lib/bytes: split the hexdump related functions to separate package

Package hexdump implements reading and writing bytes from and into
hexadecimal number.
It support parsing output from hexdump(1) tool.

15 files changed, 410 insertions, 355 deletions

diff --git a/README.md b/README.md
index 1e94ca10..3a3d440b 100644
--- a/README.md
+++ b/README.md
@@ -102,6 +102,11 @@ A library for working with slice of float64.
 [**git**](https://pkg.go.dev/git.sr.ht/~shulhan/pakakeh.go/lib/git)::
 A wrapper for git command line interface.
 
+[**hexdump**](https://pkg.go.dev/git.sr.ht/~shulhan/pakakeh.go/lib/hexdump)::
+Package hexdump implements reading and writing bytes from and into
+hexadecimal number.
+It support parsing output from hexdump(1) tool.
+
 [**http**](https://pkg.go.dev/git.sr.ht/~shulhan/pakakeh.go/lib/http)::
 Package http extends the standard http package with simplified routing handler
 and builtin memory file system.
diff --git a/lib/binary/apo_file_test.go b/lib/binary/apo_file_test.go
index 52d54500..ac5912dc 100644
--- a/lib/binary/apo_file_test.go
+++ b/lib/binary/apo_file_test.go
@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: 2024 M. Shulhan <ms@kilabit.info>
+//
 // SPDX-License-Identifier: BSD-3-Clause
 
 package binary
@@ -9,7 +10,7 @@ import (
 	"path/filepath"
 	"testing"
 
-	libbytes "git.sr.ht/~shulhan/pakakeh.go/lib/bytes"
+	"git.sr.ht/~shulhan/pakakeh.go/lib/hexdump"
 	"git.sr.ht/~shulhan/pakakeh.go/lib/test"
 )
 
@@ -47,7 +48,7 @@ func TestOpenApo(t *testing.T) {
 	}
 
 	var gotDump bytes.Buffer
-	libbytes.DumpPrettyTable(&gotDump, `empty`, gotb)
+	hexdump.PrettyPrint(&gotDump, `empty`, gotb)
 
 	var exp = string(tdata.Output[`empty`])
 	test.Assert(t, `empty`, exp, gotDump.String())
@@ -141,7 +142,7 @@ func testWrite(t *testing.T, tcase testCaseWrite, apow *ApoFile) {
 	}
 
 	var gotDump bytes.Buffer
-	libbytes.DumpPrettyTable(&gotDump, tcase.tag, gotb)
+	hexdump.PrettyPrint(&gotDump, tcase.tag, gotb)
 
 	test.Assert(t, tcase.tag, tcase.expHexdump, gotDump.String())
 }
diff --git a/lib/bytes/bytes.go b/lib/bytes/bytes.go
index b47b0a85..3bbf529b 100644
--- a/lib/bytes/bytes.go
+++ b/lib/bytes/bytes.go
@@ -7,9 +7,6 @@ package bytes
 
 import (
 	"bytes"
-	"fmt"
-	"io"
-	"strconv"
 	"unicode"
 
 	inbytes "git.sr.ht/~shulhan/pakakeh.go/internal/bytes"
@@ -323,156 +320,6 @@ func MergeSpaces(in []byte) (out []byte) {
 	return out
 }
 
