.gitignore

@@ -1,3 +1 @@
 *.exe
-test_data/
-tmp/

README.md

@@ -3,14 +3,12 @@ Because I couldn't find a good program for my usecase, I wrote this simple Go pr
 
 ## Installation
 
-If you have go installed, the easiest way to install and update is `go get`:
+If you have go installed, the easiest way to install is `go get`:
 
 ```
-go get -u "github.com/JaCoB1123/dupe-finder"
+go get "github.com/JaCoB1123/dupe-finder"
 ```
 
-Otherwise you can download the latest binary from the [releases](https://github.com/JaCoB1123/dupe-finder/releases) page.
-
 ## Usage
 
 dupe-finder supports the following options:
@@ -36,15 +34,15 @@ dupe-finder supports the following options:
 Find all duplicate files in `~/` and save the results to `dupes.json`
 ```
 > dupe-finder --to-file dupes.json ~/
-```
+``̀`
 
 Load previous results from `dupes.json` and delete all duplicates located in ~/.cache
 ```
 > dupe-finder --from-file dupes.json --delete-dupes-in ~/.cache
-```
+``̀`
 
-Find all duplicate files in `~/` and `/mnt/EXT`. Prompt which file to keep for each set of duplicates and move the others to /dupes/.
+Find all duplicate files in `~/' and `/mnt/EXT`. Prompt which file to keep for each set of duplicates and move the others to /dupes/.
 ```
 > dupe-finder --delete-prompt --move-files /dupes/ ~/ /mnt/EXT
-```
+``̀`
 

clustering.go

@@ -1,46 +0,0 @@
-package main
-
-import (
-	"slices"
-
-	"github.com/steakknife/hamming"
-)
-
-type imageCluster struct {
-	images []similarImage
-}
-
-type similarImage struct {
-	path     string
-	distance int
-}
-
-func (fm *FilesMap) getImageClusters() []imageCluster {
-	var clusters []imageCluster
-
-	for len(fm.Images) > 0 {
-		file := fm.Images[0]
-		fm.Images = slices.Delete(fm.Images, 0, 1)
-
-		var currentCluster []similarImage
-		currentCluster = append(currentCluster, similarImage{path: file.path})
-		for otherIndex := len(fm.Images) - 1; otherIndex >= 0; otherIndex-- {
-			otherFile := fm.Images[otherIndex]
-			var distance = hamming.Uint64(file.imageHash, otherFile.imageHash)
-			if distance > 5 {
-				continue
-			}
-
-			fm.Images = slices.Delete(fm.Images, otherIndex, otherIndex+1)
-			currentCluster = append(currentCluster, similarImage{path: otherFile.path, distance: distance})
-		}
-
-		if len(currentCluster) <= 1 {
-			continue
-		}
-
-		clusters = append(clusters, imageCluster{images: currentCluster})
-	}
-
-	return clusters
-}

file.go

@@ -1,82 +0,0 @@
-package main
-
-import (
-	"crypto/sha1"
-	"encoding/base64"
-	"image"
-	_ "image/jpeg"
-	_ "image/png"
-	"io"
-	"os"
-	"path/filepath"
-	"strconv"
-
-	"github.com/corona10/goimagehash"
-)
-
-func remove(path string) {
-	if !*force {
-		return
-	}
-
-	if *moveToFolder == "" {
-		os.Remove(path)
-		return
-	}
-
-	moveButDontOvewrite(path, *moveToFolder)
-}
-
-func moveButDontOvewrite(path string, targetPath string) {
-	num := 0
-
-	filename := filepath.Base(path)
-
-	target := filepath.Join(targetPath, filename)
-
-	for {
-		_, err := os.Stat(target)
-		if os.IsNotExist(err) {
-			os.Rename(path, target)
-			return
-		}
-
-		target = filepath.Join(targetPath, filename+"."+strconv.Itoa(num))
-		num++
-	}
-}
-
-func calculateImageHash(path string) (uint64, error) {
-	f, err := os.Open(path)
-	if err != nil {
-		return 0, err
-	}
-	defer f.Close()
-
-	img, _, err := image.Decode(f)
-	if err != nil {
-		return 0, err
-	}
-	hash, err := goimagehash.DifferenceHash(img)
-	if err != nil {
-		return 0, err
-	}
-
-	return hash.GetHash(), nil
-}
-
-func calculateFileHash(path string) (string, error) {
-	f, err := os.Open(path)
-	if err != nil {
-		return "", err
-	}
-	defer f.Close()
-
-	h := sha1.New()
-	if _, err := io.Copy(h, f); err != nil {
-		return "", err
-	}
-
-	stringHash := base64.RawStdEncoding.EncodeToString(h.Sum(nil))
-	return stringHash, nil
-}

filesmap.go

@@ -1,178 +0,0 @@
-package main
-
-import (
-	"errors"
-	"flag"
-	"fmt"
-	"image"
-	"os"
-	"path/filepath"
-	"sync"
-
-	"github.com/vbauerster/mpb/v8"
-)
-
-// FilesMap is a struct for listing files by Size and Hash to search for duplicates
-type FilesMap struct {
-	Images          []imageEntry
