terminfo-0.3.1.2: Haskell bindings to the terminfo library.Source codeContentsIndex
System.Console.Terminfo.Base
Portabilityportable (FFI)
Stabilityexperimental
Maintainerjudah.jacobson@gmail.com
Contents
Initialization
Capabilities
Output
TermOutput
Monoid functions
Description

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.

Synopsis
data Terminal
setupTerm :: String -> IO Terminal
setupTermFromEnv :: IO Terminal
data SetupTermError
data Capability a
getCapability :: Terminal -> Capability a -> Maybe a
tiGetFlag :: String -> Capability Bool
tiGuardFlag :: String -> Capability ()
tiGetNum :: String -> Capability Int
tiGetStr :: String -> Capability String
tiGetOutput1 :: forall f. OutputCap f => String -> Capability f
class OutputCap f
class (Monoid s, OutputCap s) => TermStr s
data TermOutput
runTermOutput :: Terminal -> TermOutput -> IO ()
hRunTermOutput :: Handle -> Terminal -> TermOutput -> IO ()
termText :: String -> TermOutput
tiGetOutput :: String -> Capability ([Int] -> LinesAffected -> TermOutput)
type LinesAffected = Int
Monoid (mempty, mappend, mconcat)
(<#>) :: Monoid m => m -> m -> m
Initialization
data Terminal Source
setupTerm :: String -> IO TerminalSource

Initialize the terminfo library to the given terminal entry.

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

setupTermFromEnv :: IO TerminalSource

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.

data SetupTermError Source
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Capabilities
data Capability a Source
A feature or operation which a Terminal may define.
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getCapability :: Terminal -> Capability a -> Maybe aSource
tiGetFlag :: String -> Capability BoolSource

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.

tiGuardFlag :: String -> Capability ()Source
Look up a boolean capability in the terminfo database, and fail if it's not defined.
tiGetNum :: String -> Capability IntSource
Look up a numeric capability in the terminfo database.
tiGetStr :: String -> Capability StringSource
Look up a string capability in the terminfo database. NOTE: This function is deprecated; use tiGetOutput1 instead.
Output

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.

tiGetOutput1 :: forall f. OutputCap f => String -> Capability fSource

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.

class OutputCap f Source
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class (Monoid s, OutputCap s) => TermStr s Source
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TermOutput
data TermOutput Source
An action which sends output to the terminal. That output may mix plain text with control characters and escape sequences, along with delays (called "padding") required by some older terminals.
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runTermOutput :: Terminal -> TermOutput -> IO ()Source
Write the terminal output to the standard output device.
hRunTermOutput :: Handle -> Terminal -> TermOutput -> IO ()Source
Write the terminal output to the terminal or file managed by the given Handle.
termText :: String -> TermOutputSource
tiGetOutput :: String -> Capability ([Int] -> LinesAffected -> TermOutput)Source
Look up an output capability in the terminfo database.
type LinesAffected = IntSource
A parameter to specify the number of lines affected. Some capabilities (e.g., clear and dch1) use this parameter on some terminals to compute variable-length padding.
Monoid functions
Monoid (mempty, mappend, mconcat)
(<#>) :: Monoid m => m -> m -> mSource
An operator version of mappend.
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