-// ParseHexDump parse the default output of [hexdump](1) utility from
-// parameter in back into stream of byte.
-//
-// An example of default output of hexdump is
-//
-//	0000000 7865 5f70 6964 2f72 0000 0000 0000 0000
-//	0000010 0000 0000 0000 0000 0000 0000 0000 0000
-//	*
-//	0000060 0000 0000 3030 3030 3537 0035 3030 3130
-//
-// The first column is the address and the rest of the column is the data.
-//
-// Each data column is 16-bit words in big-endian order, so in the above
-// example, the first byte would be 65, second byte is 78 and so on.
-// If parameter networkByteOrder is true, the first byte would be 78, second
-// by is 65, and so on.
-//
-// The asterisk "*" means that the address from 0000020 to 0000050 is equal
-// to the previous line, 0000010.
-//
-// [hexdump]: https://man.archlinux.org/man/hexdump.1
-func ParseHexDump(in []byte, networkByteOrder bool) (out []byte, err error) {
-	var (
-		logp        = `ParseHexDump`
-		parser      = NewParser(in, []byte(" \n"))
-		d      byte = 255 // Just to make the first for-loop pass.
-
-		token      []byte
-		vint64     int64
-		x          int
-		isAsterisk bool
-	)
-	for d != 0 {
-		// Read the address.
-		token, d = parser.Read()
-		if len(token) == 0 {
-			break
-		}
-		if len(token) == 1 {
-			if token[0] != '*' {
-				break
-			}
-			isAsterisk = true
-			continue
-		}
-
-		vint64, err = strconv.ParseInt(string(token), 16, 64)
-		if err != nil {
-			return nil, fmt.Errorf(`%s: %w`, logp, err)
-		}
-
-		if isAsterisk {
-			if len(out) > 0 {
-				var start = len(out)
-				if start < 16 {
-					start = 0
-				} else {
-					start -= 16
-				}
-				var (
-					prevRow      = out[start:]
-					identicalRow = int((vint64 - int64(len(out))) / 16)
-				)
-				for x = 0; x < identicalRow; x++ {
-					out = append(out, prevRow...)
-				}
-			}
-		}
-
-		// Read the two-hex, 16-bit words.
-		for x = 0; x < 8; x++ {
-			token, d = parser.Read()
-			if len(token) == 0 {
-				break
-			}
-
-			vint64, err = strconv.ParseInt(string(token), 16, 64)
-			if err != nil {
-				return nil, fmt.Errorf(`%s: %w`, logp, err)
-			}
-
-			switch len(token) {
-			case 2:
-				out = append(out, byte(vint64))
-			case 4:
-				if networkByteOrder {
-					out = append(out, byte(vint64>>8))
-					out = append(out, byte(vint64))
-				} else {
-					out = append(out, byte(vint64))
-					out = append(out, byte(vint64>>8))
-				}
-			}
-
-			if d == '\n' {
-				break
-			}
-		}
-		// Ignore trailing characters.
-		if d != '\n' {
-			parser.SkipLine()
-		}
-	}
-	return out, nil
-}
-
-// PrintHex will print each byte in slice as hexadecimal value into N column
-// length.
-func PrintHex(title string, data []byte, col int) {
-	var (
-		start, x int
-		c        byte
-	)
-	fmt.Print(title)
-	for x, c = range data {
-		if x%col == 0 {
-			if x > 0 {
-				fmt.Print(" ||")
-			}
-			for y := start; y < x; y++ {
-				if data[y] >= 33 && data[y] <= 126 {
-					fmt.Printf(" %c", data[y])
-				} else {
-					fmt.Print(" .")
-				}
-			}
-			fmt.Printf("\n%4d -", x)
-			start = x
-		}
-
-		fmt.Printf(" %02X", c)
-	}
-	rest := col - (x % col)
-	if rest > 0 {
-		for y := 1; y < rest; y++ {
-			fmt.Print("   ")
-		}
-		fmt.Print(" ||")
-	}
-	for y := start; y <= x; y++ {
-		if data[y] >= 33 && data[y] <= 126 {
-			fmt.Printf(" %c", data[y])
-		} else {
-			fmt.Print(" .")
-		}
-	}
-
-	fmt.Println()
-}
-
 // ReadHexByte read two hexadecimal characters from "data" start from index
 // "x" and convert them to byte.
 // It will return the byte and true if its read exactly two hexadecimal
@@ -722,58 +569,6 @@ func WordIndexes(s []byte, word []byte) (idxs []int) {
 	return idxs
 }
 
-// DumpPrettyTable write each byte in slice data as hexadecimal, ASCII
-// character, and integer with 8 columns width.
-func DumpPrettyTable(w io.Writer, title string, data []byte) {
-	const ncol = 8
-
-	fmt.Fprintf(w, "%s\n", title)
-	fmt.Fprint(w, "          |  0  1  2  3  4  5  6  7 | 01234567 |   0   1   2   3   4   5   6   7 |\n")
-	fmt.Fprint(w, "          |  8  9  A  B  C  D  E  F | 89ABCDEF |   8   9   A   B   C   D   E   F |\n")
-
-	var (
-		chunks = SplitEach(data, ncol)
-		chunk  []byte
-		x      int
-		y      int
-		c      byte
-	)
-	for x, chunk = range chunks {
-		fmt.Fprintf(w, `%#08x|`, x*ncol)
-
-		// Print as hex.
-		for y, c = range chunk {
-			fmt.Fprintf(w, ` %02x`, c)
-		}
-		for y++; y < ncol; y++ {
-			fmt.Fprint(w, `   `)
-		}
-
-		// Print as char.
-		fmt.Fprint(w, ` | `)
-		for y, c = range chunk {
-			if c >= 33 && c <= 126 {
-				fmt.Fprintf(w, `%c`, c)
-			} else {
-				fmt.Fprint(w, `.`)
-			}
-		}
-		for y++; y < ncol; y++ {
-			fmt.Fprint(w, ` `)
-		}
-
-		// Print as integer.
-		fmt.Fprint(w, ` |`)
-		for y, c = range chunk {
-			fmt.Fprintf(w, ` %3d`, c)
-		}
-		for y++; y < ncol; y++ {
-			fmt.Fprint(w, `    `)
-		}
-		fmt.Fprintf(w, " |%d\n", x*ncol)
-	}
-}
-
 // WriteUint16 write uint16 value "v" into "data" start at position "x".
 // If x is out range, the data will not change.
 func WriteUint16(data []byte, x uint, v uint16) {
diff --git a/lib/bytes/bytes_example_test.go b/lib/bytes/bytes_example_test.go
index 0c2fbf49..6615f36d 100644
--- a/lib/bytes/bytes_example_test.go
+++ b/lib/bytes/bytes_example_test.go
@@ -5,9 +5,7 @@
 package bytes_test
 
 import (
-	"bytes"
 	"fmt"
-	"log"
 	"math"
 
