RE: [gentoo-dev] Checking availability of a package from an ebuil d

RE: [gentoo-dev] Checking availability of a package from an ebuil d

[Sean Mitchell]

Hi Dan...

> This may be trivial, but I can't find out how to do it. How 
> can I check from 
> within an ebuild whether or not a package is installed? For 
> example whether 
> virtual/x11 is available. (Even if it's not in USE).

I've been using ls /var/db/pkg... 

Sean

------------------------------------------------------------------------
 Sean Mitchell                                        Software Engineer
 smitchell@phoenix-interactive.com       Phoenix Interactive Design Inc
 tel. 519-679-2913 x237                        4th Floor, 137 Dundas St
 fax. 519 679 6773                          London, ON, Canada  N6A 1E9
                           ICQ# 104246806
------------------------------------------------------------------------ 

Re: [gentoo-dev] Checking availability of a package from an ebuil d

[Dan Armak]

On Wednesday 18 July 2001 15:56, you wrote:
> Hi Dan...
>
> > This may be trivial, but I can't find out how to do it. How
> > can I check from
> > within an ebuild whether or not a package is installed? For
> > example whether
> > virtual/x11 is available. (Even if it's not in USE).
>
> I've been using ls /var/db/pkg...
 Well, that's obvious. But I'd like something build-in to the ebuild format, 
like USE.
-- 

Dan Armak
Gentoo Linux Developer
Matan, Israel

RE: [gentoo-dev] Checking availability of a package from an ebuil d

[Sean Mitchell]

> No I mean when _writing_ an ebuild, I want it to do different 
> things based on 
> whether some packages are installed.


But should you? I guess it really depends on the specifics of what you are
doing, but as a general statement I think that an ebuild shouldn't make a
decision on how to build a package based on the fact that I currently have
something installed. I think the USE variables (plus the system you proposed
earlier) are the Way.

Let's say I install vorbis (to continue our earlier discussion) to play
around with for a while but I don't set the USE for it. I decide I don't
like it and unmerge it. In the meantime I've merged a bunch of audio
utilities that have decided to build in vorbis support and now get snivelly
because it's not there anymore.

This may not be in the least applicable to the situation you are working on,
but I think it merits a mention....

Cheers,

Sean

------------------------------------------------------------------------
 Sean Mitchell                                        Software Engineer
 smitchell@phoenix-interactive.com       Phoenix Interactive Design Inc
 tel. 519-679-2913 x237                        4th Floor, 137 Dundas St
 fax. 519 679 6773                          London, ON, Canada  N6A 1E9
                           ICQ# 104246806
------------------------------------------------------------------------
 

Re: [gentoo-dev] Checking availability of a package from an ebuil d

[Dan Armak]

On Wednesday 18 July 2001 17:47, you wrote:
> > No I mean when _writing_ an ebuild, I want it to do different
> > things based on
> > whether some packages are installed.
>
> But should you? I guess it really depends on the specifics of what you are
> doing, but as a general statement I think that an ebuild shouldn't make a
> decision on how to build a package based on the fact that I currently have
> something installed. I think the USE variables (plus the system you
> proposed earlier) are the Way.
>
> Let's say I install vorbis (to continue our earlier discussion) to play
> around with for a while but I don't set the USE for it. I decide I don't
> like it and unmerge it. In the meantime I've merged a bunch of audio
> utilities that have decided to build in vorbis support and now get snivelly
> because it's not there anymore.
>
> This may not be in the least applicable to the situation you are working
> on, but I think it merits a mention....
>

I agree. If what I suggested (i.e. interactive decisions) is implemented, 
there'll be no problems. On the other hand, while we continue to use USE 
flags, such decisions may need to be made. But what I had in mind really was 
an unusual case.

-- 

Dan Armak
Gentoo Linux Developer
Matan, Israel