1 files changed, 123 insertions, 0 deletions
diff --git a/src/os/exec/lp_windows.go b/src/os/exec/lp_windows.go
new file mode 100644
index 000000000..c3efd67e9
--- /dev/null
+++ b/src/os/exec/lp_windows.go
@@ -0,0 +1,123 @@
+// Copyright 2010 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 exec
+
+import (
+	"errors"
+	"os"
+	"strings"
+)
+
+// ErrNotFound is the error resulting if a path search failed to find an executable file.
+var ErrNotFound = errors.New("executable file not found in %PATH%")
+
+func chkStat(file string) error {
+	d, err := os.Stat(file)
+	if err != nil {
+		return err
+	}
+	if d.IsDir() {
+		return os.ErrPermission
+	}
+	return nil
+}
+
+func hasExt(file string) bool {
+	i := strings.LastIndex(file, ".")
+	if i < 0 {
+		return false
+	}
+	return strings.LastIndexAny(file, `:\/`) < i
+}
+
+func findExecutable(file string, exts []string) (string, error) {
+	if len(exts) == 0 {
+		return file, chkStat(file)
+	}
+	if hasExt(file) {
+		if chkStat(file) == nil {
+			return file, nil
+		}
+	}
+	for _, e := range exts {
+		if f := file + e; chkStat(f) == nil {
+			return f, nil
+		}
+	}
+	return ``, os.ErrNotExist
+}
+
+// LookPath searches for an executable binary named file
+// in the directories named by the PATH environment variable.
+// If file contains a slash, it is tried directly and the PATH is not consulted.
+// LookPath also uses PATHEXT environment variable to match
+// a suitable candidate.
+// The result may be an absolute path or a path relative to the current directory.
+func LookPath(file string) (f string, err error) {
+	x := os.Getenv(`PATHEXT`)
+	if x == `` {
+		x = `.COM;.EXE;.BAT;.CMD`
+	}
+	exts := []string{}
+	for _, e := range strings.Split(strings.ToLower(x), `;`) {
+		if e == "" {
+			continue
+		}
+		if e[0] != '.' {
+			e = "." + e
+		}
+		exts = append(exts, e)
+	}
+	if strings.IndexAny(file, `:\/`) != -1 {
+		if f, err = findExecutable(file, exts); err == nil {
+			return
+		}
+		return ``, &Error{file, err}
+	}
+	if f, err = findExecutable(`.\`+file, exts); err == nil {
+		return
+	}
+	if pathenv := os.Getenv(`PATH`); pathenv != `` {
+		for _, dir := range splitList(pathenv) {
+			if f, err = findExecutable(dir+`\`+file, exts); err == nil {
+				return
+			}
+		}
+	}
+	return ``, &Error{file, ErrNotFound}
+}
+
+func splitList(path string) []string {
+	// The same implementation is used in SplitList in path/filepath;
+	// consider changing path/filepath when changing this.
+
+	if path == "" {
+		return []string{}
+	}
+
+	// Split path, respecting but preserving quotes.
+	list := []string{}
+	start := 0
+	quo := false
+	for i := 0; i < len(path); i++ {
+		switch c := path[i]; {
+		case c == '"':
+			quo = !quo
+		case c == os.PathListSeparator && !quo:
+			list = append(list, path[start:i])
+			start = i + 1
+		}
+	}
+	list = append(list, path[start:])
+
+	// Remove quotes.
+	for i, s := range list {
+		if strings.Contains(s, `"`) {
+			list[i] = strings.Replace(s, `"`, ``, -1)
+		}
+	}
+
+	return list
+}