diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c799d12
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+
+*.exe
diff --git a/go.mod b/go.mod
index fde6242..ae6cef0 100644
--- a/go.mod
+++ b/go.mod
@@ -1,4 +1,5 @@
-module utf8tmpl
+module vultras.su/util/combo
 
 go 1.16
 
+require vultras.su/core/cli v0.0.0-20240104195345-5d79542278a0 // indirect
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..050dbca
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+vultras.su/core/cli v0.0.0-20240104195345-5d79542278a0 h1:acA77oEg7hDuUchyBvw7scG9gayVLFAC9/CGuqyfLSA=
+vultras.su/core/cli v0.0.0-20240104195345-5d79542278a0/go.mod h1:rYu/sFWE3vUkDSSJCZt+K1aVaso0MYcZ+tmxQd4whdQ=
diff --git a/install b/install
deleted file mode 100755
index f1cf507..0000000
--- a/install
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/bin/sh
-
-exec go install
-
diff --git a/main.go b/main.go
index eb559df..38a5ac8 100644
--- a/main.go
+++ b/main.go
@@ -1,40 +1,17 @@
 package main
 
 import(
-	"fmt"
 	"os"
-	"utf8tmpl/tmpl"
-	"utf8tmpl/pin"
+	"vultras.su/util/combo/tmpl"
+	"vultras.su/util/combo/pin"
+	"vultras.su/core/cli/mtool"
+)
+
+var root = mtool.T("combo").Subs(
+	tmpl.Tool,
+	pin.Tool,
 )
 
 func main() {
-	var(
-		utilName string
-		args []string
-	)
-	
-
-	utilsMap := map[string]  interface{}  {
-		"tmpl" : tmpl.Run,
-		"pin" : pin.Run,
-	}
-
-	if len(os.Args)<2  {
-		for k, _ := range utilsMap {
-			fmt.Printf("%s\n", k)
-		}
-		os.Exit(0)
-	} else {
-		utilName = os.Args[1]
-		args = os.Args[1:]
-	}
-
-	if _, ok := utilsMap[utilName] ; !ok {
-		fmt.Printf("%s: %s: no such util\n", os.Args[0], utilName )
-		os.Exit(1)
-	}
-
-	status := utilsMap[utilName].(func([]string) int )(args)
-
-	os.Exit(status)
+	root.Run(os.Args[1:])
 }
diff --git a/pin/pin.go b/pin/pin.go
index fa2a213..6951592 100644
--- a/pin/pin.go
+++ b/pin/pin.go
@@ -1,25 +1,27 @@
 package pin
 
-import(
-	"os"
+import (
 	"fmt"
-	"strconv"
-	"log"
-	"flag"
+	//"strconv"
+	//"log"
+	"vultras.su/core/cli/mtool"
+	"os"
 )
 
-var(
+var (
 	Lflag bool
 	lval int
-	arg0 string
 	delim rune = '\n'
-	status int = 0
 	nVal int
 	chrs []rune
+	Tool = mtool.T("pin").Func(Run).Desc(
+		"print all the possible PIN combinations made of custom characters",
+	).Usage(
+		"<tmpl_chars>",
+	)
 )
 
-func
-Pow(x, p int) int {
+func Pow(x, p int) int {
 	ret := 1 
 	for i:=0 ; i<p ; i++ {
 		ret *= x
@@ -27,8 +29,7 @@ Pow(x, p int) int {
 	return ret
 }
 
-func
-GetPin(s []rune, l int, i int) string {
+func GetPin(s []rune, l int, i int) string {
 	ret := ""
 	slen := len(s)
 	for j:=0 ; j<l ; j++ {
@@ -37,8 +38,7 @@ GetPin(s []rune, l int, i int) string {
 	return ret
 }
 
-func
-printPins(s []rune, l int) {
+func printPins(s []rune, l int) {
 	n := Pow(len(s), l)
 	for i:=0 ; i<n ; i++ {
 		pin := GetPin(s, l, i)
@@ -48,8 +48,7 @@ printPins(s []rune, l int) {
 	}
 }
 
-func
-Fits(s []rune) bool {
+func Fits(s []rune) bool {
 	a := make([]int, len(chrs))
 	for i, v1 := range chrs {
 		for _, v2 := range s {
@@ -64,57 +63,58 @@ Fits(s []rune) bool {
 	return true
 }
 
