Ncols=95
Nthreads=4
for acol in $(seq 1 ${Ncols}); do
  echo "awk -vN=${acol} '"'{if($N in uniq){uniq[$N]++}else{uniq[$N]++}}END{for(k in uniq){print k," => ",uniq[k]}}'"' my_big_file > column${acol}.uniq" > tmpscript${acol}.sh
  echo doing column $acol
  sem -j${Nthreads} sh tmpscript${acol}.sh
done