I'm not terribly happy with the state of Perl/CPAN support for the INI file format.
I have this requirement of modifying php.ini files programmatically from Perl like: set register_globals to On/Off, add/remove some extension (via the extension=foo lines), adding/removing some functions from the disabled_functions list, etc. So I would like to find a CPAN module that can just set/unset a parameter and leave formatting/comments alone as much as possible.
Turns out that among a dozen or so of INI modules on CPAN, a few of them do not do writes at all (e.g. Config::INI::Access or Config::Format::INI). And a few that do, write a la dump. That is, they just rewrite the whole INI file with the in-memory structure. All comments and formatting (even ordering, in some cases) are lost. Example: Config::INI::Writer and Tie::Cfg. And, last time I tried, I couldn't even install Config::IniHash from the CPAN client. Not good.
So I ended up with Config::IniFiles. And I needed to patch two features in before I could even read php.ini and write to it properly. This is an old module, which although still maintained, probably needs a rewrite or modernization. One reviewer in CPAN Ratings also wrote that this module fails in edge cases and the test suite is incomplete.
But, at least this module gets the work done. It tries to maintain comments, and even has a host of other features like delta, multiline, default section, etc. Most features seem to be rather exotic to me personally, but then none of the other INI modules on CPAN has the basic features that I needed.