charnames(3)
NAME
charnames - define character names for "amed}" string
literal escapes
SYNOPSIS
use charnames ':full';
print "REEK SMALL LETTER SIGMA} is called sigma.0;
use charnames ':short';
print "reek:Sigma} is an upper-case sigma.0;
use charnames qw(cyrillic greek);
print "igma} is Greek sigma, and e} is Cyrillic b.0;
print charnames::viacode(0x1234); # prints "ETHIOPIC
SYLLABLE SEE"
printf "%04X", charnames::vianame("GOTHIC LETTER AHSA");
# prints "10330"
DESCRIPTION
Pragma "use charnames" supports arguments ":full",
":short" and script names. If ":full" is present, for
expansion of "HARNAME}" string "CHARNAME" is first
looked in the list of standard Unicode names of chars. If
":short" is present, and "CHARNAME" has the form
"SCRIPT:CNAME", then "CNAME" is looked up as a letter in
script "SCRIPT". If pragma "use charnames" is used with
script name arguments, then for "HARNAME}" the name
"CHARNAME" is looked up as a letter in the given scripts
(in the specified order).
- For lookup of "CHARNAME" inside a given script "SCRIPT
NAME" this pragma looks for the names - SCRIPTNAME CAPITAL LETTER CHARNAME
SCRIPTNAME SMALL LETTER CHARNAME
SCRIPTNAME LETTER CHARNAME - in the table of standard Unicode names. If "CHARNAME" is
lowercase, then the "CAPITAL" variant is ignored, other
wise the "SMALL" variant is ignored. - Note that ".}" is compile-time, it's a special form
of string constant used inside double-quoted strings: in
other words, you cannot use variables inside the
".}". If you want similar run-time functionality,
use charnames::vianame(). - For the C0 and C1 control characters (U+0000..U+001F,
U+0080..U+009F) as of Unicode 3.1, there are no official
Unicode names but you can use instead the ISO 6429 names
(LINE FEED, ESCAPE, and so forth). In Unicode 3.2 (as of
Perl 5.8) some naming changes take place ISO 6429 has been
updated, see "ALIASES". Also note that the U+UU80,
U+0081, U+0084, and U+0099 do not have names even in ISO
6429. - Since the Unicode standard uses "U+HHHH", so can you:
"+263a}" is the Unicode smiley face, or "HITE
SMILING FACE}".
CUSTOM TRANSLATORS
- The mechanism of translation of ".}" escapes is gen
eral and not hardwired into charnames.pm. A module can install custom translations (inside the scope which "use"s
the module) with the following magic incantation: - use charnames (); # for $char
- names::hint_bits
sub import {shift;
$^H |= $charnames::hint_bits;
$^H{charnames} = translator; - }
- Here translator() is a subroutine which takes "CHARNAME"
as an argument, and returns text to insert into the string
instead of the "HARNAME}" escape. Since the text to
insert should be different in "bytes" mode and out of it,
the function should check the current state of
"bytes"-flag as in:
use bytes (); # for- $bytes::hint_bits
sub translator {if ($^H & $bytes::hint_bits) {return bytes_translator(@_);}
else {return utf8_translator(@_);} - }
- charnames::viacode(code)
- Returns the full name of the character indicated by the
numeric code. The example
print charnames::viacode(0x2722);- prints "FOUR TEARDROP-SPOKED ASTERISK".
- Returns undef if no name is known for the code.
- This works only for the standard names, and does not yet
apply to custom translators. - Notice that the name returned for of U+FEFF is "ZERO WIDTH
NO-BREAK SPACE", not "BYTE ORDER MARK". - charnames::vianame(name)
Returns the code point indicated by the name. The example
printf "%04X", charnames::vianame("FOUR TEARDROP- SPOKED ASTERISK");
- prints "2722".
- Returns undef if the name is unknown.
- This works only for the standard names, and does not yet
apply to custom translators.
ALIASES
- A few aliases have been defined for convenience: instead
of having to use the official names - LINE FEED (LF)
FORM FEED (FF)
CARRIAGE RETURN (CR)
NEXT LINE (NEL) - (yes, with parentheses) one can use
LINE FEED
FORM FEED
CARRIAGE RETURN
NEXT LINE
LF
FF
CR
NEL- One can also use
BYTE ORDER MARK
BOM- and
ZWNJ
ZWJ- for ZERO WIDTH NON-JOINER and ZERO WIDTH JOINER.
- For backward compatibility one can use the old names for
certain C0 and C1 controls
old new- HORIZONTAL TABULATION CHARACTER TABULATION
VERTICAL TABULATION LINE TABULATION
FILE SEPARATOR INFORMATION SEPARATOR FOUR
GROUP SEPARATOR INFORMATION SEPARATOR - THREE
RECORD SEPARATOR INFORMATION SEPARATOR TWO
UNIT SEPARATOR INFORMATION SEPARATOR ONE
PARTIAL LINE DOWN PARTIAL LINE FORWARD
PARTIAL LINE UP PARTIAL LINE BACKWARD - but the old names in addition to giving the character will
also give a warning about being deprecated.
ILLEGAL CHARACTERS
If you ask by name for a character that does not exist, a
warning is given and the Unicode replacement character
"FFD}" is returned.
If you ask by code for a character that does not exist, no
warning is given and "undef" is returned. (Though if you
ask for a code point past U+10FFFF you do get a warning.)
BUGS
- Since evaluation of the translation function happens in a
middle of compilation (of a string literal), the transla
tion function should not do any "eval"s or "require"s.
This restriction should be lifted in a future version of
Perl.