Command line file filtering with haskell http://chiselapp.com/user/mwm/repository/eddie/

Latest on Hackage:1.0.0

This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.

BSD3 licensed by Mike Meyer
Maintained by mwm@mired.org

What is eddie?

A command line tool for running Haskell functions over text files.

It is also useful for prototyping Haskell text processing functions that you will later copy into a program.

Why is eddie?

This project actually started in response to a code bounty for a clojure shell scripting tool. That resulted in a specification for the requested program that had all the features of eddie, and then some. However, clojure code embedded on the command line looks clumsy, so the project was shelved.

In haskell, functional expression are much simpler and more elegant. In particular, in looking for haskell command line tools, I found http://www.haskell.org/haskellwiki/Simple_unix_tools, which convinced me that the original design would be not merely usable, but elegant if the expressions were done in haskell. Hence, eddie.

Why not ghc -e?

Eddie adds features to make using it for shell scripting easier:

  • When given file arguments, eddie feeds them to your function.
  • Eddie can easily add modules to the namespace you use.
  • Eddie has options for processing things a line or file at a time.
  • Eddie uses either Text or ByteStrings by default, not lists of characters.

More information

The best place to start is the manual. That's available in the source tree in both man format in eddie.1, and in html in eddie.html. The latter is also available online.


Install or build with cabal as usual.


Testing is done with the haskell shelltestrunner package (which can be installed with cabal). Run shelltest tests in the source directory to run the tests with the currently installed eddie. Use shelltest tests -w eddie.hs to run them using the current source. Use shelltest tests -w dist/build/eddie/eddie to run them with the compiled binary.


The documenation is built with pandoc from eddie.md. Use the -s flag, and convert from pandoc's markdown to your chosen format.

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