#define __STDC_WANT_LIB_EXT1__  1
#include <stdlib.h>
#include <stdio.h>

void my_handler( const char *msg, void *ptr, errno_t error )
{
    fprintf( stderr, "rt-constraint violation caught: " );
    fprintf( stderr, msg );
    fprintf( stderr, "\n" );
}

void main( void )
{
    constraint_handler_t    old_handler;

    old_handler = set_constraint_handler_s( my_handler );
    if( getenv_s( NULL, NULL, 0, NULL ) ) {
        printf( "getenv_s failed\n" );
    }
    set_constraint_handler_s( old_handler );
}