A shell script is a computer program designed to be run by the Unix/Linux shell which could be one of the following:
- The Bourne Shell
- The C Shell
- The Korn Shell
- The GNU Bourne-Again Shell
A shell is a command-line interpreter and typical operations performed by shell scripts include file manipulation, program execution, and printing text.
Extended Shell Scripts
Shell scripts have several required constructs that tell the shell environment what to do and when to do it. Of course, most scripts are more complex than the above one.
The shell is, after all, a real programming language, complete with variables, control structures, and so forth. No matter how complicated a script gets, it is still just a list of commands executed sequentially.
The following script uses the read command which takes the input from the keyboard and assigns it as the value of the variable PERSON and finally prints it on STDOUT.
#!/bin/sh # Author : Zara Ali # Copyright (c) Shout4Education # Script follows here: echo "What is your name?" read PERSON echo "Hello, $PERSON"
Here is a sample run of the script −
$./test.sh What is your name? Zara Ali Hello, Zara Ali
Subsequent part of this tutorial will cover Unix/Linux Shell Scripting in detail.