http://qs321.pair.com?node_id=485318


in reply to Re: join program in one-liner
in thread join program in one-liner

Same as yours, but cut out unnecessary space and get rid of the END block:

# 1 2 3 4 #23456789012345678901234567890123456789012345 perl -lne'$a[$.].=$_;$.=0if eof}{print for@a'

BTW, perldoc perlvar says:

$. is reset when the filehandle is closed, but not when an open filehandle is reopened without an intervening close(). For more details, see "I/O Operators" in perlop. Because "<>" never does an explicit close, line numbers increase across ARGV