The language has a special command $ to run applications and operating system commands with the specified parameters. The script takes the entire line up to the newline character and execute it. There must be a space between the $ and the command line. If this command is used in an expression, it captures the standard output and returns it as a string. Otherwise, the standard output will be visible in the console. You can specify expressions with %{Expression} as in a backquoted string. If any parameter contains a space, enclose that parameter in any quotes - "a b", 'c d', `e f`. If the executable application or command terminates with an error code other than zero, the script will also stop working and return an error.