#! /bin/sh

# there must be a plan9port installation present
if test "x$PLAN9" = x; then
	echo PLAN9 variable not set >&2
	exit 1
fi

# check that PATH does not contain settings that might
# cause problems
hasbin=false
hasusrbin=false
hasinfernobin=false
hasplan9bin=false

for p in `echo $PATH | tr ' :' '_ '`; do
	case $p in
	/usr/bin)
		hasusrbin=:
		;;
	/bin)
		hasbin=:
		;;
	$PLAN9/bin)
		if $hasbin && $hasusrbin; then :
		else
			echo 'Error: $PLAN9/bin in PATH is not behind /bin and /usr/bin, which will cause problems' >&2
			exit 1
		fi
		hasplan9bin=:
		;;	
	*/inferno/*/bin*)
		if $hasplan9bin; then :
		else
			echo 'Error: PATH seems to contain an inferno /bin, that comes before $PLAN9/bin' >&2
			echo 'This will cause problems, because of the mk binary.'
			exit 1
		fi
		;;
	esac
done
if $hasplan9bin; then :
else
	echo 'Error: PATH does not contain $PLAN9/bin' >&2
	exit 1	
fi


# check whether we are inside of a pf9 tree,
# and try to guess a value for PF9

if test "x$PF9" = x; then 
	if pwd | grep /src > /dev/null; then
		PF9=`pwd | sed 's,/src.*,,'`
	else
		PF9=`pwd`
	fi
fi

if test -f "$PF9/pf9.defaults"; then
	
	# derive default value for objtype from cputype
	test "$objtype" || objtype=$cputype

	# save them as used-defined settings
	user_objtype=$objtype
	user_cputype=$cputype

	# load distribution defaults
	. $PF9/pf9.defaults

	# user settings have precedence
	test -z "$user_objtype" || objtype=$user_objtype
	test -z "$user_cputype" || cputype=$user_cputype
		
	export \
		PF9 \
		cputype \
		objtype

else
	cat <<EOF >&2
Not able to find the base directory. Please either move into
the sys/src hierarchy or into the base directory
and re-run $0.

EOF
	exit 1
fi

cat <<EOF
PF=$PF9
cputype=$cputype
objtype=$objtype
--
EOF

cpusys=`cat  $PF9/$cputype/sysname`
PATH=$PF9/$cpusys/bin:$PF9/$cputype/bin:$PATH



shell=$SHELL
if echo $shell | grep 'rc$' > /dev/null; then
	shell=rc
fi
exec $shell