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Diffstat (limited to 'contrib/perl5/lib/Env.pm')
-rw-r--r-- | contrib/perl5/lib/Env.pm | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/contrib/perl5/lib/Env.pm b/contrib/perl5/lib/Env.pm new file mode 100644 index 000000000000..b0afc3b2dbf5 --- /dev/null +++ b/contrib/perl5/lib/Env.pm @@ -0,0 +1,77 @@ +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<Env> 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<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 + + @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 $PATH; + +=head1 AUTHOR + +Chip Salzenberg E<lt>F<chip@fin.uucp>E<gt> + +=cut + +sub import { + my ($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; |