 	"git.sr.ht/~shulhan/pakakeh.go/lib/ascii"
@@ -305,35 +303,6 @@ func ExampleMergeSpaces() {
 	//  a
 }
 
-func ExampleParseHexDump() {
-	var (
-		in = []byte("0000000 6548 6c6c 2c6f 7720 726f 646c 0021")
-
-		out []byte
-		err error
-	)
-
-	out, err = libbytes.ParseHexDump(in, false)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	fmt.Printf(`%s`, libbytes.TrimNull(out))
-	// Output:
-	// Hello, world!
-}
-
-func ExamplePrintHex() {
-	title := "PrintHex"
-	data := []byte("Hello, world !")
-	libbytes.PrintHex(title, data, 5)
-	// Output:
-	// PrintHex
-	//    0 - 48 65 6C 6C 6F || H e l l o
-	//    5 - 2C 20 77 6F 72 || , . w o r
-	//   10 - 6C 64 20 21    || l d . !
-}
-
 func ExampleReadHexByte() {
 	fmt.Println(libbytes.ReadHexByte([]byte{}, 0))
 	fmt.Println(libbytes.ReadHexByte([]byte("x0"), 0))
@@ -492,22 +461,6 @@ func ExampleWordIndexes() {
 	// []
 }
 
-func ExampleDumpPrettyTable() {
-	var (
-		data = []byte{1, 2, 3, 'H', 'e', 'l', 'l', 'o', 254, 255}
-		bb   bytes.Buffer
-	)
-
-	libbytes.DumpPrettyTable(&bb, `DumpPrettyTable`, data)
-	fmt.Println(bb.String())
-	// Output:
-	// DumpPrettyTable
-	//           |  0  1  2  3  4  5  6  7 | 01234567 |   0   1   2   3   4   5   6   7 |
-	//           |  8  9  A  B  C  D  E  F | 89ABCDEF |   8   9   A   B   C   D   E   F |
-	// 0x00000000| 01 02 03 48 65 6c 6c 6f | ...Hello |   1   2   3  72 101 108 108 111 |0
-	// 0x00000008| fe ff                   | ..       | 254 255                         |8
-}
-
 func ExampleWriteUint16() {
 	data := []byte("Hello, world!")
 
diff --git a/lib/bytes/bytes_test.go b/lib/bytes/bytes_test.go
index 94d474f0..d41e399d 100644
--- a/lib/bytes/bytes_test.go
+++ b/lib/bytes/bytes_test.go
@@ -1,80 +1,16 @@
-// Copyright 2023, Shulhan <ms@kilabit.info>. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
+// SPDX-FileCopyrightText: 2023 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: BSD-3-Clause
 
 package bytes
 
 import (
 	"fmt"
-	"os"
-	"path"
 	"testing"
 
 	"git.sr.ht/~shulhan/pakakeh.go/lib/test"
 )
 
-func TestParseHexDump(t *testing.T) {
-	var (
-		tdata *test.Data
-		err   error
-	)
-
-	tdata, err = test.LoadData(`testdata/ParseHexDump_test.txt`)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	var (
-		tag string
-		in  []byte
-		exp []byte
-		got []byte
-	)
-	for tag, in = range tdata.Input {
-		exp = tdata.Output[tag]
-
-		got, err = ParseHexDump(in, false)
-		if err != nil {
-			test.Assert(t, tag, string(exp), err.Error())
-			continue
-		}
-
-		test.Assert(t, tag, string(exp), string(got))
-	}
-}
-
-func TestParseHexDumpExpDirTar(t *testing.T) {
-	var (
-		tdata *test.Data
-		err   error
-	)
-
-	tdata, err = test.LoadData(`testdata/ParseHexDump_exp_dir_tar_test.txt`)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	var (
-		tag     = `exp_dir.tar`
-		expFile = path.Join(`testdata`, tag)
-
-		exp []byte
-		got []byte
-	)
-
-	got, err = ParseHexDump(tdata.Input[tag], false)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	exp, err = os.ReadFile(expFile)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	test.Assert(t, tag, exp, got)
-}
-
 func TestTrimNull(t *testing.T) {
 	type testCase struct {
 		in  []byte
diff --git a/lib/dns/message_test.go b/lib/dns/message_test.go
index 9d833389..824ace68 100644
--- a/lib/dns/message_test.go
+++ b/lib/dns/message_test.go
@@ -1,6 +1,6 @@
-// Copyright 2018, Shulhan <ms@kilabit.info>. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
+// SPDX-FileCopyrightText: 2018 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: BSD-3-Clause
 
 package dns
 
@@ -9,7 +9,7 @@ import (
 	"encoding/json"
 	"testing"
 
