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| -rw-r--r-- | pod/perluniintro.pod | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/pod/perluniintro.pod b/pod/perluniintro.pod index c94f3d289f..8a7a055935 100644 --- a/pod/perluniintro.pod +++ b/pod/perluniintro.pod @@ -596,9 +596,21 @@ string are necessary UTF-8 encoded, or that any of the characters have code points greater than 0xFF (255) or even 0x80 (128), or that the string has any characters at all. All the C<is_utf8()> does is to return the value of the internal "utf8ness" flag attached to the -$string. If the flag is on, characters added to that string will be -automatically upgraded to UTF-8 (and even then only if they really -need to be upgraded, that is, if their code point is greater than 0xFF). +$string. If the flag is off, the bytes in the scalar are interpreted +as a single byte encoding. If the flag is on, the bytes in the scalar +are interpreted as the (multibyte, variable-length) UTF-8 encoded code +points of the characters. Bytes added to an UTF-8 encoded string are +automatically upgraded to UTF-8. If mixed non-UTF8 and UTF-8 scalars +are merged (doublequoted interpolation, explicit concatenation, and +printf/sprintf parameter substitution), the result will be UTF-8 encoded +as if copies of the byte strings were upgraded to UTF-8: for example, + + $a = "ab\x80c"; + $b = "\x{100}"; + print "$a = $b\n"; + +the output string will be UTF-8-encoded "ab\x80c\x{100}\n", but note +that C<$a> will stay single byte encoded. Sometimes you might really need to know the byte length of a string instead of the character length. For that use the C<bytes> pragma |