Windows version added

asprintf.c

@@ -2,21 +2,34 @@
 #include <stdlib.h>
 #include "asprintf.h"
 
+#ifndef va_copy
+#define va_copy __va_copy
+#endif
+
 int vasprintf(char** pbuffer, const char* format, va_list ap)
 {
     va_list ap2;
-    int len;
-    FILE* f;
+    size_t len;
     
+#if defined(vxWorks)
+    FILE* f;
     /* print to null device to get required buffer length */
-    f = fopen("/null","w");
-    if (f == NULL) return -1;
-    __va_copy(ap2, ap);
-    len = vfprintf(f, format, ap2);
+    if ((f = fopen("/null","w")) != NULL)
+    {
+        len = vfprintf(f, format, ap2);
+        fclose(f);
+    }
+#elif defined(_WIN32)
+    len = _vscprintf(format, ap);
+#else
+    len = vsnprintf(NULL, 0, format, ap);
+#endif
     va_end(ap2);
-    fclose(f);
-    if (len < 0) return len;
-
+    if (len <= 0)
+    {
+        fprintf(stderr, "vasprintf: too old version on vsnprintf\n");
+        return len;
+    }
     *pbuffer = malloc(len+1);
     if (*pbuffer == NULL) return -1;
     return vsprintf(*pbuffer, format, ap);