-	libbytes "git.sr.ht/~shulhan/pakakeh.go/lib/bytes"
+	"git.sr.ht/~shulhan/pakakeh.go/lib/hexdump"
 	"git.sr.ht/~shulhan/pakakeh.go/lib/test"
 )
 
@@ -974,7 +974,7 @@ func TestMessageAddAuthority(t *testing.T) {
 	// Compare the message packet.
 
 	bb.Reset()
-	libbytes.DumpPrettyTable(&bb, msg.Question.String(), msg.packet)
+	hexdump.PrettyPrint(&bb, msg.Question.String(), msg.packet)
 
 	exp = tdata.Output[`packet`]
 	test.Assert(t, `AddAuthority`, string(exp), bb.String())
@@ -2101,7 +2101,7 @@ func TestUnpackMessage_OPT(t *testing.T) {
 		bbuf   bytes.Buffer
 	)
 	for _, tcase = range listCase {
-		stream, err = libbytes.ParseHexDump(tdata.Input[tcase], true)
+		stream, err = hexdump.Parse(tdata.Input[tcase], true)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -2125,7 +2125,7 @@ func TestUnpackMessage_OPT(t *testing.T) {
 			t.Fatal(err)
 		}
 		bbuf.Reset()
-		libbytes.DumpPrettyTable(&bbuf, msg.Question.String(), stream)
+		hexdump.PrettyPrint(&bbuf, msg.Question.String(), stream)
 		tcase += `.hexdump`
 		test.Assert(t, tcase, string(tdata.Output[tcase]), bbuf.String())
 	}
@@ -2161,7 +2161,7 @@ func TestUnpackMessage_SVCB(t *testing.T) {
 		msg    *Message
 	)
 	for _, name = range listCase {
-		stream, err = libbytes.ParseHexDump(tdata.Input[name], true)
+		stream, err = hexdump.Parse(tdata.Input[name], true)
 		if err != nil {
 			t.Fatal(logp, err)
 		}
diff --git a/lib/dns/zone_test.go b/lib/dns/zone_test.go
index d8b80814..b4f3feb1 100644
--- a/lib/dns/zone_test.go
+++ b/lib/dns/zone_test.go
@@ -1,6 +1,6 @@
-// Copyright 2018, Shulhan <ms@kilabit.info>. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
+// SPDX-FileCopyrightText: 2018 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: BSD-3-Clause
 
 package dns
 
@@ -10,7 +10,7 @@ import (
 	"strconv"
 	"testing"
 
-	libbytes "git.sr.ht/~shulhan/pakakeh.go/lib/bytes"
+	"git.sr.ht/~shulhan/pakakeh.go/lib/hexdump"
 	"git.sr.ht/~shulhan/pakakeh.go/lib/test"
 )
 
@@ -75,7 +75,7 @@ func TestParseZone(t *testing.T) {
 		)
 		for x, msg = range zone.messages {
 			bb.Reset()
-			libbytes.DumpPrettyTable(&bb, msg.Question.String(), msg.packet)
+			hexdump.PrettyPrint(&bb, msg.Question.String(), msg.packet)
 
 			vstr = fmt.Sprintf(`message_%d.hex`, x)
 			vbytes = tdata.Output[vstr]
@@ -155,7 +155,7 @@ func TestParseZone_SVCB(t *testing.T) {
 
 		for x, msg = range zone.messages {
 			out.Reset()
-			libbytes.DumpPrettyTable(&out, msg.Question.String(), msg.packet)
+			hexdump.PrettyPrint(&out, msg.Question.String(), msg.packet)
 
