Golang : Intercept and compare HTTP response code example

Problem :

You want to query a website and intercept the response code. You also want to compare the response code to a built in HTTP response codes in net/http package. How to do that?

Solution :

Use the http.Head() function to query a website. The return codes can be compared with the == operator.

For example :

 package main

 import (
 "fmt"
 "net/http"
 "os"
 )

 func main() {
 url := "https://www.socketloop.com"

 response, err := http.Head(url)

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 if response.StatusCode != http.StatusOK { // <------- here !
 fmt.Printf("%s returns non-200 status code. \n", url)
 fmt.Printf("The reply : %v \n", response.StatusCode)
 } else {
 fmt.Println(response)
 }
 }

Happy coding!

References :

  StatusContinue = 100  // access with http.StatusContinue
  StatusSwitchingProtocols = 101

  StatusOK = 200
  StatusCreated = 201
  StatusAccepted = 202
  StatusNonAuthoritativeInfo = 203
  StatusNoContent = 204
  StatusResetContent = 205
  StatusPartialContent = 206

  StatusMultipleChoices = 300
  StatusMovedPermanently  = 301
  StatusFound = 302
  StatusSeeOther = 303
  StatusNotModified = 304
  StatusUseProxy = 305
  StatusTemporaryRedirect = 307

  StatusBadRequest = 400
  StatusUnauthorized = 401
  StatusPaymentRequired = 402
  StatusForbidden = 403
  StatusNotFound = 404
  StatusMethodNotAllowed = 405
  StatusNotAcceptable = 406
  StatusProxyAuthRequired = 407
  StatusRequestTimeout = 408
  StatusConflict = 409
  StatusGone = 410
  StatusLengthRequired = 411
  StatusPreconditionFailed = 412
  StatusRequestEntityTooLarge = 413
  StatusRequestURITooLong = 414
  StatusUnsupportedMediaType = 415
  StatusRequestedRangeNotSatisfiable = 416
  StatusExpectationFailed = 417
  StatusTeapot = 418

  StatusInternalServerError = 500
  StatusNotImplemented = 501
  StatusBadGateway = 502
  StatusServiceUnavailable = 503
  StatusGatewayTimeout = 504
  StatusHTTPVersionNotSupported = 505

https://www.socketloop.com/tutorials/golang-how-to-return-http-status-code