in reply to match substitution

I tried the following back reference:
use utf8;
my $str = "725-275 is an entry - and will be at 423-569 -but- not at 0
+12-457."; 
$str =~ s/(\d{3})-(\d{3})/\1\_\2/g;

print "$str\n"

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which produced the following result: 
725_275 is an entry - and will be at 423_569 -but- not at 012_457.

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I am getting some strange characters if I use \x{2014}! I am not sure about the hyphen to dash substitution. Update: I just saw ikegami's reply!

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Re^2: match substitution
by ikegami (Patriarch) on Jan 27, 2010 at 00:42 UTC
    Actually, it produces 
    \1 better written as $1 at a.pl line 3.
\2 better written as $2 at a.pl line 3.
725_275 is an entry - and will be at 423_569 -but- not at 012_457.

    [download]
    if you don't disable warnings. \1 and \2 are not a valid Perl variables.
[reply]
[d/l]
[select]
      Thanks for pointing it out. You are right, I get the same when I turn the warnings on!
      UPDATE:
      use strict;
use warnings;
#use utf8;
my $str = "725-275 is an entry - and will be at 423-569 -but- not at 0
+12-457."; 

print "before: $str\n";

$str =~ s/([0-9]{3})-([0-9]{3})/$1\x{2014}$2/g;

print "after: $str\n"

produces:
before: 725-275 is an entry - and will be at 423-569 -but- not at 012-
+457.
after: 725—275 is an entry - and will be at 423—569 -but- not at 012—4
+57.

      [download]
[reply]
[d/l]
        Wow! Thanks!
[reply]

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