git: 9front

ref: c2a5d7e3f28e86aeef1e4e37e2b88e46af90b62c
dir: /sys/lib/man/permind/dup2.awk/

View raw version 
$NF!=lastf2 {if(last2!="") print last2
	 lastf2=lastf1; last2=last1; lastf1=$NF; last1=$0}
$NF==lastf2 {print}
END {print last2; print last1}