Commit | Line | Data |
---|---|---|
a0ed51b3 LW |
1 | package utf8; |
2 | ||
d5448623 GS |
3 | $utf8::hint_bits = 0x00800000; |
4 | ||
075d4edd | 5 | our $VERSION = '1.07'; |
b75c8c73 | 6 | |
a0ed51b3 | 7 | sub import { |
d5448623 | 8 | $^H |= $utf8::hint_bits; |
a0ed51b3 LW |
9 | $enc{caller()} = $_[1] if $_[1]; |
10 | } | |
11 | ||
12 | sub unimport { | |
d5448623 | 13 | $^H &= ~$utf8::hint_bits; |
a0ed51b3 LW |
14 | } |
15 | ||
16 | sub AUTOLOAD { | |
17 | require "utf8_heavy.pl"; | |
daf4d4ea | 18 | goto &$AUTOLOAD if defined &$AUTOLOAD; |
bd7017d3 | 19 | require Carp; |
daf4d4ea | 20 | Carp::croak("Undefined subroutine $AUTOLOAD called"); |
a0ed51b3 LW |
21 | } |
22 | ||
23 | 1; | |
24 | __END__ | |
25 | ||
26 | =head1 NAME | |
27 | ||
b3419ed8 | 28 | utf8 - Perl pragma to enable/disable UTF-8 (or UTF-EBCDIC) in source code |
a0ed51b3 LW |
29 | |
30 | =head1 SYNOPSIS | |
31 | ||
32 | use utf8; | |
33 | no utf8; | |
34 | ||
2c9359a2 | 35 | # Convert a Perl scalar to/from UTF-8. |
973655a8 SB |
36 | $num_octets = utf8::upgrade($string); |
37 | $success = utf8::downgrade($string[, FAIL_OK]); | |
38 | ||
2c9359a2 | 39 | # Change the native bytes of a Perl scalar to/from UTF-8 bytes. |
973655a8 SB |
40 | utf8::encode($string); |
41 | utf8::decode($string); | |
42 | ||
786c9463 | 43 | $flag = utf8::is_utf8(STRING); # since Perl 5.8.1 |
973655a8 SB |
44 | $flag = utf8::valid(STRING); |
45 | ||
a0ed51b3 LW |
46 | =head1 DESCRIPTION |
47 | ||
393fec97 | 48 | The C<use utf8> pragma tells the Perl parser to allow UTF-8 in the |
b3419ed8 | 49 | program text in the current lexical scope (allow UTF-EBCDIC on EBCDIC based |
70122e76 | 50 | platforms). The C<no utf8> pragma tells Perl to switch back to treating |
b3419ed8 | 51 | the source text as literal bytes in the current lexical scope. |
a0ed51b3 | 52 | |
19b49582 JH |
53 | B<Do not use this pragma for anything else than telling Perl that your |
54 | script is written in UTF-8.> The utility functions described below are | |
2575c402 JW |
55 | directly usable without C<use utf8;>. |
56 | ||
57 | Because it is not possible to reliably tell UTF-8 from native 8 bit | |
58 | encodings, you need either a Byte Order Mark at the beginning of your | |
59 | source code, or C<use utf8;>, to instruct perl. | |
19b49582 | 60 | |
2575c402 JW |
61 | When UTF-8 becomes the standard source format, this pragma will |
62 | effectively become a no-op. For convenience in what follows the term | |
63 | I<UTF-X> is used to refer to UTF-8 on ASCII and ISO Latin based | |
64 | platforms and UTF-EBCDIC on EBCDIC based platforms. | |
a0ed51b3 | 65 | |
a74e8b45 JH |
66 | See also the effects of the C<-C> switch and its cousin, the |
67 | C<$ENV{PERL_UNICODE}>, in L<perlrun>. | |
68 | ||
ad0029c4 | 69 | Enabling the C<utf8> pragma has the following effect: |
a0ed51b3 | 70 | |
4ac9195f | 71 | =over 4 |
a0ed51b3 LW |
72 | |
73 | =item * | |
74 | ||
393fec97 | 75 | Bytes in the source text that have their high-bit set will be treated |
2fa62f66 | 76 | as being part of a literal UTF-X sequence. This includes most |
c20e2abd | 77 | literals such as identifier names, string constants, and constant |
8f8cf39c JH |
78 | regular expression patterns. |
79 | ||
80 | On EBCDIC platforms characters in the Latin 1 character set are | |
81 | treated as being part of a literal UTF-EBCDIC character. | |
a0ed51b3 | 82 | |
4ac9195f MS |
83 | =back |
84 | ||
ae90e350 JH |
85 | Note that if you have bytes with the eighth bit on in your script |
86 | (for example embedded Latin-1 in your string literals), C<use utf8> | |
87 | will be unhappy since the bytes are most probably not well-formed | |
2fa62f66 AT |
88 | UTF-X. If you want to have such bytes under C<use utf8>, you can disable |
89 | this pragma until the end the block (or file, if at top level) by | |
90 | C<no utf8;>. | |
ae90e350 | 91 | |
1b026014 NIS |
92 | =head2 Utility functions |
93 | ||
8800c35a JH |
94 | The following functions are defined in the C<utf8::> package by the |
95 | Perl core. You do not need to say C<use utf8> to use these and in fact | |
19b49582 | 96 | you should not say that unless you really want to have UTF-8 source code. |
1b026014 NIS |
97 | |
98 | =over 4 | |
99 | ||
973655a8 | 100 | =item * $num_octets = utf8::upgrade($string) |
1b026014 | 101 | |
2575c402 | 102 | Converts in-place the internal octet sequence in the native encoding |
78ea37eb | 103 | (Latin-1 or EBCDIC) to the equivalent character sequence in I<UTF-X>. |
2575c402 JW |
104 | I<$string> already encoded as characters does no harm. Returns the |
105 | number of octets necessary to represent the string as I<UTF-X>. Can be | |
106 | used to make sure that the UTF-8 flag is on, so that C<\w> or C<lc()> | |
107 | work as Unicode on strings containing characters in the range 0x80-0xFF | |
