Safe Haskell	Safe
Language	Haskell98

System.Console.ANSI

Contents

Basic data types
Cursor movement by character
Cursor movement by line
Directly changing cursor position
Clearing parts of the screen
Scrolling the screen
Select Graphic Rendition mode: colors and other whizzy stuff
Cursor visibilty changes
Changing the title
Checking if handle supports ANSI

Description

Provides ANSI terminal support for ANSI terminal software running on a Unix-like operating system or on a Windows operating system (where supported) or on other Windows operating systems where the terminal in use is not ANSI-enabled.

The ANSI escape codes are described at http://en.wikipedia.org/wiki/ANSI_escape_code and provide a rich range of functionality for terminal control, which includes:

Colored text output, with control over both foreground and background colors
Hiding or showing the cursor
Moving the cursor around
Clearing parts of the screen

The most frequently used parts of this ANSI command set are exposed with a platform independent interface by this module. Every function exported comes in three flavours:

Vanilla: has an IO () type and doesn't take a Handle. This just outputs the ANSI command directly on to the terminal corresponding to stdout. Commands issued like this should work as you expect on both Windows and Unix.
Chocolate: has an IO () type but takes a Handle. This outputs the ANSI command on the terminal corresponding to the supplied handle. Commands issued like this should also work as you expect on both Windows and Unix.
Strawberry: has a String type and just consists of an escape code which can be added to any other bit of text before being output. This version of the API is often convenient to use, but will not work on Windows operating systems where the terminal in use is not ANSI-enabled (such as those before Windows 10 Threshold 2). On versions of Windows where the terminal in use is not ANSI-enabled, these codes will always be the empty string, so it is possible to use them portably for e.g. coloring console output on the understanding that you will only see colors if you are running on an operating system that is Unix-like or is a version of Windows where the terminal in use is ANSI- enabled.

Example:

-- Set colors and write some text in those colors.
sgrExample :: IO ()
sgrExample = do
    setSGR [SetColor Foreground Vivid Red]
    setSGR [SetColor Background Vivid Blue]
    putStr "Red-On-Blue"
    setSGR [Reset]
    putStr "White-On-Black"

For many more examples, see the project's extensive Example.hs file.

Synopsis

Basic data types

module System.Console.ANSI.Types

Cursor movement by character

cursorUp #

Arguments

:: Int	Number of lines or characters to move
-> IO ()

cursorDown #

Arguments

:: Int	Number of lines or characters to move
-> IO ()

cursorForward #

Arguments

:: Int	Number of lines or characters to move
-> IO ()

cursorBackward #

Arguments

:: Int	Number of lines or characters to move
-> IO ()

hCursorUp #

Arguments

:: Handle
-> Int	Number of lines or characters to move
-> IO ()

hCursorDown #

Arguments

:: Handle
-> Int	Number of lines or characters to move
-> IO ()

hCursorForward #

Arguments

:: Handle
-> Int	Number of lines or characters to move
-> IO ()

hCursorBackward #

Arguments

:: Handle
-> Int	Number of lines or characters to move
-> IO ()

cursorUpCode #

Arguments

:: Int	Number of lines or characters to move
-> String

cursorDownCode #

Arguments

:: Int	Number of lines or characters to move
-> String

cursorForwardCode #

Arguments

:: Int	Number of lines or characters to move
-> String

cursorBackwardCode #

Arguments

:: Int	Number of lines or characters to move
-> String

Cursor movement by line

The difference between movements "by character" and "by line" is that *Line functions additionally move the cursor to the start of the line, while functions like cursorUp and cursorDown keep the column the same.

