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a0ed51b3 LW |
1 | package utf8; |
2 | ||
d5448623 GS |
3 | $utf8::hint_bits = 0x00800000; |
4 | ||
a04477f8 | 5 | our $VERSION = '1.19'; |
b75c8c73 | 6 | |
a0ed51b3 | 7 | sub import { |
d5448623 | 8 | $^H |= $utf8::hint_bits; |
a0ed51b3 LW |
9 | } |
10 | ||
11 | sub unimport { | |
d5448623 | 12 | $^H &= ~$utf8::hint_bits; |
a0ed51b3 LW |
13 | } |
14 | ||
15 | sub AUTOLOAD { | |
16 | require "utf8_heavy.pl"; | |
daf4d4ea | 17 | goto &$AUTOLOAD if defined &$AUTOLOAD; |
bd7017d3 | 18 | require Carp; |
daf4d4ea | 19 | Carp::croak("Undefined subroutine $AUTOLOAD called"); |
a0ed51b3 LW |
20 | } |
21 | ||
22 | 1; | |
23 | __END__ | |
24 | ||
25 | =head1 NAME | |
26 | ||
b3419ed8 | 27 | utf8 - Perl pragma to enable/disable UTF-8 (or UTF-EBCDIC) in source code |
a0ed51b3 LW |
28 | |
29 | =head1 SYNOPSIS | |
30 | ||
291cc134 KW |
31 | use utf8; |
32 | no utf8; | |
a0ed51b3 | 33 | |
291cc134 | 34 | # Convert the internal representation of a Perl scalar to/from UTF-8. |
836ccc8e | 35 | |
291cc134 | 36 | $num_octets = utf8::upgrade($string); |
98695e13 | 37 | $success = utf8::downgrade($string[, $fail_ok]); |
973655a8 | 38 | |
291cc134 KW |
39 | # Change each character of a Perl scalar to/from a series of |
40 | # characters that represent the UTF-8 bytes of each original character. | |
836ccc8e | 41 | |
291cc134 KW |
42 | utf8::encode($string); # "\x{100}" becomes "\xc4\x80" |
43 | utf8::decode($string); # "\xc4\x80" becomes "\x{100}" | |
973655a8 | 44 | |
ca3d51ba KW |
45 | # Convert a code point from the platform native character set to |
46 | # Unicode, and vice-versa. | |
47 | $unicode = utf8::native_to_unicode(ord('A')); # returns 65 on both | |
48 | # ASCII and EBCDIC | |
49 | # platforms | |
a04477f8 KW |
50 | $native = utf8::unicode_to_native(65); # returns 65 on ASCII |
51 | # platforms; 193 on | |
52 | # EBCDIC | |
ca3d51ba | 53 | |
ac8b87d7 EB |
54 | $flag = utf8::is_utf8($string); # since Perl 5.8.1 |
55 | $flag = utf8::valid($string); | |
973655a8 | 56 | |
a0ed51b3 LW |
57 | =head1 DESCRIPTION |
58 | ||
393fec97 | 59 | The C<use utf8> pragma tells the Perl parser to allow UTF-8 in the |
a04477f8 KW |
60 | program text in the current lexical scope. The C<no utf8> pragma tells Perl |
61 | to switch back to treating the source text as literal bytes in the current | |
62 | lexical scope. (On EBCDIC platforms, technically it is allowing UTF-EBCDIC, | |
63 | and not UTF-8, but this distinction is academic, so in this document the term | |
64 | UTF-8 is used to mean both). | |
a0ed51b3 | 65 | |
19b49582 JH |
66 | B<Do not use this pragma for anything else than telling Perl that your |
67 | script is written in UTF-8.> The utility functions described below are | |
2575c402 JW |
68 | directly usable without C<use utf8;>. |
69 | ||
70 | Because it is not possible to reliably tell UTF-8 from native 8 bit | |
71 | encodings, you need either a Byte Order Mark at the beginning of your | |
72 | source code, or C<use utf8;>, to instruct perl. | |
19b49582 | 73 | |
2575c402 | 74 | When UTF-8 becomes the standard source format, this pragma will |
a04477f8 | 75 | effectively become a no-op. |
a0ed51b3 | 76 | |
a74e8b45 | 77 | See also the effects of the C<-C> switch and its cousin, the |
127161e0 | 78 | C<PERL_UNICODE> environment variable, in L<perlrun>. |
a74e8b45 | 79 | |
ad0029c4 | 80 | Enabling the C<utf8> pragma has the following effect: |
a0ed51b3 | 81 | |
4ac9195f | 82 | =over 4 |
a0ed51b3 LW |
83 | |
84 | =item * | |
85 | ||
a04477f8 KW |
86 | Bytes in the source text that are not in the ASCII character set will be |
87 | treated as being part of a literal UTF-8 sequence. This includes most | |
c20e2abd | 88 | literals such as identifier names, string constants, and constant |
8f8cf39c JH |
89 | regular expression patterns. |
90 | ||
4ac9195f MS |
91 | =back |
92 | ||
a04477f8 KW |
93 | Note that if you have non-ASCII, non-UTF-8 bytes in your script (for example |
94 | embedded Latin-1 in your string literals), C<use utf8> will be unhappy. If | |
95 | you want to have such bytes under C<use utf8>, you can disable this pragma | |