-func
-Run(args []string) int {
-	arg0 = args[0]
-	flagSet := flag.NewFlagSet(args[0], flag.ExitOnError)
-	flagSet.IntVar(&lval, "l", 0,
-		"Add combinations with less number of chars starting with arg.")
-	flagSet.BoolVar(&Lflag, "L", false,
-		"Set less number to 1. Overrides l flag.")
-	flagSet.IntVar(&nVal, "n", 1, "Max repeats of the rune." )
-	flagSet.Parse(args[1:])
-	args = flagSet.Args()
-	flagSet.Usage = func() {
-		fmt.Fprintf(os.Stderr, "Usage of %s: %s [options] <tmpl_chars> [len]\n", arg0)
-		flagSet.PrintDefaults()
+func Run(flags *mtool.Flags) {
+	var (
+		length int
+		rFlag bool
+	)
+	flags.IntVar(
+		&lval, "min", 0,
+		"min length of the output pins",
+	)
+	flags.BoolVar(
+		&Lflag, "m", false,
+		"set the '-min' flag value to 1 (overrides it)",
+	)
+	flags.IntVar(
+		&length, "max", 0,
+		"max length of the output pins",
+	)
+
+	flags.IntVar(&nVal, "rep", 1, "max repeats of the rune." )
+	flags.BoolVar(&rFlag, "R", false, "make the maximum repeat equal to the length of input chars" )
+
+	args := flags.Parse()
+
+	if len(args) == 0 {
+		flags.Usage()
 		os.Exit(1)
 	}
 
-	var(
-		err error
-		n int
-	)
-
-	if len(args) == 0 {
-		flagSet.Usage()
-	}
-
 	chrs = []rune(args[0])
-	if len(args) == 2 {
-		n, err = strconv.Atoi(args[1])
-	} else if len(args) == 1 {
-		n = len(chrs)
-	}
 
-	if err!=nil {
-		log.Fatal(err)
+	if length == 0 {
+		length = len(chrs)
 	}
 
 	if Lflag {
 		lval = 1
 	}
 
+	if rFlag {
+		nVal = len(chrs)
+	}
+
 	if lval != 0 {
-		if lval > n {
-			flagSet.Usage()
+		if lval > length {
+			flags.Usage()
+			os.Exit(1)
 		}
-		for i := lval ; i<=n ; i++ {
+		for i := lval ; i<=length ; i++ {
 			printPins(chrs, i)
 		}
 	} else {
-		printPins(chrs, n)
+		printPins(chrs, length)
 	}
 
-	return status
 }
diff --git a/readme b/readme.md
similarity index 87%
rename from readme
rename to readme.md
index ac83819..37657ea 100644
--- a/readme
+++ b/readme.md
@@ -1,4 +1,5 @@
-# utf8tmpl
+# combo
 
 ## Description
+
 Set of utils to implement templates based on UTF-8 characters.
diff --git a/taskfile.yml b/taskfile.yml
new file mode 100644
index 0000000..1813fd1
--- /dev/null
+++ b/taskfile.yml
@@ -0,0 +1,7 @@
+version: 3
+
+tasks:
+  build:
+    desc: build the binary
+    cmds:
+      - go build
diff --git a/tmpl/tmpl.go b/tmpl/tmpl.go
index 5e48822..1fafb99 100644
--- a/tmpl/tmpl.go
+++ b/tmpl/tmpl.go
@@ -5,33 +5,30 @@ import (
 	"fmt"
 	"bufio"
 	"io"
+	"vultras.su/core/cli/mtool"
 )
 
 var(
-	arg0 string
 	delim rune
-	status int
+	Tool = mtool.T("tmpl").Func(Run).Desc(
+		"substitute the inputted runes with the specified words",
+	).Usage(
+		"[n_utf8_chars] [n_strings]",
+	)
 )
 
 
-func
-usage() {
-	fmt.Fprintf(os.Stderr, "usage: %s [n_utf8_chars] [n_strings]\n", arg0)
-	os.Exit(1)
-}
-
-func
-Run(args []string) int {
-	status = 0
+func Run(flags *mtool.Flags) {
 	delim = '\n'
-	arg0 = args[0]
+	args := flags.Parse()
 	
-	if len(args)<3 || len(args[1]) != len(args)-2 {
-		usage()
+	if len(args)<2 || len(args[0]) != len(args)-1 {
+		flags.Usage()
+		os.Exit(1)
 	}
 
-	chrs := []rune(args[1])
-	args = args[2:]
+	chrs := []rune(args[0])
+	args = args[1:]
 
 	tmpl := make(map[rune] string)
 	for i, s := range args {
@@ -45,18 +42,13 @@ Run(args []string) int {
 			break
 		}
 		s = s[:len(s)-1]
-		for _, c := range []rune(s) {
+		for _, c := range s {
 			s, ok := tmpl[c]
 			if !ok {
-				/*fmt.Fprintf(os.Stderr, "%s: '%s': no such character in template string\n",
-					arg0, string(c) )*/
-				s = string(c)	
+				s = string(c)
 			}
 			fmt.Printf("%s", s)
 		}
 		fmt.Printf("%s", string(delim))
 	}
-
-
-	return status
 }