Why is Unix useful in shell programming?

Answer 1

The shell is both a command language and a programming language that provides an interface to the UNIX operating system (Bourne, 1978).

The shell is the part of the operating system that the user interacts with, and is arguably the most important part of the operating system. Files can be created, renamed, moved and read from the shell. Computer hardware can be installed, used and removed through the shells. Program applications and scripting can be written, compiled, and ran through the shell.

Answer 2

There are several shell programs for Unix, not just one. That in itself is an advantage.

The shell environment can be customized, scripted (programmed), and extended very easily. If you don't like the way it is doing something it is fairly easy to change the behavior.

Answer 3

The shell is the interface between the user and the operating system. Without it a user could not do anything on the system.

Shell programming allows a user to extend, modify, etc., the behavior of the environment through the shell. In essence, it allows the user to add features and behaviors of their environment.

Shell programming also allows users to dynamically activate tasks in an attended or unattended mode, such as running production jobs at periodic intervals.

Answer 4

Because that is what "shell programming" is - writing programs for a Unix shell. No Unix, no shell.