File report-iface.patch of Package arpwatch

--- a/arpsnmp.c
+++ b/arpsnmp.c
@@ -68,6 +68,7 @@ int	snmp_add(u_int32_t, u_char *, time_t
 __dead	void usage(void) __attribute__((volatile));
 
 char *prog;
+char *interface;
 
 extern int optind;
 extern int opterr;
--- a/arpwatch.c
+++ b/arpwatch.c
@@ -118,6 +118,7 @@ struct rtentry;
 #endif
 
 char *prog;
+char *interface;
 
 int can_checkpoint;
 int swapped;
@@ -214,7 +215,7 @@ main(int argc, char **argv)
 	register int fd;
 #endif
 	register pcap_t *pd;
-	register char *interface, *rfilename;
+	register char *rfilename;
 	struct bpf_program code;
 	char errbuf[PCAP_ERRBUF_SIZE];
 	char* serveruser = NULL;
--- a/report.c
+++ b/report.c
@@ -73,6 +73,8 @@ struct rtentry;
 char *watcher = WATCHER;
 char *watchee = WATCHEE;
 
+extern char *interface;
+
 static int cdepth;	/* number of outstanding children */
 
 static char *fmtdate(time_t);
@@ -339,6 +341,8 @@ report(register char *title, register u_
 		(void)fprintf(f, fmt, "previous timestamp", fmtdate(*t2p));
 	if (t1p && t2p && *t1p && *t2p)
 		(void)fprintf(f, fmt, "delta", fmtdelta(*t1p - *t2p));
+	if (interface)
+		(void)fprintf(f, fmt, "interface", interface);
 
 	if (debug) {
 		fflush(f);