LabVIEW
HTTP Client - Failed to Load Library (Ubuntu only, fine under Windows)
Most likely one of the shared library dependencies is not correctly installed on your Ubuntu system. What Ubuntu version and bitness (32 bit or 64 bit) do you have? Which variant of LabVIEW did you install (32 bit or 64 bit)?
You probably have a 64 bit Ubuntu version and run a 32 bit LabVIEW version. That usually works but can cause problems for extra libraries since not every 32 bit library is likely installed by default in your system.
Generally speaking you have to find out which libraries the httpclient library depends on and then possibly find secondary dependencies of those libraries too. As far as I know httpclient itself uses libcurl and several other such open source libraries which should be installed by default together with LabVIEW. One of them might use other libraries that NI considers default libraries for Linux and does not include with the LabVIEW installer.
Or also a possibility you installed some other program in your Ubuntu system that came with it's own older version of one of those libraries and also manipulated the LD_PATH variable or created public symlinks for them, so that when the LabVIEW library gets loaded and asks for one of these libraries it gets served the old library which is missing a specific export that the LabVIEW provided library needs. As soon as a single import in a library can not be satisfied the loading of the entire library will eventually fail.
That hierarchy helps nothing. The problem is not in LabVIEW but in one of the shared libraries. You will have to use the command line and use tools like ldd to list the dependencies.
Something like:
ldd httpClient.so
after you changed to the directory where this file is.
Then look at all the dependencies and try to find them on your system and do the same with each of them until you find the culprit.
The problem is not likely inside the /usr/local/natinst/LabVIEW-2015/resource/
folder itself! These are libraries that NI installs during LabVIEW installation and are only really used when you execute your program inside the LabVIEW IDE.
But these libraries are not self contained. Most of them rely on system libraries such as libc, and various other ones that are USUALLY present on any reasonable Linux distribution but there is no guarantee about that, thanks to the very varied world of Linux. That is one of the reasons one can not simply develop an application for Linux and then say it will work on every Linux distribution. Each distribution has its own ideas about what tools it packs into the main system, and accordingly what dependencies get installed alongside with them and in what version.
You will likely have to start at libni_httpClient.so and list its dependencies, then find each of them, which could be anywhere in /usr/lib and even the system /lib directory and possibly in other directories that your distribution might add to the /etc/ld.so.conf file to search for additional libraries. Then list all dependencies of each of those files too and continue like that until you found them all. One of them is likely not present.
If you can't find any dependency that is not present, you might have a more complicated problem that one of your system libraries really is an older (or sometimes newer version) than what the NI libraries where build against and is missing a particular exported function.
All this is the Linux version of DLL hell, as you can encounter it on Windows too. While the Linux ELF standard tries to avoid some of the problems that cause DLL hell on Windows, it is basically completely helpless against the diversification of the Linux world and bad discipline of library developers, who often forget to do a sensible versioning for their libraries or even worse, discontinue or change APIs at their whim.
