Makefile If-Then Else and Loops

conditional-directive
text-if-true
endif

conditional-directive
text-if-true
else
text-if-false
endif

conditional-directive
text-if-one-is-true
else conditional-directive
text-if-true
else
text-if-false
endif

ifeq (arg1, arg2)
ifeq 'arg1' 'arg2'
ifeq "arg1" "arg2"
ifeq "arg1" 'arg2'
ifeq 'arg1' "arg2"

ifneq (arg1, arg2)
ifneq 'arg1' 'arg2'
ifneq "arg1" "arg2"
ifneq "arg1" 'arg2'
ifneq 'arg1' "arg2"

ifdef variable-name

ifndef variable-name

$(foreach var, list, text)

ifeq ($(strip $(OS)),Linux)
        PYTHON = /usr/bin/python
        FIND = /usr/bin/find
endif

LIST_OF_THINGS_TO_DO = do_this do_that
$(LIST_OF_THINGS_TO_DO):
       run $@ > [email protected]

SUBDIRS = snafu fubar
$(SUBDIRS):
     cd $@ && $(MAKE)