 			tag = fmt.Sprintf(`%s:message_%d.hex`, name, x)
 			stream = tdata.Output[tag]
diff --git a/lib/hexdump/hexdump.go b/lib/hexdump/hexdump.go
new file mode 100644
index 00000000..50c0a3ce
--- /dev/null
+++ b/lib/hexdump/hexdump.go
@@ -0,0 +1,217 @@
+// SPDX-FileCopyrightText: 2024 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package hexdump implements reading and writing bytes from and into
+// hexadecimal number.
+// It support parsing output from hexdump(1) tool.
+package hexdump
+
+import (
+	"fmt"
+	"io"
+	"strconv"
+
+	"git.sr.ht/~shulhan/pakakeh.go/lib/bytes"
+)
+
+// Parse parse the default output of [hexdump(1)] utility from parameter in
+// back into stream of byte.
+//
+// An example of default output of hexdump is
+//
+//	0000000 7865 5f70 6964 2f72 0000 0000 0000 0000
+//	0000010 0000 0000 0000 0000 0000 0000 0000 0000
+//	*
+//	0000060 0000 0000 3030 3030 3537 0035 3030 3130
+//
+// The first column is the address and the rest of the column is the data.
+//
+// Each data column is 16-bit words in little-endian order, so in the above
+// example, the first byte would be 65, second byte is 78 and so on.
+// If parameter networkByteOrder (big-endian) is true, the first byte would be
+// 78, second by is 65, and so on.
+//
+// The asterisk "*" means that the values from address 0000020 to 0000050 is
+// equal to the previous line, 0000010.
+//
+// [hexdump(1)]: https://man.archlinux.org/man/hexdump.1
+func Parse(in []byte, networkByteOrder bool) (out []byte, err error) {
+	var (
+		logp        = `ParseHexDump`
+		parser      = bytes.NewParser(in, []byte(" \n"))
+		d      byte = 255 // Just to make the first for-loop pass.
+
+		token      []byte
+		vint64     int64
+		x          int
+		isAsterisk bool
+	)
+	for d != 0 {
+		// Read the address.
+		token, d = parser.Read()
+		if len(token) == 0 {
+			break
+		}
+		if len(token) == 1 {
+			if token[0] != '*' {
+				break
+			}
+			isAsterisk = true
+			continue
+		}
+
+		vint64, err = strconv.ParseInt(string(token), 16, 64)
+		if err != nil {
+			return nil, fmt.Errorf(`%s: %w`, logp, err)
+		}
+
+		if isAsterisk {
+			if len(out) > 0 {
+				var start = len(out)
+				if start < 16 {
+					start = 0
+				} else {
+					start -= 16
+				}
+				var (
+					prevRow      = out[start:]
+					identicalRow = int((vint64 - int64(len(out))) / 16)
+				)
+				for x = 0; x < identicalRow; x++ {
+					out = append(out, prevRow...)
+				}
+			}
+		}
+
+		// Read the two-hex, 16-bit words.
+		for x = 0; x < 8; x++ {
+			token, d = parser.Read()
+			if len(token) == 0 {
+				break
+			}
+
+			vint64, err = strconv.ParseInt(string(token), 16, 64)
+			if err != nil {
+				return nil, fmt.Errorf(`%s: %w`, logp, err)
+			}
+
+			switch len(token) {
+			case 2:
+				out = append(out, byte(vint64))
+			case 4:
+				if networkByteOrder {
+					out = append(out, byte(vint64>>8))
+					out = append(out, byte(vint64))
+				} else {
+					out = append(out, byte(vint64))
+					out = append(out, byte(vint64>>8))
+				}
+			}
+
+			if d == '\n' {
+				break
+			}
+		}
+		// Ignore trailing characters.
+		if d != '\n' {
+			parser.SkipLine()
+		}
+	}
+	return out, nil
+}
+
+// Print print each byte in slice as hexadecimal value into N column length.
+func Print(title string, data []byte, col int) {
+	var (
+		start, x int
+		c        byte
+	)
+	fmt.Print(title)
+	for x, c = range data {
+		if x%col == 0 {
+			if x > 0 {
+				fmt.Print(` ||`)
+			}
+			for y := start; y < x; y++ {
+				if data[y] >= 33 && data[y] <= 126 {
+					fmt.Printf(` %c`, data[y])
+				} else {
+					fmt.Print(` .`)
+				}
+			}
+			fmt.Printf("\n%4d -", x)
+			start = x
+		}
+
+		fmt.Printf(` %02X`, c)
+	}
+	rest := col - (x % col)
+	if rest > 0 {
+		for y := 1; y < rest; y++ {
+			fmt.Print(`   `)
+		}
+		fmt.Print(` ||`)
+	}
+	for y := start; y <= x; y++ {
+		if data[y] >= 33 && data[y] <= 126 {
+			fmt.Printf(` %c`, data[y])
+		} else {
+			fmt.Print(` .`)
+		}
+	}
+
+	fmt.Println()
+}
+
+// PrettyPrint write each byte in slice data as hexadecimal, ASCII
+// character, and integer with 8 columns width.
+func PrettyPrint(w io.Writer, title string, data []byte) {
+	const ncol = 8
+
+	fmt.Fprintf(w, "%s\n", title)
+	fmt.Fprint(w, "          |  0  1  2  3  4  5  6  7 | 01234567 |   0   1   2   3   4   5   6   7 |\n")
+	fmt.Fprint(w, "          |  8  9  A  B  C  D  E  F | 89ABCDEF |   8   9   A   B   C   D   E   F |\n")
+
+	var (
+		chunks = bytes.SplitEach(data, ncol)
+		chunk  []byte
+		x      int
+		y      int
+		c      byte
+	)
+	for x, chunk = range chunks {
+		fmt.Fprintf(w, `%#08x|`, x*ncol)
