====== make ======
Things worth knowing about ''make'' and ''Makefiles''.

====== Makefiles ======

===== Hints =====
  * a literal '''$''' has to be escaped by doubling it:
<code make>
bla:
        rm $$(echo "-rf /")
</code>
  * place a dash ('''-''') in front of a command to have ''make'' ignore it's return value:
<code make>
bla:
        -rm $$(echo "-rf /")
</code>

===== $(builtins ) =====
  * subst 
<code make>
$(OBJECTS) :
        javac $(subst .class,.java,$@)
</code>
  * filter
<code make>
FILES = Bla.java Blub.java Wrong.here
$(filter %.java,$(FILES)) :
        javac $@
$(filter %.here,$(FILES)) :
        echo "Wrong here?!"
</code>

===== Static Patterns =====
<file>
targets ...: target-pattern: prereq-patterns ...
        commands
</file>
Sample usage:
<code make>
objects = foo.o bar.o
all: $(objects)
$(objects): %.o: %.c
        $(CC) -c $(CFLAGS) $< -o $@
</code>

===== Misc Goodies =====

 * recursing paths:
<code make>
PATH=/a/b/c/d/e/f/g/h

PLIST:=
define recurse
ifneq ($(strip $(shell dirname ${1})),/)
$$(eval $$(call recurse,$(shell dirname ${1})))
PLIST+= $(shell dirname ${1})
endif
endef

all: $(eval $(call recurse,${PATH}))
	@for i in ${PLIST}; do echo $$i; done
</code>

 * a more advanced version of the above:
<code make>
PATH=/a/b/c/d/e/f/g/h
ifneq (${REVERSE},)
REVERSE:=true
endif
REVERSE?=false

PLIST:=
define get_dirname
$(strip $(shell dirname ${1}))
endef

define list_add
ifneq (${2},${3})
PLIST += $$(call get_dirname,${1})
endif
endef

define recurse
DNAME:=$$(call get_dirname,${1})
ifneq ($${DNAME},/)
$$(eval $$(call list_add,${1},$${REVERSE},true))
$$(eval $$(call recurse,$${DNAME}))
$$(eval $$(call list_add,${1},$${REVERSE},false))
endif
endef

all: $(eval $(call recurse, ${PATH}))
	@for i in ${PLIST}; do echo $$i; done
</code>

====== Links ======
[[http://www.gnu.org/software/make/manual/html_node/index.html|GNU Make Manual]]