96 | until the end the block (or file, if at top level) by C<no utf8;>. | |
ae90e350 | 97 | |
1b026014 NIS |
98 | =head2 Utility functions |
99 | ||
8800c35a JH |
100 | The following functions are defined in the C<utf8::> package by the |
101 | Perl core. You do not need to say C<use utf8> to use these and in fact | |
2f7e5073 | 102 | you should not say that unless you really want to have UTF-8 source code. |
1b026014 NIS |
103 | |
104 | =over 4 | |
105 | ||
308a4ae1 | 106 | =item * C<$num_octets = utf8::upgrade($string)> |
1b026014 | 107 | |
a04477f8 | 108 | (Since Perl v5.8.0) |
836ccc8e | 109 | Converts in-place the internal representation of the string from an octet |
a04477f8 | 110 | sequence in the native encoding (Latin-1 or EBCDIC) to UTF-8. The |
836ccc8e | 111 | logical character sequence itself is unchanged. If I<$string> is already |
a04477f8 KW |
112 | stored as UTF-8, then this is a no-op. Returns the |
113 | number of octets necessary to represent the string as UTF-8. Can be | |
2575c402 | 114 | used to make sure that the UTF-8 flag is on, so that C<\w> or C<lc()> |
a04477f8 KW |
115 | work as Unicode on strings containing non-ASCII characters whose code points |
116 | are below 256. | |
78ea37eb | 117 | |
a04477f8 KW |
118 | B<Note that this function does not handle arbitrary encodings>; |
119 | use L<Encode> instead. | |
1b026014 | 120 | |
308a4ae1 | 121 | =item * C<$success = utf8::downgrade($string[, $fail_ok])> |
1b026014 | 122 | |
a04477f8 | 123 | (Since Perl v5.8.0) |
730d7228 | 124 | Converts in-place the internal representation of the string from |
a04477f8 | 125 | UTF-8 to the equivalent octet sequence in the native encoding (Latin-1 |
836ccc8e DM |
126 | or EBCDIC). The logical character sequence itself is unchanged. If |
127 | I<$string> is already stored as native 8 bit, then this is a no-op. Can | |
128 | be used to | |
2575c402 JW |
129 | make sure that the UTF-8 flag is off, e.g. when you want to make sure |
130 | that the substr() or length() function works with the usually faster | |
131 | byte algorithm. | |
78ea37eb | 132 | |
a04477f8 | 133 | Fails if the original UTF-8 sequence cannot be represented in the |
ac8b87d7 | 134 | native 8 bit encoding. On failure dies or, if the value of I<$fail_ok> is |
2575c402 | 135 | true, returns false. |
78ea37eb | 136 | |
2575c402 JW |
137 | Returns true on success. |
138 | ||
a04477f8 KW |
139 | B<Note that this function does not handle arbitrary encodings>; |
140 | use L<Encode> instead. | |
78ea37eb | 141 | |
308a4ae1 | 142 | =item * C<utf8::encode($string)> |
1b026014 | 143 | |
a04477f8 | 144 | (Since Perl v5.8.0) |
2575c402 | 145 | Converts in-place the character sequence to the corresponding octet |
a04477f8 | 146 | sequence in UTF-8. That is, every (possibly wide) character gets |
836ccc8e | 147 | replaced with a sequence of one or more characters that represent the |
a04477f8 | 148 | individual UTF-8 bytes of the character. The UTF8 flag is turned off. |
836ccc8e DM |
149 | Returns nothing. |
150 | ||
291cc134 | 151 | my $a = "\x{100}"; # $a contains one character, with ord 0x100 |
ca3d51ba | 152 | utf8::encode($a); # $a contains two characters, with ords (on |
a04477f8 KW |
153 | # ASCII platforms) 0xc4 and 0x80. On EBCDIC |
154 | # 1047, this would instead be 0x8C and 0x41. | |
78ea37eb | 155 | |
a04477f8 KW |
156 | B<Note that this function does not handle arbitrary encodings>; |
157 | use L<Encode> instead. | |
094ce63c | 158 | |
308a4ae1 | 159 | =item * C<$success = utf8::decode($string)> |
1b026014 | 160 | |
a04477f8 KW |
161 | (Since Perl v5.8.0) |
162 | Attempts to convert in-place the octet sequence encoded as UTF-8 to the | |
836ccc8e | 163 | corresponding character sequence. That is, it replaces each sequence of |
a04477f8 | 164 | characters in the string whose ords represent a valid UTF-8 byte |
836ccc8e | 165 | sequence, with the corresponding single character. The UTF-8 flag is |
a04477f8 KW |
166 | turned on only if the source string contains multiple-byte UTF-8 |
167 | characters. If I<$string> is invalid as UTF-8, returns false; | |
836ccc8e DM |
168 | otherwise returns true. |
169 | ||
ca3d51ba KW |
