Turns Ruby into a versatile command line utility
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Failed to load latest commit information.
LICENSE Create LICENSE Aug 16, 2018
README.md File.join when looking for .rbrc Aug 22, 2018
rb File.join when looking for .rbrc Aug 22, 2018

README.md

rb

With 9 lines of Ruby replace most of the command line tools that you use to process text inside of the terminal.

Here's the code

#!/usr/bin/env ruby
File.join(Dir.home, '.rbrc').tap { |f| load f if File.exists?(f) }

def execute(_, code)
  puts _.instance_eval(&code)
rescue Errno::EPIPE
  exit
end

single_line = ARGV.delete('-l')
code = eval("Proc.new { #{ARGV.join(' ')} }")
single_line ? STDIN.each { |l| execute(l.chomp, code) } : execute(STDIN.each_line, code)

Clone this repo and copy the rb file to somewhere in your path (or just copy and paste the above).

With this you can use ruby as a command line utility much more ergonomically than invoking it the standard way.

There's only one switch -l which runs your code on each line separately. Otherwise you get an Enumerator that returns the lines of stdin. It's instance_evaled so some methods need self to work, eg. self[-1]

Install

Just paste this line into your terminal to install rb:

sudo curl https://raw.githubusercontent.com/thisredone/rb/master/rb -o /usr/local/bin/rb && sudo chmod +x /usr/local/bin/rb

Examples

Extract docker images from running containers
> docker ps | rb drop 1 | rb -l split[1]

# ubuntu
# postgres
Display how much time ago containers have exited
> docker ps -a | rb grep /Exited/ | rb -l 'split.last.ljust(20) + " => " + split(/ {2,}/)[-2]'

# angry_hamilton      => Exited (0) 18 hours ago
# dreamy_lamport      => Exited (0) 3 days ago
# prickly_hypatia     => Exited (0) 2 weeks ago
Sort df -h output by Use%
> df -h | rb 'drop(1).sort_by { |l| l.split[-2].to_f }'

# udev                         3,9G     0  3,9G   0% /dev
# tmpfs                        3,9G     0  3,9G   0% /sys/fs/cgroup
# /dev/sda1                    511M  3,4M  508M   1% /boot/efi
# /dev/sda2                    237M   85M  140M  38% /boot

# or leave the header if you want
> df -h | rb '[first].concat drop(1).sort_by { |l| l.split[-2].to_f }'

# Filesystem                   Size  Used Avail Use% Mounted on
# udev                         3,9G     0  3,9G   0% /dev
# tmpfs                        3,9G     0  3,9G   0% /sys/fs/cgroup
# /dev/sda1                    511M  3,4M  508M   1% /boot/efi
# /dev/sda2                    237M   85M  140M  38% /boot
Count files by their extension
> find . -type f | rb 'group_by(&File.method(:extname)).map { |ext, o| "#{ext.chomp}: #{o.size}" }'

# : 3
# .rb: 19
# .md: 1

Extending rb

The ~/.rbrc file is loaded if it's available. Anything defined in there will be available inside rb scripts.

# ~/.rbrc

class String
  def black; "\033[30m#{self}\033[0m" end
  def red;   "\033[31m#{self}\033[0m" end
end
> ls | rb first.red