package Env; =head1 NAME Env - perl module that imports environment variables =head1 SYNOPSIS use Env; use Env qw(PATH HOME TERM); =head1 DESCRIPTION Perl maintains environment variables in a pseudo-hash named %ENV. For when this access method is inconvenient, the Perl module C allows 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 (C). 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 @path = split(/:/, $PATH); or modify it $PATH .= ":."; however you'd like. To remove a tied environment variable from the environment, assign it the undefined value undef $PATH; =head1 AUTHOR Chip Salzenberg EFE =cut sub import { my ($callpack) = caller(0); my $pack = shift; my @vars = grep /^[A-Za-z_]\w*$/, (@_ ? @_ : keys(%ENV)); return unless @vars; eval "package $callpack; use vars qw(" . join(' ', map { '$'.$_ } @vars) . ")"; die $@ if $@; foreach (@vars) { tie ${"${callpack}::$_"}, Env, $_; } } sub TIESCALAR { bless \($_[1]); } sub FETCH { my ($self) = @_; $ENV{$$self}; } sub STORE { my ($self, $value) = @_; if (defined($value)) { $ENV{$$self} = $value; } else { delete $ENV{$$self}; } } 1;