BACKUP_SOURCE ?= .
BACKUP_TARGET ?= ..
BACKUP_DATE   ?= $(shell date +'%y%m%d-%H%M%S')

_BACKUP_SOURCE = $(notdir $(shell cd $(BACKUP_SOURCE); pwd))

backup: distclean
	tar -C .. $(_BACKUP_SOURCE) -cjf $(BACKUP_TARGET)/$(_BACKUP_SOURCE)-$(BACKUP_DATE).tar.bz2

purge-last-backup:
	$(RM) -f $(shell ls $(BACKUP_TARGET)/$(_BACKUP_SOURCE)-*.tar.bz2 | tail -1)