Commit | Line | Data |
a0ed51b3 |
1 | package utf8; |
2 | |
d5448623 |
3 | $utf8::hint_bits = 0x00800000; |
4 | |
b75c8c73 |
5 | our $VERSION = '1.00'; |
6 | |
a0ed51b3 |
7 | sub import { |
d5448623 |
8 | $^H |= $utf8::hint_bits; |
a0ed51b3 |
9 | $enc{caller()} = $_[1] if $_[1]; |
10 | } |
11 | |
12 | sub unimport { |
d5448623 |
13 | $^H &= ~$utf8::hint_bits; |
a0ed51b3 |
14 | } |
15 | |
16 | sub AUTOLOAD { |
17 | require "utf8_heavy.pl"; |
daf4d4ea |
18 | goto &$AUTOLOAD if defined &$AUTOLOAD; |
19 | Carp::croak("Undefined subroutine $AUTOLOAD called"); |
a0ed51b3 |
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 |
28 | |
29 | =head1 SYNOPSIS |
30 | |
31 | use utf8; |
32 | no utf8; |
33 | |
34 | =head1 DESCRIPTION |
35 | |
393fec97 |
36 | The C<use utf8> pragma tells the Perl parser to allow UTF-8 in the |
b3419ed8 |
37 | program text in the current lexical scope (allow UTF-EBCDIC on EBCDIC based |
70122e76 |
38 | platforms). The C<no utf8> pragma tells Perl to switch back to treating |
b3419ed8 |
39 | the source text as literal bytes in the current lexical scope. |
a0ed51b3 |
40 | |
393fec97 |
41 | This pragma is primarily a compatibility device. Perl versions |
42 | earlier than 5.6 allowed arbitrary bytes in source code, whereas |
43 | in future we would like to standardize on the UTF-8 encoding for |
44 | source text. Until UTF-8 becomes the default format for source |
45 | text, this pragma should be used to recognize UTF-8 in the source. |
46 | When UTF-8 becomes the standard source format, this pragma will |
b3419ed8 |
47 | effectively become a no-op. For convenience in what follows the |
ad0029c4 |
48 | term I<UTF-X> is used to refer to UTF-8 on ASCII and ISO Latin based |
b3419ed8 |
49 | platforms and UTF-EBCDIC on EBCDIC based platforms. |
a0ed51b3 |
50 | |
ad0029c4 |
51 | Enabling the C<utf8> pragma has the following effect: |
a0ed51b3 |
52 | |
4ac9195f |
53 | =over 4 |
a0ed51b3 |
54 | |
55 | =item * |
56 | |
393fec97 |
57 | Bytes in the source text that have their high-bit set will be treated |
ad0029c4 |
58 | as being part of a literal UTF-8 character. This includes most |
c20e2abd |
59 | literals such as identifier names, string constants, and constant |
60 | regular expression patterns. On EBCDIC platforms characters in |
61 | the Latin 1 character set are treated as being part of a literal |
ad0029c4 |
62 | UTF-EBCDIC character. |
a0ed51b3 |
63 | |
4ac9195f |
64 | =back |
65 | |
ae90e350 |
66 | Note that if you have bytes with the eighth bit on in your script |
67 | (for example embedded Latin-1 in your string literals), C<use utf8> |
68 | will be unhappy since the bytes are most probably not well-formed |
69 | UTF-8. If you want to have such bytes and use utf8, you can disable |
70 | utf8 until the end the block (or file, if at top level) by C<no utf8;>. |
71 | |
1b026014 |
72 | =head2 Utility functions |
73 | |
74 | The following functions are defined in the C<utf8::> package by the perl core. |
75 | |
76 | =over 4 |
77 | |
78 | =item * $num_octets = utf8::upgrade($string); |
79 | |
8dd9dd9f |
80 | Converts (in-place) internal representation of string to Perl's internal |
ad0029c4 |
81 | I<UTF-X> form. Returns the number of octets necessary to represent |
8dd9dd9f |
82 | the string as I<UTF-X>. Can be used to make sure that the |
83 | UTF-8 flag is on, so that C<\w> or C<lc()> work as expected on strings |
84 | containing characters in the range 0x80-0xFF. Note that this should |
85 | not be used to convert |
13a6c0e0 |
86 | a legacy byte encoding to Unicode: use Encode for that. Affected |
87 | by the encoding pragma. |
1b026014 |
88 | |
8dd9dd9f |
89 | =item * utf8::downgrade($string[, FAIL_OK]) |
1b026014 |
90 | |
7d865a91 |
91 | Converts (in-place) internal representation of string to be un-encoded |
92 | bytes. Returns true on success. On failure dies or, if the value of |
93 | FAIL_OK is true, returns false. Can be used to make sure that the |
8dd9dd9f |
94 | UTF-8 flag is off, e.g. when you want to make sure that the substr() |
95 | or length() function works with the usually faster byte algorithm. |
13a6c0e0 |
96 | Note that this should not be used to convert Unicode back to a legacy |
97 | byte encoding: use Encode for that. B<Not> affected by the encoding |
98 | pragma. |
1b026014 |
99 | |
100 | =item * utf8::encode($string) |
101 | |
13a6c0e0 |
102 | Converts (in-place) I<$string> from logical characters to octet |
8dd9dd9f |
103 | sequence representing it in Perl's I<UTF-X> encoding. Same as |
7d865a91 |
104 | Encode::encode_utf8(). Note that this should not be used to convert |
105 | a legacy byte encoding to Unicode: use Encode for that. |
094ce63c |
106 | |
107 | =item * $flag = utf8::decode($string) |
1b026014 |
108 | |
ad0029c4 |
109 | Attempts to convert I<$string> in-place from Perl's I<UTF-X> encoding |
7d865a91 |
110 | into logical characters. Same as Encode::decode_utf8(). Note that this |
111 | should not be used to convert Unicode back to a legacy byte encoding: |
112 | use Encode for that. |
1b026014 |
113 | |
70122e76 |
114 | =item * $flag = utf8::valid(STRING) |
115 | |
116 | [INTERNAL] Test whether STRING is in a consistent state. Will return |
117 | true if string is held as bytes, or is well-formed UTF-8 and has the |
118 | UTF-8 flag on. Main reason for this routine is to allow Perl's |
119 | testsuite to check that operations have left strings in a consistent |
120 | state. |
121 | |
1b026014 |
122 | =back |
123 | |
7d865a91 |
124 | C<utf8::encode> is like C<utf8::upgrade>, but the UTF8 flag is |
125 | cleared. See L<perlunicode> for more on the UTF8 flag and the C API |
126 | functions C<sv_utf8_upgrade>, C<sv_utf8_downgrade>, C<sv_utf8_encode>, |
094ce63c |
127 | and C<sv_utf8_decode>, which are wrapped by the Perl functions |
128 | C<utf8::upgrade>, C<utf8::downgrade>, C<utf8::encode> and |
7d865a91 |
129 | C<utf8::decode>. Note that in the Perl 5.8.0 implementation the |
130 | functions utf8::valid, utf8::encode, utf8::decode, utf8::upgrade, |
131 | and utf8::downgrade are always available, without a C<require utf8> |
132 | statement-- this may change in future releases. |
f1e62f77 |
133 | |
393fec97 |
134 | =head1 SEE ALSO |
a0ed51b3 |
135 | |
8058d7ab |
136 | L<perlunicode>, L<bytes> |
a0ed51b3 |
137 | |
138 | =cut |