I'm investigating the behaviour of a script that is normally run as an automated process (e.g. cron, Jenkins). The script can (eventually) invoke commands that behave differently (seeking user input) when run interactively; for example,
patch will ask what to do with a reversed patch, and
svn will ask for passwords, but I need to see what happens when they're run non-interactively.
patch that it's non-interactive is fairly easy; I just need to redirect
stdout to be a non-tty:
$ </dev/null > >(cat) /path/to/myscript --args
svn will connect to the controlling terminal if it exists; editing the scripts to pass
--non-interactive isn't really an option as this is coming from several levels deep and it'd be difficult to be certain I'd found every invocation.
Is there a way to invoke a script/command non-interactively, without a controlling terminal (so that
/dev/tty doesn't exist)? I'd prefer stdout/stderr to still go to my terminal.
(I found the question Run script in a non interactive shell? but the answers to that discuss the differences between the cron and user environment; I've already eliminated all differences except non-interactivity.)