Introduction to the tree command

From UnixCasts.com (formerly Learning the UNIX command line on OS X)

Apr 15, 2024

Hey there!

It’s time for our 7th installment of UNIX command line tips. In the previous newsletter, we talked about curly brace expansion in bash.

This week we're going to shift focus to a useful little utility that I've come to use more often in recent months, which is the tree command.

The tree command in UNIX

The tree command, a handy alternative to ls , is a command which list the contents of directories in a tree-like format. It's really great when you need to view files and directories in a structured manner. In the examples that follow, I’m going to show the directory contents of a plugin for vim called vim-gitgutter, which I find to be very helpful when I work with git repositories.

Installation

On OS X, installation of the tree command is a breeze when using brew:

brew install tree

Basic usage

Using the vim-gitgutter directory on my local machine, let’s look at a few options that the tree command offers.

By default, the tree command displays output based on the current working directory:

☺ tree
.
├── README.mkd
├── doc
│   ├── gitgutter.txt
│   └── tags
├── plugin
│   └── gitgutter.vim
└── screenshot.png

2 directories, 5 files

Alternatively, you can specify a directory argument as well:

☺ tree ~/.vim/bundle/vim-gitgutter 
/Users/chip/.vim/bundle/vim-gitgutter
├── README.mkd
├── doc
│   ├── gitgutter.txt
│   └── tags
├── plugin
│   └── gitgutter.vim
└── screenshot.png

2 directories, 5 files

Listing directories only

At times, it's also nice just to view the directory structure using the -d option:

☺ tree -d
.
├── doc
└── plugin

2 directories

Showing human readable file sizes

It's also useful to know that there are options that are more similar to what the ls command provides, such as when you pass the -h flag for viewing human readable file and directory sizes:

☺ tree -h
.
├── [9.6K]  README.mkd
├── [ 136]  doc
│   ├── [7.5K]  gitgutter.txt
│   └── [1.0K]  tags
├── [ 102]  plugin
│   └── [ 16K]  gitgutter.vim
└── [ 16K]  screenshot.png

2 directories, 5 files

Displaying file permissions

There is also the ability to view file and directory permissions using the -p flag:

☺ tree -p
.
├── [-rw-r--r--]  README.mkd
├── [drwxr-xr-x]  doc
│   ├── [-rw-r--r--]  gitgutter.txt
│   └── [-rw-r--r--]  tags
├── [drwxr-xr-x]  plugin
│   └── [-rw-r--r--]  gitgutter.vim
└── [-rw-r--r--]  screenshot.png

2 directories, 5 files

There are many more options available for using the tree command, so next time you need to view a directory in a more structured way, please take a closer look at the man pages for tree.

For more UNIX tips, please check out UnixCasts.com.

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