5.2.41 Querying the terminfo database

The ncurses library relies on the terminfo database to look up the special character sequences it needs to output to a terminal. The terminfo database is the lower-level library upon which ncurses is built.

It is sometimes useful to check the terminfo database to see if it has information on a terminal, or to see which escape sequences need to be executed to perform these low level operations. This library provides two procedures to query this database.

Procedure: setupterm #:optional terminal

When called with one string argument – a string with the name of a terminal as it would appear in the terminfo database – setupterm the terminfo database for the terminal with the given name. When called with zero arguments, the name of terminal in the TERM environment variable is used. If it is found, one of the symbols terminal or hardcopy is returned. If the terminal is not found in the terminfo database, #f is returned.

If the terminal is found, then the tiget procedure can be used to query terminfo capabilities for this terminal.

Procedure: tiget capability

This procedure searches the terminfo database for the currently active terminal for information on capability, which is a short string that contains a terminfo capability, such as ‘am’ or ‘blink’.

If a capability by that name is found for the current terminal, an integer, string, or boolean will be returned depending on the capability. If a capability by that name is not found, #f will be returned. It is not possible to distinguish between capabilities that are false, and capabilities that are not present.