title: Makefile: depend on every file of a directory
body: <p>I'd like to do a Makefile that runs either with gnumake or makepp that packs all the files under given directiories:</p>
  
  <pre><code>DIRS:=$(shell find . -mindepth 2 -maxdepth 2 -not -name mp3 -not -name ".*" -type d)
  PACKAGES = $(DIRS:%=%.npk)
  
  all: packages
  
  packages: $(PACKAGES)
  
  %.npk: %/*
      npack c $@ @^
  
  .PHONY: all packages
  </code></pre>
  
  <p>the problem is that there's no such thing as %/* in the dependencies.
  I need the targets (X.npk) to depend on every file in directory X, but I don't know what the files are when I write the Makefile, 'cause they're generated later.</p>
  
  <p>An example:</p>
  
  <pre><code>./dirA/x
  ./dirA/y
  ./dirB/e
  ./dirB/f
  </code></pre>
  
  <p>I'd like to create ./dirA.npk (depending on x,y), ./dirB.npk (e,f)
  There's nothing I know about the dirs or the files in advance except that the find used in the 1st line finds all the dirs.</p>