Env(3pm) Perl Programmers Reference Guide Env(3pm)

# [NAME](#NAME)

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

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#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](#LIMITATIONS)

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

# [AUTHOR](#AUTHOR)

Chip Salzenberg <*chip@fin.uucp*> and Gregor N. Purdy <*gregor@focusresearch.com*>

2026-10-21 perl v5.44.0

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Document: Env(3pm) from perl 5.44.0-r2 (Chainguard OS)
Source: https://github.com/Perl/perl5.git