Missing key appears in the text

[ezaton]

I have a script with some variables which might be in use. For example - I might have 'Connection-UserAgent'. If I do, the script runs correctly, however, if I don't, I will get the following command output:
/usr/bin/sudo /usr/sbin/openconnect {s:Connection-UserAgent}
So handling of a missing key will not leave it empty.

This could affect a standardised condition of 'if a key exists, use it, or else leave empty', with currently missing if/then options in the language (without complex constructs of one-line-shell-handling all possible conditions).

Thanks!