my( $p, $index ) = ( 0, "\0" );
vec( $index, ++$p, 32 ) = tell( RAMFILE ) while <RAMFILE>;

## then to randomly access line $n of the file

my $nthLine = substr( $bigstring, vec( $index, $n, 32 ), vec( $index, $n+1, 32 ) - vec( $index, $n, 32 ) );