env [OPTION]... [-] [NAME=VALUE]... [COMMAND [ARG]...]
Set each NAME to VALUE in the environment and run COMMAND.
-i, --ignore-environment
start with an empty environment
-0, --null
end each output line with 0 byte rather than newline
-u, --unset=NAME
remove variable from the environment
--help display this help and exit
--version
output version information and exit
A mere - implies -i. If no COMMAND, print the resulting environment.