matdehaast

  var wg sync.WaitGroup
  var mu sync.Mutex
  completedCount := 0

  for i := 0; i < len(transfers); i++ {
    wg.Add(1)
    go func(index int, transfer Transfer) {
     defer wg.Done()

     res, _ := client.CreateTransfers([]Transfer{transfer})
     for _, err := range res {
      if err.Result != 0 {
       log.Printf("Error creating transfer %d: %s", err.Index, err.Result)
      }
     }

     mu.Lock()
     completedCount++
     if completedCount%100 == 0 {
      fmt.Printf("%d\n", completedCount)
     }
     mu.Unlock()
    }(i, transfers[i])
   }

  wg.Wait()
  fmt.Printf("All %d transfers completed\n", len(transfers))