charnames(3)

NAME

       charnames - define character names for "\N{named}" string literal
       escapes

SYNOPSIS

         use charnames ':full';
         print "\N{GREEK SMALL LETTER SIGMA} is called sigma.\n";

         use charnames ':short';
         print "\N{greek:Sigma} is an upper-case sigma.\n";

         use charnames qw(cyrillic greek);
         print "\N{sigma} is Greek sigma, and \N{be} is Cyrillic b.\n";

         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 "\N{CHARNAME}" 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 argu-
       ments, then for "\N{CHARNAME}" 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 "SCRIPTNAME" 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, otherwise the "SMALL" variant is
       ignored.

       Note that "\N{...}" is compile-time, it's a special form of string con-
       stant used inside double-quoted strings: in other words, you cannot use
       variables inside the "\N{...}".  If you want similar run-time function-
       ality, 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 Uni-
       code 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: "\N{U+263a}" is
       the Unicode smiley face, or "\N{WHITE SMILING FACE}".

CUSTOM TRANSLATORS

       The mechanism of translation of "\N{...}" escapes is general 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 $charnames::hint_bits
           sub import {
               shift;
               $^H |= $charnames::hint_bits;
               $^H{charnames} = \&translator;
           }

       Here translator() is a subroutine which takes "CHARNAME" as an argu-
       ment, and returns text to insert into the string instead of the
       "\N{CHARNAME}" 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 cus-
       tom 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 cus-
       tom 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 "\x{FFFD}" 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 translation function should not
       do any "eval"s or "require"s.  This restriction should be lifted in a
       future version of Perl.

perl v5.8.0                       2002-06-01                      charnames(3)