List or Set environment variables and optionally run a utility
Syntax env [-i] [name=value ...] [utility [argument ...]]
env executes utility after modifying the environment as specified on the command line.
The option name=value specifies an environmental variable, name, with a value of value.
The option `-i' causes env to completely ignore the environment it inherits.
If no utility is specified, env prints out the names and
values of the variables in the environment, with one name=value pair per line.
This is the same as running printenv.
"Each time we changed our environment, our environment changed our behavior, and our new behavior demanded a new environment" ~ Laurence J. Peter
env man page - Apple.com
set - Set a variable