tarch

#!/bin/bash -e

usage() { echo "tarch file"; }
if [[ -z $1 ]]; then usage; exit 1; fi

total=$(tar cf - "$1"  | wc -c)
gzip=$(tar czf - "$1"  | wc -c)
bzip2=$(tar cjf - "$1" | wc -c)

gzip_goal=$(echo "scale=2; ${gzip} / ${total} * 100" | bc)
bzip2_goal=$(echo "scale=2; ${bzip2} / ${total} * 100" | bc)

printf "gzip :${gzip}B %4s%s\n" "$gzip_goal" "%"
printf "bzip2:${bzip2}B %4s%s\n" "$bzip2_goal" "%"
echo "total:${total}B"
echo

# set green
tput setaf 2

if [[ $gzip_goal < $bzip2_goal ]]
then
  delta=$(echo "$bzip2_goal - $gzip_goal" | bc)
  echo "It turns out that gzip is ~${delta}% smaller than bzip2. A miracle!"
else
  delta=$(echo "$gzip_goal - $bzip2_goal" | bc)
  printf "bzip2 is %0.f%s smaller than gzip.\n" "${delta}" "%"
fi

# set normal
tput sgr0