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*Embarrased look* sorry I shouldn't of missed that..
Sorry to hassle you but I am stuck yet again. The lnptest program just records
collision after collision. I have no other IR devices in the area (as far as I
know anyway) It doesn't display any of the data I am sending it and the RCX
doesn't show anything being recieved either.
Any ideas/suggestions please ?
In lugnet.robotics.rcx.legos, Martin Cornelius writes:
> Michael Marklew wrote:
> > However,
> > I can not get the demo lnptest to run. I get
> >
> > ./lnptest: error in loading shared libraries: liblnp.so.0: cannot open • shared
> > object file: No such file or directory
> >
> > I checked the makefile and it points to ../liblnp which is where the • complied
> > library is.
>
>
> Well, it's mentioned in the README ;-), but obviously not detailed
> enough.
>
> The problem is: the dynamic loader doesn't find the library you linked
> against. The dynamic loader is a program that is started whenever you
> execute a dynamically linked program, and makes sure the dynamic
> libraries used by your program are mapped into memory. By default, the
> dynamic loader looks for dynamic libs in some standard places, which are
> listed in file /etc/ld.so.conf. However, the dynamic loader doesn't scan
> this directories (this might take far too long), instead it get's the
> needed information from binary file /etc/ld.so.cache.
>
> So, the option a sysadmin would take:
>
> copy liblnp.so.0.0.1 into one of the directories listed in
> /etc/ld.so.conf, perhaps /usr/local/lib, and (as root) run
> /sbin/ldconfig. This will scan the directories listed in ld.so.conf,
> update the cache file, and create a symbolic link from liblnp.so.0.0.1
> to liblnp.so.0. The link is created, because the actual name of the
> library stored in the library itself, the so called soname, is
> liblnp.so.0. This is also the name stored in your program during
> compilation.
>
> If you don't want to touch system files, this is the safe user way:
>
> If you set Environment Variable LD_LIBRARY_PATH to a colon separated
> list of paths ( like PATH ), the dynamic loader will scan all
> directories in this list for dynamic libraries. This is the way i use
> this mechanism: i have a lib diectory under my HOME, where i put all my
> self-made dynamical libs, and set LD_LIBRARY_PATH in my HOME/.bashrc to
> this directory. Recall, the dynamic loader looks for the soname, what is
> liblnp.so.0. So i follow the common trend to copy liblnp.so.0.0.1 to
> ~/lib, and create a symbolic link from liblnp.so.0.0.1 to liblnp.so.0.
> However, you could also just rename it.
>
> The third option is to link partly statically, which means, system libs
> are linked dynamically, but the linking of liblnp ist static. You
> arrange this by simply removing the shared libs, (actually you only have
> to remove the symbolic link liblnp.so), before making lnptest.c. In this
> case, the linker sees no dynamic library and falls back to static
> linking against liblnp.a. If you never plan to use several different
> programs linked against liblnp simultanously, this maybe the way to go.
>
> BTW, you can test which dynamic libs are used/found to run <program> by:
> $> ldd <program>
>
> hope that doesn't confuse you even more, Martin
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Message has 1 Reply:
 | | RE: LNP Example please
|
| I have observed the same behavior... only by night. I think it must be the tower receiving echoes of its own packets. The sollution: place the tower far away from objects that can reflect light (including yourself). I also changed the tower battery (...) (25 years ago, 12-Feb-00, to lugnet.robotics.rcx.legos)
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Message is in Reply To:
| | Re: LNP Example please
|
| (...) Well, it's mentioned in the README ;-), but obviously not detailed enough. The problem is: the dynamic loader doesn't find the library you linked against. The dynamic loader is a program that is started whenever you execute a dynamically (...) (25 years ago, 10-Feb-00, to lugnet.robotics.rcx.legos)
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