[dpdk-dev] dynamic log level syntax

[dpdk-dev] dynamic log level syntax

[Stephen Hemminger]

After using dynamic logging for a while, I think there was a poor design choice
on using regular expressions to match logging string.  The naming policy looks
like a hierarchy and the matching is with regular expressions. For most other
applications where a hierarchy is implied, a globbing rather than regular
expression match is used.

Instead of current regex based
	--log-level="pmd\.net\.i40e\..*"

Globbing would use
	--log-level="pmd.net.i40e.*"

Part of the problem as well with current choice is that seperator
(period) is also the regular expression match any character value.

Glibc doesn't have an easy to use version of this matching.
The only close function is fnmatch and it wants slash for separator.

Unfortunately, changing the syntax now would be an API nuisance.
Some of the examples in the current documentation are unclear or
incorrect on this.