#!/bin/bash

# convertatemp--Temperature conversion script that lets the user enter
#   a temperature in Fahrenheit, Celsius, or Kelvin and receive the
#   equivalent temperature in the other two units as the output

if test $Argc -eq 0  {
  cat << """ >&2
Usage: $0 temperature[F|C|K]
where the suffix:
   F    indicates input is in Fahrenheit (default)
   C    indicates input is in Celsius
   K    indicates input is in Kelvin
"""
> !2
Usage: $0 temperature[F|C|K]
where the suffix:
   F    indicates input is in Fahrenheit (default)
   C    indicates input is in Celsius
   K    indicates input is in Kelvin
EOF
  exit 1
}

setglobal unit = $[echo $1|sed -e 's/[-[:digit:]]*//g' | tr '[:lower:]' '[:upper:]]
setglobal temp = $[echo $1|sed -e 's/[^-[:digit:]]*//g]

match $(unit:=F)
{
  with F  # Fahrenheit to Celsius formula:  Tc = (F - 32) / 1.8
  setglobal farn = $temp
  setglobal cels = $[echo "scale=2;($farn - 32) / 1.8" | bc]
  setglobal kelv = $[echo "scale=2;$cels + 273.15" | bc]
  

  with C  # Celsius to Fahrenheit formula: Tf = (9/5)*Tc+32
  setglobal cels = $temp
  setglobal kelv = $[echo "scale=2;$cels + 273.15" | bc]
  setglobal farn = $[echo "scale=2;(1.8 * $cels) + 32" | bc]
  

  with K  # Celsius = Kelvin - 273.15, then use Cels -> Fahr formula
  setglobal kelv = $temp
  setglobal cels = $[echo "scale=2; $kelv - 273.15" | bc]
  setglobal farn = $[echo "scale=2; (1.8 * $cels) + 32" | bc]
  

  with *
  echo "Given temperature unit is not supported"
  exit 1
}  

echo "Fahrenheit = $farn"
echo "Celsius    = $cels"
echo "Kelvin     = $kelv"

exit 0