initial work for issue #10

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"io"
@@ -285,6 +286,10 @@ func main() {
 
 	r := reader.New(source, offormatters, colors, fGroup, isStdin, printRelative)
 
+	isFirst := true
+	lastData := make([]byte, fGroup.Width)
+	repeatedCount := 0
+
 	// Dump hex
 	for {
 		select {
@@ -296,26 +301,49 @@ func main() {
 		s, err := r.Read()
 		if err != nil {
 			if errors.Is(err, io.EOF) {
+				// End of File
 				break
 			}
 
 			_, _ = fmt.Fprintln(os.Stderr, fmt.Sprintf(`error while reading file: %v`, err))
 			os.Exit(1)
 		}
 
-		// Print formatted line
-		// <optional offset formatter #1><split><format 1><split><format N...><optional split><optional offset formatter #2>
-		_, _ = fmt.Println(s)
+		data := r.GetData()
+
+		if !isFirst && bytes.Equal(data, lastData) {
+			repeatedCount++
+		} else {
+			if repeatedCount > 0 {
+				_, _ = fmt.Println("\t" + fmt.Sprintf(`-- last line repeated %[1]d times (%[2]d bytes (0x%04[2]x))`, 1+repeatedCount, (1+repeatedCount)*fGroup.Width))
+			}
+
+			repeatedCount = 0
+
+			// Print formatted line
+			// <optional offset formatter #1><split><format 1><split><format N...><optional split><optional offset formatter #2>
+			_, _ = fmt.Println(s)
+		}
 
 		if usingLimit && r.GetReadBytes() >= limit {
 			// Limit is set and found
 			break
 		}
+
+		lastData = data
+		isFirst = false
 	}
 
 	err := source.Close()
 	if err != nil {
 		_, _ = fmt.Fprintf(os.Stderr, `couldn't close file: %v`, err)
 		os.Exit(1)
 	}
+
+	if repeatedCount > 0 {
+		_, _ = fmt.Println("\t" + fmt.Sprintf(`-- last line repeated %[1]d times (%[2]d bytes (0x%04[2]x))`, repeatedCount, repeatedCount*fGroup.Width))
+	}
+
+	_, _ = fmt.Println()
+	_, _ = fmt.Println(fmt.Sprintf(`Read %d bytes total`, r.GetReadBytes()))
 }

pkg/reader/reader.go

@@ -28,8 +28,9 @@ type Reader struct {
 	growHint               int                             // Grow hint for sb strings.Builder variable for speed
 	formatterGroup         base.FormatterGroup
 	colors                 ReaderColors
-	isEven                 bool // change background color for printed line
-	printRelativeOffset    bool // Print relative offset?
+	isEven                 bool   // change background color for printed line
+	printRelativeOffset    bool   // Print relative offset?
+	data                   []byte // Raw bytes data for accessing repeating data, etc
 }
 
 func New(r io.ReadSeekCloser, offsetFormatter []offFormatters.OffsetFormatter, colors ReaderColors, formatterGroup base.FormatterGroup, isStdin bool, useRelativeOffset bool) *Reader {
@@ -51,6 +52,7 @@ func New(r io.ReadSeekCloser, offsetFormatter []offFormatters.OffsetFormatter, c
 		colors:                 colors,
 		isEven:                 false,
 		printRelativeOffset:    useRelativeOffset,
+		data:                   make([]byte, formatterGroup.Width),
 	}
 
 	for _, f := range reader.offsetFormatters {
@@ -115,8 +117,8 @@ func (r *Reader) Read() (string, error) {
 	r.sb.Grow(r.growHint)
 
 	// Fetch bytes with selected formatters
-	tmp := make([]byte, r.formatterGroup.Width)
-	bytesReadCount, err := r.r.Read(tmp)
+	r.data = make([]byte, r.formatterGroup.Width)
+	bytesReadCount, err := r.r.Read(r.data)
 	if err != nil {
 		return ``, err
 	}
@@ -141,7 +143,7 @@ func (r *Reader) Read() (string, error) {
 	}
 
 	// Print the formatted bytes
-	r.sb.WriteString(r.formatterGroup.Print(tmp[0:bytesReadCount]))
+	r.sb.WriteString(r.formatterGroup.Print(r.data[0:bytesReadCount]))
 
 	if r.printRelativeOffset {
 		// Print relative offset
@@ -160,3 +162,8 @@ func (r *Reader) Read() (string, error) {
 func (r *Reader) GetReadBytes() uint64 {
 	return r.readTotalBytes
 }
+
+// GetData return raw data read in Read()
+func (r *Reader) GetData() []byte {
+	return r.data
+}