Question

I’m trying to include some Visa Code into my mex file but can’t figure out why the functions arn’t resolved. The code and matlab output is shown below. Does anybody have a hint what I’m doing wrong?
cheers

eac

SourceFile:

#include "mex.h" 
#include <stdio.h> /* For printf(). */
#include <string.h> /* For strcpy(), strcat(). */
#include <time.h> /* For clock(). */
#include "visa.h" /* Agilent VISA routines. */
#define VISA_ADDRESS "USB0::0x0957::0x17A6::MY51136169::0::INSTR"
#define IEEEBLOCK_SPACE 5000000

ViSession defaultRM, vi;

void do_command(char *command); /* Send command. */

void mexFunction(int nlhs, mxArray *plhs[],
    int nrhs, const mxArray *prhs[]) {

        do_command("*RST");
}

void do_command(command)
char *command;
{
    char message[80];
    strcpy(message, command);
    strcat(message, "\n");
    viPrintf(vi, message);

}

Matlab Output:

>> mex HelloWorld.c -Lvisa32.lib
Writing library for HelloWorld.mexw32 
c:\users\pehrlich\appdata\local\temp\mex_c04c6da5-c5ef-49d8-a8aa-c5107c66b1fa\helloworld.obj .text: undefined reference to '_viPrintf' 

  D:\MATLAB\R2006B\BIN\MEX.PL: Error: Link of 'HelloWorld.mexw32' failed. 

??? Error using ==> mex
Unable to complete successfully.

Answer 1

You are not using the right flags to mex.

Instead of telling mex where to look for libraries :

>> mex HelloWorld.c -Lvisa32.lib

tell it what libraries to use (note the lower case) :

>> mex HelloWorld.c -lvisa32.lib