Perl正则表达式匹配图释

Question

I'm trying to remove certain emoticons from a string, but I can't figure out how to match emoticons consisting of special characters and letters, for example :D or :-D (it works for emoticons like ":-)" ). I tried

$message =~ s/\\:D//;

and few other variations, but nothing seems to work. Where am I wrong?

EDIT: I was actually stupid and didn't realize I made all the letters lowercase before this command, so all the emoticons were already changed to ":d". Thanks for help.

Answer 1

use strict; use warnings;

my $s = "Hello ;-) :D :-D <3 World!";
my @emoticons = qw' ;-) :D :-D <3 ';

my $pat = join '|', map qr/\Q$_\E/, @emoticons;
$s =~ s/$pat//g;
$s =~ s/ +/ /g;

print "$s\n";

Output:

Hello World!

Answer 2

You can write some unit tests:

sub assert_equals($$) {
  my ($expected, $actual) = @_;
  $expected eq $actual or die "expected <$expected>, got <$actual>\n";
}

sub no_smilies($) {
  my ($message) = @_;
  $message =~ s/:D\b//g;
  return $message;
}

sub test() {
  assert_equals("", no_smilies(":D"));
  ...
}

Then you can do the rest using trial and error.

Answer 3

You could try something like this for starters:

s/[:;]-?[D)]//

Add characters into the [] classes as you discover new and interesting emoticons.