Michael Whatcott
Michael Whatcott

Reputation: 5955

How to reliably detect os/platform in Go

Here's what I'm currently using, which I think gets the job done, but there's got to be a better way:

func isWindows() bool {
    return os.PathSeparator == '\\' && os.PathListSeparator == ';'
}

As you can see, in my case all I need to know is how to detect windows but I'd like to know the way to detect any platform/os.

Play:

http://play.golang.org/p/r4lYWDJDxL

Upvotes: 130

Views: 128929

Answers (10)

The first answer from @nemo is the most appropriate, i just wanted to point out that if you are currently a user of gopls language server the build tags may not work as intended.

There's no solution or workaround at the time of writing, the most you can do is change your editor's lsp configs (vscode, neovim, emacs, etc) to select a build tag in order to being able to edit the files with that tag without errors. Editing files with another tag will not work, and trying to select multiple tags fails as well. This is the current progress of the issue github@go/x/tools/gopls

Upvotes: 0

Kassab
Kassab

Reputation: 143

I found this library, gets the job done. https://github.com/matishsiao/goInfo

   package main

   import (
       "github.com/matishsiao/goInfo"
   )

   func main() {
        gi := goInfo.GetInfo()
        gi.VarDump()
     }

result:

GoOS: linux
Kernel: Linux
Core: 4.4.0
Platform: unknown
OS: GNU/Linux
Hostname: ec4f6b107fa7
CPUs: 8

play: https://go.dev/play/p/SvgfJ7wcltu

Upvotes: -1

Gil
Gil

Reputation: 69

Use path:

package main
  
// Importing fmt and path/filepath
import (
    "fmt"
    "path/filepath"
)
  
// Calling main
func main() {
    fmt.Println(filepath.Join("/", "/")) // out: /
    fmt.Println(filepath.Join(""))// out: 
    fmt.Println(filepath.Join("dirname", "dirsubname")) // out: dirname/subdirname
    fmt.Println(filepath.Join(".")) // out: .
  
}
  • path - Standard library

Or use GOOS:

os := runtime.GOOS
    switch os {
    case "windows":
        fmt.Println("Windows")
    case "darwin":
        fmt.Println("MAC operating system")
    case "linux":
        fmt.Println("Linux")
    default:
        fmt.Printf("%s.\n", os)
    }

Upvotes: 1

hookenz
hookenz

Reputation: 38849

It's 2022 and the correct answer for go 1.18+ is:

At runtime you want:

if runtime.GOOS == "windows" {
  // windows specific code here...
}

If you need to determine the filesystem path separator character

Use: os.PathSeparator

Examples:

  • c:\program files
  • /usr/local/bin

If you need the Path List separator as used by the PATH environment variable

Use: os.PathListSeparator

Examples:

  • /usr/local/bin:/usr/local:
  • "C:\windows";"c:\windows\system32";

Upvotes: 13

Dr.Mr.Dr
Dr.Mr.Dr

Reputation: 51

I tested in Go 1.17.1 which really worked for me.

package main

import (
        "fmt"
        "runtime"
)
func main(){
        fmt.Println(runtime.GOOS)
}

Output:
darwin

Upvotes: 1

nemo
nemo

Reputation: 57599

Detection at compile time

If you're doing this to have different implementations depending on the OS, it is more useful to have separate files with the implementation of that feature and add build tags to each of the files. This is used in many places in the standard library, for example in the os package.

These so-called "Build constraints" or "Build tags" are explained here.

Say you have the constant PATH_SEPARATOR and you want that platform-dependent, you would make two files, one for Windows and one for the (UNIX) rest:

/project/path_windows.go
/project/path_unix.go

The code of these files would then be:

path_windows.go

// +build windows

package project

const PATH_SEPARATOR = '\\'

path_unix.go

// +build !windows

package project

const PATH_SEPARATOR = '/'

You can now access PATH_SEPARATOR in your code and have it platform dependant.

Detection at runtime

If you want to determine the operating system at runtime, use the runtime.GOOS variable:

if runtime.GOOS == "windows" {
    fmt.Println("Hello from Windows")
}

While this is compiled into the runtime and therefore ignores the environment, you can nevertheless be relatively certain that the value is correct. The reason for this is that every platform that is worth distinguishing needs rebuilding due to different executable formats and thus has a new GOOS value.

Upvotes: 210

ENG618
ENG618

Reputation: 1012

Since this is an older question and answer I have found another solution.

You could simply use the constants defined in the os package. This const returns a rune so you would need to use string conversion also.

string(os.PathSeparator)
string(os.PathListSeparator)

Example: https://play.golang.org/p/g6jnF7W5_pJ

Upvotes: 2

Elijah
Elijah

Reputation: 13594

With regards to detecting the platform, you can use Distribution Detector project to detect the Linux distribution being run.

Upvotes: 0

Bill.Caffery
Bill.Caffery

Reputation: 464

I just stumbled on this looking for something else and noticed the age of this post so I'll add a more updated addition. If you're just trying to handle the correct filepath I would use filepath.Join(). Its takes all of the guesswork out of os issues. If there is more you need, other than just filepath, using the runtime constants (runtime.GOOS & runtime.GOARCH) are the way to go: playground example

Upvotes: 1

Tyler Egeto
Tyler Egeto

Reputation: 5495

Have you looked at the runtime package? It has a GOOS const: http://golang.org/pkg/runtime/#pkg-constants

Upvotes: 23

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