+
+		// Print as hex.
+		for y, c = range chunk {
+			fmt.Fprintf(w, ` %02x`, c)
+		}
+		for y++; y < ncol; y++ {
+			fmt.Fprint(w, `   `)
+		}
+
+		// Print as char.
+		fmt.Fprint(w, ` | `)
+		for y, c = range chunk {
+			if c >= 33 && c <= 126 {
+				fmt.Fprintf(w, `%c`, c)
+			} else {
+				fmt.Fprint(w, `.`)
+			}
+		}
+		for y++; y < ncol; y++ {
+			fmt.Fprint(w, ` `)
+		}
+
+		// Print as integer.
+		fmt.Fprint(w, ` |`)
+		for y, c = range chunk {
+			fmt.Fprintf(w, ` %3d`, c)
+		}
+		for y++; y < ncol; y++ {
+			fmt.Fprint(w, `    `)
+		}
+		fmt.Fprintf(w, " |%d\n", x*ncol)
+	}
+}
diff --git a/lib/hexdump/hexdump_example_test.go b/lib/hexdump/hexdump_example_test.go
new file mode 100644
index 00000000..24058ca2
--- /dev/null
+++ b/lib/hexdump/hexdump_example_test.go
@@ -0,0 +1,61 @@
+// SPDX-FileCopyrightText: 2024 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+package hexdump_test
+
+import (
+	"bytes"
+	"fmt"
+	"log"
+
+	libbytes "git.sr.ht/~shulhan/pakakeh.go/lib/bytes"
+	"git.sr.ht/~shulhan/pakakeh.go/lib/hexdump"
+)
+
+func ExampleParse() {
+	var (
+		in = []byte(`0000000 6548 6c6c 2c6f 7720 726f 646c 0021`)
+
+		out []byte
+		err error
+	)
+
+	out, err = hexdump.Parse(in, false)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf(`%s`, libbytes.TrimNull(out))
+
+	// Output:
+	// Hello, world!
+}
+
+func ExamplePrettyPrint() {
+	var (
+		data = []byte{1, 2, 3, 'H', 'e', 'l', 'l', 'o', 254, 255}
+		bb   bytes.Buffer
+	)
+
+	hexdump.PrettyPrint(&bb, `PrettyPrint`, data)
+	fmt.Println(bb.String())
+	// Output:
+	// PrettyPrint
+	//           |  0  1  2  3  4  5  6  7 | 01234567 |   0   1   2   3   4   5   6   7 |
+	//           |  8  9  A  B  C  D  E  F | 89ABCDEF |   8   9   A   B   C   D   E   F |
+	// 0x00000000| 01 02 03 48 65 6c 6c 6f | ...Hello |   1   2   3  72 101 108 108 111 |0
+	// 0x00000008| fe ff                   | ..       | 254 255                         |8
+}
+
+func ExamplePrint() {
+	title := `Print`
+	data := []byte(`Hello, world !`)
+	hexdump.Print(title, data, 5)
+
+	// Output:
+	// Print
+	//    0 - 48 65 6C 6C 6F || H e l l o
+	//    5 - 2C 20 77 6F 72 || , . w o r
+	//   10 - 6C 64 20 21    || l d . !
+}
diff --git a/lib/hexdump/hexdump_test.go b/lib/hexdump/hexdump_test.go
new file mode 100644
index 00000000..e1c21b8f
--- /dev/null
+++ b/lib/hexdump/hexdump_test.go
@@ -0,0 +1,76 @@
+// SPDX-FileCopyrightText: 2024 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+package hexdump_test
+
+import (
+	"os"
+	"path"
+	"testing"
+
+	"git.sr.ht/~shulhan/pakakeh.go/lib/hexdump"
+	"git.sr.ht/~shulhan/pakakeh.go/lib/test"
+)
+
+func TestParse(t *testing.T) {
+	var (
+		tdata *test.Data
+		err   error
+	)
+
+	tdata, err = test.LoadData(`testdata/Parse_test.txt`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var (
+		tag string
+		in  []byte
+		exp []byte
+		got []byte
+	)
+	for tag, in = range tdata.Input {
+		exp = tdata.Output[tag]
+
+		got, err = hexdump.Parse(in, false)
+		if err != nil {
+			test.Assert(t, tag, string(exp), err.Error())
+			continue
+		}
+
+		test.Assert(t, tag, string(exp), string(got))
+	}
+}
+
+func TestParseExpDirTar(t *testing.T) {
+	var (
+		tdata *test.Data
+		err   error
+	)
+
+	tdata, err = test.LoadData(`testdata/Parse_exp_dir_tar_test.txt`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var (
+		tag     = `exp_dir.tar`
+		expFile = path.Join(`testdata`, tag)
+
+		exp []byte
+		got []byte
+	)
+
+	got, err = hexdump.Parse(tdata.Input[tag], false)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	exp, err = os.ReadFile(expFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	test.Assert(t, tag, exp, got)
+}
diff --git a/lib/bytes/testdata/ParseHexDump_exp_dir_tar_test.txt b/lib/hexdump/testdata/Parse_exp_dir_tar_test.txt
index dceff86f..0c50929e 100644
--- a/lib/bytes/testdata/ParseHexDump_exp_dir_tar_test.txt
+++ b/lib/hexdump/testdata/Parse_exp_dir_tar_test.txt
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2024 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
 >>> exp_dir.tar
 0000000 7865 5f70 6964 2f72 0000 0000 0000 0000
 0000010 0000 0000 0000 0000 0000 0000 0000 0000
diff --git a/lib/bytes/testdata/ParseHexDump_test.txt b/lib/hexdump/testdata/Parse_test.txt
index e326072d..72cbe110 100644
--- a/lib/bytes/testdata/ParseHexDump_test.txt
+++ b/lib/hexdump/testdata/Parse_test.txt
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2024 M. Shulhan <ms@kilabit.info>
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
 >>> trailing new line
 0000000 6548 6c6c 2c6f 7720 726f 646c 0a21
 
