Question

我在make gnu文件上运行以下代码

apps := $(shell tbd run apps)
apps := $(subst ],,$(subst [,,$(app)))

现在我要打印应用程序值，并尝试使用

@echo $(app)

我遇到了错误

Makefile:12: *** commands commence before first target. Stop.

更新：

当前我的代码就像

apps := $(shell tbd run apps)
apps := $(subst ],,$(subst [,,$(apps)))


build:
    @for app in $(apps) ; do \
     bsd start $$app ; \
    done

如果我这样尝试，就会出错

start: 
   apps := $(shell tbd run apps)
   apps := $(subst ],,$(subst [,,$(apps)))

build:
    @for app in $(apps) ; do \
        bsd start $$app ; \
    done

Answer 1

如果您只想打印某些规则的东西，请使用info函数...

$(info $(app))

Answer 2

您不能在外壳程序调用中有意义地放置一个Makefile函数调用。我想你真的只是在寻找

build:
    tbd run apps \
    | sed 's/\[//;s/\]//' \
    | xargs -n 1 bsd start

尝试从gnu make中的命令获取值时出错

2 个答案: