Select Code to Download

 $ perl -del
  DB<1> x 0+( () = join('','<c>','x'x(1<<30),'</c>') =~ m{<c.*?/c>}g )
...
0  1
  DB<4> x 0+( () = join('','<c>','x'x((1<<31)-7),'</c>') =~ m{<c.*?/c>
+}g )
0  0

 $ perl -del
  DB<2> x 0+( () = join('',('<c>','x'x((1<<30)-10),'</c>')x2) =~ m{<c.
+*?/c>}g )
0  2
  DB<1> x 0+( () = join('',('<c>','x'x((1<<30)-10),'</c>')x3) =~ m{<c.
+*?/c>}g )
0  0

 $ perl -del
  DB<1> $x = join('',('<c>','x'x((1<<30)-10),'</c>')x2); while( $x =~ 
+m{<c.*?/c>}g ) { print pos($x), $/ }
...
2147483642
  DB<1> $x = join('',('<c>','x'x((1<<30)-10),'</c>')x3); while( $x =~ 
+m{<c.*?/c>}g ) { print pos($x), $/ }
  DB<2>