diff --git a/lib/bytes/testdata/exp_dir.tar b/lib/hexdump/testdata/exp_dir.tar
index 465deda2..465deda2 100644
--- a/lib/bytes/testdata/exp_dir.tar
+++ b/lib/hexdump/testdata/exp_dir.tar
diff --git a/lib/hexdump/testdata/exp_dir.tar.license b/lib/hexdump/testdata/exp_dir.tar.license
new file mode 100644
index 00000000..5dd7fe5c
--- /dev/null
+++ b/lib/hexdump/testdata/exp_dir.tar.license
@@ -0,0 +1,3 @@
+SPDX-FileCopyrightText: 2024 M. Shulhan <ms@kilabit.info>
+
+SPDX-License-Identifier: BSD-3-Clause
diff --git a/lib/memfs/internal/test/embed/embed_test.go b/lib/memfs/internal/test/embed/embed_test.go
index 1dcfc954..06b16d3a 100644
--- a/lib/memfs/internal/test/embed/embed_test.go
+++ b/lib/memfs/internal/test/embed/embed_test.go
@@ -16,7 +16,7 @@ func generate_testdata() *memfs.Node {
 		GenFuncName: "generate_testdata",
 	}
 	node.SetMode(0o20000000755)
-	node.SetModTimeUnix(1709751019, 629372161)
+	node.SetModTimeUnix(1699901114, 455911441)
 	node.SetName("/")
 	node.SetSize(0)
 	node.AddChild(_memFS_getNode(memFS, "/direct", generate_testdata_direct))
@@ -37,7 +37,7 @@ func generate_testdata_direct() *memfs.Node {
 		GenFuncName: "generate_testdata_direct",
 	}
 	node.SetMode(0o20000000755)
-	node.SetModTimeUnix(1709751019, 626038828)
+	node.SetModTimeUnix(1569586540, 0)
 	node.SetName("direct")
 	node.SetSize(0)
 	node.AddChild(_memFS_getNode(memFS, "/direct/add", generate_testdata_direct_add))
@@ -52,7 +52,7 @@ func generate_testdata_direct_add() *memfs.Node {
 		GenFuncName: "generate_testdata_direct_add",
 	}
 	node.SetMode(0o20000000755)
-	node.SetModTimeUnix(1709751019, 626038828)
+	node.SetModTimeUnix(1569586540, 0)
 	node.SetName("add")
 	node.SetSize(0)
 	node.AddChild(_memFS_getNode(memFS, "/direct/add/file", generate_testdata_direct_add_file))
@@ -69,7 +69,7 @@ func generate_testdata_direct_add_file() *memfs.Node {
 		Content:     []byte("\x54\x65\x73\x74\x20\x64\x69\x72\x65\x63\x74\x20\x61\x64\x64\x20\x66\x69\x6C\x65\x2E\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 626038828)
+	node.SetModTimeUnix(1569586540, 0)
 	node.SetName("file")
 	node.SetSize(22)
 	return node
@@ -84,7 +84,7 @@ func generate_testdata_direct_add_file2() *memfs.Node {
 		Content:     []byte("\x54\x65\x73\x74\x20\x64\x69\x72\x65\x63\x74\x20\x61\x64\x64\x20\x66\x69\x6C\x65\x20\x32\x2E\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 626038828)
+	node.SetModTimeUnix(1569586540, 0)
 	node.SetName("file2")
 	node.SetSize(24)
 	return node
@@ -98,7 +98,7 @@ func generate_testdata_exclude() *memfs.Node {
 		GenFuncName: "generate_testdata_exclude",
 	}
 	node.SetMode(0o20000000755)
-	node.SetModTimeUnix(1710216708, 236975330)
+	node.SetModTimeUnix(1633792794, 467899662)
 	node.SetName("exclude")
 	node.SetSize(0)
 	node.AddChild(_memFS_getNode(memFS, "/exclude/dir", generate_testdata_exclude_dir))
@@ -116,7 +116,7 @@ func generate_testdata_exclude_dir() *memfs.Node {
 		GenFuncName: "generate_testdata_exclude_dir",
 	}
 	node.SetMode(0o20000000700)
-	node.SetModTimeUnix(1710216708, 236975330)
+	node.SetModTimeUnix(1629620045, 798024232)
 	node.SetName("dir")
 	node.SetSize(0)
 	return node
@@ -131,7 +131,7 @@ func generate_testdata_exclude_index_link_css() *memfs.Node {
 		Content:     []byte("\x62\x6F\x64\x79\x20\x7B\x0A\x7D\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 626038828)
+	node.SetModTimeUnix(1562038157, 0)
 	node.SetName("index-link.css")
 	node.SetSize(9)
 	return node
