peu2degc

#!/bin/bash
# This script's framework was created using makescript 
# version v1.0.2, dated 2019-07-18
# Makescript and its accompanying scripts are copyrighted
# by Aetesaki (c) 2018
# 
# peu2degc (c) 2019 aetesaki
#
# ##################################################
# HISTORY:
# ##################################################
#
# * 2019-07-19 - v0.0.0  - First Creation
# * 2019-07-19 - v0.0.1  - converting degf2degc to degc2degf
# * 2019-07-19 - v0.0.2  - renaming script variable to degc2degf
# * 2019-07-19 - v0.0.3  - converting degc2degf to degctopeu
# * 2019-07-19 - v0.0.4  - converting degc2peu to peu2degc
# * 2019-07-21 - v1.0.0  - release version
#
# ##################################################
# Initializing constants and variables
# ##################################################
# Setting constants
version="v1.0.0"            # Sets version variable
lastEdited="2019-07-21"     # Sets last edited variable
[ ! -t 0 ] && pipe=$(cat)   # if stdin is open dump stdin to $pipe
# Declaring variables
declare peu celcius	# temperature variables
# Declare all variables to be used in the script 
# ##################################################
# short help function
# ##################################################
shorthelp() {
    # Edit as required
    cat << EOF
Usage: peu2degc [peu]
       peu2degc --help
       peu2degc --version"
EOF
}
# ##################################################
# no arguments gives short help
# ##################################################
if [ "$#" == "0" ]; then
	# check if $pipe is empty
	if [ -z "$pipe" ]; then
		# display shorthelp and exit
		shorthelp
		exit 1
	else
		# else set arguments to $pipe
		set -- "$pipe"
	fi
fi 
# ##################################################
# -- help
# ##################################################
if [ "$1" == "--help" ]; then
    shorthelp
    # Write options and explanations
    cat << EOF
   --help                 Displays this text and exit.
   --version              Displays the version of the script and exit.
EOF
    # Write information on arguments afterwards
    # Write examples as required
    exit 0
fi 
# ##################################################
# -- version
# ##################################################
if [ "$1" == "--version" ]; then
    cat << EOF
peu2degc ${version}, dated ${lastEdited}
(c) 2019 aetesaki
EOF
    exit 0
fi
# ##################################################
# Main section
# ##################################################
# Write your script here
# copy first argument to $peu
peu=$1
# Check for valid argument
if ! [[ $peu =~ ^[+-]?[0-9]+([.][0-9]+)?$ ]]; then
	echo "Peu temperature measurement is not a number" >&2
	exit 1
fi

# convert peu to celsius
celsius=$(awk "BEGIN {printf \"%.2f\n\", ($peu/0.8)+18}")

# echo the converted temperature
echo $celsius