I don't know about the Y part of your quasi-XY Problem, but the X part might be approached like this (among several possibilities):

perl -wMstrict -le
"my $lines = do {
   local $/ = qq(\cD);
   my $in = <STDIN>;
   chomp $in;
   $in
   };
 print $lines
"
qwert
asdf
zx^D
qwert
asdf
zx
[download]

Note that you still have to enter a newline after the ^D, and also, oddly, you can enter other characters between the ^D and the newline, but they will not be captured by the script.

C:\@Work\Perl\monks\zemane>perl -wMstrict -le
"my $lines = do {
   local $/ = qq(\cD);
   my $in = <STDIN>;
   chomp $in;
   $in
   };
 print $lines
"
the cow
jumped over
the moo^Dn whoops!
the cow
jumped over
the moo
[download]

Also note that this code captures the multi-line input as a single line, not as an array, but that's a detail, a mere detail!