Linux Agent: de-bash is_valid_plugin()

[rawiriblundell]

is_valid_plugin() tries to be too clever, and in doing so it breaks portability.

This PR replaces it with a far simpler, more obvious and portable approach.

[jonaskluger]

Hello Rawiri,

thank you for this pull request. We will have a closer look at your patch and discuss internally on how and if we can implement it into the official code base.

Internal Ref: CMK-4332

[rawiriblundell]

Hi,
this is another obvious and simple change that has been sitting here inexplicably for several months. Can we please get this merged?

Cheers

[svenpanne]

Well, it's obviously not obvious at all. 😉 This PR has 2 bugs in it:

• The patterns in the case were missing a dot (it's all about extensions).
• A test for being a file was missing (ignore directories).

I have just committed a fixed version of this PR to master.

Apart from that: The reason that we are a bit slow regarding PRs and issues on GitHub is simply manpower. We are doing this on a best-effort basis, and we're trying to improve response times, but sometimes this doesn't really work well...