[Ffmpeg-devel] Purpose of lib*-uninstalled.pc files

[Måns Rullgård]

Aurelien Jacobs <aurel at gnuage.org> writes:

> On Thu, 16 Nov 2006 01:25:23 +0000
> M?ns Rullg?rd <mru at inprovide.com> wrote:
>
>> The configure script currently creates two sets of pkgconfig files.
>> One lot is installed, and this part I understand.  Also created are
>> similar pkgconfig files called libavformat-uninstalled.pc etc.  The
>> purpose of these I do not quite understand, even after perusing the
>> list archives.  These files are not installed, and neither are they
>> referenced anywhere in the ffmpeg tree.  Are they serving a purpose
>> I am failing to see, or are they cruft that can be disabled without
>> causing anyone discomfort?  These files are obviously not doing any
>> damage where they are, but I like keeping the configure script nice
>> and tidy.  A quick Google search doesn't turn up evidence of anyone
>> else using those files so unless someone shouts they'll be history.
>
> The name of those files seems quite self-explanatory.
> The purpose is to link an app to an uninstalled version of ffmpeg
> using pkg-config.
> Let's imagine you built ffmpeg sources in ~/ffmpeg and you want to
> build proga (which use lavc and use pkg-config to detect it).
> Then you simply need to `export PKG_CONFIG_PATH=~/ffmpeg` before
> compiling proga and your done. pkg-config will automatically pick-up
> the -uninstalled version of .pc files.
>
> I don't know if many people use this feature, but this is a standard
> pkg-config feature, and I can imagine situations where it would be
> pretty handy.

I thought the normal way of allowing applications to use a library was
to install it.  This pkgconfig thing has never made much sense to me.

-- 
M?ns Rullg?rd
mru at inprovide.com