# vulgar AND broken
my @lines;
$lines[@lines - s/^\+//] .= $_ while <DATA>;
print @lines
__DATA__
This 
+is 
+supposed 
+to 
+be 
+one 
+line!
Oops

##</code><code>##

$lines[@lines - s/^\+//] .= substr $_,0,-1 while <DATA>;

##</code><code>##

$lines[ @lines + 1 - s -^\053|\012--g ] .= $_  while <DATA>;