steshaw / hoe

Haskell One-liner Evaluator

hoe: Haskell One-liner Evaluator

About

hoe is AWK like text processor, but can use Haskell. It can process text files in various ways depends on types of given scripts.

Usage

To show basic usage, run hoe --help.

hoe Haskell One-liner Evaluator, (c) Hideyuki Tanaka

hoe [OPTIONS] SCRIPT [FILES]

Common flags:
  -i --inplace[=EXT]  Edit files in place (make backup if EXT supplied)
  -m --mod[=ITEM]     Import a module before running the script
  -? --help           Display help message
  -V --version        Print version information
  -v --verbose        Loud verbosity
  -q --quiet          Quiet verbosity

• Sort lines

$ ls | hoe 'lines >>> sort'
LICENSE
README.md
Setup.hs
cabal.sandbox.config
dist
hoe.cabal
src
template
test

• Drop lines

ls | hoe 'lines >>> drop 3'
cabal.sandbox.config
dist
hoe.cabal
src
template
test

• Add "> " to line head.

ls | hoe 'map ("> " ++)'
> LICENSE
> README.md
> Setup.hs
> cabal.sandbox.config
> dist
> hoe.cabal
> src
> template
> test

It also accepts Char -> Char functions.

• To uppercase

$ ls | hoe 'toUpper'
LICENSE
README.MD
SETUP.HS
CABAL.SANDBOX.CONFIG
DIST
HOE.CABAL
SRC
TEMPLATE
TEST

Of course, it can evaluate simple values.

• Calculate a integer value

$ hoe '2^100'
1267650600228229401496703205376

• Make many files

$ hoe 'forM [1..10] $ \i -> writeFile ("file."++show i) ""'