diff --git a/cat/cat b/cat/cat
deleted file mode 100755
index b7e49d5..0000000
Binary files a/cat/cat and /dev/null differ
diff --git a/cat/cat.go b/cat/cat.go
index 528351a..b8b8be7 100644
--- a/cat/cat.go
+++ b/cat/cat.go
@@ -5,29 +5,33 @@ import(
 	"os"
 	"io"
 	"log"
+	"flag"
 )
 type Catter struct {
-	warn log.Logger
-	oup os.File
-	bufSiz
+	warn *log.Logger
+	out *os.File
+	bufSiz int
 	buf []byte
 }
 
-func New(out os.File, warn log.Logger, bufSiz int) *Catter {
+func New(out *os.File, warn *log.Logger, bufSiz int) *Catter {
 	c := new(Catter)
+	c.out = out
 	c.warn = warn
 	c.bufSiz = bufSiz
-	c.buf = make([]byte, bufSiz)
+	c.buf = make([]byte, c.bufSiz)
 	return c
 }
 
-func (c Catter) Cat(files []os.File) error {
-	status = 0
-	for _, file ;= range files {
+func (c Catter) Cat(files []*os.File) error {
+	for _, file := range files {
 		for {
-			n, err := file.Read(buf)
+			n, err := file.Read(c.buf)
 			if n>0 {
-				c.out.FPrintf("%s", buf[:n])
+				_, err := c.out.Write(c.buf[:n])
+				if err != nil {
+					return err
+				}
 			}
 			if err == io.EOF {
 				break
@@ -36,16 +40,31 @@ func (c Catter) Cat(files []os.File) error {
 			}
 		}
 	}
-	return err
+	return nil
 }
 
-func (c Catter)Open(filePaths []string) []os.File {
-	files := make([]os.File, len(filepaths))
+func (c Catter)OpenArr(filePaths []string) []*os.File {
+	files := make([]*os.File, len(filePaths))
 	for i, filePath := range filePaths {
-		files[i], err := os.Open(filePath)
+		var err error
+		files[i], err = os.Open(filePath)
 		if err != nil {
 			c.warn.Println(err)
 		}
 	}
 	return files
+}
+
+func Run(args []string) int {
+	flagSet := flag.NewFlagSet(args[0], flag.ExitOnError)
+	flagSet.Parse(args[1:])
+	status := 0
+	warn := log.New(os.Stderr, args[0]+": ", 0)
+	c := New(os.Stdout, warn, 512)
+	files := c.OpenArr(flagSet.Args())
+	err := c.Cat(files)
+	if err != nil {
+		status = 1
+	}
+	return status
 }
\ No newline at end of file
diff --git a/cat/main.go b/cat/main.go
deleted file mode 100644
index 2e0a613..0000000
--- a/cat/main.go
+++ /dev/null
@@ -1,17 +0,0 @@
-package main
-
-import(
-	"fmt"
-	"os"
-	"io"
-	"log"
-	"flag"
-	"cat"
-)
-
-func main() {
-	flag.Parse()
-	status := 0
-	c = cat.New(os.Stdout, warn, 512)
-	os.Exit(status)
-}
diff --git a/echo/echo.go b/echo/echo.go
new file mode 100644
index 0000000..7869284
--- /dev/null
+++ b/echo/echo.go
@@ -0,0 +1,75 @@
+/* Simple 'echo' implementation. */
+package echo
+
+import (
+	"os"
+	"flag"
+	"strings"
+)
+
+type Echoer struct {
+	out *os.File
+	backslashMap map[string] string
+}
+func (e Echoer)BackslashInterpret(str string) string {
+	for k, v := range e.backslashMap {
+		str  = strings.ReplaceAll(str, k, v)
+	}
+	return str
+}
+
+func (e Echoer)Echo(str string) {
+	e.out.Write( []byte(str[:len(str)]) )
+}
+
+func New(out *os.File, backslashMap map[string] string) *Echoer {
+	e := new(Echoer)
+	e.out = out
+	e.backslashMap = backslashMap
+	return e
+}
+func Run(args []string) int {
+	var(
+		newLineStr string
+		newLineFlag bool
+		joinStr string
+		joinStrsFlag bool
+		backslashSeqFlag bool
+	)
+	seqs := map[string] string {
+		"\\\\" : "\\",
+		"\\a" : "\a",
+		"\\b" : "\b",
+		/*"\\c" : "\c",
+		"\\e" : "\e",*/
+		"\\f" : "\f",
+		"\\n" : "\n",
+		"\\r" : "\r",
+		"\\t" : "\t",
+		"\\v" : "\v",
+	}
+	e := New(os.Stdout, seqs)
+	flagSet := flag.NewFlagSet(args[0], flag.ExitOnError)
+	flagSet.BoolVar(&newLineFlag, "n", false,
+	                            "Don't add new line character('-N' is lower priority).")
