set TERM to different
values for two terminals that cannot share the same configuration.  For example,
always setting TERM to xterm-color can lead to problems if you run ELinks under
the Linux console.  This is because the Linux console does not support
underlining and ELinks will not know that underlined characters will have to be
color highlighted so they stand out.

In short, ELinks does not use termcap or terminfo.  ELinks uses $TERM, but only
to distinguish between terminals in its own configuration.  That is, you need
only configure your terminal within ELinks: Go to the Setup menu and select
Terminal Options.  If $TERM is set to 'screen' when you configure ELinks'
terminal settings, ELinks will remember to use those settings when $TERM is
'screen'.


Options
~~~~~~~

Apart from the last charset option configurable through the Setup -> Character
Set submenu in the Main menu, the rest can be configured using the Terminal
Options dialog.


Terminal type
^^^^^^^^^^^^^
		
It maps roughly to the terminal type, such as Linux console, XTerm, VT100 etc.
It matters mostly when drawing frames and borders around dialog windows.  As
already mentioned, it also turns on certain features which try to compensate for
``missing'' terminal capabilities when drawing.  Special highlighting of
underlined text if underlining is not supported is one such thing.

`-----------------------`-----------------------------------------------------
Type			Notes
------------------------------------------------------------------------------
No frames		Dumb terminal type / ASCII art
VT 100 frames		Works in most terminals
Linux or OS/2 frames	Linux console / you get double frames and other goodies
KOI-8
FreeBSD			FreeBSD console
------------------------------------------------------------------------------

The default is to assume dumb terminal/ASCII art.


Color mode
^^^^^^^^^^

The color mode controls what colors are used and how they are output to the
terminal.  The available color modes are:

`-----------------------`-----------------------------------------------------
Mode			Color codes
------------------------------------------------------------------------------
Mono mode		Only 2 colors are used
16 color mode		Uses the common ANSI colors
88 color mode		Uses XTerm RGB codes (if compiled in)
256 color mode		Uses XTerm RGB codes (if compiled in)
------------------------------------------------------------------------------

The default is to use mono mode.


Switch fonts for line drawing (aka 11m hack)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This is related to the drawing of frames and window borders controlled by the
option above.  It controls whether to switch fonts when drawing lines, enabling
both local characters and lines working at the same time.

This boolean option only makes sense with the Linux console.  Off by default.


Restrict frames in cp850/852
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This is related to the drawing of frames and window borders controlled by the
option above.  If enabled, it restricts the characters used when drawing lines.

This boolean option only makes sense with the Linux console using the cp850/852
character sets.  Off by default.


Block cursor
^^^^^^^^^^^^

Move cursor to the bottom right corner when done drawing, if possible.  This is
particularly useful when we have a block cursor, so that text colors are
displayed correctly.  If you are using a screen reader you do not want to enable
this since the cursor is strategically positioned near relevant text of selected
dialog elements.

This boolean option is off by default.


Transparency
^^^^^^^^^^^^

Determines whether or not to set the background to black.  This is particularly
useful when using a terminal (typically in some windowing environment) with
a background image or a transparent background.  If this option is enabled the
background will be visible in ELinks as well.

Note that this boolean option makes sense only when colors are enabled.  On by
default.


Text underlining capability
^^^^^^^^^^^^^^^^^^^^^^^^^^^

This boolean option controls whether to underline text or instead, enhance the
color.

Note: not all terminals support text underlining, so it is off by default.


UTF-8 I/O
^^^^^^^^^

This boolean option controls outputting of I/O in UTF-8 for Unicode terminals.

Note that currently, only a subset of UTF-8 according to the terminal
codepage is used.  This is off by default.


Character Set
^^^^^^^^^^^^^

Codepage of the charset used for displaying content on terminal.

The value 'System' (which is the default) will set the charset according to the
current locale.  The default is to use the charset of the current locale.


Terminal Configurations
~~~~~~~~~~~~~~~~~~~~~~~

Built-in configurations exists for the following terminals:

 - linux
 - vt100
 - vt110
 - xterm
 - xterm-color
 - xterm-88color
 - xterm-256color

The last two configurations requires that support for either 88 or 256 colors
is compiled in to xterm.

GNU Screen is VT100-compatible, so select 'VT 100 frames'.  GNU Screen also
supports colors just fine, so select '16 colors', or, if you are running Screen
within a terminal emulator that supports 256 colors and you have compiled both
Screen and ELinks to support it, choose '256 colors'.