add comments, fiddle with function publicity

1 files changed, 3 insertions, 0 deletions

diff --git a/ping.go b/ping.go
index a41b4ab..ba825e8 100644
--- a/ping.go
+++ b/ping.go
@@ -7,6 +7,9 @@ import (
 	"strings"
 )
 
+// Ping sends one ICMP echo packet to the given IP and times how long
+// it takes to get a response, in milleseconds.  Returns -1 if no
+// response is received.
 func Ping(ip net.IP) float64 {
 	cmd := exec.Command("ping",
 		"-n", // numeric