my @patterns = (qr/#.*/, qr{$^\s+}, qr{\s+$}, qr/^,/);
sub apply_patterns
{
  $_[0] =~ s/$_// for (@patterns[ @_[ 1 .. $#_ ] ]);
}
##</code><code>##

my %patterns = 
(
  comment => qr/#.*/,
  leadingSpaces => qr{$^\s+},
  trailingSpaces => qr{\s+$},
  leadingComma => qr/^,/
);

while(my $line = <FILE1>)
{
  $line =~ s/$_// for %patterns{qw/comment trailingSpaces/};
}