#!/bin/bash
# script:       bash2html
# purpose:      take input  and convert all bash escape codes to html
# author:      	Florian Loeffler <webmaster@geek-blog.de>
# site:			http://www.geek-blog.de/projekte/bash2html
# copyright:   	licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License
#				(see http://creativecommons.org/licenses/by-nc-sa/3.0/)
# version:		0.1

# global variables
SCRIPTNAME=`basename $0 .sh`
SCRIPTDIR=`dirname $0`
MIN_ARGS=1

EXIT_SUCCESS=0
EXIT_FAILURE=1
EXIT_ERROR=2
EXIT_BUG=10

# preset defaults
INPUT_FILE=$1
OUTPUT_FILE="`basename $INPUT_FILE 2>/dev/null`.html"
FILTER_FILE="$SCRIPTDIR/bash2html.sed"

# pre-initialization of option variables with defaults
VERBOSE_FLAG=0

# functions
function usage {
	echo -ne "Purpose: take input  and convert all bash escape codes to html\n\n" >&2
	echo -ne "Usage: $SCRIPTNAME -i INPUT_FILE [-o OUTPUT_FILE] [-h] [-v] [-f FILTER_FILE]\n" >&2
	echo -ne "Usage: $SCRIPTNAME INPUT_FILE [-o OUTPUT_FILE] [-h] [-v] [-f FILTER_FILE]\n\n" >&2
	echo -ne "\t-h\t\tdisplay this help\n" >&2
	echo -ne "\t-v\t\tbe verbose (unused so far)\n" >&2
	echo -ne "\t-i FILENAME\tfile containing the input text\n" >&2
	echo -ne "\t-o FILENAME\tfile to write the converted text to\n\t\t\tIf OUTPUT_FILE is not specified it defaults to 'INPUT_FILE.html'.\n\t\t\tExisting files are NOT overwritten.\n" >&2
	echo -ne "\t-f FILENAME\tfile containing the sed filter script to use for the conversion\n\t\t\tThis defaults to 'bash2html.sed'.\n" >&2

	if [ $# = 1 ]
	then
		exit $1
	else
		exit $EXIT_FAILURE
	fi
}


# test minimal number of arguments
if (( $# < $MIN_ARGS ))
then
	echo "Too few arguments." >&2
	usage $EXIT_ERROR
fi


# parse arguments and set flags if necessary
while getopts ':vhi:o:f:' OPTION
do
	case $OPTION in
		v)	# verbosity	
			VERBOSE_FLAG=1
		;;

		h)	# help	
			usage $EXIT_SUCCESS
		;;
		
		i)	# input file
			INPUT_FILE=$OPTARG
			OUTPUT_FILE="$INPUT_FILE.html"
		;;

		o)	# output file
			OUTPUT_FILE=$OPTARG
		;;

		f)	# file containing the sed filter script
			FILTER_FILE=$OPTARG
		;;

		\?)	# unknown option	
			echo "Unknown option \"-$OPTARG\"." >&2
			usage $EXIT_ERROR
		;;
		
		:)	# missing argument for an option
			echo "Option \"-$OPTARG\" is missing an argument." >&2
			usage $EXIT_ERROR
		;;
		
		*)	# this should not be reached (because \? catches unknown options)
			echo "Option not implemented." >&2
			usage $EXIT_BUG
		;;
	esac
done
shift `expr $OPTIND - 1`


# do stuff ;)
if [ -e $OUTPUT_FILE ]; then
	echo -ne "WARNING!! File '$OUTPUT_FILE' already exists. I won't overwrite it.\n"
	exit $EXIT_FAILURE
fi

echo -ne "Using sed filter script from '$FILTER_FILE'.\n"
echo -ne "Processing..."
OUTPUT_TEXT=`sed -n -f $FILTER_FILE $INPUT_FILE`
echo -ne "done.\n\n"

echo "$OUTPUT_TEXT" > $OUTPUT_FILE
echo "$OUTPUT_TEXT"
echo -ne "\nResult also saved to '$OUTPUT_FILE'.\n"
echo -ne "done.\n"

exit $EXIT_SUCCESS