messy.sh

cat {i:targetdata} > {o:filledup} && \
  let "fillup_lines_cnt = "$(wc -l {i:targetdata} | awk '{ printf $1 }')" * 2" && \
  tail -n +2 {i:rawdata} \
  | awk -F"\t" '$9 != "{p:gene}" { $12 "\tN" }' \
  | sort \
  | uniq \
  | shuf --random-source={i:randsrc} \
  | head -n $fillup_lines_cnt \
  >> {o:filledup}