diff --git a/tools/cpdir.go b/tools/cpdir.go
new file mode 100644
index 0000000..8d9a537
--- /dev/null
+++ b/tools/cpdir.go
@@ -0,0 +1,102 @@
+// Copyright 2013 <chaishushan{AT}gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ingore
+
+//
+// Copy dir, support regexp.
+//
+// Example:
+//	cpdir src dst
+//	cpdir src dst "\.go$"
+//	cpdir src dst "\.tiff?$"
+//	cpdir src dst "\.tiff?|jpg|jpeg$"
+//
+// Help:
+//	cpdir -h
+//
+package main
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"regexp"
+)
+
+const usage = `
+Usage: cpdir src dst [filter]
+       cpdir -h
+
+Example:
+  cpdir src dst
+  cpdir src dst "\.go$"
+  cpdir src dst "\.tiff?$"
+  cpdir src dst "\.tiff?|jpg|jpeg$"
+    
+Report bugs to <chaishushan{AT}gmail.com>.
+`
+
+func main() {
+	if len(os.Args) < 3 {
+		fmt.Fprintln(os.Stderr, usage[1:len(usage)-1])
+		os.Exit(0)
+	}
+	filter := ".*"
+	if len(os.Args) > 3 {
+		filter = os.Args[3]
+	}
+	total := cpDir(os.Args[2], os.Args[1], filter)
+	fmt.Printf("total %d\n", total)
+}
+
+func cpDir(dst, src, filter string) (total int) {
+	entryList, err := ioutil.ReadDir(src)
+	if err != nil && !os.IsExist(err) {
+		log.Fatal("cpDir: ", err)
+	}
+	for _, entry := range entryList {
+		if entry.IsDir() {
+			cpDir(dst+"/"+entry.Name(), src+"/"+entry.Name(), filter)
+		} else {
+			mathed, err := regexp.MatchString(filter, entry.Name())
+			if err != nil {
+				log.Fatal("regexp.MatchString: ", err)
+			}
+			if mathed {
+				srcFname := filepath.Clean(src + "/" + entry.Name())
+				dstFname := filepath.Clean(dst + "/" + entry.Name())
+				fmt.Printf("copy %s\n", srcFname)
+
+				cpFile(dstFname, srcFname)
+				total++
+			}
+		}
+	}
+	return
+}
+
+func cpFile(dst, src string) {
+	err := os.MkdirAll(filepath.Dir(dst), 0666)
+	if err != nil && !os.IsExist(err) {
+		log.Fatal("cpFile: ", err)
+	}
+	fsrc, err := os.Open(src)
+	if err != nil {
+		log.Fatal("cpFile: ", err)
+	}
+	defer fsrc.Close()
+
+	fdst, err := os.Create(dst)
+	if err != nil {
+		log.Fatal("cpFile: ", err)
+	}
+	defer fdst.Close()
+	if _, err = io.Copy(fdst, fsrc); err != nil {
+		log.Fatal("cpFile: ", err)
+	}
+}
diff --git a/tools/lookpath.go b/tools/lookpath.go
new file mode 100644
index 0000000..b8a505c
--- /dev/null
+++ b/tools/lookpath.go
@@ -0,0 +1,44 @@
+// Copyright 2014 <chaishushan{AT}gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ingore
+
+// Lookpath is a simple which.
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Printf(`Usage: lookpath COMMAND [...]
+Write the full path of COMMAND(s) to standard output.
+
+Report bugs to <chaishushan@gmail.com>.
+`)
+		os.Exit(0)
+	}
+	for i := 1; i < len(os.Args); i++ {
+		path, err := exec.LookPath(os.Args[i])
+		if err != nil {
+			fmt.Printf("lookpath: no %s in (%v)\n", os.Args[i], GetEnv("PATH"))
+			os.Exit(0)
+		}
+		fmt.Println(path)
+	}
+}
+
+func GetEnv(key string) string {
+	key = strings.ToUpper(key) + "="
+	for _, env := range os.Environ() {
+		if strings.HasPrefix(strings.ToUpper(env), key) {
+			return env[len(key):]
+		}
+	}
+	return ""
+}
diff --git a/tools/lsdir.go b/tools/lsdir.go
new file mode 100644
index 0000000..9617b66
--- /dev/null
+++ b/tools/lsdir.go
@@ -0,0 +1,97 @@
+// Copyright 2013 <chaishushan{AT}gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ingore
+
+//
+// List files, support file/header regexp.
