./t < twtxt.txt
				tail has no -r option: https://www.gnu.org/software/coreutils/manual/html_node/tail-invocation\n> GNU tail can output any amount of data (some other versions of tail cannot). It also has no -r option (print in reverse), since reversing a file is really a different job from printing the end of a file; BSD tail (which is the one with -r) can only reverse files that are at most as large as its buffer, which is typically 32 KiB. A more reliable and versatile way to reverse files is the GNU tac command.
				Funnily enough, GNU
tail has no -r option: https://www.gnu.org/software/coreutils/manual/html_node/tail-invocation> GNU tail can output any amount of data (some other versions of tail cannot). It also has no -r option (print in reverse), since reversing a file is really a different job from printing the end of a file; BSD tail (which is the one with -r) can only reverse files that are at most as large as its buffer, which is typically 32 KiB. A more reliable and versatile way to reverse files is the GNU tac command.
awk job. I'm also learning.
				tail, maybe they're right.