https://github.com/thisredone/rb
Turns Ruby into a versatile command line utility
https://github.com/thisredone/rb
Last synced: 10 months ago
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Turns Ruby into a versatile command line utility
- Host: GitHub
- URL: https://github.com/thisredone/rb
- Owner: thisredone
- License: mit
- Created: 2018-08-14T02:31:27.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2023-02-16T14:51:16.000Z (about 3 years ago)
- Last Synced: 2025-04-01T11:05:05.721Z (11 months ago)
- Language: Ruby
- Size: 20.5 KB
- Stars: 1,495
- Watchers: 30
- Forks: 42
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- awesome-list - rb
README
# 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
```ruby
#!/usr/bin/env ruby
File.join(Dir.home, '.rbrc').tap { |f| load f if File.exist?(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_eval`ed 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
```bash
> docker ps | rb drop 1 | rb -l split[1]
# ubuntu
# postgres
```
###### Display how much time ago containers have exited
```shell
> 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%`
```shell
> 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
```shell
> find . -type f | rb 'group_by(&File.method(:extname)).map { |ext, o| "#{ext.chomp}: #{o.size}" }'
# : 3
# .rb: 19
# .md: 1
```
###### This problem http://vegardstikbakke.com/unix/
```ruby
ls | rb 'group_by { |x| x[/\d+/] }.select { |_, y| y.one? }.keys'
```
## Extending rb
The `~/.rbrc` file is loaded if it's available. Anything defined in there will be available inside `rb` scripts.
```ruby
# ~/.rbrc
class String
def black; "\033[30m#{self}\033[0m" end
def red; "\033[31m#{self}\033[0m" end
end
```
```shell
> ls | rb first.red
```
## Alternatives
For a more portable solution, note you can run `ruby` with the `-e` flag.
[`$<`](https://ruby-doc.org/3.2.1/globals_rdoc.html#:~:text=%24%3C,as%20ARGF.) is a two-character global equivalent to [`ARGF`](https://ruby-doc.org/3.2.1/ARGF.html). `ARGF` gives you access to the standard input and includes `Enumerable`.
```shell
> docker ps | ruby -e '$<.drop(1).each{puts _1.split[1]}'
# ubuntu
# postgres
```
```shell
> docker ps -a | ruby -e '$<.grep(/Exited/).each{puts _1.split.last.ljust(20) + " => " + _1.split(/ {2,}/)[-2]}'
# angry_hamilton => Exited (0) 18 hours ago
# dreamy_lamport => Exited (0) 3 days ago
# prickly_hypatia => Exited (0) 2 weeks ago
```