Running main.go to open a webpage from command line?

Technical Discussion
1

(also what is ‘back tick’?? I used back ticks for the code and it looks like carp.)
I made a simple webpage, using go:


import (

"fmt"

"net/http"

)

func handlerFunc(w http.ResponseWriter, r *http.Request) {

fmt.Fprint(w, "<h1>Welcome to my website!</h1>")

}

func main() {

http.HandleFunc("/", handlerFunc)

http.ListenAndServe(":80", nil)

}```

When I try `>go run main.go` Windows opens a new command window temporarily, but not the browser page. I have confirmed that Go is installed correctly, the Go workspace is installed, all paths are installed.

How do I get this to open a browser?
3

Check the return value of the call to http.ListenAndServe(), it will probably tell you that you can’t bind port 80, as you need to be superuser/administrator to do so.

Use a port that is greater than 1024.

1 Like
5

Yep, have tried 8080, 8000, 3000 and others. It has just occurred to me — should I be keeping all Go work files in the Go workspace location (D:\Documents\Go)? Am completely new to Go so this is my first attempt at running a webpage from the command line. I am actually working in an xampp directory. I use xampp for other local development.

Have attached images of what exactly happens. The first are the popups that launch after running main.

web-from-cmd-error
web-from-cmd-error960×540 144 KB

Next, is my path info. I am pretty sure this is all correct.

go-path
go-path960×540 185 KB

6
  1. You can specify the port from range 1025 to 65535 in your PC.
  2. The popup window “Windows Security Alert” is to alert that there is a service(Your Go app) needs to use a port to communicate via the internet. Hit the Allow access button will do no harm to your PC since this app is just your Go web app.

Correct me if I was wrong.

7

Please use fmt.Println to print the error result of listen and serve, and make sure that the window does not close before reading the output. As a last resort you can just throw a timer.Sleep after printing.

Then copy and paste the error you see.

Also, be need to have xampp, at least not the apache!

8

The popup is just from the windows av.

I use xampp for other local development, without issues. It is running while I do this.

I did this to print the error and nothing printed:

func main() {
    http.HandleFunc("/", handlerFunc)
    http.ListenAndServe(":8000", nil)
    a := http.ListenAndServe(":8000", nil)
    fmt.Println(a)

}

9

If this really doesn’t print anything, then your server is running and should serve your content. Have you tried opening http://localhost:8000?

10

Two small observations around:

  • Your above code serves pages so you need a browser to access the page served by this server. Don’t expect from your code to open any browser.
  • If you have other servers in your sistem take care about used ports and don’t use them in your Go program.
11

BINGO!!!

So, this is my first foray into server programming… I have no idea what I am doing. I thought running go main opened a browser, but what it does instead is create something server-related, and I must then open a browser manually and enter the url. Doing that makes it all work as expected.

Thanks all for the patient and positive feedback!!!

12

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