Env - phpMan

NAME
    Env - perl module that imports environment variables as scalars or
    arrays

SYNOPSIS
        use Env;
        use Env qw(PATH HOME TERM);
        use Env qw($SHELL @LD_LIBRARY_PATH);

DESCRIPTION
    Perl maintains environment variables in a special hash named %ENV. For
    when this access method is inconvenient, the Perl module "Env" allows
    environment variables to be treated as scalar or array variables.

    The "Env::import()" function ties environment variables with suitable
    names to global Perl variables with the same names. By default it ties
    all existing environment variables ("keys %ENV") to scalars. If the
    "import" function receives arguments, it takes them to be a list of
    variables to tie; it's okay if they don't yet exist. The scalar type
    prefix '$' is inferred for any element of this list not prefixed by '$'
    or '@'. Arrays are implemented in terms of "split" and "join", using
    $Config::Config{path_sep} as the delimiter.

    After an environment variable is tied, merely use it like a normal
    variable. You may access its value

        @path = split(/:/, $PATH);
        print join("\n", @LD_LIBRARY_PATH), "\n";

    or modify it

        $PATH .= ":/any/path";
        push @LD_LIBRARY_PATH, $dir;

    however you'd like. Bear in mind, however, that each access to a tied
    array variable requires splitting the environment variable's string
    anew.

    The code:

        use Env qw(@PATH);
        push @PATH, '/any/path';

    is almost equivalent to:

        use Env qw(PATH);
        $PATH .= ":/any/path";

    except that if $ENV{PATH} started out empty, the second approach leaves
    it with the (odd) value "":/any/path"", but the first approach leaves it
    with ""/any/path"".

    To remove a tied environment variable from the environment, assign it
    the undefined value

        undef $PATH;
        undef @LD_LIBRARY_PATH;

LIMITATIONS
    On VMS systems, arrays tied to environment variables are read-only.
    Attempting to change anything will cause a warning.

AUTHOR
    Chip Salzenberg <chip AT fin.uucp> and Gregor N. Purdy
    <gregor AT focusresearch.com>