@@ -146,7 +146,7 @@ func generate_testdata_exclude_index_link_html() *memfs.Node {
 		Content:     []byte("\x3C\x68\x74\x6D\x6C\x3E\x3C\x2F\x68\x74\x6D\x6C\x3E\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 629372161)
+	node.SetModTimeUnix(1588592347, 0)
 	node.SetName("index-link.html")
 	node.SetSize(14)
 	return node
@@ -161,7 +161,7 @@ func generate_testdata_exclude_index_link_js() *memfs.Node {
 		Content:     []byte("\x66\x75\x6E\x63\x74\x69\x6F\x6E\x20\x58\x28\x29\x20\x7B\x7D\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 629372161)
+	node.SetModTimeUnix(1562038157, 0)
 	node.SetName("index-link.js")
 	node.SetSize(16)
 	return node
@@ -175,7 +175,7 @@ func generate_testdata_include() *memfs.Node {
 		GenFuncName: "generate_testdata_include",
 	}
 	node.SetMode(0o20000000755)
-	node.SetModTimeUnix(1710216708, 236975330)
+	node.SetModTimeUnix(1629623653, 749800911)
 	node.SetName("include")
 	node.SetSize(0)
 	node.AddChild(_memFS_getNode(memFS, "/include/dir", generate_testdata_include_dir))
@@ -193,7 +193,7 @@ func generate_testdata_include_dir() *memfs.Node {
 		GenFuncName: "generate_testdata_include_dir",
 	}
 	node.SetMode(0o20000000700)
-	node.SetModTimeUnix(1710216708, 236975330)
+	node.SetModTimeUnix(1564836597, 0)
 	node.SetName("dir")
 	node.SetSize(0)
 	return node
@@ -208,7 +208,7 @@ func generate_testdata_include_index_css() *memfs.Node {
 		Content:     []byte("\x62\x6F\x64\x79\x20\x7B\x0A\x7D\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 626038828)
+	node.SetModTimeUnix(1562038157, 0)
 	node.SetName("index.css")
 	node.SetSize(9)
 	return node
@@ -223,7 +223,7 @@ func generate_testdata_include_index_html() *memfs.Node {
 		Content:     []byte("\x3C\x68\x74\x6D\x6C\x3E\x3C\x2F\x68\x74\x6D\x6C\x3E\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 629372161)
+	node.SetModTimeUnix(1588592347, 0)
 	node.SetName("index.html")
 	node.SetSize(14)
 	return node
@@ -238,7 +238,7 @@ func generate_testdata_include_index_js() *memfs.Node {
 		Content:     []byte("\x66\x75\x6E\x63\x74\x69\x6F\x6E\x20\x58\x28\x29\x20\x7B\x7D\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 629372161)
+	node.SetModTimeUnix(1562038157, 0)
 	node.SetName("index.js")
 	node.SetSize(16)
 	return node
@@ -253,7 +253,7 @@ func generate_testdata_index_css() *memfs.Node {
 		Content:     []byte("\x62\x6F\x64\x79\x20\x7B\x0A\x7D\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 626038828)
+	node.SetModTimeUnix(1562038157, 0)
 	node.SetName("index.css")
 	node.SetSize(9)
 	return node
@@ -268,7 +268,7 @@ func generate_testdata_index_html() *memfs.Node {
 		Content:     []byte("\x3C\x68\x74\x6D\x6C\x3E\x3C\x2F\x68\x74\x6D\x6C\x3E\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 629372161)
+	node.SetModTimeUnix(1588592347, 0)
 	node.SetName("index.html")
 	node.SetSize(14)
 	return node
@@ -283,7 +283,7 @@ func generate_testdata_index_js() *memfs.Node {
 		Content:     []byte("\x66\x75\x6E\x63\x74\x69\x6F\x6E\x20\x58\x28\x29\x20\x7B\x7D\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 629372161)
+	node.SetModTimeUnix(1562038157, 0)
 	node.SetName("index.js")
 	node.SetSize(16)
 	return node
@@ -298,7 +298,7 @@ func generate_testdata_plain() *memfs.Node {
 		Content:     []byte("\x54\x68\x69\x73\x20\x69\x73\x20\x61\x20\x70\x6C\x61\x69\x6E\x20\x74\x65\x78\x74\x2E\x0A"),
 	}
 	node.SetMode(0o644)
-	node.SetModTimeUnix(1709751019, 629372161)
+	node.SetModTimeUnix(1562038157, 0)
 	node.SetName("plain")
 	node.SetSize(22)
 	return node