are per-application use-flags centrally stored?

[Tschew]

As a summer project I wanted to build a simple editor for /etc/portage/package.use but I'm not sure whether it's worth the effort.

Are per-application use-flags stored in any other place than the individual ebuilds? (it would take ages to read all ebuilds and assemble a database, and it would have to be kept up to date, although that would be easy given the first step, with timestamps)

What I was thinking of was just a list ordered by the typical portage categories and then per-application (maybe even per-version if that is supported in package.use, haven't checked yet) The individual packages would have check marks to enable and disable the different use flags

This would write a package.use with entries for ALL applications (although this has to be thought over as I'm not sure what the performance impact would be, and whether it would be desirable, if it is too slow, only packages diverging from the default useflags would be written to file)

So.. does portage store per-application useflags somewhere central or is everything on an ebuild basis? (of course, not being centralised would not prevent my writing the app, just significantly complicate it!)

PS: I know about /usr/portage/use.local.desc, but it obviously lists only a fraction of useflags and it does (obviously) not list global flags that apply to certain packages.

[bemis]

you mention that you know about $PORTDIR/profiles/use.local.desc -- that coupled with $PORTDIR/profiles/use.desc should cover all of the available use flags for any given application -- a simple script using euse would probably be a step in the direction you were looking for?

you could also "cheat" and look at the existing code for apps like ufed to see if you can work from their existing codebase?

[Tschew]

you mention that you know about $PORTDIR/profiles/use.local.desc -- that coupled with $PORTDIR/profiles/use.desc should cover all of the available use flags for any given application -- a simple script using euse would probably be a step in the direction you were looking for?

not really, use.desc only lists descriptions, not which package uses which useflag, use.local.desc is of course very valuable

you could also "cheat" and look at the existing code for apps like ufed to see if you can work from their existing codebase?

yes, that was the plan of attack, but I first wanted to see whether anyone else is working on something better than ufed

yep, as the extent of its editing capabilities suggested, and the source confirmed, ufed just reads use.desc/local.use.desc.. so I will definately have to read the ebuilds one-by-one... I'll have to write a test for that and see how long it will take to produce the list from that

Also, I specifically do not want to touch /etc/make.conf as people are usually quite creative and produce very good, nicely commented USE="$USE blah blah" ... etc stuff and I don't even want to think about trying to write something like that from a C++ app... (although reading it is straightforward) I'm only concerned about package.use

[ticho]

My opinion is that USEflags are so numerous and different (and often a single USEflag has a different meaning for different packages), that any attempt at an user-friendly flag editor like ufed is predestined to be unusable.

It is easy enough to edit a single line in a text file already, why cover system configuration under additional layer of user interfaces?

This said, I wish you all the best in the development of such tool, if you consider it needed. Scratch your itch.

[Genone]

You probably want to have a look at this thread, you really don't want to parse ebuilds yourself.

[Tschew]

My opinion is that USEflags are so numerous and different (and often a single USEflag has a different meaning for different packages

That's why I want to build a per-package useflag editor.

that any attempt at an user-friendly flag editor like ufed is predestined to be unusable

Yep, I totally agree, but a ufed clone is not what I want to do. It only reads use.local.desc and sets whatever flags you select in make.conf, which completely defeats the purpose of local useflags doesn't it? All I want to write is a tool to add lines to /etc/portage/package.use on a per-package basis because it is just so damn useful to keep tools like revdep-rebuild etc.. from breaking your precious configuration. And since there are so many packages (and their useflags differ in effect from package to package) I think that a category/list based editor would be easier to use than having to add applications + useflags by hand by looking them up with emerge -pv package and then adding the ones you want to the package.use ... also, what about all those packages you emerged by just specifying 'USE="..." emerge package' because you were lazy?

I think it should be worth my while.

You probably want to have a look at this thread, you really don't want to parse ebuilds yourself.

Well.. kuroo seems to be able to extract the useflags just fine. I'll have to check its initialisation code. Also, portage itself extracts useflags just fine...

Thanks for your help guys.

[Genone]

You probably want to have a look at this thread, you really don't want to parse ebuilds yourself.

Well.. kuroo seems to be able to extract the useflags just fine. I'll have to check its initialisation code. Also, portage itself extracts useflags just fine...

That's why I suggested you look at the referenced thread, it contains the relevant code/tools to lookup ebuild use flags
(don't use the current kuroo code, AFAIK it's using a broken concept, I'm working with the author to fix that)