This module provides a low-level interface to the C functions of the terminfo library.

NOTE: Since this library is built on top of the curses interface, it is not thread-safe.

Initialize the terminfo library to the given terminal entry.

Throws a SetupTermError if the terminfo database could not be read.

Initialize the terminfo library, using the TERM environmental variable. If TERM is not set, we use the generic, minimal entry dumb.

Throws a SetupTermError if the terminfo database could not be read.

Look up a boolean capability in the terminfo database.

Unlike tiGuardFlag, this capability never fails; it returns False if the capability is absent or set to false, and returns True otherwise.

Terminfo contains many string capabilities for special effects. For example, the cuu1 capability moves the cursor up one line; on ANSI terminals this is accomplished by printing the control sequence "\ESC[A". However, some older terminals also require "padding", or short pauses, after certain commands. For example, when TERM=vt100 the cuu1 capability is "\ESC[A$<2>", which instructs terminfo to pause for two milliseconds after outputting the control sequence.

The TermOutput monoid abstracts away all padding and control sequence output. Unfortunately, that datatype is difficult to integrate into existing String-based APIs such as pretty-printers. Thus, as a workaround, tiGetOutput1 also lets us access the control sequences as Strings. The one caveat is that it will not allow you to access padded control sequences as Strings. For example:

 > t <- setupTerm "vt100"
 > isJust (getCapability t (tiGetOutput1 "cuu1") :: Maybe String)
 False
 > isJust (getCapability t (tiGetOutput1 "cuu1") :: Maybe TermOutput)
 True

String capabilities will work with software-based terminal types such as xterm and linux. However, you should use TermOutput if compatibility with older terminals is important. Additionally, the visualBell capability which flashes the screen usually produces its effect with a padding directive, so it will only work with TermOutput.

Look up an output capability which takes a fixed number of parameters (for example, Int -> Int -> TermOutput).

For capabilities which may contain variable-length padding, use tiGetOutput instead.