Qt Mobility Library Question on OS X

[goetz]

Ah, ok. That's quite true. I never used it though I cannot comment further. I only stumbled over the (DY)LD_LIBRARY_PATH once I switched to the Mac :-)

[tobias.hunger]

Using that kind of concatenation of LD_LIBRARY_PATH is dangerous (at least in Linux). You really should make sure the LD_LIBRARY_PATH does not contain empty path elements ever.

This is due to the loader evaluating LD_LIBRARY_PATH to find libraries an executable depends on. For some reason a empty path element (the thing between the ':' or ':' and the end of the string) is considered to be the current directory. So if you have LD_LIBRARY_PATH set to "/some/path::/some/other/path" then the loader will check the current directory for libraries. This is a security issue as anybody can make you run code for them if they can get you to start any executable while in a directory where they can put a library.

As I said before: This is the case in Linux. I am not sure the MacOS loader behaves in the same way... So check before following this potentially dangerous advice.

[goetz]

This can prevent creating new empty paths:

@
if [ "x$DYLD_LIBRARY_PATH" = "x" ]; then
export DYLD_LIBRARY_PATH="/path/to/my/lib"
else
export DYLD_LIBRARY_PATH="$DYLD_LIBRARY_PATH:/path/to/my/lib"
fi
@

[kyleplattner]

Again I would emphasize the great need for some sort of installer to minimize these risks. Perhaps adding it and all its dependencies to aptitude?

[goetz]

There is no aptitude in a standard Mac OS X installation.

On a Debian or Ubunut box there might be already a package repository (known as PPA: Personal Package Archive), that can be added to apt/sources.list. I'm pretty sure they will be in the official repositories sometime the packages are sort-of stable.

[kyleplattner]

Do you have any sort of general timeline idea of when that will happen?

[goetz]

Sorry, no. I'm neither into the planning of the Trolls on finishing Qt Mobility nor into that of Launchpad for their Ubuntu plans. I would not depend on anything you find on the net, unless it's from Launchpad or Nokia.

[kyleplattner]

Can I add:

@if [ "x$DYLD_LIBRARY_PATH" = "x" ]; then
export DYLD_LIBRARY_PATH="/path/to/my/lib"
else
export DYLD_LIBRARY_PATH="$DYLD_LIBRARY_PATH:/path/to/my/lib"
fi@

directly to my .profile file and only change the two file paths?

[goetz]

Yes, you can. And additionally to .bashrc too.

[kyleplattner]

Great to know, I will try it. Thanks.