Add nl command and -n option for cat command.

Changed cat/tac command to receive data from standard input when the argument is "-".

CHANGELOG.md

@@ -1,12 +1,15 @@
 # Changelog
 All notable changes to this project will be documented in this file. The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.11.0] - 2021-11-20
+## [0.12.1] - 2021-11-20
 ### Added
  - base64 command.
  - cp command.
+ - nl command.
+ - -n option for cat command
 ### Changed
  - Reduce mimixbox binary size by compile option (7.5MB --> 5.4MB)
+ - cat/tac command to receive data from standard input when the argument is "-".
 ## [0.9.1] - 2021-11-19
 ### Added
  - basename command.

cmd/mimixbox/main.go

@@ -50,7 +50,7 @@ type options struct {
 
 var osExit = os.Exit
 
-const version = "0.11.0"
+const version = "0.12.1"
 
 const (
 	ExitSuccess int = iota // 0

docs/introduction/en/CommandAppletList.md

@@ -15,6 +15,7 @@
 |    mkdir | Make directories|
 |    mkfifo | Make FIFO (Named pipe)|
 |       mv | Rename SOURCE to DESTINATION, or move SOURCE(s) to DIRECTORY|
+|       nl| Write each FILE to standard output with line numbers added|
 |     path | Manipulate filename path|
 |     rm   | Remove file(s) or directory(s)|
 |     rmdir   | Remove directory|

internal/applets/applet.go

@@ -41,6 +41,7 @@ import (
 	"mimixbox/internal/applets/shellutils/true"
 	"mimixbox/internal/applets/shellutils/which"
 	"mimixbox/internal/applets/textutils/cat"
+	"mimixbox/internal/applets/textutils/nl"
 	"mimixbox/internal/applets/textutils/tac"
 	"os"
 	"sort"
@@ -72,6 +73,7 @@ func init() {
 		"mkdir":     {mkdir.Run, "Make directories"},
 		"mkfifo":    {mkfifo.Run, "Make FIFO (named pipe)"},
 		"mv":        {mv.Run, "Rename SOURCE to DESTINATION, or move SOURCE(s) to DIRECTORY"},
+		"nl":        {nl.Run, "Write each FILE to standard output with line numbers added"},
 		"path":      {path.Run, "Manipulate filename path"},
 		"rm":        {rm.Run, "Remove file(s) or directory(s)"},
 		"rmdir":     {rmdir.Run, "Remove directory"},

internal/applets/textutils/cat/cat.go

@@ -18,7 +18,6 @@ package cat
 
 import (
 	"fmt"
-	"io"
 	mb "mimixbox/internal/lib"
 	"os"
 
@@ -27,7 +26,7 @@ import (
 
 const cmdName string = "cat"
 
-const version = "1.0.2"
+const version = "1.0.3"
 
 var osExit = os.Exit
 
@@ -38,6 +37,7 @@ const (
 )
 
 type options struct {
+	Number  bool `short:"n" long:"number" description:"Print with line number"`
 	Version bool `short:"v" long:"version" description:"Show cat command version"`
 }
 
@@ -50,34 +50,25 @@ func Run() (int, error) {
 		return ExitFailuer, nil
 	}
 
-	if len(args) == 0 {
-		for {
-			if !mb.Parrot() {
-				break
-			}
-		}
+	if len(args) == 0 || mb.Contains(args, "-") {
+		mb.Parrot(opts.Number)
 		return ExitSuccess, nil
 	}
 
-	for _, file := range args {
-		err := cat(file)
-		if err != nil {
-			return ExitFailuer, err
-		}
+	strLisr, err := mb.Concatenate(args, false)
+	if err != nil {
+		return ExitFailuer, nil
 	}
 
-	return ExitSuccess, nil
-}
-
-func cat(path string) error {
-	f, err := os.Open(path)
-	if err != nil {
-		return err
+	if opts.Number {
+		mb.PrintStrListWithNumberLine(strLisr, true)
+	} else {
+		for _, str := range strLisr {
+			fmt.Print(str)
+		}
 	}
-	defer f.Close()
 
