--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/smpp-trx-sa/enq_link_stat.c	Wed Oct 11 21:22:32 2023 -0800
@@ -0,0 +1,50 @@
+/*
+ * This module tracks and logs the times of enquire_link packets
+ * from the SMPP server.
+ */
+
+#include <sys/types.h>
+#include <sys/file.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <time.h>
+#include <unistd.h>
+
+extern char fmt_time[32];
+
+static int status_fd, status_enable;
+static char last_enq_time[32];
+
+void
+log_enquire_link_open(filename)
+	char *filename;
+{
+	status_fd = open(filename, O_WRONLY|O_CREAT|O_TRUNC, 0666);
+	if (status_fd < 0) {
+		perror(filename);
+		exit(1);
+	}
+	status_enable = 1;
+}
+
+static void
+write_enq_link_times()
+{
+	char buf[128];
+
+	sprintf(buf, "%s\n%s\n", last_enq_time, fmt_time);
+	lseek(status_fd, 0, SEEK_SET);
+	write(status_fd, buf, strlen(buf));
+}
+
+void
+log_enquire_link_item()
+{
+	if (!status_enable)
+		return;
+	if (last_enq_time[0])
+		write_enq_link_times();
+	strcpy(last_enq_time, fmt_time);
+}