From: porkchop@invalid.foo   
      
   On Tue, 18 Nov 2025 20:17:24 -0000 (UTC), Michael Sanders wrote:   
      
   > If you manage an improvement, please do post it here in the group   
   > so I can learn more too.   
      
   /*   
    * Robust UTF-8 capability test?   
    *   
    * This test checks:   
    *   1. Locale reports UTF-8   
    *   2. Wide-character conversion works (mbrtowc)   
    *   3. Terminal accepts UTF-8 output (optional: write test char)   
    *   
    * Result returned:   
    *   0 = No UTF-8 support detected   
    *   1 = UTF-8 *likely* supported   
    */   
      
   #include    
   #include    
   #include    
   #include    
   #include    
      
   /* return 1 if UTF-8 capable, else 0 */   
      
   int utf8_capable(void) {   
       /* 1 check locale */   
       const char *loc = setlocale(LC_CTYPE, "");   
       if (!loc) return 0;   
       if (!strstr(loc, "UTF-8") && !strstr(loc, "utf8")) return 0;   
      
       /* 2 check UTF-8 decoding with mbrtowc */   
       {   
           const char *test = "✓"; /* E2 9C 93 */   
           wchar_t wc = 0;   
           mbstate_t st;   
           memset(&st, 0, sizeof(st));   
      
           size_t n = mbrtowc(&wc, test, strlen(test), &st);   
      
           if (n == (size_t)-1 || n == (size_t)-2) return 0;  /* decode error */   
           if (wc == 0) return 0;  /* returned null? impossible for ✓ */   
       }   
      
       /* 3 ensure terminal accepts UTF-8 by writing */   
       if (fwrite("✓", 3, 1, stdout) != 1) {   
           return 0; /* write failed — suppress error message, just say no */   
       }   
      
       return 1;   
   }   
      
   int main(void) {   
       if (utf8_capable()) printf("\nUTF-8 OK\n");   
       else printf("\nNOT UTF-8\n");   
       return 0;   
   }   
      
   --   
   :wq   
   Mike Sanders   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)