_sprintf_test.c

#include <stdio.h>
#include <shlwapi.h>

int
main(int argc, char* argv[]) {
  char buf[256];
  strcpy(buf, "XXXXXXXXXXXXXXX");
  _snprintf(buf, 8, "1234%s", "abcdef"); 
  puts(buf);
  return 0;
}

// mingw 1234abcdXXXXXXX, msvc 1234abcdXXXXXXX

wnsprintf_test.c

#include <stdio.h>
#include <shlwapi.h>

int
main(int argc, char* argv[]) {
  char buf[256];
  strcpy(buf, "XXXXXXXXXXXXXXX");
  wnsprintf(buf, 8, "1234%s", "abcdef"); 
  puts(buf);
  return 0;
}

// mingw 1234abc, msvc 1234abc