-	_, err = io.Copy(os.Stdout, f)
-	return err
+	return ExitSuccess, nil
 }
 
 func parseArgs(opts *options) ([]string, error) {

internal/applets/textutils/nl/nl.go

@@ -0,0 +1,105 @@
+//
+// mimixbox/internal/applets/textutils/nl/nl.go
+//
+// Copyright 2021 Naohiro CHIKAMATSU
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package nl
+
+import (
+	"fmt"
+	mb "mimixbox/internal/lib"
+	"os"
+
+	"github.com/jessevdk/go-flags"
+)
+
+const cmdName string = "nl"
+
+const version = "1.0.0"
+
+var osExit = os.Exit
+
+// Exit code
+const (
+	ExitSuccess int = iota // 0
+	ExitFailuer
+)
+
+type options struct {
+	Version bool `short:"v" long:"version" description:"Show nl command version"`
+}
+
+func Run() (int, error) {
+	var opts options
+	var args []string
+	var err error
+
+	if args, err = parseArgs(&opts); err != nil {
+		return ExitFailuer, nil
+	}
+
+	if len(args) == 0 || mb.Contains(args, "-") {
+		var nr int = 1
+		for {
+			input, next := mb.Input()
+			if !next {
+				break
+			}
+			if input != "" {
+				mb.PrintStrWithNumberLine(nr, input+"\n")
+				nr++
+			} else {
+				fmt.Println("")
+			}
+		}
+		return ExitSuccess, nil
+	}
+
+	str, err := mb.Concatenate(args, true)
+	if err != nil {
+		return ExitFailuer, nil
+	}
+	mb.PrintStrListWithNumberLine(str, false)
+
+	return ExitSuccess, nil
+}
+
+func parseArgs(opts *options) ([]string, error) {
+	p := initParser(opts)
+
+	args, err := p.Parse()
+	if err != nil {
+		return nil, err
+	}
+
+	if opts.Version {
+		showVersion()
+		osExit(ExitSuccess)
+	}
+
+	return args, nil
+}
+
+func initParser(opts *options) *flags.Parser {
+	parser := flags.NewParser(opts, flags.Default)
+	parser.Name = cmdName
+	parser.Usage = "[OPTIONS] FILE_PATH"
+
+	return parser
+}
+
+func showVersion() {
+	description := cmdName + " version " + version + " (under Apache License verison 2.0)\n"
+	fmt.Print(description)
+}

internal/applets/textutils/tac/tac.go

@@ -27,7 +27,7 @@ import (
 
 const cmdName string = "tac"
 
-const version = "1.0.1"
+const version = "1.0.2"
 
 var osExit = os.Exit
 
@@ -50,7 +50,7 @@ func Run() (int, error) {
 		return ExitFailuer, nil
 	}
 
-	if len(args) == 0 {
+	if len(args) == 0 || mb.Contains(args, "-") {
 		tacUserInput()
 		return ExitSuccess, nil
 	}

internal/lib/file.go

@@ -17,6 +17,7 @@
 package mb
 
 import (
+	"bufio"
 	"io"
 	"io/fs"
 	"os"
@@ -155,3 +156,21 @@ func Copy(src string, dest string) error {
 	}
 	return nil
 }
+
+func ReadFileToStrList(path string) ([]string, error) {
+	var strList []string
+
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		strList = append(strList, scanner.Text()+"\n")
+	}
+
+	strList[len(strList)-1] = strings.TrimRight(strList[len(strList)-1], "\n")
+	return strList, nil
+}

internal/lib/shell.go

@@ -65,17 +65,22 @@ func Question(ask string) bool {
 	}
 }
 
-func Parrot() bool {
+func Parrot(withNl bool) {
 	var response string
-
-	_, err := fmt.Scanln(&response)
-	if err != nil {
-		if !strings.Contains(err.Error(), "expected newline") {
-			return false // Ctrl+D or other error.
+	var nl int = 1
+	for {
+		_, err := fmt.Scanln(&response)
+		if err != nil {
+			if !strings.Contains(err.Error(), "expected newline") {
+				break // Ctrl+D or other error.
+			}
+		}
+		if withNl {
+			PrintStrWithNumberLine(nl, response)
+		} else {
+			fmt.Println(response)
 		}
 	}
-	fmt.Println(response)
-	return true
 }
 
 func Input() (string, bool) {
@@ -106,3 +111,49 @@ func WrapString(src string, column int) string {
 	}
 	return strings.Join(buf, "\n")
 }
+
+func Concatenate(path []string, lfAtTheJoint bool) ([]string, error) {
+	var strList []string
+	var index int
+
+	for _, file := range path {
+		list, err := ReadFileToStrList(file)
+		if err != nil {
+			return nil, err
+		}
+
+		// In the case of the cat command, the beginning of the new file is
+		// concatenated to the end of the previous file.
+		// In the case of nl command, do not concatenate the new file at the end
+		// of the previous file. The end of file (EOF) is replaced with a newline.
+		index = len(strList) - 1
+		if lfAtTheJoint { // for nl command
+			list[len(list)-1] = list[len(list)-1] + "\n"
+			strList = append(strList, list...)
+		} else { // for cat command
+			if index > 0 {
+				strList[index] = strList[index] + list[0]
+				strList = append(strList, list[1:]...)
+			} else {
+				strList = append(strList, list...)
+			}
+		}
+	}
+	return strList, nil
+}
+
+func PrintStrListWithNumberLine(strList []string, countEmpryLine bool) {
+	var nl int = 1
+	for _, s := range strList {
+		if s == "\n" && !countEmpryLine {
+			fmt.Print(s)
+			continue
+		}
+		PrintStrWithNumberLine(nl, s)
+		nl++
+	}
+}
+
+func PrintStrWithNumberLine(nl int, str string) {
+	fmt.Printf("%6d  %s", nl, str)
+}