List out all the Shells Using Linux Commands

When you're operating out of a Linux environment, the shell is your primary tool for interacting with the OS. It's your command interpreter — it translates what you type into what the OS can interpret and carry out. From basic operations like looking at files to running complex scripts, the shell makes it all possible.

Linux can accommodate other shells beyond its default Bash shell, such as Zsh, Fish, and Dash. They each have different characteristics, performances, and customizability. Bash, for example, scripts robustly, Zsh has excellent auto-suggestions, whereas Fish is suited for beginners.

What Are Linux Shells

A shell in Linux is similar to your computer's "interpreter" – it takes your typed commands (like ls, cd, or mkdir) and interprets them for the operating system to execute. It's mostly how users interact with Linux systems through the command line interface (CLI). Some of the most widely used Linux shells are:

• Bash (Bourne Again Shell) – Most Linux distributions like Ubuntu, Debian, and Fedora's default shell.
• Zsh (Z Shell) – Smart autocompletion and default in macOS.
• Fish (Friendly Interactive Shell) – New, friendly shell with built-in help and syntax highlighting.

For More details refer Different Shells in Linux

Method 1: Using cat command

In this it displays a list of all valid login shells available on your Linux system and also shows full shell paths like /bin/bash, /usr/bin/zsh, etc

Example:

cat /etc/shells

The list of all the shells which are currently installed in our Linux system is stored in the 'shells' file which is present in /etc folder of the system. It has read-only access by default and is modified automatically whenever we install a new shell in our system. As we can see, the cat command displays the various installed shells along with their installation paths.

Method 2: Use of grep command with Regular Expressions.

It skips all the comment lines (starting with #) in the /etc/shells file and only shows the active shells that your system recognizes.

Example:

grep '^[^#]' /etc/shells

Method 3: Explore the /usr/bin/ Directory

It lists all files in /usr/bin/ ending with “sh and also helpful to see lesser-known shells like dash, csh, or any custom ones and also helpful for to see lesser-known shells like dash, csh, or any custom ones.

Example:

ls /usr/bin/ | grep 'sh$'

Method 4: Use which to Check Specific Shells

It Tells you the exact installation path of each specified shell (if installed).

which bash zsh fish

Shell Comparison Table

Choosing the right shell can improve your productivity, script performance, and overall experience. While Bash is the most widely used shell, alternatives like Zsh, Fish, and Dash offer unique features and use cases.

Conclusion

Knowing the various Linux shells that are running on your system puts you in control, flexible, and performing better. From cat /etc/shells to inquiring with which, each facilitates your knowing what shells are enabled and where they reside. Programs such as grep and viewing /usr/bin/ make it simple to look deeper.

Knowing the differences between shells such as Bash, Zsh, Fish, and Dash allows you to choose the appropriate one for your requirements — whether it's automation, usability, or performance. Knowing your environment is the first step towards being more productive on Linux.