net: document where service names come from?

[TomitaSilvestruSC]

Found in net/http/server.go:

type Server struct {
	Addr    string  // TCP address to listen on, ":http" if empty

What is this ":http" exactly? Presumably an alias, but I can't find any concrete documentation to know what it resolves to.

go/src/net/http/server.go

Line 2477 in 964fe4b

Addr string // TCP address to listen on, ":http" if empty

[bradfitz]

https://golang.org/pkg/net/#Listen references
https://golang.org/pkg/net/#Dial which says "The port must be a literal port number or a service name."

Perhaps we should mention that comes from /etc/services (or equivalent, depending on OS).

[cuonglm]

@bradfitz How about mention that service name is defined in RFC 6335, and assigned by IANA

For each OS:

• *nix: /etc/services
• Windows: %WINDIR%\system32\drivers\etc\services
• Plan 9: /lib/ndb/{local,global}

Document each OS seems too much details.

[luka-zitnik]

Is there missing a description of the address format in general? -- Empty host or port, port "0", square brackets for ipv6 addresses, ... As a reader of the comment I would also be interested in what does using the service name effectively means -- will it be port 80 or a dynamically assigned port from the 80** range?

Can we do something like this?

type Server struct {

	// TCP address to listen on, ":http" (all IP addresses,
	// default http port) if empty
	// See package net for description of the address format
	Addr string