1Unicode::UTF8(3) User Contributed Perl Documentation Unicode::UTF8(3)
2
6 Unicode::UTF8 - Encoding and decoding of UTF-8 encoding form
7
9 use Unicode::UTF8 qw[decode_utf8 encode_utf8];
10 use warnings FATAL => 'utf8'; # fatalize encoding glitches
12 $string = decode_utf8($octets);
13 $octets = encode_utf8($string);
14
16 This module provides functions to encode and decode UTF-8 encoding form
17 as specified by Unicode and ISO/IEC 10646:2011.
18
20 decode_utf8
21 $string = decode_utf8($octets);
22 $string = decode_utf8($octets, $fallback);
23 Returns an decoded representation of $octets in UTF-8 encoding as a
25 character string.
26 $fallback is an optional "CODE" reference which provides a error-
28 handling mechanism, allowing customization of error handling. The
29 default error-handling mechanism is to replace any ill-formed UTF-8
30 sequences or encoded code points which can't be interchanged with
31 REPLACEMENT CHARACTER (U+FFFD).
32 $string = $fallback->($octets, $is_usv, $position);
34 $fallback is invoked with three arguments: $octets, $is_usv and
36 $position. $octets is a sequence of one or more octets containing the
37 maximal subpart of the ill-formed subsequence or encoded code point
38 which can't be interchanged. $is_usv is a boolean indicating whether or
39 not $octets represent a encoded Unicode scalar value. $position is a
40 unsigned integer containing the zero based octet position at which the
41 error occurred within the octets provided to decode_utf8(). $fallback
42 must return a character string consisting of zero or more Unicode
43 scalar values. Unicode scalar values consist of code points in the
44 range U+0000..U+D7FF and U+E000..U+10FFFF.
45 encode_utf8
47 $octets = encode_utf8($string);
48 $octets = encode_utf8($string, $fallback);
49 Returns an encoded representation of $string in UTF-8 encoding as an
51 octet string.
52 $fallback is an optional "CODE" reference which provides a error-
54 handling mechanism, allowing customization of error handling. The
55 default error-handling mechanism is to replace any code points which
56 can't be interchanged or represented in UTF-8 encoding form with
57 REPLACEMENT CHARACTER (U+FFFD).
58 $string = $fallback->($codepoint, $is_usv, $position);
60 $fallback is invoked with three arguments: $codepoint, $is_usv and
62 $position. $codepoint is a unsigned integer containing the code point
63 which can't be interchanged or represented in UTF-8 encoding form.
64 $is_usv is a boolean indicating whether or not $codepoint is a Unicode
65 scalar value. $position is a unsigned integer containing the zero
66 based character position at which the error occurred within the string
67 provided to encode_utf8(). $fallback must return a character string
68 consisting of zero or more Unicode scalar values.Unicode scalar values
69 consist of code points in the range U+0000..U+D7FF and
70 U+E000..U+10FFFF.
71 valid_utf8
73 $boolean = valid_utf8($octets);
74 Returns a boolean indicating whether or not the given $octets consist
76 of well-formed UTF-8 sequences.
77
79 None by default. All functions can be exported using the ":all" tag or
80 individually.
81
83 Can't decode a wide character string
84 (F) Wide character in octets.
85 Can't validate a wide character string
87 (F) Wide character in octets.
88 Can't decode ill-formed UTF-8 octet sequence <%s> in position %u
90 (W utf8) Encountered an ill-formed UTF-8 octet sequence. <%s>
91 contains a hexadecimal representation of the maximal subpart of the
92 ill-formed subsequence.
93 Can't interchange noncharacter code point U+%X in position %u
95 (W utf8, nonchar) Noncharacters are code points that are
96 permanently reserved in the Unicode Standard for internal use. They
97 are forbidden for use in open interchange of Unicode text data.
98 Noncharacters consist of the values U+nFFFE and U+nFFFF (where n is
99 from 0 to 10^16) and the values U+FDD0..U+FDEF.
100 Can't represent surrogate code point U+%X in position %u
102 (W utf8, surrogate) Surrogate code points are designated only for
103 surrogate code units in the UTF-16 character encoding form.
104 Surrogates consist of code points in the range U+D800 to U+DFFF.
105 Can't represent super code point \x{%X} in position %u
107 (W utf8, non_unicode) Code points greater than U+10FFFF. Perl's
108 extended codespace.
109 Can't decode ill-formed UTF-X octet sequence <%s> in position %u
111 (F) Encountered an ill-formed octet sequence in Perl's internal
112 representation of wide characters.
113 The sub-categories: "nonchar", "surrogate" and "non_unicode" is only
115 available on Perl 5.14 or greater. See perllexwarn for available
116 categories and hierarchies.
117
119 Here is a summary of features for comparison with Encode's UTF-8
120 implementation:
121 • Simple API which makes use of Perl's standard warning categories.
123 • Recognizes all noncharacters regardless of Perl version
125 • Implements Unicode's recommended practice for using U+FFFD.
127 • Better diagnostics in warning messages
129 • Detects and reports inconsistency in Perl's internal representation
131 of wide characters (UTF-X)
132 • Preserves taintedness of decoded $octets or encoded $string
134 • Better performance ~ 600% - 1200% (JA: 600%, AR: 700%, SV: 900%,
136 EN: 1200%, see benchmarks directory in git repository)
137
139 It's the author's belief that this UTF-8 implementation is conformant
140 with the Unicode Standard Version 6.0. Any deviations from the Unicode
141 Standard is to be considered a bug.
142
144 Encode
145 <http://www.unicode.org/>
146
148 BUGS
149 Please report any bugs by email to "bug-unicode-utf8 at rt.cpan.org",
150 or through the web interface at
151 <http://rt.cpan.org/Public/Dist/Display.html?Name=Unicode-UTF8>. You
152 will be automatically notified of any progress on the request by the
153 system.
154 SOURCE CODE
156 This is open source software. The code repository is available for
157 public review and contribution under the terms of the license.
158 <http://github.com/chansen/p5-unicode-utf8>
160 git clone http://github.com/chansen/p5-unicode-utf8
162
164 Christian Hansen "chansen@cpan.org"
165
167 Copyright 2011-2017 by Christian Hansen.
168 This is free software; you can redistribute it and/or modify it under
170 the same terms as the Perl 5 programming language system itself.
171perl v5.38.0 2023-07-21 Unicode::UTF8(3)