In this article, we are going to create a config file and use it in our shell script.

Prerequisites

Besides having a terminal open, you need basic knowledge of creating scripts and config files.

Write script

Now, we are going to create a script and config file. The extension of the configuration file is .conf. Create a script called sample_script.sh and write this code in it:

sample_script.sh

#!/bin/bash 
typeset -A config 
config=( 
	[username]="student" 
	[password]="" 
	[hostname]="ubuntu" 
) 
while read line 
do 
	if echo $line | grep -F = &>/dev/null 
	then 
		varname=$(echo "$line" | cut -d '=' -f 1) 
		config[$varname]=$(echo "$line" | cut -d '=' -f 2-) 
	fi 
done < sampleconfig.conf 
echo ${config[username]} 
echo ${config[password]} 
echo ${config[hostname]} 
echo ${config[PROMPT_COMMAND]}

We will now create a configuration file. Create a file called sampleconfig.conf and write the following code in it:

password=training 
echo rm -rf / 
PROMPT_COMMAND='ls -l' 
hostname=ubuntu; echo rm -rf /

How script works

After running the script username, password, and hostname, it will display the command we mentioned in  PROMPT_COMMAND.