git: 9front

ref: 8f5ab25e8696f51f2be8a6743edc2de68c9451d6
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}