--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libcoding/utf8_decode2.c	Sat Aug 05 00:46:23 2023 +0000
@@ -0,0 +1,43 @@
+/*
+ * This library module implements the function for converting UTF-8 input
+ * to UCS-2 in outgoing SMS composition.
+ */
+
+#include <sys/types.h>
+
+utf8_to_ucs2(inbuf, outbuf, outmax, outlenp)
+	u_char *inbuf;
+	u_short *outbuf;
+	unsigned outmax, *outlenp;
+{
+	u_char *ip = inbuf;
+	u_short *op = outbuf;
+	unsigned outcnt = 0, c, n, uni;
+
+	while (c = *ip++) {
+		if (c < 0x80) {
+			uni = c;
+			goto gotuni;
+		}
+		if (c < 0xC0 || c > 0xEF)
+			return(-1);
+		uni = c & 0x1F;
+		if (c >= 0xE0)
+			n = 2;
+		else
+			n = 1;
+		for (; n; n--) {
+			c = *ip++;
+			if (c < 0x80 || c > 0xBF)
+				return(-1);
+			uni <<= 6;
+			uni |= c & 0x3F;
+		}
+gotuni:		if (outcnt >= outmax)
+			return(-2);
+		*op++ = uni;
+		outcnt++;
+	}
+	*outlenp = outcnt;
+	return(0);
+}