Re: [SPOILER] Perl 'Easy' Quiz #2005-2

I am submitting four solutions.

I am not convinced that "maskit"
will work for all input strings,
but I have not found an example 
where it does not work correctly.

sub maskit{
 my $mask = '#@%';
 ($_ = $_[0]) =~ s/\.([^.]*)$/$mask$1/;
 tr /\.//d;
 { no warnings; s/$mask($1)$/.$1/; }
 return $_;
}



Interesting use of functions.

sub reverseit {
 $_ = reverse $_[0];
 my $i = 1 + index $_, '.';
 (my $prefix = substr $_, $i) =~ tr/.//d;
 substr( $_, $i,  -$i + length $_  , $prefix);
 $_ = reverse $_;
}



Very short.

sub oneatatime{
 $_ = $_[0];
 while (s/\.(.*\..*)/$1/){} 
 return $_;
}

Recursive version of "very short"

sub recurse{
 $_ = $_[0];
 if (s/\.(.*\..*)/$1/){
  recurse($_)
 } else {
  return $_;
 }
}