How to fix Undefined symbols for architecture x86_64

Im trying to connect a C program to Matlab, im launching the C program from terminal but i keep getting this error:

Undefined symbols for architecture x86_64:

"_engClose", referenced from:

_main in first-e0c476.o

"_engEvalString", referenced from:

_main in first-e0c476.o

"_engGetVariable", referenced from:

_main in first-e0c476.o

"_engOpen", referenced from:

_main in first-e0c476.o

"_engOutputBuffer", referenced from:

_main in first-e0c476.o

"_engPutVariable", referenced from:

_main in first-e0c476.o

"_mexPrintf_800", referenced from:

_main in first-e0c476.o

"_mxCreateDoubleMatrix_800", referenced from:

_main in first-e0c476.o

"_mxDestroyArray_800", referenced from:

_main in first-e0c476.o

"_mxGetNumberOfElements_800", referenced from:

_main in first-e0c476.o

"_mxGetPr_800", referenced from:

_main in first-e0c476.o

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

any help is greatly appreciated.

Answer 1

[Abhishek gangwar]

May be this issue is because of you do not a function named mexFunction in your MEX-file and that function needs to have a specific signature, if it is the senario, define that function in your MEX-file. Let me know if you are still having this issue after doing as I suggested.

[Alex Manak]

How do I find the MEX file?

and what exactly am i adding to it?

[Abhishek gangwar]

Go through the link, i have attached one

[Alex Manak]

By mex file, do you mean the mex folder

[Alex Manak]

This is at the bottom of my mex.h file:

MEXFUNCTION_LINKAGE

/*

* mexFunction is the user-defined C routine that is called upon invocation

* of a MEX-function.

*/

void mexFunction(

int nlhs, /* number of expected outputs */

mxArray *plhs[], /* array of pointers to output arguments */

int nrhs, /* number of inputs */

const mxArray *prhs[] /* array of pointers to input arguments */

);

#endif /* mex_h */