pub fn systemd_argument(value: &str) -> Result<String>Expand description
Quote a value as one argument in a systemd unit directive.
systemd splits a command line on whitespace unless the word is quoted, and
inside a double-quoted word it honours C-style backslash escapes — so both
\ and " must be escaped. Specifier expansion (%h, %i, …) happens
regardless of quoting, so % is doubled to keep it literal.