Use as shared library

[Calmly145]

It there a possibility to make the library as an shared library for a unix arm based system?
I'm trying to use it on raspbian, but i cannot get the linking of the libraries right.

[GlitchedPolygons]

Hm, its only dependency is MbedTLS, which is being maintained by ARM themselves.
It should therefore build just fine, as long as you have CMake and a compatible compiler installed. You can force building shared libs by passing -DBUILD_SHARED_LIBS=ON to the cmake command.
If you want to build the MbedTLS dependency as a shared library as well, you need to pass -DUSE_SHARED_MBEDTLS_LIBRARY=ON (it has its own parameter for that).

But yeah, I know that linking libraries in C ain't always fun...
I don't have a Pi to test this on atm, but if you manage to get it to work please post it here so I can close the issue and others can learn too :)

Cheers

[Calmly145]

I did manager to make the library a shared library. At least the MbedTLs dependencies. The l8w8jwt is still static. This was all done with Cmake
But the including the library in my project is a pain. As not all the links are working well with the files as i'm using gcc for my project.
But i will give an update when i can
ps. you do not make use of jansson, correct ?

[GlitchedPolygons]

I did manager to make the library a shared library. At least the MbedTLs dependencies. The l8w8jwt is still static. This was all done with Cmake
But the including the library in my project is a pain. As not all the links are working well with the files as i'm using gcc for my project.
But i will give an update when i can

Thanks for the info! I'll look into it as soon as I have the time. Sounds strange, it should build shared libs with that option..

ps. you do not make use of jansson, correct ?

Correct. The only significant (in terms of heaviness) dependency is MbedTLS. The other 3 you can check out inside the lib/ folder. Jansson is not one of them.

[Calmly145]

I got the first part working to build the shared libraries and install them with the following method:

• git clone https://github.com/GlitchedPolygons/l8w8jwt.git
• cd ./l8w8jwt/
• mkdir build
• cd build
• cmake .. -DBUILD_SHARED_LIBS=ON -DUSE_SHARED_MBEDTLS_LIBRARY=ON
• make all && sudo make install
• sudo cp /home/username/l8w8jwt/build/libl8w8jwt.so /usr/lib
• sudo chmod 777 /usr/lib/libl8w8jwt.so
• ldconfig

And then add -ll8w8jwt to you gcc build command.

But i'm currently a bit stuck on, how to #include l8w8jwt/decode.h

[GlitchedPolygons]

Did you include the l8w8jwt include directory via GCC's -I argument too?

[Calmly145]

to add the library i did

gcc -o -Wall Project -g "all the other libraries" -ll8w8jwt

The include is for in my source code header file
#include <l8w8jwt/decode.h>
Which i think i'm doing something wrong. Or maybe a wrong link

[GlitchedPolygons]

try adding -Ipath/to/l8w8jwt/include

https://www.rapidtables.com/code/linux/gcc/gcc-i.html

[Calmly145]

if i add that piece to the gcc builder. It is missing the other parts
In file included from ../../../l8w8jwt/include/l8w8jwt/decode.h:34:0,
from ../main/project.c:3:
../../../l8w8jwt/include/l8w8jwt/claim.h:31:23: fatal error: chillbuff.h: No such file or directory
#include "chillbuff.h"

Currently trying to move and fix the header files linking

[GlitchedPolygons]

ah, true! Those are needed as well. Add -Ipath/to/l8w8jwt/lib/chillbuff/include, and the same thing for checknum and jsmn respectively.
Or you could also switch to using CMake for you project too, so you can just add_subdirectory(path/to/l8w8jwt) and then link using CMake

[Calmly145]

I made it easier, by coping the header files to the same file . So you don't get to many -I links in the build command

l8w8jwt/include

When i build that piece i get no error and i get the proper output from the example piece of code

[GlitchedPolygons]

I understand :)

I'll close this issue then, and wish you good luck with your project!

[Calmly145]

Maybe an idea, to add these steps to your guide. So other people can also use it for there projects in this way

[GlitchedPolygons]

The intended usage is definitively with a build system (CMake in this case). It's so much more pleasant!

But if you're okay with it, I could add a small GCC section inside the README.md that links to our conversation in this issue?

[Calmly145]

I understand that is the use case for the project. But it's a little extra for the people who do it with gcc. And gives an extra option for your library to be used :)

I'm oke with linking to this conversation