#!/bin/bash
#
# Create the build info header file
#
# Usage: build_info [--build] [build-info-data-file build-info-header-file]
#	 build_info --create build-info-data-file title author [major-version minor-version build-sequence]
#	 build_info --help
#
# Author: Graham Cobb 10-Dec-2001
#
#
USAGE="Usage: $0 [--help] [[--build] [build-info-data-file build-info-header-file]] [--create build-info-data-file title author [major-version minor-version build-sequence]]"
BUILD_INFO_VERSION=1

do_help=
do_create=
while [ $# -gt 0 ]; do
	case "$1" in
	--help)		shift ; do_help=y ;;
	--create)	shift ; do_create=y ;;
	--build)	shift ;;
	--)		shift ; break ;;
	-*)		echo "$0: ${1}: invalid option" >&2
			echo "$USAGE" >& 2
			exit 2 ;;
	*)		break ;;
	esac
done

if [ -n "$do_help" ]; then
	echo "This is build_info version $BUILD_INFO_VERSION"
	echo
	cat << HERE_EOF
    build_info --help

This help text.

    build_info [--build] [build-info-data-file build-info-header-file]

build_info creates a C header file which provides information about the build
environment for a program which can be used to display version information to
a user of the program.

The script creates build_info.h (by default) which defines the following
constants (macros):

BUILD_TITLE - The program title.  This can be any text string but is usually
either a short name (e.g. build_info) or a one-line description (e.g. 
"Create build information header file"). (*)

BUILD_AUTHOR - The program author.  This can be any text string but is usually
either the original author or the most recent modifier. (*)

BUILD_VER - The program version.  This is a text string of the form
<major-version>.<minor-version> (e.g. "10.3"). (*)

BUILD_VER_MAJOR - Major version number.  This is a numeric form of the major
version (e.g. 10). (*)

BUILD_VER_MINOR - Minor version number.  This is a numeric form of the minor
version (e.g. 3). (*)

BUILD_SEQ_NUM - The sequential build number.  This is a number which is
incremented by one each time the script is run. (*)

BUILD_SEQ_ID - Text form of the sequential build number.  This is BUILD_SEQ_NUM
as a string (e.g. "305"). (*)

BUILD_FULL_VER - Major, minor and build number: <major-version>.
<minor-version>-<build-number> (e.g. "10.3-305"). (*)

BUILD_BUILDER - Builder username.  This is the username of the user running
the script (e.g. "cobb").

BUILD_HOST - Builder hostname.  This is the hostname of the system running
the script.

BUILD_DATE - Build date.

BUILD_TIME - Build time

BUILD_YEAR - Year from build date (as a text string)

* - These items are derived from information stored in the build information
data file (build_info.dat by default).

    build_info --create build-info-data-file title author [major-version minor-version build-sequence]

The data file can be created using the --create option.  This requires the
data file name (usually build_info.dat), the title and the author.  The version
numbers and initial build sequence number can also be specified as required
(default is 1.0-0).
HERE_EOF
	exit 0
fi

if [ -n "$do_create" ]; then
# Create the data file
	if [ $# -lt 3 ]; then
		echo "$0: Create option must specify file name, title and author" >&2
		echo "$USAGE" >& 2
		exit 2 
	fi
	data_file=$1
	BUILD_TITLE=$2
	BUILD_AUTHOR=$3
	BUILD_VER_MAJOR=${4-1}
	BUILD_VER_MINOR=${5-0}
	BUILD_SEQ_NUM=${6-0}
	
	# Drop through to creating the data file
	
else
# Normal case: output the header file
	data_file=${1-build_info.dat}
	header_file=${1-build_info.h}

	# Read data file
	. $data_file
	BUILD_SEQ_NUM=$((BUILD_SEQ_NUM+1))
	HOSTNAME=`hostname`
	DATE=`date "+%d-%b-%Y"`
	TIME=`date "+%T %Z"`
	YEAR=`date "+%Y"`

	# Create header file
	echo "#define BUILD_TITLE \"${BUILD_TITLE}\"" >$header_file
	echo "#define BUILD_AUTHOR \"${BUILD_AUTHOR}\"" >>$header_file
	echo "#define BUILD_VER \"${BUILD_VER_MAJOR}.${BUILD_VER_MINOR}\"" >>$header_file
	echo "#define BUILD_VER_MAJOR ${BUILD_VER_MAJOR}" >>$header_file
	echo "#define BUILD_VER_MINOR ${BUILD_VER_MINOR}" >>$header_file
	echo "#define BUILD_SEQ_NUM ${BUILD_SEQ_NUM}" >>$header_file
	echo "#define BUILD_SEQ_ID \"${BUILD_SEQ_NUM}\"" >>$header_file
	echo "#define BUILD_FULL_VER \"${BUILD_VER_MAJOR}.${BUILD_VER_MINOR}-${BUILD_SEQ_NUM}\"" >>$header_file
	echo "#define BUILD_BUILDER \"${USER}\"" >>$header_file
	echo "#define BUILD_HOST \"${HOSTNAME}\"" >>$header_file
	echo "#define BUILD_DATE \"${DATE}\"" >>$header_file
	echo "#define BUILD_TIME \"${TIME}\"" >>$header_file
	echo "#define BUILD_YEAR \"${YEAR}\"" >>$header_file

fi

# Create data file
echo "BUILD_INFO_DATA_VERSION=${BUILD_INFO_VERSION}" >$data_file
echo "BUILD_TITLE=\"${BUILD_TITLE}\"" >>$data_file
echo "BUILD_AUTHOR=\"${BUILD_AUTHOR}\"" >>$data_file
echo "BUILD_VER_MAJOR=${BUILD_VER_MAJOR}" >>$data_file
echo "BUILD_VER_MINOR=${BUILD_VER_MINOR}" >>$data_file
echo "BUILD_SEQ_NUM=${BUILD_SEQ_NUM}" >>$data_file