KDE_FULL_SESSION and version detection

[Lubos Lunak]

On Sunday 04 February 2007 20:41, Kevin Krammer wrote:
> On Sunday 04 February 2007 20:14, Lubos Lunak wrote:
> > On Sunday 04 February 2007 17:48, Aaron J. Seigo wrote:
> > > hi all...
> > >
> > > we need a way to differentiate a KDE4 session from a KDE3 session at
> > > runtime. this is useful for, for instance, xdg-utils scripts.
> > >
> > > a thought that occurred to me is including a version string in
> > > KDE_FULL_SESSION rather that just setting it to 'true'. simply looking
> > > for kde4-config may not be (well, is not) sufficient. thoughts?
> >
> >  There's bound to be somebody[*] silly enough to
> > write 'test "$KDE_FULL_SESSION" = "true"' instead of
> > simply 'test -n "$KDE_FULL_SESSION"', so the question is whether we care.
>
> Since sombody[*] is me, wouldn't the proposed check test for non-zero
> length content of the variable instead of "true" as documented on
> http://wiki.kde.org/tiki-?page=Environment+Variables

 That's the intention, it's set to something when full session is running, 
it's not set to something when not. Search me why contents of boolean envvars 
should matter.

> If the value is not intended to be checked, wouldn't it be better to write
> something like "will be set to some random junk at KDE startup"?

 It is set to some random junk, namely "true" :). I don't know who wrote that 
page, $KDE_FULL_SESSION used to be internal for quite some time. Now it's 
probably too late anyway.

> >  Also, doing this would mean asserting that we don't care about even
> > basic KDE3 vs KDE4 backwards compatibility.
>
> I am afraid there is a collision about having the same executable name for
> KDE3 tools and KDE4 tools and the option of installing into the same
> prefix.

 I think that would be solvable if somebody wanted to do that.

-- 
Lubos Lunak
KDE developer
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