+static char* strip_bad_chars(char *s) {
+ char *p, *d;
+
+ for (p = s, d = s; *p; p++)
+ if ((*p >= 'a' && *p <= 'z') ||
+ (*p >= 'A' && *p <= 'Z') ||
+ (*p >= '0' && *p <= '9') ||
+ *p == '-' ||
+ *p == '_')
+ *(d++) = *p;
+
+ *d = 0;
+
+ return s;
+}
+