108 | (on ASCII and derivatives). | |
78ea37eb TS |
109 | |
110 | B<Note that this function does not handle arbitrary encodings.> | |
2575c402 JW |
111 | Therefore Encode is recommended for the general purposes; see also |
112 | L<Encode>. | |
1b026014 | 113 | |
973655a8 | 114 | =item * $success = utf8::downgrade($string[, FAIL_OK]) |
1b026014 | 115 | |
2575c402 JW |
116 | Converts in-place the internal octet sequence in I<UTF-X> to the |
117 | equivalent octet sequence in the native encoding (Latin-1 or EBCDIC). | |
118 | I<$string> already encoded as native 8 bit does no harm. Can be used to | |
119 | make sure that the UTF-8 flag is off, e.g. when you want to make sure | |
120 | that the substr() or length() function works with the usually faster | |
121 | byte algorithm. | |
78ea37eb | 122 | |
2575c402 JW |
123 | Fails if the original I<UTF-X> sequence cannot be represented in the |
124 | native 8 bit encoding. On failure dies or, if the value of C<FAIL_OK> is | |
125 | true, returns false. | |
78ea37eb | 126 | |
2575c402 JW |
127 | Returns true on success. |
128 | ||
129 | B<Note that this function does not handle arbitrary encodings.> | |
130 | Therefore Encode is recommended for the general purposes; see also | |
131 | L<Encode>. | |
78ea37eb | 132 | |
1b026014 NIS |
133 | =item * utf8::encode($string) |
134 | ||
2575c402 JW |
135 | Converts in-place the character sequence to the corresponding octet |
136 | sequence in I<UTF-X>. The UTF8 flag is turned off, so that after this | |
137 | operation, the string is a byte string. Returns nothing. | |
78ea37eb TS |
138 | |
139 | B<Note that this function does not handle arbitrary encodings.> | |
2575c402 JW |
140 | Therefore Encode is recommended for the general purposes; see also |
141 | L<Encode>. | |
094ce63c | 142 | |
2575c402 | 143 | =item * $success = utf8::decode($string) |
1b026014 | 144 | |
2575c402 JW |
145 | Attempts to convert in-place the octet sequence in I<UTF-X> to the |
146 | corresponding character sequence. The UTF-8 flag is turned on only if | |
147 | the source string contains multiple-byte I<UTF-X> characters. If | |
148 | I<$string> is invalid as I<UTF-X>, returns false; otherwise returns | |
149 | true. | |
78ea37eb TS |
150 | |
151 | B<Note that this function does not handle arbitrary encodings.> | |
2575c402 JW |
152 | Therefore Encode is recommended for the general purposes; see also |
153 | L<Encode>. | |
78ea37eb | 154 | |
8800c35a JH |
155 | =item * $flag = utf8::is_utf8(STRING) |
156 | ||
2575c402 JW |
157 | (Since Perl 5.8.1) Test whether STRING is in UTF-8 internally. |
158 | Functionally the same as Encode::is_utf8(). | |
8800c35a | 159 | |
70122e76 JH |
160 | =item * $flag = utf8::valid(STRING) |
161 | ||
8800c35a JH |
162 | [INTERNAL] Test whether STRING is in a consistent state regarding |
163 | UTF-8. Will return true is well-formed UTF-8 and has the UTF-8 flag | |
164 | on B<or> if string is held as bytes (both these states are 'consistent'). | |
165 | Main reason for this routine is to allow Perl's testsuite to check | |
166 | that operations have left strings in a consistent state. You most | |
167 | probably want to use utf8::is_utf8() instead. | |
70122e76 | 168 | |
1b026014 NIS |
169 | =back |
170 | ||
7d865a91 JH |
171 | C<utf8::encode> is like C<utf8::upgrade>, but the UTF8 flag is |
172 | cleared. See L<perlunicode> for more on the UTF8 flag and the C API | |
173 | functions C<sv_utf8_upgrade>, C<sv_utf8_downgrade>, C<sv_utf8_encode>, | |
094ce63c AT |
174 | and C<sv_utf8_decode>, which are wrapped by the Perl functions |
175 | C<utf8::upgrade>, C<utf8::downgrade>, C<utf8::encode> and | |
7edb8f2b RGS |
176 | C<utf8::decode>. Also, the functions utf8::is_utf8, utf8::valid, |
177 | utf8::encode, utf8::decode, utf8::upgrade, and utf8::downgrade are | |
178 | actually internal, and thus always available, without a C<require utf8> | |
179 | statement. | |
f1e62f77 | 180 | |
8f8cf39c JH |
181 | =head1 BUGS |
182 | ||
183 | One can have Unicode in identifier names, but not in package/class or | |
184 | subroutine names. While some limited functionality towards this does | |
185 | exist as of Perl 5.8.0, that is more accidental than designed; use of | |
186 | Unicode for the said purposes is unsupported. | |
187 | ||
188 | One reason of this unfinishedness is its (currently) inherent | |
189 | unportability: since both package names and subroutine names may need | |
190 | to be mapped to file and directory names, the Unicode capability of | |
191 | the filesystem becomes important-- and there unfortunately aren't | |
192 | portable answers. | |
193 | ||
393fec97 | 194 | =head1 SEE ALSO |
a0ed51b3 | 195 | |
2575c402 | 196 | L<perlunitut>, L<perluniintro>, L<perlrun>, L<bytes>, L<perlunicode> |
a0ed51b3 LW |
197 | |
198 | =cut |