A command line printer of tree structures (e.g. directory tree) written in Ruby.

This library can be used to build a tree structure, and render or print it like an ASCII graph.

e.g. it can be used to implement a directory tree printer just like the Linux utility tree. See bin/tree.rb

gem install cli-tree

1. require 'cli-tree'
2. Create a TreeNode: tree = TreeNode.new(node_name, children = [])
3. Add more TreeNode objects to children: tree.children << child_node
4. Add more TreeNode objects to child_node, and so on.
5. Call puts tree.render or tree.print to print the tree.

TreeNode methods:

• initialize(name, children = [])
• TreeNode.from_h(hash): hash is {name: "string", children: [hash1, ...]}
• TreeNode.from_json(json): similar to from_h
• to_h: convert TreeNode to Hash
• to_json(**kwargs): kwargs refer to JSON#generate
• render: draw an ASCII tree graph
• print(stream: STDOUT, prefix: ''): puts the rendered text to a stream

require 'cli-tree'
# the tree and all nodes are TreeNode objects
tree = TreeNode.new("root", [
 TreeNode.new("foo", [
 TreeNode.new("bar"),
 TreeNode.new("baz"),
 ])
])
puts tree.render

or build the tree from a Hash or JSON:

require 'cli-tree'
data = {
 name: "root", # every node must have a name
 children: [ # and an optional children array
 { # non-leaf child must be a Hash
 name: "foo",
 children: [
 "bar", # leaf child can be a String
 "baz",
 ],
 },
 ],
}
tree = TreeNode.from_h(data)
tree.print

Output:

root
└── foo
 ├── bar
 └── baz