8 Terminal Commands Every Web Developer Should Know About

The terminal is one of the most important productivity tools in a developer’s arsenal. Mastering it can have a very positive effect on your workflow, as many everyday tasks get reduced to writing a simple command and hitting Enter.

In this article we’ve prepared for you a collection of Unix commands that will help you get the most out of your terminal. Some of them are built in, others are free tools that are time-tested and can be installed in less than a minute.

Curl

Curl is a command line tool for making requests over HTTP(s), FTP and dozens of other protocols you may have not heard about. It can download files, check response headers, and freely access remote data.

In web development curl is often used for testing connections and working with RESTful APIs.

# Fetch the headers of a URL.
curl -I http://google.com
HTTP/1.1 302 Found
Cache-Control: private
Content-Type: text/html; charset=UTF-8
Referrer-Policy: no-referrer
Location: http://www.google.com/?gfe_rd=cr&ei=0fCKWe6HCZTd8AfCoIWYBQ
Content-Length: 258
Date: Wed, 09 Aug 2017 11:24:01 GMT

# Make a GET request to a remote API.
curl http://numbersapi.com/random/trivia
29 is the number of days it takes Saturn to orbit the Sun.

Curl commands can get much more complicated than this. There are tons of options for controlling headers, cookies, authentication, and more.

Tree

Tree is a tiny command line utility that shows you a visual representation of the files in a directory. It works recursively, going over each level of nesting and drawing a formated tree of all the contents. This way you can quickly glance over and find the files you are looking for.

tree
.
├── css
│   ├── bootstrap.css
│   ├── bootstrap.min.css
├── fonts
│   ├── glyphicons-halflings-regular.eot
│   ├── glyphicons-halflings-regular.svg
│   ├── glyphicons-halflings-regular.ttf
│   ├── glyphicons-halflings-regular.woff
│   └── glyphicons-halflings-regular.woff2
└── js
    ├── bootstrap.js
    └── bootstrap.min.js

There is also the option to filter the results using a simple regEx-like pattern:

tree -P '*.min.*'
.
├── css
│   ├── bootstrap.min.css
├── fonts
└── js
    └── bootstrap.min.js

Tmux

According to its Wiki, Tmux is a terminal multiplexer, which translated in human language would mean that it’s a tool for connecting multiple terminals to a single terminal session.

It lets you switch between programs in one terminal, add split screen panes, and attach multiple terminals to the same session, keeping them in sync. Tmux is especially useful when working on a remote server, as it lets you create new tabs without having to log in again.

Disk usage – du

The du command generates reports on the space usage of files and directories. It is very easy to use and can work recursively, going through each subdirectory and returning the individual size of every file.

A common use case for du is when one of your drives is running out of space and you don’t know why. Using this command you can quickly see how much storage each folder is taking, thus finding the biggest memory hoarder.

# Running this will show the space usage of each folder in the current directory.
# The -h option makes the report easier to read.
# -s prevents recursiveness and shows the total size of a folder.
# The star wildcard (*) will run du on each file/folder in current directory.

du -sh *

1.2G    Desktop
4.0K    Documents
40G     Downloads
4.0K    Music
4.9M    Pictures
844K    Public
4.0K    Templates
6.9M    Videos

There is also a similar command called df (Disk Free) which returns various information about the available disk space (the opposite of du).

Git

Git is by far the most popular version control system right now. It is one of the defining tools of modern web dev and we just couldn’t leave it out of our list.

There are plenty of third-party apps and tools available but most people prefer to access git natively though the terminal. The git CLI is really powerful and can handle even the most tangled project history.

If you want to learn more about git, we recommend checking out our tutorial Learn Git in 30 Minutes.

Tar

Tar is the default Unix tool for working with file archives. It allows you to quickly bundle multiple files into one package, making it easier to store and move them later on.

tar -cf archive.tar file1 file2 file3

Using the -x option it can also extract existing .tar archives.

tar -xf archive.tar

Note that most other formats such as .zip and .rar cannot be opened by tar and require other command utilities such as unzip.

Many modern Unix systems run an expanded version of tar (GNU tar) that can also perform file size compression:

# Create compressed gzip archive. tar -czf file.tar.gz inputfile1 inputfile2 # Extract .gz archive. tar -xzf file.tar.gz

If your OS doesn’t have that version of tar, you can use gzip, zcat or compress to reduce the size of file archives.

md5sum

Unix has several built in hashing commands including md5sum, sha1sum and others. These command line tools have various applications in programming, but most importantly they can be used for checking the integrity of files.

For example, if you have downloaded an .iso file from an untrusted source, there is some chance that the file contains harmful scripts. To make sure the .iso is safe, you can generate an md5 or other hash from it.

md5sum ubuntu-16.04.3-desktop-amd64.iso 

0d9fe8e1ea408a5895cbbe3431989295  ubuntu-16.04.3-desktop-amd64.iso

You can then compare the generated string to the one provided from the original author (e.g. UbuntuHashes).

Htop

Htop is a more powerful alternative to the built-in top task manager. It provides an advanced interface with many options for monitoring and controlling system processes.

Although it runs in the terminal, htop has very good support for mouse controls. This makes it much easier to navigate the menus, select processes, and organize the tasks thought sorting and filtering.