Programming Ruby 3.3

Command Expressions

If you enclose a string in backquotes (sometimes called backticks) or use the delimited form %x{…}, the string will (by default) be executed as a command by your underlying operating system. The value returned is the standard output of that command. Newlines will not be stripped, so the value you get back will likely have a trailing return or linefeed character.

`date`                 # => "Thu Nov  2 17:16:02 CDT 2023\n"
`ls`.split[34]         # => "irb.md"
%x{echo "hello there"} # => "hello there\n"

You can use expression expansion and all the usual escape sequences in the command string:

0..3.each do |i|
  status = `dbmanager status id=#{i}`
  # ...
end

The exit status of the command is available in the global ...