main() cannot call method in another file

[Cam]

Hi everyone on Golang group,

I'm having difficulty with some simple code, and appreciate if someone can point out a solution.

There is a simple main package that looks like this:

github.com/username/playground/

                                                            hello.go

                                                            main.go

hello.go:

package main

import "fmt"

func SayHello() {

  fmt.Println("Hello")

}

main.go

package main

func main() {

  SayHello()

}

Trying to run main.go is producing an error:

# command-line-arguments
go/src/github.com/username/playground/main.go:4:2: undefined: SayHello

Why is this error happening? Is my packaging done wrong?

[Tamás Gulácsi]

"go run" builds and runs what you tell it: only main.go.

If you have a package with more files, use "go build && playground".

[Guy Allard]

Use:

go run *.go

or

go build *.go

[Chris Hines]

go run <dir> works now too and pulls in all the files in the package at <dir> so "go run ." is a nice shortcut that works more like the other subcommands of the go tool.

[Cam]

Your suggestions helped me build the files with the same project structure:

// From folder username/

go build playground/*.go

// From folder playground/

go build *.go

go build .

Thanks !!