#!/bin/bash
# unit-conversion.sh
# Must have 'units' utility installed.


convert_units ()  # Takes as arguments the units to convert.
{
  cf=$(units "$1" "$2" | sed --silent -e '1p' | awk '{print $2}')
  # Strip off everything except the actual conversion factor.
  echo "$cf"
}  

Unit1=miles
Unit2=meters
cfactor=`convert_units $Unit1 $Unit2`
quantity=3.73

result=$(echo $quantity*$cfactor | bc)

echo "There are $result $Unit2 in $quantity $Unit1."

#  What happens if you pass incompatible units,
#+ such as "acres" and "miles" to the function?

exit 0

# Exercise: Edit this script to accept command-line parameters,
#           with appropriate error checking, of course.