tile38/vendor/github.com/nats-io/go-nats/examples/nats-sub.go

72 lines
1.6 KiB
Go

// Copyright 2012-2018 The NATS Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build ignore
package main
import (
"flag"
"log"
"runtime"
"github.com/nats-io/go-nats"
)
// NOTE: Use tls scheme for TLS, e.g. nats-sub -s tls://demo.nats.io:4443 foo
func usage() {
log.Fatalf("Usage: nats-sub [-s server] [-t] <subject> \n")
}
func printMsg(m *nats.Msg, i int) {
log.Printf("[#%d] Received on [%s]: '%s'\n", i, m.Subject, string(m.Data))
}
func main() {
var urls = flag.String("s", nats.DefaultURL, "The nats server URLs (separated by comma)")
var showTime = flag.Bool("t", false, "Display timestamps")
log.SetFlags(0)
flag.Usage = usage
flag.Parse()
args := flag.Args()
if len(args) < 1 {
usage()
}
nc, err := nats.Connect(*urls)
if err != nil {
log.Fatalf("Can't connect: %v\n", err)
}
subj, i := args[0], 0
nc.Subscribe(subj, func(msg *nats.Msg) {
i += 1
printMsg(msg, i)
})
nc.Flush()
if err := nc.LastError(); err != nil {
log.Fatal(err)
}
log.Printf("Listening on [%s]\n", subj)
if *showTime {
log.SetFlags(log.LstdFlags)
}
runtime.Goexit()
}