+static const char *find_digit_prefix(const char *s, int *v)
+{
+ const char *p;
+ int ver;
+ char ch;
+
+ for (p = s, ver = 0;
+ '0' <= (ch = *p) && ch <= '9';
+ p++)
+ ver = ver * 10 + ch - '0';
+ *v = ver;
+ return p;
+}
+
+
+static int version_cmp(const char *a, const char *b)
+{
+ while (1) {
+ int va, vb;
+
+ a = find_digit_prefix(a, &va);
+ b = find_digit_prefix(b, &vb);
+ if (va != vb)
+ return va - vb;
+
+ while (1) {
+ int ca = *a;
+ int cb = *b;
+ if ('0' <= ca && ca <= '9')
+ ca = 0;
+ if ('0' <= cb && cb <= '9')
+ cb = 0;
+ if (ca != cb)
+ return ca - cb;
+ if (!ca)
+ break;
+ a++;
+ b++;
+ }
+ if (!*a && !*b)
+ return 0;
+ }
+}
+