# GNU MAKE

MAIN: https://devhints.io/makefile



MAGIC VARIABLES
---------------

out.o: src.c src.h
    $@      # target                (out.o)
    $<      # first prerequisite    (src.c)
    $^      # all prerequisite      (src.c src.h)

%.o: %.c
    $*      # the matched "stem"    (foo in foo.o/foo.c)

also:
    $+      # all prerequisite with dup
    $?      # prerequisites (new ones)
    $|

    $(@D)   # target directory



ASSIGNMENTS
-----------

 =      asignment (dynamic, renewing)
:=      one time assignment
?=      safe assignemnt (no effect on prev. dynamic assignments)
+=      append
!=      exec shell cmd and assign


COMMAND PREFIX
--------------

-       ignore errors
@       don't print
+       always run