#!/bin/bash
# Skript: bash_example.sh
# Credit to: http://www.pro-linux.de/artikel/2/111/
# 1,ein-shellskript-template.html
#
# I have added some usefull functions that I am using in many
# of my scripts
# Find this script here: http://phynformatik.de
# Janosch Maier <janosch.maier@phynformatik.de>
#
# This work is licensed under the
# Creative Commons Attribution-Share Alike License
# 
# You are free
# to Share - to copy, distribute and transmit the work
# to Remix - to adapt the work
# to make commercial use of the work
#
# Under the following conditions:
# Attribution — You must attribute the work in the manner
# specified by the author or licensor (but not in any way
# that suggests that they endorse you or your use of the work).
# Share Alike — If you alter, transform, or build upon this
# work, you may distribute the resulting work only under the
# same or similar license to this one.
version="0.1"
lastChange="02.01.2012"

#### CONFIG - DO NOT MAKE CHANGES HERE ####
# PATH has to be a trusted value
# Try to make this script save in unsave environments
# "." cannot be in PATH
PATH=/bin:/sbin:/usr/bin:/usr/sbin/:/usr/local/bin:/usr/local/sbin
export PATH

# Environment variable IFS should always be
# "<space><tab><newliene>" or undefined
# Same as with PATH
if [ -z "$IFS" ]
then
        IFS="
"
        export IFS
fi


#### YOU CAN START MAKING CHANGES FROM HERE ON ####
# Define global variables for later use
# Name of the script is its filename (without possible suffix .sh)
SCRIPTNAME=$(basename $0 .sh)
# Define Exit values
EXIT_SUCCESS=0
EXIT_FAILURE=1
EXIT_ERROR=2
EXIT_BUG=10
# Logfile will be put under current working directory
LOGFILE=`readlink -f "$SCRIPTNAME.log"`

# Error values
ERROR="ERROR"
WARNING="WARNING"
INFO="INFO"
NOTICE="NOTICE"

# Default values for options
VERBOSE=false
DEBUGLEVEL=1


#### FUNCTIONS FOR LATER USE ####
# Print usage message
function usage {
	echo "Usage: $SCRIPTNAME [-h] [-v] [-d debuglevel] file ...
 
  -h		show this help
  -v		be verbose
  -d		set debug level (1-9)"
	[[ $# -eq 1 ]] && exit $1 || exit $EXIT_FAILURE
}

# Log stuff to the defined logfile
# Call "log $ERROR|$WARNING|$INFO|$NOTICE message"
function log {
	case $1 in
		$ERROR)
			if [ $DEBUGLEVEL -ge 1 ]
			then
				shift
				echo "$(date '+%F %T') $ERROR: $@" >> $LOGFILE
			fi
			;;
		$WARNING)
			if [ $DEBUGLEVEL -ge 3 ]
			then
				shift
				echo "$(date '+%F %T') $WARNING: $@" >> $LOGFILE
			fi
			;;
		$INFO)
			if [ $DEBUGLEVEL -ge 5 ]
			then
				shift
				echo "$(date '+%F %T') $INFO: $@" >> $LOGFILE
			fi
			;;
		$NOTICE)
			if [ $DEBUGLEVEL -ge 7 ]
			then
				shift
				echo "$(date '+%F %T') $NOTICE: $@" >> $LOGFILE
			fi
			;;
		*)
			echo "$(date '+%F %T') BUG: $@" >> $LOGFILE
			;;
	esac
}

# Echo a string if verbose mode is set
# Log as an Info message in any case
function echo_verbose {
	if [ "$VERBOSE" == "true" ]
	then
		echo $@
	fi
	log $INFO "$@"
}

# Echo a string and put it to Error log
function echo_error {
        log $ERROR "$@"
        echo "$ERROR: $@" >&2
}

# Run external command and only procced, when exit code is 0
function try {
	$@
	returnValue=$?
	echo "$returnValue"
	if [ $returnValue -ne 0 ]
	then
		log $ERROR "$@ exited with return value $returnValue. Script will stop here."
		echo "$@ exited with return value $returnValue. Script will stop here."
		exit $EXIT_FAILURE
	fi
}


#### GETTING ALL OPTIONS #####
# Option -h gives some help
# Option -v makes the script verbose
# Option -o has one option argument therefore o:
while getopts ':o:d:vh' OPTION ; do
	case $OPTION in
		v) VERBOSE=true
		;;
 		h) usage $EXIT_SUCCESS
 		;;
		d) DEBUGLEVEL="$OPTARG"
		;;
 		\?) echo "Unknown Option \"-$OPTARG\"." >&2
 		usage $EXIT_ERROR
 		;;
		:) echo "Option \"-$OPTARG\" needs an argument." >&2
		usage $EXIT_ERROR
		;;
		*) echo "There should never happen..." >&2
		usage $EXIT_BUG
		;;
	esac
done


#### DO CHECKS ON THE ARGUMENTS ####
# $OPTIND is number of options gotten by getopts + 1
# Therefore shift arguments gotte by OPTIND - 1
shift $(( OPTIND - 1 ))

# Check if the number of arguments gotten is correct
if (( $# < 1 || $# > 2)) ; then
	echo "One or two arguments needed." >&2
	log $ERROR "1 or 2 arguments needed. $# arguments gotten"
	usage $EXIT_ERROR
fi


#### DO SOME STUFF HERE ####
# Do something for all other arguments
for ARG ; do
	echo_verbose "Doing stuff for an argument"
	echo $ARG
done

# The script succeded doing its work
exit $EXIT_SUCCESS