Auto tools makefile getting started

1# define the .vimrc file to following contents
2cat ~/.vimrc
3set noexpandtab
4set autoindent

 1.DEFAULT_GOAL:=build
 2
 3fmt:
 4	echo "this is fmt...."
 5
 6.PHONY:vet
 7vet:fmt
 8	echo "this is vet..."
 9
10
11build:vet
12	echo "this is build..."

1echo "this is fmt...."
2this is fmt....
3echo "this is vet..."
4this is vet...
5echo "this is build..."
6this is build...

 1#Ignore if has directory or file  same name in current directory
 2.PHONY:clean all
 3# Set the global variables to use in back  commands
 4CC=gcc
 5INCLUDE_DIR=
 6C_FLAGS=
 7
 8# All sub dirs except debug directory, because the debug directory to last compile
 9# Use awk to exclude debug
10SUBDIRS=$(shell ls -l | grep ^d | awk '{if($$9 != "debug") if($$9 != "include") print $$9}')
11
12#Lastly go to debug directory 
13#DEBUG=$(shell ls -l | grep ^d | awk '{if($$9 == "debug") print $$9}')
14
15#save current folder path to ROOT_DIR
16ROOT_DIR=$(shell pwd)
17
18#Finally application's name
19BIN=myapp
20
21#the obj file directory
22OBJS_DIR=debug/obj
23
24#the bin file directory
25BIN_DIR=debug/bin
26
27#store the all .c source file to CUR_SOURCE directory
28CUR_SOURCE=${wildcard *.c}
29
30#construct the all obj file with .c file
31CUR_OBJS=${patsubst %.c, %.o, $(CUR_SOURCE)}
32
33#export all variables to sub directory's Makefile
34export CC BIN OBJS_DIR BIN_DIR ROOT_DIR
35
36#order to exec target 
37all:$(SUBDIRS) $(CUR_OBJS) DEBUG
38
39
40# recurseive exec sub dirs make
41# per exec echo the sub dir
42$(SUBDIRS):ECHO
43	make -C $@
44
45DEBUG:ECHO
46	#go to debug directory exec make
47	make -C debug
48
49# echo the current sub dir
50ECHO:
51	@echo $(SUBDIRS)
52
53
54# compile the c file to obj save to relative obj dir
55$(CUR_OBJS):%.o:%.c
56	$(CC) -c $^ -o $(ROOT_DIR)/$(OBJS_DIR)/$@
57
58clean:
59	rm -rf $(OBJS_DIR)/*.o
60	rm -rf $(BIN_DIR)/*

1build: prebuild
2	$(call print-target)
3	GOOS=linux GOARCH=amd64 go build -trimpath  -ldflags="-s -w"  -o detector main.go
4
5define print-target
6    @printf "Executing target: \033[36m$@\033[0m\n"
7endef