Mini Shell

#!/usr/bin/sh
#
# sas_transport_lun_scan
#
# Selectively enable individual LUNs behind a SAS end device
#
# ACTION=="add", SUBSYSTEM=="sas_transport", ATTR{sas_address}=="sas_addr", \
#    PROGRAM="sas_transport_lun_scan lun"
#

[ -z "$DEVPATH" ] && exit 1

if [ -n "$1" ]; then
    LUN=$1
else
    LUN=-
fi
ID=${DEVPATH##*/end_device-}
HOST=${ID%%:*}
CHANNEL=${ID%%-*}
CHANNEL=${CHANNEL#*:}
if [ -f /sys"$DEVPATH"/scsi_target_id ]; then
    TARGET=$(cat /sys"$DEVPATH"/scsi_target_id)
fi
[ -z "$TARGET" ] && exit 1
echo 0 "$TARGET" $LUN > /sys/class/scsi_host/host"$HOST"/scan