A simple Haskell progress bar for the console. Heavily borrows from TJ Holowaychuk's Node.JS project progress.

Packages Using ascii-progress

• codex
• xdcc

import Control.Concurrent (threadDelay) import Control.Monad (unless) import System.Console.AsciiProgress (Options(..), displayConsoleRegions, isComplete, def, newProgressBar, tick) main :: IO () main = displayConsoleRegions $ do pg <- newProgressBar def { pgWidth = 50 } loop pg where loop pg = do b <- isComplete pg unless b $ do threadDelay $ 200 * 1000 tick pg loop pg

Full documentation on hackage

Though still rudimentary, there's support for running multiple concurrent progress bars. The multi-example shows off this feature:

The bin directory contains the example above and a more complex example which uses http-conduit to download an image from imgur, printing the progress using the package.

To build the examples, just configure and compile with -fexamples:

git clone https://github.com/yamadapc/haskell-ascii-progress cabal install -j --only-dep -fexamples cabal configure -fexamples cabal run example # ... cabal run download-example 

ascii-progress uses an Options data type for configuring the progress bar. Available options are:

A format String for the progress bar. The following placeholders are supported:

• ":eta" (ETA displayed in seconds)
• ":current" (current tick)
• ":total" (total number of ticks)
• ":percent" (percentage completed)
• ":elapsed" (elapsed time in seconds)
• ":bar" (the actual progress bar)

main = do pg <- newProgressBar def { pgFormat = ":current/:total [:bar]" } -- ...

The character used on the completed part of the bar

There's an example which mimicks the NPM3 progress-bar. It looks like:

Working ╢████████████████████████████████████░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░╟ 

The character used on the completed part of the bar

The total amount of ticks for the bar to be completed

The progress bar's total width in columns

What to output when the progress bar is done. The same format placeholders used in pgFormat may be used.

If all else fails, you can provide a function which determines how a progress-bar is rendered.

This package is published to hackage as ascii-progress, so you can install it with:

cabal install ascii-progress 

It's also part of stackage.

This code is licensed under the MIT license for Pedro Tacla Yamada. For more information please refer to the LICENSE file.