2015/advent10.sh

   1 val=${1-1} rounds=${2-5}
   2 echo "running $rounds iterations on initial input $val"
   3 exec 3>&1
   4 # visit rounds val
   5 visit() {
   6     echo "starting visit $@" >&3
   7     if [[ $1 == 0 ]]; then
   8         echo $val | sed 's/\(.\)/\1\n/g'
   9         return
  10     fi
  11     exec < <(visit $(($1 - 1)) $val)
  12     read prev
  13     lines=1
  14     index=1
  15     count=1
  16     summary="($prev"
  17     while read next; do
  18         [[ ! $next ]] && continue
  19         lines=$((lines + 1))
  20         if [[ $lines -lt 70 ]]; then
  21             summary+="$next"
  22         elif [[ $lines == 70 ]]; then
  23             summary+=...
  24         fi
  25         if [[ $next == $prev ]]; then
  26             count=$((count+1))
  27         else
  28             echo $count
  29             echo $prev
  30             prev=$next count=1
  31         fi
  32     done
  33     echo $count
  34     echo $prev
  35     echo "$summary)" >&3
  36     echo "visit $1 parsed $lines bytes" >&3
  37 }
  38 echo "final length $(visit $rounds $val | wc -l)"