---
name: "base"
section: "3p"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/base/3p"
---

# base(3p)

Establish an ISA relationship with base classes at compile time

## NAME

base - Establish an ISA relationship with base classes at compile time

## SYNOPSIS

```
    package Baz;
    use base qw(Foo Bar);
```

## DESCRIPTION

Unless you are using the `"fields"` pragma, consider this module discouraged in favor of the lighter-weight `"parent"`.

Allows you to both load one or more modules, while setting up inheritance from those modules at the same time.  Roughly similar in effect to

```
    package Baz;
    BEGIN {
        require Foo;
        require Bar;
        push @ISA, qw(Foo Bar);
    }
```

When `"base"` tries to `"require"` a module, it will not die if it cannot find the module's file, but will die on any other error.  After all this, should your base class be empty, containing no symbols, `"base"` will die. This is useful for inheriting from classes in the same file as yourself but where the filename does not match the base module name, like so:

```
        # in Bar.pm
        package Foo;
        sub exclaim { "I can have such a thing?!" }
        package Bar;
        use base "Foo";
```

There is no *Foo.pm*, but because `"Foo"` defines a symbol (the `"exclaim"` subroutine), `"base"` will not die when the `"require"` fails to load *Foo.pm*.

`"base"` will also initialize the fields if one of the base classes has it. Multiple inheritance of fields is **NOT** supported, if two or more base classes each have inheritable fields the 'base' pragma will croak. See fields for a description of this feature.

The base class' `"import"` method is **not** called.

## DIAGNOSTICS

- Base class package "%s" is empty.

  base.pm was unable to require the base package, because it was not found in your path.

- Class 'Foo' tried to inherit from itself

  Attempting to inherit from yourself generates a warning.

  ```
      package Foo;
      use base 'Foo';
  ```

## HISTORY

This module was introduced with Perl 5.004\_04.

## CAVEATS

Due to the limitations of the implementation, you must use base *before* you declare any of your own fields.

## SEE ALSO

fields