title: .PHONY in linux makefile
body: <pre><code>SUBDIRS = foo bar baz
  
  .PHONY: dirs $(SUBDIRS)
  
  dirs: $(SUBDIRS)
  
  $(SUBDIRS):
  
  @echo $@
  
  @ls $@
  </code></pre>
  
  <p>Anybody can just help me out to understand this make-file?
  If possible explain me each statement (why do we need it?, what is the purpose? etc.)</p>
  
  <p>And how exactly this make-file works?</p>