Commit | Line | Data |
---|---|---|
a0d0e21e LW |
1 | package Env; |
2 | ||
3 | =head1 NAME | |
4 | ||
cb1a09d0 AD |
5 | Env - perl module that imports environment variables |
6 | ||
7 | =head1 SYNOPSIS | |
8 | ||
9 | use Env; | |
10 | use Env qw(PATH HOME TERM); | |
a0d0e21e LW |
11 | |
12 | =head1 DESCRIPTION | |
13 | ||
14 | Perl maintains environment variables in a pseudo-associative-array | |
15 | named %ENV. For when this access method is inconvenient, the Perl | |
16 | module C<Env> allows environment variables to be treated as simple | |
17 | variables. | |
18 | ||
19 | The Env::import() function ties environment variables with suitable | |
20 | names to global Perl variables with the same names. By default it | |
21 | does so with all existing environment variables (C<keys %ENV>). If | |
22 | the import function receives arguments, it takes them to be a list of | |
23 | environment variables to tie; it's okay if they don't yet exist. | |
24 | ||
25 | After an environment variable is tied, merely use it like a normal variable. | |
26 | You may access its value | |
27 | ||
28 | @path = split(/:/, $PATH); | |
29 | ||
30 | or modify it | |
31 | ||
32 | $PATH .= ":."; | |
33 | ||
34 | however you'd like. | |
35 | To remove a tied environment variable from | |
36 | the environment, assign it the undefined value | |
37 | ||
38 | undef $PATH; | |
39 | ||
40 | =head1 AUTHOR | |
41 | ||
42 | Chip Salzenberg <chip@fin.uucp> | |
43 | ||
44 | =cut | |
45 | ||
46 | sub import { | |
47 | my ($callpack) = caller(0); | |
48 | my $pack = shift; | |
49 | my @vars = @_ ? @_ : keys(%ENV); | |
50 | ||
51 | foreach (@vars) { | |
52 | tie ${"${callpack}::$_"}, Env, $_ if /^[A-Za-z_]\w*$/; | |
53 | } | |
54 | } | |
55 | ||
56 | sub TIESCALAR { | |
57 | bless \($_[1]); | |
58 | } | |
59 | ||
60 | sub FETCH { | |
61 | my ($self) = @_; | |
62 | $ENV{$$self}; | |
63 | } | |
64 | ||
65 | sub STORE { | |
66 | my ($self, $value) = @_; | |
67 | if (defined($value)) { | |
68 | $ENV{$$self} = $value; | |
69 | } else { | |
70 | delete $ENV{$$self}; | |
71 | } | |
72 | } | |
73 | ||
74 | 1; |