Golang Module

calendar2021-11-01 · 1 min read · golang module  ·
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1~$ mkdir greetings
2~$ cd greetings
3~$ go mod init example.com/greetings

In a text editor, create greetings.go with the following content:

 1package greetings
 2
 3import "fmt"
 4
 5// Hello returns a greeting for the named person.
 6func Hello(name string) string {
 7    // Return a greeting that embeds the name in a message.
 8    message := fmt.Sprintf("Hi, %v. Welcome!", name)
 9    return message
10}
...
go

Call it from another module

1~$ cd ..
2~$ mkdir hello
3~$ cd hello
4~$ go mod init example.com/hello

In a text editor, create hello.go with the following content:

 1package main
 2
 3import (
 4    "fmt"
 5
 6    "example.com/greetings"
 7)
 8
 9func main() {
10    // Get a greeting message and print it.
11    message := greetings.Hello("Gladys")
12    fmt.Println(message)
13}
...
go

Edit example.com/hello module to use your local example.com/greetings module. Inside 'hello' directory:

1~$ go mod edit -replace example.com/greetings=../greetings

Then, tidy it

1~$ go mod tidy

The go.mod file in example.com/hello module should now be:

1module example.com/hello
2
3go 1.16
4
5replace example.com/greetings => ../greetings
6
7require example.com/greetings v0.0.0-00010101000000-000000000000

Then, from hello directory, run it.

1~$ go run .
2Hi, Gladys. Welcome!

NOTE: This example was directly taken from https://golang.org/doc/tutorial/create-module so check it there for further details.