Makefile

https://devhints.io/makefile
https://gist.github.com/isaacs/62a2d1825d04437c6f08
http://www.gnu.org/software/make/manual/make.html
http://www.schacherer.de/frank/technology/tools/make.html#example

TENKAICHI_USER := $(shell getent passwd tenkaichi)
#LOGS_DIR := $(shell [ -e /tenkaichi/logs/ ] && echo 1 || echo 0 ))

define create_user 
  $(info Creating tenkaichi user & group)
  $(shell useradd --home-dir /tenkaichi --user-group --password $1$XZ3glFTm$310GteJW3A8/JBLT9pbQl/ tenkaichi);
  $(shell mkhomedir_helper tenkaichi);
endef


install:
  ifeq ($(TENKAICHI_USER),)
    $(call create_user)
  endif