Pipeable Ruby - forget about grep / sed / awk / wc ... use pure, readable Ruby!

Install

sudo gem install pru

Working with rvm / many gemsets -> only install once (1.9 recommended)

rvm 1.9.2 exec gem install pru
echo 'alias pru="rvm 1.9.2 exec pru"' >> ~/.bash_profile

Usage

pru supports mapping and reducing.

Map works on each line as String
Reduce works on all lines as Array

something | pru 'map'
something | pru 'map' 'reduce'
something | pru '' 'reduce'
something | pru --reduce 'reduce'

-r, --reduce CODE                reduce via CODE

-I, --libdir DIR                 Add DIR to load path
    --require LIB                Require LIB (also comma-separated)

-h, --help                       Show this.
-v, --version                    Show Version

Examples

# grep --- all lines including foo
ls -al | grep foo
ls -al | pru /foo/

# grep --- all lines including current date
ls -al | grep $(date +"%Y-%m-%d")
ls -al | pru 'include?(Time.now.strftime("%Y-%m-%d"))'

# grep --- all lines including foo but not self
ps -ef | grep foo | grep -v grep
ps -ef | pru 'include?("foo") and not include?("pru")'

# awk --- return second item
ls -al | awk '{print $2}'
ls -al | pru 'split(" ")[1]'

# awk --- count and average of all integers on second position
ls -al | awk '{ s += $2; } END {print "average" ,int(s/NR);print "count ",int(NR)}'
ls -al | pru 'split(" ")[1]' '"average #{mean(&:to_i)}\ncount #{size}"'

# wc --- count lines
ls -al | wc -l
ls -al | pru --reuduce 'size'

# sed -- replace a 5 with five
ls -al | sed 's/5/five/'
ls -al | pru 'gsub(/5/,"five")'

# every second line
ls -al | pru 'i % 2 == 0'

# paste-friendly mime-types
curl https://github.com/mattetti/mimetype-fu/raw/master/lib/mime_types.yml | grep image | pru 'gsub(/(.*): (.*)/, %{"\\1" => "\\2",})'

# number of files by date:
ls -al | pru 'split(" ")[5]' 'grouped.map{|d, f| "#{d} : #{f.size}" }'

# quotes inside a string
something | pru 'include?(%{"string"})'

# Find a gem version matching a requirement e.g. ~> 1.0.0
curl http://rubygems.org/api/v1/versions/bundler | pru --require json 'JSON.parse(self).map{|g|g["number"]}.find{|v| Gem::Requirement.new("~>1.0.1").satisfied_by? Gem::Version.new(v) }'

Authors

Contributors

• John Hobbs
• Vasiliy Ermolovich
• Jens Wille

Michael Grosser
michael@grosser.it
Hereby placed under public domain, do what you want, just do not hold me accountable...