The vty package

[Tags:bsd3, library, program, test]

vty is terminal GUI library in the niche of ncurses. It is intended to be easy to use, have no confusing corner cases, and good support for common terminal types.

Included in the source distribution is a program test/interactive_terminal_test.hs that demonstrates the various features.

Developers: See the Graphics.Vty module.

Users: See the Graphics.Vty.Config module.

If your terminal is not behaving as expected the results of the vty-interactive-terminal-test executable should be sent to the Vty maintainter to aid in debugging the issue.

Notable infelicities: Assumes UTF-8 character encoding support by the terminal; Poor signal handling; Requires terminfo.

Project is hosted on

git clone git://

© 2006-2007 Stefan O'Rear; BSD3 license.

© Corey O'Connor; BSD3 license.

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Versions 3.0.0, 3.0.1, 3.0.2, 3.0.4, 3.1.0, 3.1.2, 3.1.4, 3.1.6, 3.1.8,,, 4.0.0,,,,,,,,,,,,,,,,,, 4.7.1, 4.7.2, 4.7.3, 4.7.4, 4.7.5, 5.0.0, 5.0.1, 5.0.2, 5.1.0, 5.1.1, 5.1.3, 5.1.4, 5.2.0, 5.2.1, 5.2.2, 5.2.3, 5.2.4, 5.2.5, 5.2.6, 5.2.7, 5.2.8, 5.2.9, 5.2.10, 5.2.11, 5.3, 5.3.1, 5.4.0, 5.5.0, 5.6, 5.7, 5.7.1, 5.8, 5.8.1, 5.9, 5.9.1, 5.10, 5.11, 5.11.1
Change log CHANGELOG
Dependencies base (==4.*), blaze-builder (>= && <0.4), bytestring, containers, data-default (>=0.5.3), deepseq (>=1.1 && <1.4), directory, filepath (>=1.0 && <2.0), hashable (>=1.2), lens (>= && <4.4), mtl (>= && <2.3), parallel (>=2.2 && <3.3), parsec (>=2 && <4), terminfo (>=0.3 && <0.5), text (>=0.11.3), transformers (>=, unix, utf8-string (==0.3.*), vector (>=0.7), vty [details]
License BSD3
Maintainer Corey O'Connor (
Stability Unknown
Category User Interfaces
Home page
Uploaded Thu Jul 31 05:26:44 UTC 2014 by CoreyOConnor
Distributions Debian:5.4.0, LTSHaskell:5.11.1, NixOS:5.11.1, Stackage:5.11.1, Tumbleweed:5.5.0
Downloads 20199 total (145 in the last 30 days)
0 []
Status Docs available [build log]
Successful builds reported [all 1 reports]




Maintainer's Corner

For package maintainers and hackage trustees

Readme for vty

Readme for vty-5.1.4

vty is a terminal interface library.

Project is hosted on

git clone git://


  • Automatic handling of window resizes.

  • Supports Unicode characters on output, automatically setting and resetting UTF-8 mode for xterm. Other terminals are assumed to support

  • Efficient output.

  • Minimizes repaint area, thus virtually eliminating the flicker problem that plagues ncurses programs.

  • A pure, compositional interface for efficiently constructing display images.

  • Automatically decodes keyboard keys into (key,[modifier]) tuples.

  • Automatically supports refresh on Ctrl-L.

  • Automatically supports timeout after 50ms for lone ESC (a barely noticable delay)

  • Interface is designed for relatively easy compatible extension.

  • Supports all ANSI SGR-modes (defined in console_codes(4)) with a type-safe interface.

  • Properly handles cleanup, but not due to signals.

Known Issues

  • Signal handling of STOP, TERM and INT are non existent.

  • The character encoding of the terminal is assumed to be UTF-8.

  • Terminfo is assumed to be correct unless the terminal (as declared by TERM) starts with xterm or ansi. This means that some terminals will not have correct special key support (shifted F10 etc)

  • Uses the TIOCGWINSZ ioctl to find the current window size, which appears to be limited to Linux and *BSD.

Platform Support

Posix Terminals

Uses terminfo to determine terminal protocol. Some special rules for Mac terminal applications. The special rules might be invalid on newer Mac OS.



Development Notes


Profiling appears to cause issues with coverage when enabled. To evaluate coverage configure as follows:

rm -rf dist ; cabal configure --enable-tests --enable-library-coverage \
  --disable-library-profiling \


rm -rf dist ; cabal configure --enable-tests --disable-library-coverage \
  --enable-library-profiling \