// Copyright 2013 Google Inc. All rights reserved. // Copyright 2016 the gousb Authors. All rights reserved. // // 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. package gousb // To enable internal debugging, set the GOUSB_DEBUG environment variable. import ( "io" "io/ioutil" "log" // TODO(kevlar): make a logger "os" ) var debug *log.Logger const debugEnvVarName = "GOUSB_DEBUG" func init() { out := io.Writer(ioutil.Discard) if os.Getenv(debugEnvVarName) != "" { out = os.Stderr } debug = log.New(out, "gousb: ", log.LstdFlags|log.Lshortfile) }