/usr/bin/lb is in live-build 3.0~a57-1ubuntu11.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73  | #!/bin/sh
## live-build(7) - System Build Scripts
## Copyright (C) 2006-2012 Daniel Baumann <daniel@debian.org>
##
## This program comes with ABSOLUTELY NO WARRANTY; for details see COPYING.
## This is free software, and you are welcome to redistribute it
## under certain conditions; see COPYING for details.
set -e
# Including common functions
( . "${LIVE_BUILD}/scripts/build.sh" > /dev/null 2>&1 || true ) || . /usr/lib/live/build.sh
# Setting static variables
DESCRIPTION="$(Echo 'utility to build Debian Live systems')"
HELP="FIXME"
USAGE="FIXME"
case "${1}" in
	-h|--help)
		if [ -x "$(which man 2>/dev/null)" ]
		then
			man lb
			exit 0
		else
			${0} --usage
			exit 0
		fi
		;;
	""|-u|--usage)
		Usage
		;;
	-v|--version)
		echo "${VERSION}"
		exit 0
		;;
	*)
		COMMAND="lb_${1}"
		shift
		ENV=""
		for _FILE in config/environment config/environment.binary
		do
			if [ -e "${_FILE}" ]
			then
				ENV="${ENV} $(grep -v '^#' ${_FILE})"
			fi
		done
		if [ -x "${LIVE_BUILD}/scripts/build/${COMMAND}" ]
		then
			SCRIPT="${LIVE_BUILD}/scripts/build/${COMMAND}"
		elif [ -x /usr/lib/live/build/${COMMAND} ]
		then
			SCRIPT=/usr/lib/live/build/"${COMMAND}"
		elif [ -x "$(which ${COMMAND} 2>/dev/null)" ]
		then
			SCRIPT="${COMMAND}"
		else
			Echo_error "no such script: ${COMMAND}"
			exit 1
		fi
		Echo "[%s] %s" "$(date +'%F %T')" "${COMMAND} ${*}"
		LB=1 ${ENV} exec "${SCRIPT}" "${@}"
		;;
esac
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