1 files changed, 82 insertions, 0 deletions
diff --git a/src/pkg/os/exec/lp_windows.go b/src/pkg/os/exec/lp_windows.go
new file mode 100644
index 000000000..b7efcd68b
--- /dev/null
+++ b/src/pkg/os/exec/lp_windows.go
@@ -0,0 +1,82 @@
+// 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.EPERM
+	}
+	return nil
+}
+
+func findExecutable(file string, exts []string) (string, error) {
+	if len(exts) == 0 {
+		return file, chkStat(file)
+	}
+	f := strings.ToLower(file)
+	for _, e := range exts {
+		if strings.HasSuffix(f, e) {
+			return file, chkStat(file)
+		}
+	}
+	for _, e := range exts {
+		if f := file + e; chkStat(f) == nil {
+			return f, nil
+		}
+	}
+	return ``, os.ENOENT
+}
+
+// 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.
+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 strings.Split(pathenv, `;`) {
+			if f, err = findExecutable(dir+`\`+file, exts); err == nil {
+				return
+			}
+		}
+	}
+	return ``, &Error{file, ErrNotFound}
+}