moved cw_is_utf8 to format_is_utf8.

FossilOrigin-Name: d68e3bec6f9bcf6255ff7e71ae3980a77b207ed1e5bd03cef5778094484108c0

src/cw/format_is_utf8.c

@@ -0,0 +1,66 @@
+/*
+    This file is part of actube.
+
+    actube is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    libcapwap is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Foobar.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+/**
+ * @file
+ * @brief Implementation for format_is_utf8
+ */
+
+#include "format.h"
+
+/**
+ * Check if a string is in UTF8 format
+ * @param str String to check
+ * @param len Length of the string
+ * @return 0 if the string is not in UTF8 format, otherwise it is UTF8.
+ */
+
+int format_is_utf8(unsigned char *str, size_t len)
+{
+	size_t i = 0;
+	size_t j = 0;
+	size_t bytes = 0;
+
+	while (i < len) {
+		j = i;
+		if (str[i] < 0x20) {
+			return 0;
+		}
+		if (str[i] <= 0x7F)
+			bytes = 0;
+		else if (str[i] >= 0xC0 /*11000000 */  && str[i] <= 0xDF /*11011111 */ )
+			bytes = 1;
+		else if (str[i] >= 0xE0 /*11100000 */  && str[i] <= 0xEF /*11101111 */ )
+			bytes = 2;
+		else if (str[i] >= 0xF0 /*11110000 */ 
+			 && str[i] <= 0xF4 /* Cause of RFC 3629 */ )
+			bytes = 3;
+		else {
+			return 0;
+		}
+		i += 1;
+		while (i < len && bytes > 0 && str[i] >= 0x80 && str[i] <= 0xBF) {
+			i += 1;
+			bytes -= 1;
+		}
+		if (bytes != 0) {
+			return 0;
+		}
+	}
+	return 1;
+}