Intro

Nowadays Golang is so popular language. In Feb 2022 it has 11 place on the TIOBE index. Also, a lot of tools and apps are written or rewritten in this lang. Some company like Cloudflare even use it for scripting. Inspired by this article I would like to check does Go is comfortable for scripting and does it good alternative to Python?

Start

For testing, I’ll use a famous example😁

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package main

import "fmt"

func main(){
    fmt.Println("Hello, World") 
}

Saved it with the name goscript.go

That’s all. Simple command go run goscript.go will run this script and you will see a greeting. But it seems very simple, doesn’t it? And use go run command instead run script by /.goscript.go like BASH or Python is not comfortable. So let’s find another approach

Shebang

Shebang - is the first line of script that has information how to run it. Some examples of it:
#!/bin/bash - Execute the file using the Bash shell
#!/bin/env python3 - Execute the file using Python interpreter

Go shebang

Let’s try to use the same for Go. #!/bin/env go run

Don’t forget to do file executable chmod +x goscript.go
Trying to run it:

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$ ./goscript.go
Failed to execute process './goscript.go'. Reason:
The file './goscript.go' specified the interpreter '/bin/env go run',
which is not an executable command.

It happens because shebang can have only one argument but we need two for a running script.

Workaround 1

Of course, I’m not the first man who faced this issue. Internet searching led me to this topic on StackOverflow In this topic user recommends to use //usr/bin go run $0 $@ ; exit like shebang.

I know on my computer Go installed in another place. Find this place you may by using the command whereis go

My result:

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$ whereis go
go: /usr/local/go

I changed the path for go and try to run it

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$./goscript.go
./goscript.go: 1: ./goscript.go: //usr/local/go: Permission denied

Hmm, it’s strange that there is a problem with permission. Let’s try to find a solution for it.

Workaround Improvement

In the same topic, little bit below user suggests to use this command:
///usr/bin/true; exec /usr/bin/env go run "$0" "$@"

Try one more time:

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$ ./goscript.go
./goscript.go: 1: ./goscript.go: ///usr/bin/true: not found
Hello, World

Finally, a solution to run the script was found. But I don’t like not found issue.

Gorun

Gorun is a tool enabling one to put a “bang line” in the source code of a Go program to run it, or to run such a source code file explicitly. In my case, I downloaded binary in /usr/local/bin. Changed shebang on #!/usr/local/bin/gorun and tried one more time:

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$ ./goscript.go
Hello, World

It’s working.

Summary

Go has a solution to run a script without any problem: command go run. If you want to use shebang better to use gorun for it. In other cases it’s a workaround with duct tape and I will not recommend using it.

In the next part, we will create a simple and check how comfortable using Go is for scripting.