+
−/*
+
− * This library module implements the function that distills the complex
+
− * set of possible SMS DCS octet values to just one of 4 possibilities:
+
− * 7-bit text (7), 8-bit data octets (8), UCS-2 text (16) or compressed
+
− * data (9).
+
− *
+
− * The decoding is based on the 3GPP TS 23.038 V11.0.0 spec;
+
− * reserved encodings are treated as 7-bit text as the spec instructs.
+
− */
+
−
+
−sms_dcs_classify(dcs)
+
−{
+
−	if (!(dcs & 0x80)) {
+
−		if (dcs & 0x20)
+
−			return(9);
+
−		switch (dcs & 0xC) {
+
−		case 0:
+
−			return(7);
+
−		case 4:
+
−			return(8);
+
−		case 8:
+
−			return(16);
+
−		default:
+
−			/* reserved, treating as 7-bit per the spec */
+
−			return(7);
+
−		}
+
−	}
+
−	switch (dcs & 0xF0) {
+
−	case 0x80:
+
−	case 0x90:
+
−	case 0xA0:
+
−	case 0xB0:
+
−		/* reserved, treating as 7-bit per the spec */
+
−		return(7);
+
−	case 0xC0:
+
−	case 0xD0:
+
−		return(7);
+
−	case 0xE0:
+
−		return(16);
+
−	case 0xF0:
+
−		if (dcs & 4)
+
−			return(8);
+
−		else
+
−			return(7);
+
−	}
+
−}