blob: 36a8a244555aa71e41978c2778190735c4bfca84 [file] [log] [blame]
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package os
import (
"runtime"
"syscall"
)
func hostname() (name string, err error) {
// Try uname first, as it's only one system call and reading
// from /proc is not allowed on Android.
var un syscall.Utsname
err = syscall.Uname(&un)
var buf [512]byte // Enough for a DNS name.
for i, b := range un.Nodename[:] {
buf[i] = uint8(b)
if b == 0 {
name = string(buf[:i])
break
}
}
// If we got a name and it's not potentially truncated
// (Nodename is 65 bytes), return it.
if err == nil && len(name) > 0 && len(name) < 64 {
return name, nil
}
if runtime.GOOS == "android" {
if name != "" {
return name, nil
}
return "localhost", nil
}
f, err := Open("/proc/sys/kernel/hostname")
if err != nil {
return "", err
}
defer f.Close()
n, err := f.Read(buf[:])
if err != nil {
return "", err
}
if n > 0 && buf[n-1] == '\n' {
n--
}
return string(buf[:n]), nil
}