The tree command is one of those tools that makes the CLI supreme to its GUI interface. Its use is to list files and directories in a structured manner. I find it gives me an excellent overview of the directory structure and I use it a lot to familiarize myself with new projects.
The base tree command will list all files and directories, below your current working directory.
$ tree
.
├── httpare.cabal
├── LICENSE
├── README.md
├── Setup.hs
└── src
├── Httpare
│ └── Class.hs
└── Main.hs
2 directories, 6 files
If that is too many to see, have tree just show the directory structure.
$ tree -d
.
└── src
└── Httpare
2 directories
There is a useful level parameter you can use to have tree now descend too many levels. I employ that a lot in projects with massive amounts of files, like web sites.
$ tree -L 2
.
├── httpare.cabal
├── LICENSE
├── README.md
├── Setup.hs
└── src
├── Httpare
└── Main.hs
2 directories, 5 files
You can also tell tree to exclude certain files by giving it an ignore parameter.
$ tree -I '*.hs'
.
├── httpare.cabal
├── LICENSE
├── README.md
└── src
└── Httpare
2 directories, 3 files
As with most *nix tools, tree is very flexible. You can for example have it simulate find by throwing in parameters to skip indentation, show all files, print the full paths, skip colors and the summary report.
$ tree -afin --noreport
.
./.gitignore
./httpare.cabal
./LICENSE
./README.md
./Setup.hs
./src
./src/Httpare
./src/Httpare/Class.hs
./src/Main.hs
./.travis.yml
Installation
In Ubuntu you can install tree with apt-get.
$ sudo apt-get install tree
If you are on Mac OSX you should use brew to install your *nix software.
$ sudo brew install tree