On Fri, Feb 26 2016, Jessica Yu <jeyu@xxxxxxxxxx> wrote:
@@ -2714,6 +2718,57 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
num++;
}
continue;
+ /*
+ * Warning: This implementation of the '[' conversion specifier
+ * deviates from its glibc counterpart in the following ways:
+ * (1) It does NOT support ranges i.e. '-' is NOT a special character
+ * (2) It cannot match the closing bracket ']' itself
+ * (3) A field width is required
+ * (4) '%*[' (discard matching input) is currently not supported
+ *
+ * Example usage:
+ * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]", buf1, buf2, buf3);
+ * if (ret < 3)
+ * // etc..
+ */
+ case '[':
+ {
+ char *s = (char *)va_arg(args, char *);
+ DECLARE_BITMAP(set, 256) = {0};
+ unsigned int len = 0;
+ bool negate = (*fmt == '^');
+
+ /* field width is required */
+ if (field_width == -1)
+ return num;
+
+ if (negate)
+ ++fmt;
+
+ for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
+ set_bit((u8)*fmt, set);
+
+ /* no ']' or no character set found */
+ if (!*fmt || !len)
+ return num;
+ ++fmt;
+
I think it might be useful to be able to do [^] to match any sequence of
characters. If the user passed [] the code below won't match anything,
so we'll return num anyway. In other words, I'd just omit the test for
empty character set. Other than that, LGTM.