Config::Extensions(3pm) Perl Programmers Reference Guide Config::Extensions(3pm)

# [NAME](#NAME)

Config::Extensions - hash lookup of which core extensions were built.

# [SYNOPSIS](#SYNOPSIS)

```
    use Config::Extensions '%Extensions';
    if ($Extensions{PerlIO::via}) {
        # This perl has PerlIO::via built
    }
```

# [DESCRIPTION](#DESCRIPTION)

The Config::Extensions module provides a hash %Extensions containing all the core extensions that were enabled for this perl. The hash is keyed by extension name, with each entry having one of 3 possible values:

[dynamic](#dynamic)

The extension is dynamically linked

[nonxs](#nonxs)

The extension is pure perl, so doesn't need linking to the perl executable

[static](#static)

The extension is statically linked to the perl binary

As all values evaluate to true, a simple "if" test is good enough to determine whether an extension is present.

All the data uses to generate the %Extensions hash is already present in the "Config" module, but not in such a convenient format to quickly reference.

# [AUTHOR](#AUTHOR)

Nicholas Clark <nick@ccl4.org>

2026-08-31 perl v5.44.0

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Document: Config::Extensions(3pm) from perl 5.44.0-r1 (Chainguard OS)
Source: https://github.com/Perl/perl5.git