I recently tried to install redis 2.6.7 with my own configuration file path but the file path could not be changed.
I checked "redis/utils/install_server.sh" and found there is not space between "!" and the following variable.
if [ !"$REDIS_CONFIG_FILE" ] ; then
if [ ! "$REDIS_CONFIG_FILE" ] ; then
fix issue #840, #864 and #1099