====== functions ======


[[https://www.gnu.org/software/make/manual/html_node/File-Name-Functions.html|8.3 Functions for File Names]]

  * $(**dir** /path/to/file.txt) - get path part only
  * $(**notdir** src/foo.c hacks) - result ''foo.c hacks''. 
  * $(**suffix** ...)
  * $(**basename** src/foo.c src-1.0/bar hacks) - produces the result ''src/foo src-1.0/bar hacks''. 
  * $(**addsuffix**)
  * $(**addprefix**)
  * $(**join**)
  * $(**wildcard**) - execute wildcard expansion (needed to expand wildcards in variables and arguments in functions). More: [[https://www.gnu.org/software/make/manual/html_node/Wildcard-Function.html|The Function wildcard]]
  * $(**realpath**) - NOTE: file must exist!
  * $(**abspath**) - NOTE: do not require file to exist

[[https://www.gnu.org/software/make/manual/html_node/Conditional-Functions.html|Conditional Functions]] - can be used also in recipes body:

  * $(**if**)\\ Example 1: <code make>
build:
    $(if $(filter 1,$(WORKSPACE_DETECTED)), \
      @echo
      @echo "!!! Configured workspace detected: '$(WORKSPACE_PATH)'"
    )
</code> Example 2: <code make>
$(if $(filter foo,bar),@echo match is broken,@echo match works)
$(if $(filter-out foo,bar),@echo match works,@echo match is broken)
</code>