Shells in Linux
What is Shell?
Shell is a command-line interpreter in Linux that provides a
user interface for interacting with the operating system. It
basically interprets the commands entered by the user and
executes them by interacting with the system's kernel to
perform the tasks initiated by users. Shells are a very
important component of the Linux environment, allowing users
to run commands, write scripts, and manage the system
efficiently.
It has some key concepts like "User Interface", "Command
Execution", "Command-Line Editing", "Scripting", "Job-Control",
"Environment Variables" etc.
In Linux, There are various types of shells. Below are commonly
used shells.
Bash (Bourne Again SHell)
1. Bash (Bourne Again SHell): Bash is one of the most widely
used shells in Linux environment and serves as the default
shell for many distributions. It is an extended version of the
original Bourne Shell (sh) with lot of added features and
incorporates from other shells, such as command-line editing,
history, and job control.
Features:
Command-line editing with history.
Customizable prompts.
Job control (background and foreground processes).
It has Scripting support.
Lot of customization can be done through configuration files.
Zsh (Z Shell)
2. Zsh (Z Shell): Zsh is an interactive shell with powerful
features and extensive customization options. It is basically
designed to be user-friendly and provides advanced level of
command-line editing, plugins, and theming.
Features:
Programmable completion system.
Advanced command-line editing (vi and emacs modes).
Extensive plugin architecture.
A Improved scripting capabilities.
Theming and customization options.
Ksh (KornShell)
3. Ksh (KornShell): Ksh is a powerful shell that originated as
an extension of the Bourne Shell. It is famous for advanced
scripting capabilities and interactive features.
Features:
Arithmetic operations.
Powerful scripting features.
Customizable prompts.
Command-line editing and history.
Job control.
Csh (C Shell) and Tcsh
4. Csh (C Shell) and Tcsh: Csh and Tcsh are shells known for
their C-like syntax and interactive features. Tcsh is an
enhanced version of Csh with additional features.
Features:
Command-line editing and history.
It has C-like syntax.
Job control.
Customizable prompts.
Scripting support.
Fish: Fish (Friendly Interactive SHell)
5. Fish: Fish (Friendly Interactive SHell): is known for its
user-friendly and interactive features. It focuses on
simplicity and discoverability, making it suitable for users
who are new to the command line.
Features:
User-friendly prompts.
Syntax highlighting and autocompletion.
Autosuggestions for commands.
Comprehensive help system.
Dash
6. Dash: Dash is a lightweight POSIX-compliant shell designed
for efficiency and fast script execution. It is often used as
the default /bin/sh on some systems for script execution.
Features:
Simple and minimalistic design.
POSIX-compliant scripting.
Fast execution.
Suitable for system initialization scripts.