+	flagSet.StringVar(&newLineStr, "N", "\n", "Use this instead new line character.") 
+	flagSet.BoolVar(&joinStrsFlag, "j", false, "Join strings('-J' is lower priority).")
+	flagSet.StringVar(&joinStr, "J", " ", "Use instead of space as separator.") 
+	flagSet.BoolVar(&backslashSeqFlag, "e", false, "Interpret backslash special terminal characters(Characters from join options will be interpreted too).")
+	flagSet.Parse(args[1:])
+
+	if newLineFlag {
+		newLineStr = ""	
+	}
+	if joinStrsFlag {
+		joinStr = ""
+	}
+
+	printStr := strings.Join(flagSet.Args(), joinStr) +newLineStr
+	if backslashSeqFlag {
+		printStr = e.BackslashInterpret(printStr)
+	}
+
+	e.Echo(printStr)
+	return 0
+}
diff --git a/echo/main.go b/echo/main.go
deleted file mode 100644
index 94bffa4..0000000
--- a/echo/main.go
+++ /dev/null
@@ -1,48 +0,0 @@
-/* Simple 'echo' implementation. */
-package main
-
-import (
-	"flag"
-	"fmt"
-	"strings"
-)
-
-func main() {
-	newLineFlagPtr := flag.Bool("n", false,
-	                            "Don't add new line character('-N' is lower priority).")
-	newLineStrPtr := flag.String("N", "\n", "Use this instead new line character.") 
-	joinStrsFlagPtr := flag.Bool("j", false, "Join strings('-J' is lower priority).")
-	joinStrPtr := flag.String("J", " ", "Use instead of space as separator.") 
-	backslashSeqFlagPtr := flag.Bool("e", false, "Interpret backslash special terminal characters.")
-	flag.Parse()
-
-	if *newLineFlagPtr {
-		*newLineStrPtr = ""	
-	}
-	if *joinStrsFlagPtr {
-		*joinStrPtr = ""
-	}
-
-	printStr := strings.Join(flag.Args(), *joinStrPtr)
-	if *backslashSeqFlagPtr {
-		seqs := map[string] string {
-			"\\\\" : "\\",
-			"\\a" : "\a",
-			"\\b" : "\b",
-			/*"\\c" : "\c",
-			"\\e" : "\e",*/
-			"\\f" : "\f",
-			"\\n" : "\n",
-			"\\r" : "\r",
-			"\\t" : "\t",
-			"\\v" : "\v",
-		}
-		for k, v := range seqs {
-			printStr = strings.ReplaceAll(printStr, k, v)
-		}
-	}
-
-	fmt.Printf("%s%s",
-	            printStr,
-	            *newLineStrPtr,)
-}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..5e997c6
--- /dev/null
+++ b/main.go
@@ -0,0 +1,45 @@
+package main
+
+import(
+	"fmt"
+	"os"
+	"path"
+	"github.com/jienfak/goblin/cat"
+	"github.com/jienfak/goblin/echo"
+	"github.com/jienfak/goblin/mkdir"
+)
+
+func main() {
+	var(
+		utilName string
+		args []string
+	)
+	
+
+	utilsMap := map[string]  interface{}  {
+		"cat": cat.Run,
+		"mkdir" : mkdir.Run,
+		"echo" : echo.Run,
+	}
+
+	if binBase := path.Base(os.Args[0]) ; binBase != "goblin" {
+		utilName = binBase
+		args = os.Args[:]
+	} else {
+		if len(os.Args)<2 && binBase=="goblin" {
