This crate would feel especially natural if we had "f-strings", see https://crates.io/crates/fstrings/

We could probably copy in that crate's code...the only thing we need to do is insert shell quotation. Perhaps we could extend the crate's macros to add something like f_mapped!(crate::internals::command_arg, $fmt, ...).