How to select a row using shell scripting?

Question

Consider the below example:

Parameter1 = 5
Parameter2 = 10
Parameter3 = 15
Parameter4 = 20

I want to fetch the value depending on the parameter name by providing a user input as shown below:

echo ""
echo " Enter the parameter name"
read value
Parameter = "$value"

Check if the parameter is existing within the concern file

if grep -qs "$Parameter" "Filename"
then 
    echo " Parameter exist within the concern file"
    val = #Here I want to fetch the value of the parameter that the user had input and I do not know how to do it? 

Kindly let me know how I can fetch the value of the parameter which the user had given as input.

Answer 1

If I understand you correctly, you could use something like this:

read param_name # e.g. Parameter2
value=$(awk -v param="$param_name" '$1 == param { print $3 }' filename)

This reads the name of the parameter then prints the third field on the line when the first field matches the name. The result is assigned to the shell variable $value .