Question

If we can perform this in Perl It would be fine as well.
I don’t know if this is even possible but this is what i want to be able to do. I am trying to get a memory percentage of memory being used (There may be better ways of doing this, please let me know)

I have this bash command

free -m | grep "Mem: " | awk '{print ($3/$2)*100}' 

This will return a number, but what I want to do is set a variable to the output of the command.

So var1= Output of the above command

Answer 1

I believe this is what you are looking for:

var1=$(free -m | grep "Mem: " | awk '{print ($3/$2)*100}')

Explanation:

• The $(...) syntax is called command substitution in shell.
• It spawns a subshell to execute whatever is inside the parentheses, then returns anything printed out to stdout within that subshell.

Aside:

The alternative syntax is with backticks:

var1=`free -m | grep "Mem: " | awk '{print ($3/$2)*100}')`

but it’s not the preferred method due to readability and nesting issues.