Work the Shell - Solve: a Command-Line Calculator Redux

Here's where the script stands at this point, in its entirety:

#!/bin/sh

if [ $# -gt 0 ] ; then
bc << EOF
scale=4
$@
quit
EOF
else
  /bin/echo -n "solve: "

  while read expression
  do
    if [ "$expression" = "quit" -o 
         "$expression" = "exit" ] ; then
      exit 0
    fi
bc << EOF
scale=4
$expression
quit
EOF
    /bin/echo -n "solve: "
  done

  echo ""
  echo "solved."
fi

exit 0

Neat and darn useful, I'd say. If I were to continue hacking on it, the next thing I would do is write a simple help page that I'd store in some library folder and display on entry of ? or help. It simply would explain the syntax of the expressions understood by bc (though as we're invoking bc iteratively, we can't have persistent variables and so forth, so unfortunately, this approach won't let us access the full power of the binary calculator).

To learn what type of sophisticated expressions you can enter, simply type man bc. Then, let that be your inspiration for further tweaks and mods to this script!

Next month, I'll go back to the numerology script and see what strange things we can ascertain about the apparently benign world around us. Remember, just because I got out of sequence, doesn't mean we're not out to get you, dear reader!