How can I detect OS version in Go

Question

Relatively new to Go. Seems trivial, but I can't figure out how to detect the OS version. I know I can use runtime.GOOS and runtime.GOARCH to get the platform and architecture, but say I know I'm on linux but I want to find if I'm on RH6 vice RH7, etc. is what I'm trying to figure out.

Answer 1

So there's this obscure Uname method in the syscall package that basically does it, at least on Linux. The struct it fills is a bit clunky and undocumented, but you can get the gist of it:

import (
    "fmt"
    "syscall"
)

// A utility to convert the values to proper strings.
func int8ToStr(arr []int8) string {
    b := make([]byte, 0, len(arr))
    for _, v := range arr {
        if v == 0x00 {
            break
        } 
        b = append(b, byte(v))
    }
    return string(b)
}

func main() {

    var uname syscall.Utsname
    if err := syscall.Uname(&uname); err == nil {
        // extract members:
        // type Utsname struct {
        //  Sysname    [65]int8
        //  Nodename   [65]int8
        //  Release    [65]int8
        //  Version    [65]int8
        //  Machine    [65]int8
        //  Domainname [65]int8
        // }

        fmt.Println(int8ToStr(uname.Sysname[:]), 
                    int8ToStr(uname.Release[:]), 
                    int8ToStr(uname.Version[:]))

    }
}

BTW This doesn't work on the playground, probably because of the sandbox limitations, but works on Linux. Haven't tested other systems.