title: How can pass the value of a variable to the standard input of a command?
body: <p>I'm writing a shell script that should be somewhat secure, i.e., does not pass secure data through parameters of commands and preferably does not use temporary files. How can I pass a variable to the standard input of a command?</p>
  <p>Or, if it's not possible, how can I correctly use temporary files for such a task?</p>