Loadlibrary fails in linux

I create a shared library in linux as follows.

   gcc -c -fPIC -I ../include/PERA_USB_IO rtmotion_usb_conf.c
   gcc -shared rtmotion_usb_conf.o -o rtmotion_usb_conf.so

The (shared) library can be used in a C-program like:

    #include <stdio.h>
    #include <rtmotion_usb_conf.h>
    main () {
      int x;
      x = rtm_usb_init();
      printf("x = %d\n",x);
    }

but using it in Matlab using:

    [notfound,warnings]=loadlibrary('/home/p100213/Systemen/PhilipsRobotArm/MatlabRTMUSB/rtmotion_usb_conf','/home/p100213/rosbuild_ws/PERA_USB_IO/include/PERA_USB_IO/rtmotion_usb_conf.h')

yields the warnings below. And a calllib cannot use this library. What is wrong? As if the environment is different in Matlab.

    Thanks in advance,
           Sietse

====================== output of diary

rtm_usb_init()

notfound =

   Empty cell array: 0-by-1

warnings =

Type '__mbstate_t' was not found. Defaulting to type error.

Found on line 1560 of input from line 26 of file /usr/include/_G_config.h

Type '__mbstate_t' was not found. Defaulting to type error.

Found on line 1565 of input from line 31 of file /usr/include/_G_config.h

Type '__builtin_va_list' was not found. Defaulting to type error.

Found on line 1575 of input from line 40 of file /usr/lib/gcc/x86_64-linux-gnu/4.6/include/stdarg.h

No match found for enum value expression sizeof in 15 * sizeof ( int ) - 4 * sizeof ( void *) - sizeof ( size_t ) expression ignored. Found on line 1658 of input from line 340 of file /usr/include/libio.h

Type 'char__signed__' was not found. Defaulting to type error.

Found on line 2339 of input from line 19 of file /usr/include/asm-generic/int-ll64.h

Type 'short__signed__' was not found. Defaulting to type error.

Found on line 2342 of input from line 22 of file /usr/include/asm-generic/int-ll64.h

Type 'int__signed__' was not found. Defaulting to type error.

Found on line 2345 of input from line 25 of file /usr/include/asm-generic/int-ll64.h

Type 'longlong__signed__' was not found. Defaulting to type error.

Found on line 2349 of input from line 29 of file /usr/include/asm-generic/int-ll64.h

ans =

     0

[Philip Borghesani]

How do you know those warnings are preventing calls to the library? What error do you get from a calllib call?

 calllib('rtmotion_usb_conf','rtm_usb_init')

What is the output of libfunctions rtmotion_usb_conf -full ?

[Sietse]

I used the command:

    success = calllib('/home/p100213/Systemen/PhilipsRobotArm/MatlabRTMUSB/rtmotion_usb_conf', 'rtm_usb_init')

and got:

   Error using calllib

   Library was not found

   Error in rtm_usb_init (line 41)
     success = calllib('/home/p100213/Systemen/PhilipsRobotArm/MatlabRTMUSB/rtmotion_usb_conf', 'rtm_usb_init')

BUT changing to the shorter version:

   success = calllib('rtmotion_usb_conf', 'rtm_usb_init')

IT RAN OK!!

(apparently the absolute path is a problem?)

Now i will try using the library in earnest.

   Thanks for the help!

(still wondering about all the warnings though)