Command line file filtering with haskell.
A tool to let you use short haskell expressions to filter files at the command line.
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.
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.
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
eddie.md. Use the
-s flag, and convert from pandoc's markdown to your chosen format.