src/oping.c: Improved the help output.

A short description has been added for each option. Also, print the program
version and author.

diff --git a/src/oping.c b/src/oping.c
index 06fb801..0ef6ec6 100644 (file)
--- a/src/oping.c
+++ b/src/oping.c
@@ -113,12 +113,21 @@ static void usage_exit (const char *name)
 
        name_length = (int) strlen (name);
 
-       fprintf (stderr, "Usage: %s [-46] [-c count] [-i interval]\n"
-                       "%*s[-t ttl] [-I srcaddr]\n"
-                       "%*s-f filename | host [host [host ...]]\n",
-                       name,
-                       8 + name_length, "",
-                       8 + name_length, "");
+       fprintf (stderr, "Usage: %s [OPTIONS] "
+                               "-f filename | host [host [host ...]]\n"
+
+                       "\nAvailable options:\n"
+                       "  -4|-6        force the use of IPv4 or IPv6\n"
+                       "  -c count     number of ICMP packets to send\n"
+                       "  -i interval  interval with which to send ICMP packets\n"
+                       "  -t ttl       time to live for each ICMP packet\n"
+                       "  -I srcaddr   source address\n"
+                       "  -f filename  filename to read hosts from\n"
+
+                       "\noping "PACKAGE_VERSION", http://verplant.org/liboping/\n"
+                       "by Florian octo Forster <octo@verplant.org>\n"
+                       "for contributions see `AUTHORS'\n",
+                       name);
        exit (1);
 }