Chat - a golang concurrent tcp chat server

This is a basic chat server that uses goroutines. A telnet client can be used to connect.

This program is an attempt to demonstrate the maintenance of state between goroutines using channels. This is a learning excercise.

"Do not communicate by sharing memory; instead, share memory by communicating."

Pfff... very tricky.

So I wanted to protect a map from problems arising from being accessed by several different go routines by using channels. It could probably be better written with a RWMUTEX.
I considered using the sync map included in GO 1.9 but was terrified of the warning regarding ranging through the map - no guarantee of a consistent map - I dont really know specifically what that means, but I knew I needed to range through the map and so stayed away...

I am new to GOLANG.
Postive/constructive criticism will be gratefully received

TODO:

• Close channels when the app stops. (I assume the channels in here are a concurrent travesty in terms of leaks etc.)
• stop over using channels
• Clean up messageHandler lots of boilerplate messages still lots of conditions
• Resolve ownership of the channels (Its not clear whether a separate set of network channels should be used)
• JSON Config file
• pass server port with override
• tests
• testing on other OSs - currently windows (I am sure there are CRLF issues)
• other things

Install:

---

$ go get github.com/nmmh/chat
$ cd %GO_PATH%/src/github.com/nmmh/chat/cmd/chat
$ go build; go install

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Server Usage:

---

$ ./chat

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Telnet Client Usage:

---

$ telnet 127.0.0.1 6000

---

* Usage:
*     just type stuff and press enter to chat.
*
*  Cmds:
*    /username blah (change username to blah)
*    @blah hello (whispers "hello" to blah)
*    /list (show user list)
*    /bye (quits!)
*    /help (displays this msg)

---

General structure. (Should be more staight forward now from ChatServer.Start() )

go s.sendMessages() //has the channels	
for { 
	conn, e := s.lsnr.Accept() 
	if e != nil { 
		continue 
	} 
	go s.handleClient(conn) 
}

---

Screenshot