大于Makefile中的字符串比较 [英] Greater than string comparison in a Makefile

问题描述

如何在Makefile中表达以下逻辑?

How do I express the following logic in a Makefile?

if $(XORG_VERSION) > "7.7"
   <do some thing>
fi

makefile的有条件部分仅提供ifeq或ifneq.

Conditional Parts of Makefiles only provides ifeq or ifneq.

推荐答案

您不限于使用make条件语句-每个命令都是一个shell命令，它可能会根据您的需要而复杂(包括shell条件语句)声明):

You're not restricted to using the make conditional statements - each command is a shell command which may be as complex as you need (including a shell conditional statement):

请考虑以下makefile:

dummy:
    if [ ${xyz} -gt 8 ] ; then \
        echo urk!! ${xyz} ;\
    fi

使用xyz=7 make --silent时，没有输出.当您使用xyz=9 make --silent时，它将按预期输出urk!! 9.

When you use xyz=7 make --silent, there is no output. When you use xyz=9 make --silent, it outputs urk!! 9 as expected.

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