Envallows environment variables to be treated as simple variables.
The Env::import() function ties environment variables with suitable
names to global Perl variables with the same names. By default it
does so with all existing environment variables (
keys %ENV). If
the import function receives arguments, it takes them to be a list of
environment variables to tie; it's okay if they don't yet exist.
After an environment variable is tied, merely use it like a normal variable. You may access its value
or modify it
however you'd like. To remove a tied environment variable from the environment, assign it the undefined value