--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/smsc-sendmt/smsc_addr.c	Fri Aug 25 14:28:54 2023 -0800
@@ -0,0 +1,51 @@
+/*
+ * This C module is being stashed here temporarily until we figure out
+ * where this function ultimately needs to go.  The parsing of the SMSC
+ * address is being moved out of proto-smsc-daemon to proto-smsc-sendmt,
+ * but we haven't started putting together the latter program yet.
+ */
+
+#include <ctype.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+char smsc_addr_num[21];		/* maximum of 20 digits per GSM 04.11 */
+uint8_t smsc_addr_ton_npi;
+
+void parse_smsc_addr_arg(char *arg)
+{
+	char *cp, *dp, *endp;
+	unsigned ndig;
+
+	cp = arg;
+	dp = smsc_addr_num;
+	ndig = 0;
+	while (isdigit(*cp)) {
+		if (ndig >= 20) {
+			fprintf(stderr,
+	"error: SMSC address argument exceeds GSM 04.11 limit of 20 digits\n");
+			exit(1);
+		}
+		*dp++ = *cp++;
+		ndig++;
+	}
+	if (!ndig) {
+invalid:	fprintf(stderr,
+			"error: SMSC address argument \"%s\" is invalid\n",
+			arg);
+		exit(1);
+	}
+	if (!*cp) {
+		/* default to TON=1, NPI=1, i.e., a pretend Global Title */
+		smsc_addr_ton_npi = 0x91;
+		return;
+	}
+	if (*cp++ != ',')
+		goto invalid;
+	if (!*cp)
+		goto invalid;
+	smsc_addr_ton_npi = strtoul(cp, &endp, 0);
+	if (*endp)
+		goto invalid;
+}