Commands:
-l, --list list variables (default).
-L, --list-known list valid architectures (matching some criteria).
-e, --equal <arch> compare with host Debian architecture.
-i, --is <arch-wildcard> match against host Debian architecture.
-q, --query <variable> prints only the value of <variable>.
-s, --print-set print command to set environment variables.
-u, --print-unset print command to unset environment variables.
-c, --command <command> set environment and run the command in it.
-?, --help show this help message.
--version show the version.
