3.32 Terminal Control

The following predicates form a simple access mechanism to the Unix termcap library to provide terminal independent I/O for screen terminals. The library package library(tty) builds on top of these predicates.

tty_get_capability(+Name, +Type, -Result)

Get the capability named Name from the termcap library. See termcap(5) for the capability names. Type specifies the type of the expected result, and is one of string, number or bool. String results are returned as an atom, number result as an integer and bool results as the atom on or off. If an option cannot be found this predicate fails silently. The results are only computed once. Successive queries on the same capability are fast.

tty_goto(+X, +Y)

Goto position (X, Y) on the screen. Note that the predicates line_count/2 and line_position/2 will not have a well defined behaviour while using this predicate.

tty_put(+Atom, +Lines)

Put an atom via the termcap library function tputs(). This function decodes padding information in the strings returned by tty_get_capability/3 and should be used to output these strings. Lines is the number of lines affected by the operation, or 1 if not applicable (as in almost all cases).

set_tty(-OldStream, +NewStream)

Set the output stream, used by tty_put/2 and tty_goto/2 to a specific stream. Default is user_output.