Thanks :) .
On Wednesday, 21 December 2016 15:42:55 UTC+5:30, Axel Wagner wrote:
>
> You need to pass the WaitGroup as a pointer. This way, connectionsCount
> creates a WaitGroup, increments it's counts, passes a copy of it to count
> and then waits on the original; count, however, only Done()s its copy.
>
> go vet should probably complain about that, as it contains an appropriate
> marker to not be copied.
>
> On Wed, Dec 21, 2016 at 10:35 AM, DM <subhara...@gmail.com <javascript:>>
> wrote:
>
>> I am trying write a small golang program which will periodically execute
>> lsof
>> -i:<port> to check number of open TCP connections at a port. Code looks
>> like below:-
>>
>> package main
>>
>> import (
>> "fmt"
>> "log"
>> "os/exec"
>> "strings"
>> "sync"
>> "time"
>> )
>>
>> type Lsof struct {
>> Command string
>> Pid string
>> User string
>> Fd string
>> Type string
>> Device string
>> SizeOff string
>> Node string
>> Name string
>> TCPState string
>> }
>>
>> //var result = make([]*Lsof, 0)
>> var ports = []int{30001, 30002}
>>
>> func main() {
>> done := make(chan bool)
>> ticker := time.NewTicker(5 * time.Millisecond)
>> go func() {
>> for t := range ticker.C {
>> fmt.Println("Tick at", t)
>> connectionsCount()
>> }
>> }()
>> <-done
>> }
>>
>> func connectionsCount() {
>> var wg sync.WaitGroup
>> wg.Add(len(ports))
>> for _, v := range ports {
>> go count(v, wg)
>> }
>> wg.Wait()
>> }
>>
>> func count(port int, wg sync.WaitGroup) {
>> defer wg.Done()
>> var tcpState = make(map[string]int)
>> out, err := exec.Command("/bin/sh", "-c", fmt.Sprintf("lsof -i:%d",
>> port)).Output()
>> if err != nil {
>> log.Fatal(err)
>> }
>> //fmt.Println(string(out))
>> num := strings.Split(string(out), "\n")
>> for no, n := range num {
>> if no == 0 {
>> continue
>> }
>> n = strings.TrimSpace(n)
>> if len(n) <= 0 {
>> continue
>> }
>> i := 0
>> temp := strings.Split(n, " ")
>> cleanedVal := make([]string, 10)
>> for _, v := range temp {
>> v = strings.TrimSpace(v)
>> if len(v) <= 0 {
>> continue
>> }
>> cleanedVal[i] = v
>> i++
>> }
>> if len(cleanedVal) < 8 {
>> //log.Println(n)
>> continue
>> }
>> l := new(Lsof)
>> l.Command = cleanedVal[0]
>> l.Pid = cleanedVal[1]
>> l.User = cleanedVal[2]
>> l.Fd = cleanedVal[3]
>> l.Type = cleanedVal[4]
>> l.Device = cleanedVal[5]
>> l.SizeOff = cleanedVal[6]
>> l.Node = cleanedVal[7]
>> l.Name = cleanedVal[8]
>> if l.Node == "TCP" {
>> l.TCPState = cleanedVal[9]
>> count, ok := tcpState[l.TCPState]
>> if !ok {
>> tcpState[l.TCPState] = 1
>> } else {
>> tcpState[l.TCPState] = count + 1
>> }
>> }
>> //fmt.Printf("\n%+v", *l)
>> //result = append(result, l)
>> }
>> fmt.Printf("Port=%d ", port)
>> for k, v := range tcpState {
>> fmt.Printf("{TCP State=%s,Value=%d},", k, v)
>> }
>> fmt.Println()
>> }
>>
>>
>> But on running the program I am seeing the ticker is not ticking
>> periodically. It is just ticking once:-
>>
>> Tick at 2016-12-21 14:37:03.847694697 +0530 ISTPort=30002 {TCP
>> State=(LISTEN),Value=2},Port=30001 {TCP State=(LISTEN),Value=2},
>>
>> Can someone let me know what is going wrong?
>>
>> - Go Version - 1.7.3
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "golang-nuts" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to golang-nuts...@googlegroups.com <javascript:>.
>> For more options, visit https://groups.google.com/d/optout.
>>
>
>
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to golang-nuts+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
