ref: 2fe3b28f86ed4aa291fb8a620b948abe9c6a1f84
dir: /sys/lib/man/mksearchindex/
#!/bin/rc awk ' { if($2 in a) a[$2] = a[$2] " " $1; else a[$2] = $1; } END { for(i in a) print " " a[i] " " i; } '< /sys/lib/man/lookman/index |sed 's/ \/sys\/man\/(.*)\/(.*)/ \2 \1\/\2/' | sort