networking接口启动时，是否运行/etc/network/if-up.d中的所有脚本？
如果是这样，接口文件中的post-up命令是什么？
一般来说，任何标记为可执行文件并放置在该文件夹中的脚本都会运行。 由于使用了运行部件，因此这些文件仅限于特定的一组名称。
post-up一样的事情。 在if-up.d中放置一个脚本就像使用一个指向其他地方的脚本或命令的简单方法一样。 通常，只需要为单个界面运行单个命令就可以使用up | post-up。 当你有更复杂的东西，你会创build一个脚本。
人界面
... up command post-up command Run command after bringing the interface up. If this command fails then ifup aborts, refraining from marking the interface as configured (even though it has really been configured), prints an error message, and exits with status 0. This behavior may change in the future. ... There exists for each of the above mentioned options a directory /etc/network/if-<option>.d/ the scripts in which are run (with no argu- ments) using run-parts(8) after the option itself has been processed.
人运行部分
run-parts runs all the executable files named within constraints described below, If the --lsbsysinit option is not given then the names must consist entirely of upper and lower case letters, digits, underscores, and hyphens. ... Files are run in the lexical sort order of their names unless the --reverse option is given, in which case they are run in the opposite order.