caseyperkins has asked for the wisdom of the Perl Monks concerning the following question:

Hi,
I'm trying to translate some special characters into unicoded Greek.

#This works:
use charnames ':full';
print("\N{GREEK SMALL LETTER EPSILON}\n");

#But this doesn't:
use charnames ':full';
$var = 'GREEK SMALL LETTER EPSILON';
print("\N{$var}\n");

It gives this error:
Unknown charname '$var' at C:/Perl/lib/charnames.pm line 32.
Propagated at un.pl line 3, within string Execution of un.pl aborted due to compilation errors.
shell returned 255

I need to pass the character name at runtime. But I see in the manpages that \N does not accept a variable. Nor does \x, it seems. The manpages suggest using charnames::vianame(), but all that does is return a character code, whereas I'm interested in getting back the actual unicoded character. Can anyone suggest a solution?

Many thanks.

Casey

Replies are listed 'Best First'.
Re: unicode, \N, \x, character encoding
by japhy (Canon) on Mar 02, 2006 at 19:47 UTC
    \N escapes are seen pre-interpolation (update: rather, at the same time as variable interpolation, which means the \N{...} is parsed as an entire entity, and the contents are treated as raw data). I suggest chr(charnames::vianame($name)).

    Update: you could also use eval() as shown below, but I think my previous solution is far more appropriate. 

    sub charname_to_char {
  my $name = shift;
  eval qq{
    # because $^H{charnames} doesn't propogate into here
    use charnames ':full';
    "\\N{$name}"
  };
}

    [download]
    Jeff japhy Pinyan, P.L., P.M., P.O.D, X.S.: Perl, regex, and perl hacker
    How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart
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      Hi Jeff,
      It worked! Your help is greatly appreciated.
      :-)

      Casey
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Re: unicode, \N, \x, character encoding
by ambrus (Abbot) on Mar 03, 2006 at 07:34 UTC
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