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.
function terminal-parameters \&optional terminal
This function returns an alist listing all the parameters of
terminal and their values.
function terminal-parameter terminal parameter
This function returns the value of the parameter
parameter (a symbol) of
terminal has no setting for
parameter, this function returns
function set-terminal-parameter terminal parameter value
This function sets the parameter
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:
The classification of the terminal’s background color, either
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.
After the terminal is initialized, this is set to the terminal-specific initialization function.
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
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.