From d2e133810968cd0d8f96ff538803d1579f524d36 Mon Sep 17 00:00:00 2001
From: octo <octo>
Date: Fri, 12 May 2006 15:51:27 +0000
Subject: [PATCH] Implemented `-h' option. Allow non-root users to get syntax
 information. Use correct computation of standard deviation.

---
 src/oping.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/oping.c b/src/oping.c
index 5f0940d..37f64b2 100644
--- a/src/oping.c
+++ b/src/oping.c
@@ -115,7 +115,7 @@ int read_options (int argc, char **argv)
 
 	while (1)
 	{
-		optchar = getopt (argc, argv, "46c:i:");
+		optchar = getopt (argc, argv, "46c:hi:");
 
 		if (optchar == -1)
 			break;
@@ -145,6 +145,7 @@ int read_options (int argc, char **argv)
 				}
 				break;
 
+			case 'h':
 			default:
 				usage_exit (argv[0]);
 		}
@@ -256,17 +257,17 @@ int main (int argc, char **argv)
 	int optind;
 	int i;
 
+	optind = read_options (argc, argv);
+
+	if (optind >= argc)
+		usage_exit (argv[0]);
+
 	if (geteuid () != 0)
 	{
 		fprintf (stderr, "Need superuser privileges to open a RAW socket. Sorry.\n");
 		return (1);
 	}
 
-	optind = read_options (argc, argv);
-
-	if (optind >= argc)
-		usage_exit (argv[0]);
-
 	if ((ping = ping_construct ()) == NULL)
 	{
 		fprintf (stderr, "ping_construct failed\n");
@@ -400,7 +401,7 @@ int main (int argc, char **argv)
 			num_total = (double) context->req_rcvd;
 
 			average = context->latency_total / num_total;
-			deviation = sqrt ((context->latency_total_square / num_total) - (average * average));
+			deviation = sqrt (context->latency_total_square - (num_total * average * average));
 
 			printf ("rtt min/avg/max/sdev = %.3f/%.3f/%.3f/%.3f ms\n",
 					context->latency_min,
-- 
2.11.0