use Env; # import all possible variables use Env qw(PATH HOME TERM); # import only specified variables
Perl maintains environment variables in a pseudo-associative array
named
%ENV
. Since this access method is sometimes inconvenient,
the Env module allows environment variables to be treated as
simple variables.
The
Env::import()
routine ties environment variables to global Perl
variables with the same names. By default it ties suitable, existing
environment variables (that is, variables yielded by
keys %ENV
).
An environmental
variable is considered suitable if its name begins with an alphabetic
character, and if it consists of nothing but alphanumeric characters plus
underscore.
If you supply arguments when invoking
use Env
, they are taken to
be a list of environment variables to tie. It's OK if the variables
don't yet exist.
After an environment variable is tied, you can use it like a normal variable. You may access its value:
@path = split(/:/, $PATH);
or modify it any way you like:
$PATH .= ":.";
To remove a tied environment variable from the environment, make it the undefined value:
undef $PATH;
Note that the corresponding operation performed directly against
%ENV
is not
undef
, but
delete
:
delete $ENV{PATH};
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