twopage

#!/bin/sh

# Post-process troff output to insert an extra page 
# if needed to make an even number of pages

awk '
/^p[0-9]/ {
	npage++;
	lastpage = substr($0, 2)
}
{ print }

END {
	if(npage%2){
		printf "p%d\n", lastpage+1
	}
}
' "$@"