A shell script is a text file that contains a sequence of commands for a Unix-based operating system. It is called a script because it combines a sequence of commands-that would …

Script A text file containing a series of commands that an interpreter (like shell) can read and run.

It serves as a textbook, a manual for self-study, and as a reference and source of knowledge on shell scripting techniques. The exercises and heavily-commented examples invite active …

Shell scripts are executed line-by-line by the bash program. Therefore, the first step to learning Shell scripting is to write a proper bash program and make it executable.

We will now create a simple bash script named script1.sh that displays a two-line message on the screen. Then, make the file executable and, finally, execute the script.

Google’s Shell Style Guide says not to use it for programs of more than 100 lines. It is suited to solving problems that evolve from typing at the command prompt.

It is mostly used when we need the first command to modify the shell's environment (which is impossible if it is subshelled). For example, reading into a variable: read var < <(grep foo file).