PerlIO::utf8\_strict(3) User Contributed Perl Documentation PerlIO::utf8\_strict(3)

# [NAME](#NAME)

PerlIO::utf8\_strict - Fast and correct UTF-8 IO

# [VERSION](#VERSION)

version 0.010

# [SYNOPSIS](#SYNOPSIS)

```
 open my $fh, '<:utf8_strict', $filename;
```

# [DESCRIPTION](#DESCRIPTION)

This module provides a fast and correct UTF-8 PerlIO layer. Unlike perl's default ":utf8" layer it checks the input for correctness.

# [LAYER ARGUMENTS](#LAYER_ARGUMENTS)

[allow\_noncharacters](#allow_noncharacters)

[allow\_surrogates](#allow_surrogates)

# [EXPORT](#EXPORT)

PerlIO::utf8\_strict exports no subroutines or symbols, just a perl layer "utf8\_strict"

# [DIAGNOSTICS](#DIAGNOSTICS)

[Can't decode ill-formed UTF-8 octet sequence &lt;%s&gt;](#Can)

(F) Encountered an ill-formed UTF-8 octet sequence. &lt;%s&gt; contains a hexadecimal representation of the maximal subpart of the ill-formed subsequence.

[Can't interchange noncharacter code point U+%.4X](#Can~2)

(F) Noncharacters is permanently reserved for internal use and that should never be interchanged. Noncharacters consist of the values U+nFFFE and U+nFFFF (where n is from 0 to 10^16) and the values U+FDD0..U+FDEF.

# [AUTHORS](#AUTHORS)

- Leon Timmermans &lt;leont@cpan.org&gt;
- Christian Hansen &lt;chansen@cpan.org&gt;

# [COPYRIGHT AND LICENSE](#COPYRIGHT_AND_LICENSE)

This software is copyright (c) 2012 by Leon Timmermans, Christian Hansen.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

2026-10-24 perl v5.44.0

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Document: PerlIO::utf8_strict(3pm) from perl-perlio-utf8-strict 0.010-r4 (Chainguard OS)
Source: https://cpan.metacpan.org/authors/id/L/LE/LEONT/PerlIO-utf8_strict-0.010.tar.gz