From 8ef3313d63edf13a5e608d58b9f62849d7fbe606 Mon Sep 17 00:00:00 2001
From: 0x9ef <43169346+0x9ef@users.noreply.github.com>
Date: Tue, 16 Jul 2019 21:29:17 +0300
Subject: [PATCH] Fixed buf on hostname and added optional type.

Before submitting this PR, submit https://github.com/vlang/v/pull/1188
---
 vlib/os/os.v | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/vlib/os/os.v b/vlib/os/os.v
index 49f69ee874..a17b12b53e 100644
--- a/vlib/os/os.v
+++ b/vlib/os/os.v
@@ -484,11 +484,15 @@ pub fn user_os() string {
 }
 
 // hostname returns hostname
-pub fn hostname() string {
-  mut hname := [1024]byte
-  hname[1023] = `\0`
-  C.gethostname(&hname, 1023)
-  return tos_clone(hname)
+pub fn hostname() ?string {
+  	mut hname := [256]byte
+	// https://www.ietf.org/rfc/rfc1035.txt
+	// The host name is returned as a null-terminated string.
+	res := C.gethostname(&hname, 256)
+	if res != 0 {
+		return error('os: hostname cannot get host name of PC.')
+	}
+  	return tos_clone(hname)
 }
 
 // home_dir returns path to user's home directory.