+			for k, _ := range utilsMap {
+				fmt.Printf("%s\n", k)
+			}
+			os.Exit(0)
+		}
+		utilName = os.Args[1]
+		args = os.Args[1:]
+	}
+
+	if _, ok := utilsMap[utilName] ; !ok {
+		fmt.Printf("%s: No such uitl as '%s'.", )
+		os.Exit(1)
+	}
+	status := utilsMap[utilName].(func([]string) int )(args)
+	os.Exit(status)
+}
\ No newline at end of file
diff --git a/mkdir/main.go b/mkdir/main.go
deleted file mode 100644
index 8229b3c..0000000
--- a/mkdir/main.go
+++ /dev/null
@@ -1,43 +0,0 @@
-package main
-
-import(
-	"os"
-	"flag"
-	"log"
-)
-
-func main() {
-	var (
-		parentFlag, verbFlag bool
-		 modeArg int
-	)
-	status := 0
-	flag.BoolVar(&parentFlag, "p", false, "No error if existing, make parent as needed.")
-	flag.IntVar(&modeArg, "m", 0766, "Set file `mode`.")
-	flag.BoolVar(&verbFlag, "v", false, "Print a message for each created directory.")
-	if len(os.Args) < 2 {
-		flag.Usage()
-	}
-	flag.Parse()
-	mode := os.FileMode(modeArg)
-	var verb *log.Logger
-	if verbFlag {
-		verb = log.New(os.Stdout, os.Args[0]+": ", 0)
-	}
-	warn := log.New(os.Stderr, os.Args[0]+": ", 0)
-	for _,  path := range flag.Args() {
-		var err error
-		if parentFlag {
-			err = os.MkdirAll(path, mode)
-		} else {
-			err =  os.Mkdir(path, mode)
-		}
-		if err != nil {
-			warn.Println(err)
-			status = 1
-		} else if verbFlag {
-			verb.Printf("Created directory '%s'.", path)
-		}
-	}
-	os.Exit(status)
-}
diff --git a/mkdir/mkdir.go b/mkdir/mkdir.go
new file mode 100644
index 0000000..e18f587
--- /dev/null
+++ b/mkdir/mkdir.go
@@ -0,0 +1,44 @@
+package mkdir
+
+import(
+	"os"
+	"flag"
+	"log"
+)
+
+func Run(args []string) int {
+	var (
+		parentFlag, verbFlag bool
+		 modeArg int
+	)
+	flagSet := flag.NewFlagSet(args[0], flag.ExitOnError)
+	status := 0
+	flagSet.BoolVar(&parentFlag, "p", false, "No error if existing, make parent as needed.")
+	flagSet.IntVar(&modeArg, "m", 0766, "Set file `mode`.")
+	flagSet.BoolVar(&verbFlag, "v", false, "Print a message for each created directory.")
+	if len(args) < 2 {
+		flagSet.Usage()
+	}
+	flagSet.Parse(args[1:])
+	mode := os.FileMode(modeArg)
+	var verb *log.Logger
+	if verbFlag {
+		verb = log.New(os.Stdout, flagSet.Args()[0]+": ", 0)
+	}
+	warn := log.New(os.Stderr, flagSet.Args()[0]+": ", 0)
+	for _,  path := range flagSet.Args() {
+		var err error
+		if parentFlag {
+			err = os.MkdirAll(path, mode)
+		} else {
+			err =  os.Mkdir(path, mode)
+		}
+		if err != nil {
+			warn.Println(err)
+			status = 1
+		} else if verbFlag {
+			verb.Printf("Created directory '%s'.", path)
+		}
+	}
+	return status
+}
\ No newline at end of file