Merge pull request #675 from jbenet/diag-helptext

add more help text for ipfs diag net

core/commands/diag.go

@@ -56,6 +56,31 @@ var diagNetCmd = &cmds.Command{
 Sends out a message to each node in the network recursively
 requesting a listing of data about them including number of
 connected peers and latencies between them.
+
+The given timeout will be decremented 2s at every network hop, 
+ensuring peers try to return their diagnostics before the initiator's 
+timeout. If the timeout is too small, some peers may not be reached.
+30s and 60s are reasonable timeout values, though network vary.
+The default timeout is 20 seconds.
+
+The 'vis' option may be used to change the output format.
+four formats are supported:
+ * plain text - easy to read
+ * d3 - json ready to be fed into d3view
+ * dot - graphviz format
+
+The d3 format will output a json object ready to be consumed by
+the chord network viewer, available at the following hash:
+
+    /ipfs/QmbesKpGyQGd5jtJFUGEB1ByPjNFpukhnKZDnkfxUiKn38
+
+To view your diag output, 'ipfs add' the d3 vis output, and
+open the following link:
+
+	http://gateway.ipfs.io/ipfs/QmbesKpGyQGd5jtJFUGEB1ByPjNFpukhnKZDnkfxUiKn38/chord#<your hash>
+
+The dot format can be fed into graphviz and other programs
+that consume the dot format to generate graphs of the network.
 `,
 	},