run script for chrooting a ubuntu on chromeos

#!/bin/bash

# Default program if no arguments
PROGRAM="bash"

function Error()
{
	echo "$@"
	exit -1
}

Dir="$(cd "`dirname "$0"`" && pwd)"

test -e "$Dir/chrooted/rchroot.sh" || Error "rchroot.sh doesn't exist"
test -e "$Dir/chrooted/prepare.sh" || Error "prepare.sh doesn't exist"
test -e "$Dir/chrooted/start.sh" || Error "start.sh doesn't exist"

if test "$1" = "-u"
then
	shift
	ASUSER="$1"
	shift
fi

if test -n "$1"
then
	PROGRAM="$1"
	shift
elif test -f "$Dir/defaultprogram"
then
	PROGRAM="$(cat "$Dir/defaultprogram" | head -n 1)"
else
	echo "Set a default program by settings its name in $Dir/defaultprogram"
fi

test -n "$ASUSER" && export ASUSER
"$Dir/chrooted/rchroot.sh" "$Dir" "$PROGRAM" "$@"