PSTree - Process Status Tree for UNIX in Ruby

Description

This library provides a Ruby implementation of the pstree utility, enabling developers to visualize process hierarchies as tree structures. It parses system process information and presents it in an easily readable format with proper indentation and Unicode/ASCII tree characters.

The library can be used both programmatically as a data structure and through its command-line interface for quick process tree visualization.

Installation

RubyGems

Install the latest version from RubyGems.org:

gem install pstree

Bundler

Add to your Gemfile:

gem 'pstree'

Then run:

bundle install

Requirements

Ruby 2.0 or higher
UNIX-like operating system (Linux, macOS, BSD)
/bin/ps utility available in PATH

Usage

You can display a simple process tree by executing the ruby-pstree script.

$ ruby-pstree $$
34223 -bash (flori)
└─ 37124 ruby /Users/flori/.rvm/gems/ruby-2.6.2/bin/ruby-pstree 34223 (flori)
   └─ 37129 /bin/ps axww -o ppid,pid,user,command (root)

Programmatic Usage

Access process information programmatically:

require 'pstree'

# Create a process tree for PID 1 (init)
tree = PSTree.new(1)

# Iterate over processes in the tree
tree.each do |process|
  puts "#{process.pid}: #{process.cmd}"
end

# Or get the tree as a string
puts tree.to_s

# Navigate the tree to find the pids of your favourite processes
pid_of_shell_parent_of_irb = tree.find { it.cmd =~ /irb/ }&.ppid