how to check Ctrl+C status in a mex cpp program

When I compile a c++ example of mex (dlib-20.0\dlib\matlab), an error occurs of the following codes

extern "C" bool utIsInterruptPending();
void check_for_matlab_ctrl_c(){
    if (utIsInterruptPending())
        throw mex_binding::user_hit_ctrl_c();
}

It seems that there isn't a function named "utIsInterruptPending" in matlab. Then how can we get the Ctrl+C status in a mex file?

[Walter Roberson]

Just maybe it is defined by https://sibr.gitlabpages.inria.fr/docs/0.9.6/GCoptimization_8cpp.html ?

[Mingmin]

thank you very much for answering. However, the source code you offered is:

inline static bool utIsInterruptPending() { return false; }

It is not a feature provided by MATLAB (perhaps it used to be).

Answer 1

[Umeshraja]

Hi @Mingmin,

I found the utIsInterruptPending function in the libut.lib library, which can be accessed at the following location:

<MATLAB PATH>\extern\lib\win64\mingw64\libut.lib

I assume you press Ctrl+C during a mexCallMATLAB or mexCallMATLABWithTrap. To enable this functionality, make sure to include the following at the top of your MEX-file:

#ifdef __cplusplus 
extern "C" { 
#endif
extern bool utIsInterruptPending(void);
#ifdef __cplusplus
}
#endif 

Further you will need to link against libut.lib, so the MEX command becomes:

mex myFunction.c libut.lib

The following shows a simple MEX-file which uses utIsInterruptPending:

#include "mex.h"

/* utIsInterruptPending prototype */
#ifdef __cplusplus 
extern "C" { 
#endif
extern bool utIsInterruptPending(void);
#ifdef __cplusplus
}
#endif 

void mexFunction(int nlhs, mxArray *plhs[],int nrhs, const mxArray *prhs[]) {
/* Call the PAUSE function in MATLAB */
if (mexCallMATLAB(0, NULL, 0, NULL, "pause")) {
    mexErrMsgTxt("Error evaluating callback function!");
    }
    if (utIsInterruptPending()) { /* <== Check if utIsInterruptPending (someone pressed Ctrl+C) */
            mexPrintf("Ctrl+C was pressed!\n");
            return;
            }
            mexPrintf("MEX file completed normally.\n");
            }
            

I hope this helps!

[Mingmin]

Thank you very much! It works well now!