Extensions of $, $@, and $<

The internally generated macros $, $@, and $< are useful generic terms for current targets and out-of-date relatives. To this list is added the following related macros: $(@D), $(@F), $(D), $(F), $(<D), and $(<F). The D refers to the directory part of the single character macro. The F refers to the file name part of the single character macro. These additions are useful when building hierarchical makefiles. They allow access to directory names for purposes of using the cd command of the shell. Thus, a command can be

   cd $(<D); $(MAKE) $(<F)