added oct viewer

display/oct.go

@@ -0,0 +1,54 @@
+package display
+
+import (
+	"fmt"
+	clr "github.com/logrusorgru/aurora"
+	"io"
+	"math/bits"
+	"strings"
+)
+
+type Oct struct {
+	fs        uint64 // File size
+	bw        uint8  // Bit width calculated from file size
+	palette   map[uint8]clr.Color
+	offFormat string
+}
+
+func (d *Oct) SetFileSize(s int64) {
+	d.fs = uint64(s)
+	d.bw = nearest(uint8(bits.Len64(d.fs)))
+	d.offFormat = fmt.Sprintf(`%%0%vo`, d.bw)
+}
+
+func NewOct() *Oct {
+	return &Oct{}
+}
+
+func (d Oct) Display(a []byte) string {
+	out := ``
+	for idx, b := range a {
+		if idx == 8 {
+			out += ` `
+		}
+
+		color, ok := d.palette[b]
+		if !ok {
+			color = clr.BrightFg
+		}
+
+		out += clr.Sprintf(`%03o `, clr.Colorize(b, color))
+	}
+
+	return strings.Trim(out, ` `)
+}
+
+// DisplayOffset displays offset as hexadecimal 0x00 - 0xFFFFFFFF....
+func (d Oct) DisplayOffset(r io.ReadSeeker) string {
+	off, _ := r.Seek(0, io.SeekCurrent)
+	return fmt.Sprintf(d.offFormat, off)
+}
+
+func (d *Oct) SetPalette(p map[uint8]clr.Color) {
+	d.palette = p
+}

main.go

@@ -23,7 +23,7 @@ func main() {
 	offsetDisplayS := opt.StringOptional(`offset-display`, `hex`,
 		opt.Alias(`o`),
 		opt.ArgName(`offset format`),
-		opt.Description(`One of: hex, dec`),
+		opt.Description(`One of: hex, dec, oct, per`),
 	)
 
 	formatS := opt.StringOptional(`format`, `hex,asc`,

offset.go

@@ -11,18 +11,21 @@ type offsetViewer uint8
 const (
 	OffsetHex offsetViewer = iota
 	OffsetDec
+	OffsetOct
 	OffsetPercent
 )
 
 var offsetViewers = map[offsetViewer]ShowsOffset{
 	OffsetHex:     display.NewHex(),
 	OffsetDec:     display.NewDec(),
+	OffsetOct:     display.NewOct(),
 	OffsetPercent: display.NewPercent(),
 }
 
 var offsetViewersStringToEnumMap = map[string]offsetViewer{
 	`hex`: OffsetHex,
 	`dec`: OffsetDec,
+	`oct`: OffsetOct,
 	`per`: OffsetPercent,
 }
 

viewers.go

@@ -11,6 +11,7 @@ type dataViewer uint8
 const (
 	ViewHex dataViewer = iota
 	ViewDec
+	ViewOct
 	ViewASCII
 	ViewBit
 )
@@ -20,6 +21,7 @@ var viewerEnumMap = map[dataViewer]Views{
 	ViewASCII: display.NewAscii(),
 	ViewBit:   display.NewBit(),
 	ViewDec:   display.NewDec(),
+	ViewOct:   display.NewOct(),
 }
 
 // Get enum from string
@@ -28,6 +30,7 @@ var viewersStringToEnumMap = map[string]dataViewer{
 	`asc`: ViewASCII,
 	`bit`: ViewBit,
 	`dec`: ViewDec,
+	`oct`: ViewOct,
 }
 
 type Views interface {