Shell
Shell
A shell is a user interface for access to an operating system's services. In general, operating system shells use either a command-line interface (CLI) or graphical user interface (GUI), depending on a computer's role and particular operation. It is named a shell because it is an outer layer of interface between the user and the innards of the operating system (the kernel).
Types of Shells[edit]
Command-Line Interface (CLI)[edit]
A command-line interface (CLI) is a text-based user interface used to view and manage computer files. Examples of CLI shells include the Bourne shell (sh), the C shell (csh), the Korn shell (ksh), and the Bourne Again shell (bash).
Graphical User Interface (GUI)[edit]
A graphical user interface (GUI) shell provides a graphical means of interacting with the operating system. Examples include the Windows Shell, the GNOME Shell, and the KDE Plasma Shell.
Functions of a Shell[edit]
Shells provide several functions, including:
- Command interpretation: Interpreting and executing user commands.
- Scripting: Writing and executing scripts to automate tasks.
- Job control: Managing multiple tasks within a single shell session.
- File manipulation: Navigating and manipulating the file system.
Popular Shells[edit]
- Bourne shell (sh)
- C shell (csh)
- Korn shell (ksh)
- Bourne Again shell (bash)
- Z shell (zsh)
- Friendly Interactive Shell (fish)
Shell Scripting[edit]
Shell scripting is writing a series of commands for the shell to execute. It is commonly used for task automation, program execution, and file manipulation. Shell scripts are typically written in a text editor and saved with a .sh extension.