170 | my $a = "\xc4\x80"; # $a contains two characters, with ords |
171 | # 0xc4 and 0x80 | |
172 | utf8::decode($a); # On ASCII platforms, $a contains one char, | |
a04477f8 KW |
173 | # with ord 0x100. Since these bytes aren't |
174 | # legal UTF-EBCDIC, on EBCDIC platforms, $a is | |
175 | # unchanged and the function returns FALSE. | |
78ea37eb | 176 | |
a04477f8 KW |
177 | B<Note that this function does not handle arbitrary encodings>; |
178 | use L<Encode> instead. | |
78ea37eb | 179 | |
ca3d51ba KW |
180 | =item * C<$unicode = utf8::native_to_unicode($code_point)> |
181 | ||
273e254d | 182 | (Since Perl v5.8.0) |
ca3d51ba KW |
183 | This takes an unsigned integer (which represents the ordinal number of a |
184 | character (or a code point) on the platform the program is being run on) and | |
185 | returns its Unicode equivalent value. Since ASCII platforms natively use the | |
186 | Unicode code points, this function returns its input on them. On EBCDIC | |
bc1767aa | 187 | platforms it converts from EBCDIC to Unicode. |
ca3d51ba KW |
188 | |
189 | A meaningless value will currently be returned if the input is not an unsigned | |
190 | integer. | |
191 | ||
273e254d KW |
192 | Since Perl v5.22.0, calls to this function are optimized out on ASCII |
193 | platforms, so there is no performance hit in using it there. | |
194 | ||
ca3d51ba KW |
195 | =item * C<$native = utf8::unicode_to_native($code_point)> |
196 | ||
273e254d | 197 | (Since Perl v5.8.0) |
ca3d51ba KW |
198 | This is the inverse of C<utf8::native_to_unicode()>, converting the other |
199 | direction. Again, on ASCII platforms, this returns its input, but on EBCDIC | |
200 | platforms it will find the native platform code point, given any Unicode one. | |
201 | ||
202 | A meaningless value will currently be returned if the input is not an unsigned | |
203 | integer. | |
204 | ||
273e254d KW |
205 | Since Perl v5.22.0, calls to this function are optimized out on ASCII |
206 | platforms, so there is no performance hit in using it there. | |
207 | ||
308a4ae1 | 208 | =item * C<$flag = utf8::is_utf8($string)> |
8800c35a | 209 | |
ac8b87d7 | 210 | (Since Perl 5.8.1) Test whether I<$string> is marked internally as encoded in |
a04477f8 | 211 | UTF-8. Functionally the same as C<Encode::is_utf8()>. |
8800c35a | 212 | |
308a4ae1 | 213 | =item * C<$flag = utf8::valid($string)> |
70122e76 | 214 | |
ac8b87d7 | 215 | [INTERNAL] Test whether I<$string> is in a consistent state regarding |
9a54da5c | 216 | UTF-8. Will return true if it is well-formed UTF-8 and has the UTF-8 flag |
ac8b87d7 | 217 | on B<or> if I<$string> is held as bytes (both these states are 'consistent'). |
637ec54e | 218 | Main reason for this routine is to allow Perl's test suite to check |
8800c35a | 219 | that operations have left strings in a consistent state. You most |
a04477f8 | 220 | probably want to use C<utf8::is_utf8()> instead. |
70122e76 | 221 | |
1b026014 NIS |
222 | =back |
223 | ||
7d865a91 | 224 | C<utf8::encode> is like C<utf8::upgrade>, but the UTF8 flag is |
a04477f8 KW |
225 | cleared. See L<perlunicode>, and the C API |
226 | functions C<L<sv_utf8_upgrade|perlapi/sv_utf8_upgrade>>, | |
227 | C<L<perlapi/sv_utf8_downgrade>>, C<L<perlapi/sv_utf8_encode>>, | |
228 | and C<L<perlapi/sv_utf8_decode>>, which are wrapped by the Perl functions | |
094ce63c | 229 | C<utf8::upgrade>, C<utf8::downgrade>, C<utf8::encode> and |
a04477f8 KW |
230 | C<utf8::decode>. Also, the functions C<utf8::is_utf8>, C<utf8::valid>, |
231 | C<utf8::encode>, C<utf8::decode>, C<utf8::upgrade>, and C<utf8::downgrade> are | |
7edb8f2b RGS |
232 | actually internal, and thus always available, without a C<require utf8> |
233 | statement. | |
f1e62f77 | 234 | |
8f8cf39c JH |
235 | =head1 BUGS |
236 | ||
a04477f8 KW |
237 | Some filesystems may not support UTF-8 file names, or they may be supported |
238 | incompatibly with Perl. Therefore UTF-8 names that are visible to the | |
239 | filesystem, such as module names may not work. | |
8f8cf39c | 240 | |
393fec97 | 241 | =head1 SEE ALSO |
a0ed51b3 | 242 | |
2575c402 | 243 | L<perlunitut>, L<perluniintro>, L<perlrun>, L<bytes>, L<perlunicode> |
a0ed51b3 LW |
244 | |
245 | =cut |