From cc06fe7ae65d9df967f9bd508a69266d8a1f1579 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Tue, 16 Jul 2019 01:57:03 +0200
Subject: [PATCH] os.dir(); fix vroot on Windows

---
 compiler/main.v   |  2 +-
 vlib/os/os.v      | 10 ++++++++++
 vlib/os/os_nix.v  |  4 ++++
 vlib/os/os_test.v |  9 +++++++++
 vlib/os/os_win.v  |  4 ++++
 5 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/compiler/main.v b/compiler/main.v
index ebf225a4ae..0492a0736a 100644
--- a/compiler/main.v
+++ b/compiler/main.v
@@ -933,7 +933,7 @@ fn new_v(args[]string) *V {
 	'option.v',
 	]
 	// Location of all vlib files
-	vroot := os.executable().all_before_last('/') 
+	vroot := os.dir(os.executable()) 
 	println('VROOT=$vroot') 
 	// v.exe's parent directory should contain vlib 
 	if os.dir_exists(vroot) && os.dir_exists(vroot + '/vlib/builtin') {
diff --git a/vlib/os/os.v b/vlib/os/os.v
index 5c0627d200..827f2d725e 100644
--- a/vlib/os/os.v
+++ b/vlib/os/os.v
@@ -382,6 +382,16 @@ pub fn ext(path string) string {
 	return path.right(pos)
 }
 
+
+// dir returns all but the last element of path, typically the path's directory.  
+pub fn dir(path string) string {
+	pos := path.last_index(PathSeparator) 
+	if pos == -1 {
+		return '.' 
+	} 
+	return path.left(pos) 
+} 
+
 fn path_sans_ext(path string) string {
 	pos := path.last_index('.')
 	if pos == -1 {
diff --git a/vlib/os/os_nix.v b/vlib/os/os_nix.v
index 3d553e42d7..0c0c793e0d 100644
--- a/vlib/os/os_nix.v
+++ b/vlib/os/os_nix.v
@@ -1,3 +1,7 @@
 module os 
 
 #include <dirent.h>
+
+const (
+	PathSeparator = '/' 
+) 
diff --git a/vlib/os/os_test.v b/vlib/os/os_test.v
index a50f48649e..6fb5f30956 100644
--- a/vlib/os/os_test.v
+++ b/vlib/os/os_test.v
@@ -34,6 +34,15 @@ fn test_write_and_read_string_to_file() {
   os.rm(filename)
 }
 
+fn test_dir() {
+	$if windows {
+		assert os.dir('C:\a\b\c') == 'C:\a\b' 
+ 
+	} $else { 
+		assert os.dir('/var/tmp/foo') == '/var/tmp' 
+	} 
+} 
+
 //fn test_fork() {
 //  pid := os.fork()
 //  if pid == 0 {
diff --git a/vlib/os/os_win.v b/vlib/os/os_win.v
index de3664c306..03026ac061 100644
--- a/vlib/os/os_win.v
+++ b/vlib/os/os_win.v
@@ -1,5 +1,9 @@
 module os
 
+const (
+	PathSeparator = '/' 
+) 
+
 // Ref - https://docs.microsoft.com/en-us/windows/desktop/winprog/windows-data-types
 // A handle to an object.
 type HANDLE voidptr