我在makefile中使用shell编程时遇到了一个问题

Question

代码为:

# android/device/mediatek/build/core/build_dtboimage.mk
...
my_dtbo_id := 0                                                                   
define mk_dtboimg_cfg                                                             
$(eval name := $$(basename $1)) 
echo "file name:$(name)"; 
$(eval dts_file_name := $(notdir $(name))) 
echo "terminal_name:$$(echo $(dts_file_name) | awk -F '_' '{print $$1}')"; 
$(eval terminal_name := $$(echo $(dts_file_name) | awk -F '_' '{print $$1}')) 
$(eval main_name := $$(echo $(dts_file_name) | awk -F '_' '{print $$3}')) 
echo "terminal_name :$(terminal_name), main_name :$(main_name )"; 
...

，输出为:

file name:out/target/product/k62v1_64_pax/obj/KERNEL_OBJ/arch/arm64/boot/dts/mediatek/A3700_MT6762_V02_V01
terminal_name:A3700
terminal_name:, main_name:

如上图所示，代码echo "terminal_name:$$(echo $(dts_file_name) | awk -F '_' '{print $$1}')"; 可以得到A3700的正确输出，但是我不知道为什么terminal_name和main_name的输出是null

.我期望的正确输出是terminal_name:A3700, main_name:V02，换句话说，我希望terminal_name和main_name

我该怎么做才能解决这个问题?

谢谢!

Answer 1

你把事情弄得太复杂了。

删除不必要的功能，并慷慨地使用$:

...
dts_file_name := $$(notdir $$(name))
terminal_name := $$(shell echo $$(dts_file_name) | awk -F '_' '{print $$$$1}')
main_name := $$(shell echo $$(dts_file_name) | awk -F '_' '{print $$$$3}')
$$(info terminal: $$(terminal_name), main: $$(main_name))
...