Evaluate% x () to True or False in Ruby

Question

I am doing something like this:

$printer = %x(lpstat -p | grep -q "Eileen" && echo "true" || echo "nil").chomp

if $printer == "true"
  puts "do something here"
else
  puts "do something else"
end

Is there an easier / shorter way to do this? I just check if there is a print queue, and one thing needs to be done if this happens, and the other if it is not. Thank!

Answer 1

You can test the output if lpstat -p in ruby ​​script.

printer = %x(lpstat -p)

if printer =~ /Eileen/
  puts "do something here"
else
  puts "do something else"
end

PS: you may not need to use the global here - or even a variable:

  if %x(lpstat -p) =~ /Eileen/

Answer 2

if system 'lpstat -p | grep -q "Eileen"'
  puts "do something here"
else
  puts "do something else"
end

However, this will lead to the output of the command output to stdout. If you want to avoid this, you can do:

output = %x(lpstat -p | grep -q "Eileen")
if $?.success?
  puts "do something here"
else
  puts "do something else"
end