Also keep in mind that *Line functions are not as portable. See https://github.com/feuerbach/ansi-terminal/issues/10 for the details.

cursorUpLine #

Arguments

:: Int	Number of lines to move
-> IO ()

cursorDownLine #

Arguments

:: Int	Number of lines to move
-> IO ()

hCursorUpLine #

Arguments

:: Handle
-> Int	Number of lines to move
-> IO ()

hCursorDownLine #

Arguments

:: Handle
-> Int	Number of lines to move
-> IO ()

cursorUpLineCode #

Arguments

:: Int	Number of lines to move
-> String

cursorDownLineCode #

Arguments

:: Int	Number of lines to move
-> String

Directly changing cursor position

setCursorColumn #

Arguments

:: Int	0-based column to move to
-> IO ()

hSetCursorColumn #

Arguments

:: Handle
-> Int	0-based column to move to
-> IO ()

setCursorColumnCode #

Arguments

:: Int	0-based column to move to
-> String

setCursorPosition #

Arguments

:: Int	0-based row to move to
-> Int	0-based column to move to
-> IO ()

hSetCursorPosition #

Arguments

:: Handle
-> Int	0-based row to move to
-> Int	0-based column to move to
-> IO ()

setCursorPositionCode #

Arguments

:: Int	0-based row to move to
-> Int	0-based column to move to
-> String

Clearing parts of the screen

Note that these functions only clear parts of the screen. They do not move the cursor.

clearFromCursorToScreenEnd :: IO () #

clearFromCursorToScreenBeginning :: IO () #

clearScreen :: IO () #

hClearFromCursorToScreenEnd :: Handle -> IO () #

hClearFromCursorToScreenBeginning :: Handle -> IO () #

hClearScreen :: Handle -> IO () #

clearFromCursorToScreenEndCode :: String #

clearFromCursorToScreenBeginningCode :: String #

clearScreenCode :: String #

clearFromCursorToLineEnd :: IO () #

clearFromCursorToLineBeginning :: IO () #

clearLine :: IO () #

hClearFromCursorToLineEnd :: Handle -> IO () #

hClearFromCursorToLineBeginning :: Handle -> IO () #

hClearLine :: Handle -> IO () #

clearFromCursorToLineEndCode :: String #

clearFromCursorToLineBeginningCode :: String #

clearLineCode :: String #

Scrolling the screen

scrollPageUp #

Arguments

:: Int	Number of lines to scroll by
-> IO ()

Scroll the displayed information up or down the terminal: not widely supported

scrollPageDown #

Arguments

:: Int	Number of lines to scroll by
-> IO ()

Scroll the displayed information up or down the terminal: not widely supported

hScrollPageUp #

Arguments

:: Handle
-> Int	Number of lines to scroll by
-> IO ()

Scroll the displayed information up or down the terminal: not widely supported

hScrollPageDown #

Arguments

:: Handle
-> Int	Number of lines to scroll by
-> IO ()

Scroll the displayed information up or down the terminal: not widely supported

scrollPageUpCode #

Arguments

:: Int	Number of lines to scroll by
-> String

scrollPageDownCode #

Arguments

:: Int	Number of lines to scroll by
-> String

Select Graphic Rendition mode: colors and other whizzy stuff

setSGR #

Arguments

:: [SGR]	Commands: these will typically be applied on top of the current console SGR mode. An empty list of commands is equivalent to the list `[Reset]`. Commands are applied left to right.
-> IO ()

Set the Select Graphic Rendition mode

hSetSGR #

Arguments

:: Handle
-> [SGR]	Commands: these will typically be applied on top of the current console SGR mode. An empty list of commands is equivalent to the list `[Reset]`. Commands are applied left to right.
-> IO ()

Set the Select Graphic Rendition mode

setSGRCode #

Arguments

:: [SGR]	Commands: these will typically be applied on top of the current console SGR mode. An empty list of commands is equivalent to the list `[Reset]`. Commands are applied left to right.
-> String

Cursor visibilty changes

hideCursor :: IO () #

showCursor :: IO () #

hHideCursor :: Handle -> IO () #

hShowCursor :: Handle -> IO () #

hideCursorCode :: String #

showCursorCode :: String #

Changing the title

setTitle #

Arguments

:: String	New title
-> IO ()

Set the terminal window title

hSetTitle #

Arguments

:: Handle
-> String	New title
-> IO ()

Set the terminal window title

setTitleCode #

Arguments

:: String	New Icon Name and Window Title
-> String

XTerm control sequence to set the Icon Name and Window Title.

Checking if handle supports ANSI

hSupportsANSI :: Handle -> IO Bool #

Use heuristics to determine whether the functions defined in this package will work with a given handle.

The current implementation checks that the handle is a terminal, and that the TERM environment variable doesn't say dumb (which is what Emacs sets for its own terminal).