Add Support for Commands

This ssupports sending nagios external commands to live status.
No checking is done on the content of the Commands.

command.go

@@ -0,0 +1,93 @@
+package livestatus
+
+import (
+	"fmt"
+	"net"
+	"strings"
+	"time"
+)
+
+// Command is a binding command instance.
+type Command struct {
+	cmd  string
+	vals []string
+	ls   *Livestatus
+}
+
+func newCommand(ls *Livestatus) *Command {
+	return &Command{
+		ls: ls,
+	}
+}
+
+func (c *Command) Raw(cmd string) {
+	c.cmd = cmd
+}
+
+func (c *Command) Arg(v interface{}) {
+	c.vals = append(c.vals, fmt.Sprintf("%v", v))
+}
+
+type CommandOpFunc func(*Command)
+
+func (c *Command) Op(op CommandOpFunc) {
+	op(c)
+}
+
+// KeepAliveOff disables the default keepalive from Command
+func (q *Query) KeepAliveOff() *Query {
+	q.ls.keepalive = false
+	return q
+}
+
+// Exec executes the query.
+func (c *Command) Exec() (*Response, error) {
+	resp := &Response{}
+
+	var err error
+	var conn net.Conn
+
+	if c.ls.keepConn != nil {
+		conn = c.ls.keepConn
+	} else {
+		// Connect to socket
+		conn, err = c.dial()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if !c.ls.keepalive {
+		c.ls.keepConn = nil
+		defer conn.Close()
+	} else {
+		c.ls.keepConn = conn
+	}
+
+	// Send command data
+	cmd, err := c.buildCmd(time.Now())
+	if err != nil {
+		return nil, err
+	}
+
+	conn.Write([]byte(cmd))
+	// You get nothing back from an external command
+	// no way of knowing if this has worked
+
+	return resp, nil
+}
+
+func (c *Command) buildCmd(t time.Time) (string, error) {
+	cmdStr := fmt.Sprintf("COMMAND [%d] %s", t.Unix(), c.cmd)
+	cmdStr = fmt.Sprintf("%s;%s", cmdStr, strings.Join(c.vals, ";"))
+
+	return fmt.Sprintf("%s\n", cmdStr), nil
+}
+
+func (c *Command) dial() (net.Conn, error) {
+	if c.ls.dialer != nil {
+		return c.ls.dialer()
+	} else {
+		return net.Dial(c.ls.network, c.ls.address)
+	}
+}

livestatus.go

@@ -29,6 +29,12 @@ func (l *Livestatus) Query(table string) *Query {
 	return newQuery(table, l)
 }
 
+// Command creates a new command instanc.
+func (l *Livestatus) Command() *Command {
+	l.keepalive = true
+	return newCommand(l)
+}
+
 // NewLivestatus creates a new binding instance.
 func NewLivestatus(network, address string) *Livestatus {
 	return &Livestatus{