error LNK2019: unresolved external symbol

Hi everybody,

When I try to compile my S-function builder I get the following error:

Creating library myFunction.lib and object myFunction.exp myFunction_wrapper.obj : error LNK2019: unresolved external symbol ioctl referenced in function myFunction_Outputs_wrapper myFunction.mexw64 : fatal error LNK1120: 1 unresolved externals

This is the code that I use:

static char *i2cCtrlDevName = "/dev/i2ctrl"; static int i2cCtrlDev = -1; long ret;

 i2cCtrlDev = open(i2cCtrlDevName, O_RDWR);
  if (i2cCtrlDev < 0)
  {
    printf("Error opening '%s' device file\n", i2cCtrlDevName);
    return -1;
  }

 ret = ioctl(i2cCtrlDev, I2CTRL_GET_INPUTS, 0);
 if (ret < 0) return -1;

I realize that the problem is in ioctl function, which does not recognize. If anybody knows why this happens it will be very helpful.

Thanks in advance.

[José-Luis]

That looks like a linking error. ioctl is part of a library and you are not telling your compiler where that library is.

[Maialen]

I still use this includes:

#include fcntl.h #include sys/ioctl.h #include sys/mman.h

Do I need some other file?

[José-Luis]

I don't know. You could always look inside the library and see if the functions you need are listed there.

List symbols in a library