my @conditional_lines = <DATA>;

my @all_lines = @conditional_lines;

chomp(@all_lines);
chomp(@conditional_lines);

map { s/^#// } @all_lines;
map { s/#.*$// } @all_lines;
map { s/#.*$// } @conditional_lines;

print @all_lines;
print @conditional_lines;

__DATA__
#my commented out line
a standard line
a line with a 	# comment at the end