Each terminal has a list of associated parameters. These terminal parameters are mostly a convenient way of storage for terminal-local variables, but some terminal parameters have a special meaning.
This section describes functions to read and change the parameter values
of a terminal. They all accept as their argument either a terminal or
a frame; the latter means use that frame’s terminal. An argument of
nil
means the selected frame’s terminal.
terminal-parameters
&optional terminal ¶This function returns an alist listing all the parameters of terminal and their values.
terminal-parameter
terminal parameter ¶This function returns the value of the parameter parameter (a
symbol) of terminal. If terminal has no setting for
parameter, this function returns nil
.
set-terminal-parameter
terminal parameter value ¶This function sets the parameter parameter of terminal to the specified value, and returns the previous value of that parameter.
Here’s a list of a few terminal parameters that have a special meaning:
background-mode
The classification of the terminal’s background color, either
light
or dark
.
normal-erase-is-backspace
Value is either 1 or 0, depending on whether
normal-erase-is-backspace-mode
is turned on or off on this
terminal. See DEL Does Not Delete in The Emacs Manual.
terminal-initted
After the terminal is initialized, this is set to the terminal-specific initialization function.
tty-mode-set-strings
When present, a list of strings containing escape sequences that Emacs
will output while configuring a tty for rendering. Emacs emits these
strings only when configuring a terminal: if you want to enable a mode
on a terminal that is already active (for example, while in
tty-setup-hook
), explicitly output the necessary escape
sequence using send-string-to-terminal
in addition to adding
the sequence to tty-mode-set-strings
.
tty-mode-reset-strings
When present, a list of strings that undo the effects of the strings
in tty-mode-set-strings
. Emacs emits these strings when
exiting, deleting a terminal, or suspending itself.