Shell scripting is a computer program designed to be run by a Unix shell, which is a command-line interpreter. A shell script is a text file that contains a sequence of commands for a UNIX-based operating system. The shell is a special user program that provides an interface for the user to use operating system services. It accepts human-readable commands from users and converts them into something which the kernel can understand.
Shell scripts allow several commands that would be entered manually at a command-line interface to be executed automatically, and without having to wait for a user to trigger each stage of the sequence. They are used to automate repetitive tasks and processes, saving time and reducing the risk of errors that can occur with manual execution. Shell scripts can be run on various platforms and operating systems, including Unix, Linux, macOS, and even Windows through the use of emulators or virtual machines.
Shell scripts have several required constructs that tell the shell environment what to do and when to do it. They have syntax just like any other programming language, and functions that shell scripts support include loops, variables, if/then/else statements, arrays, and shortcuts. Once complete, the file is saved typically with a .txt or .sh extension and can be edited using any text editor.
