How do i use functions in bash shell scripts?
-
Functions help organise related task into a block of code. Functions can exist in a shell environment and in a shell script.
Here's an example of a function within a shell script called
functionscript.sh
.#!/bin/bash show_status() { echo "Who is on the system" who echo "How long has the system been up" uptime } show_status
When you run the script:
$ ./functionscript.sh trainer :1 2017-09-01 08:04 (:1) How long has the system been up 18:33:06 up 19:58, 1 user, load average: 0.46, 0.67, 0.42
Line number 1
Is the name of the function followed by open/close parenthesis, followed by an open left curly bracket.Line numbers 3 - 6
Is the block code, what you need the function to do.Line number 7
Closes the function with a right curly bracket.Line number 9
Is the name of the function, which executes the function.Notes:
curly brackets are also known as curly braces
Some users also define line number one as:function show_status { code }
It is more common to use the format as per the example.
© Lightnetics 2024