+//
+// Example:
+//	lsdir dir
+//	lsdir dir "\.go$"
+//	lsdir dir "\.go$" "chaishushan"
+//	lsdir dir "\.tiff?|jpg|jpeg$"
+//
+// Help:
+//	lsdir -h
+//
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"regexp"
+)
+
+const usage = `
+Usage: lsdir dir [nameFilter [dataFilter]]
+       lsdir -h
+
+Example:
+  lsdir dir
+  lsdir dir "\.go$"
+  lsdir dir "\.go$" "chaishushan"
+  lsdir dir "\.tiff?|jpg|jpeg$"
+    
+Report bugs to <chaishushan{AT}gmail.com>.
+`
+
+func main() {
+	if len(os.Args) < 2 || os.Args[1] == "-h" {
+		fmt.Fprintln(os.Stderr, usage[1:len(usage)-1])
+		os.Exit(0)
+	}
+	dir, nameFilter, dataFilter := os.Args[1], ".*", ""
+	if len(os.Args) > 2 {
+		nameFilter = os.Args[2]
+	}
+	if len(os.Args) > 3 {
+		dataFilter = os.Args[3]
+	}
+
+	total := 0
+	filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			log.Fatal("filepath.Walk: ", err)
+			return err
+		}
+		if info.IsDir() {
+			return nil
+		}
+		relpath, err := filepath.Rel(dir, path)
+		if err != nil {
+			log.Fatal("filepath.Rel: ", err)
+			return err
+		}
+		mathed, err := regexp.MatchString(nameFilter, relpath)
+		if err != nil {
+			log.Fatal("regexp.MatchString: ", err)
+		}
+		if mathed {
+			if dataFilter != "" {
+				data, err := ioutil.ReadFile(path)
+				if err != nil {
+					fmt.Printf("ioutil.ReadFile: %s\n", path)
+					log.Fatal("ioutil.ReadFile: ", err)
+				}
+				mathed, err := regexp.MatchString(dataFilter, string(data))
+				if err != nil {
+					log.Fatal("regexp.MatchString: ", err)
+				}
+				if mathed {
+					fmt.Printf("%s\n", relpath)
+					total++
+				}
+			} else {
+				fmt.Printf("%s\n", relpath)
+				total++
+			}
+		}
+		return nil
+	})
+	fmt.Printf("total %d\n", total)
+}
diff --git a/tools/md5.go b/tools/md5.go
new file mode 100644
index 0000000..f60c8fb
--- /dev/null
+++ b/tools/md5.go
@@ -0,0 +1,121 @@
+// Copyright 2013 <chaishushan{AT}gmail.com>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build ingore
+
+//
+// Cacl dir or file MD5Sum, support regexp.
+//
+// Example:
+//	md5 file
+//	md5 dir "\.go$"
+//	md5 dir "\.tiff?$"
+//	md5 dir "\.tiff?|jpg|jpeg$"
+//
+// Help:
+//	cpdir -h
+//
+package main
+
+import (
+	"crypto/md5"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"regexp"
+	"sort"
+)
+
+const usage = `
+Usage: md5 [dir|file [filter]]
+       md5 -h
+
+Example:
+  md5 file
+  md5 dir "\.go$"
+  md5 dir "\.go$"
+  md5 dir "\.tiff?$"
+  md5 dir "\.tiff?|jpg|jpeg$"
+    
+Report bugs to <chaishushan{AT}gmail.com>.
+`
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintln(os.Stderr, usage[1:len(usage)-1])
+		os.Exit(0)
+	}
+	filter := ".*"
+	if len(os.Args) > 2 {
+		filter = os.Args[2]
+	}
+
+	if name := os.Args[1]; IsDir(name) {
+		m, err := MD5Dir(name, filter)
+		if err != nil {
+			log.Fatalf("%s: %v", name, err)
+		}
+		var paths []string
+		for path := range m {
+			paths = append(paths, path)
+		}
+		sort.Strings(paths)
+		for _, path := range paths {
+			fmt.Printf("%x *%s\n", m[path], path)
+		}
+	} else {
+		sum, err := MD5File(name)
+		if err != nil {
+			log.Fatalf("%s: %v", name, err)
+		}
+		fmt.Printf("%x *%s\n", sum, name)
+	}
+}
+
+func IsDir(name string) bool {
+	fi, err := os.Lstat(name)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return fi.IsDir()
+}
+
+func MD5Dir(root string, filter string) (map[string][md5.Size]byte, error) {
+	m := make(map[string][md5.Size]byte)
+	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if info.IsDir() {
+			return nil
+		}
+		mathed, err := regexp.MatchString(filter, path)
+		if err != nil {
+			log.Fatal("regexp.MatchString: ", err)
+		}
+		if mathed {
+			data, err := ioutil.ReadFile(path)
+			if err != nil {
+				return err
+			}
+			m[path] = md5.Sum(data)
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return m, nil
+}
+
+func MD5File(filename string) (sum [md5.Size]byte, err error) {
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return
+	}
+	sum = md5.Sum(data)
+	return
+}