From e4d7b0fcc5352abe6d0254abcacab17e69673109 Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Sun, 22 Feb 2015 19:24:53 +0100
Subject: [PATCH] client: Added support for querying the server version.

---
 client/client.go | 28 ++++++++++++++++++++++++++++
 proto/proto.go   |  3 +++
 2 files changed, 31 insertions(+)

diff --git a/client/client.go b/client/client.go
index fcb5d8d..c42c717 100644
--- a/client/client.go
+++ b/client/client.go
@@ -57,6 +57,7 @@ server:
 package client
 
 import (
+	"encoding/binary"
 	"fmt"
 	"net"
 	"strings"
@@ -187,4 +188,31 @@ func (c *Conn) Receive() (*proto.Message, error) {
 	return nil, err
 }
 
+// ServerVersion queries and returns the version of the remote server.
+func (c *Conn) ServerVersion() (major, minor, patch int, extra string, err error) {
+	m := &proto.Message{Type: proto.ConnectionServerVersion}
+	if err = c.Send(m); err != nil {
+		return 0, 0, 0, "", err
+	}
+
+	m, err = c.Receive()
+	if err != nil || m.Type != proto.ConnectionOK {
+		if err == nil {
+			err = fmt.Errorf("SERVER_VERSION command failed with status %d", m.Type)
+		}
+		return 0, 0, 0, "", err
+	}
+	if len(m.Raw) < 4 {
+		return 0, 0, 0, "", fmt.Errorf("SERVER_VERSION reply is too short")
+	}
+	version := int(binary.BigEndian.Uint32(m.Raw[:4]))
+	major = version / 10000
+	minor = version/100 - 100*major
+	patch = version - 10000*major - 100*minor
+	if len(m.Raw) > 4 {
+		extra = string(m.Raw[4:])
+	}
+	return major, minor, patch, extra, nil
+}
+
 // vim: set tw=78 sw=4 sw=4 noexpandtab :
diff --git a/proto/proto.go b/proto/proto.go
index 5e93e47..a58725d 100644
--- a/proto/proto.go
+++ b/proto/proto.go
@@ -84,6 +84,9 @@ const (
 	ConnectionMatcher = Status(100)
 	// ConnectionExpr is the internal state for parsing expressions.
 	ConnectionExpr = Status(101)
+
+	// ConnectionServerVersion is the state requesting the server version.
+	ConnectionServerVersion = Status(1000)
 )
 
 // The DataType describes the type of data in a ConnectionData message.
-- 
2.30.2