-	FilesBySize     map[int64]string
-	FilesByHash     map[string][]string
-	FilesHashing    chan fileEntry
-	FilesHashed     chan fileEntry
-	ImagesHashing   chan imageEntry
-	ImagesHashed    chan imageEntry
-	progress        *mpb.Progress
-	incomingBar     *mpb.Bar
-	fileHashingBar  *mpb.Bar
-	imageHashingBar *mpb.Bar
-	lock            sync.Mutex
-}
-
-func newFilesMap() *FilesMap {
-	return &FilesMap{
-		FilesBySize:   map[int64]string{},
-		FilesByHash:   map[string][]string{},
-		FilesHashed:   make(chan fileEntry, 100000),
-		FilesHashing:  make(chan fileEntry),
-		ImagesHashed:  make(chan imageEntry, 100000),
-		ImagesHashing: make(chan imageEntry),
-		progress:      mpb.New(mpb.WithWidth(64)),
-	}
-}
-
-func (fm *FilesMap) FileHashingWorker(wg *sync.WaitGroup) {
-	for file := range fm.FilesHashing {
-		if *verbose {
-			fmt.Fprintf(fm.progress, "Hashing file %s\n", file.path)
-		}
-
-		hash, err := calculateFileHash(file.path)
-		fm.fileHashingBar.IncrInt64(file.size)
-		fm.FilesHashed <- file
-
-		if err != nil {
-			fmt.Fprintf(fm.progress, "Error calculating Hash for file %s: %v\n", file.path, err)
-			continue
-		}
-
-		file.hash = hash
-	}
-	wg.Done()
-}
-
-func (fm *FilesMap) ImageHashingWorker(wg *sync.WaitGroup) {
-	for file := range fm.ImagesHashing {
-		if *verbose {
-			fmt.Fprintf(fm.progress, "Hashing image %s\n", file.path)
-		}
-
-		hash, err := calculateImageHash(file.path)
-		fm.imageHashingBar.IncrInt64(file.size)
-
-		if errors.Is(err, image.ErrFormat) {
-			continue
-		} else if err != nil {
-			fmt.Fprintf(fm.progress, "Error calculating Hash for image %s: %v\n", file.path, err)
-			continue
-		}
-
-		file.imageHash = hash
-		fm.ImagesHashed <- file
-	}
-	wg.Done()
-}
-
-func (fm *FilesMap) HashedWorker(done chan bool) {
-	for file := range fm.FilesHashed {
-		if *verbose {
-			fmt.Println("Finishing", file.path)
-		}
-
-		fm.lock.Lock()
-		fm.FilesByHash[file.hash] = append(fm.FilesByHash[file.hash], file.path)
-		fm.lock.Unlock()
-	}
-
-	for file := range fm.ImagesHashed {
-		if *verbose {
-			fmt.Println("Finishing", file.path)
-		}
-
-		fm.lock.Lock()
-		fm.Images = append(fm.Images, file)
-		fm.lock.Unlock()
-	}
-
-	done <- true
-}
-
-func (fm *FilesMap) WalkDirectories() int64 {
-	var countFiles int64 = 0
-	sumSize := int64(0)
-	for _, path := range flag.Args() {
-		filepath.Walk(path, func(path string, info os.FileInfo, err error) error {
-			if info.IsDir() {
-				return nil
-			}
-
-			size := info.Size()
-			if *minSize > size {
-				return nil
-			}
-
-			countFiles++
-			fm.incomingBar.SetTotal(int64(countFiles), false)
-
-			fm.hashImage(path, size)
-			count := fm.hashFile(path, size)
-			if count > 0 {
-				sumSize += size * count
-				fm.fileHashingBar.SetTotal(int64(sumSize), false)
-			}
-			return nil
-		})
-	}
-
-	fm.incomingBar.SetTotal(int64(countFiles), true)
-	close(fm.FilesHashing)
-	close(fm.ImagesHashing)
-	return countFiles
-}
-
-func (fm *FilesMap) hashFile(path string, size int64) int64 {
-	prevFile, ok := fm.FilesBySize[size]
-	if !ok {
-		fm.FilesBySize[size] = path
-		return 0
-	}
-
-	fm.FilesBySize[size] = ""
-	fm.incomingBar.Increment()
-	if *verbose {
-		fmt.Println("Incoming", path)
-	}
-
-	fm.FilesHashing <- fileEntry{path, size, ""}
-	if prevFile != "" {
-		fm.FilesHashing <- fileEntry{prevFile, size, ""}
-		return 2
-	}
-
-	return 1
-}
-
-func (fm *FilesMap) hashImage(path string, size int64) {
-	fm.ImagesHashing <- imageEntry{path, size, 0}
-}
-
-type imageEntry struct {
-	path      string
-	size      int64
-	imageHash uint64
-}
-
-type fileEntry struct {
-	path string
-	size int64
-	hash string
-}

go.mod

@@ -1,18 +0,0 @@
-module github.com/JaCoB1123/dupe-finder
-
-go 1.21
-
-require (
-	github.com/corona10/goimagehash v1.1.0
-	github.com/steakknife/hamming v0.0.0-20180906055917-c99c65617cd3
-	github.com/vbauerster/mpb/v8 v8.7.0
-)
-
-require (
-	github.com/VividCortex/ewma v1.2.0 // indirect
-	github.com/acarl005/stripansi v0.0.0-20180116102854-5a71ef0e047d // indirect
-	github.com/mattn/go-runewidth v0.0.15 // indirect
-	github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 // indirect
-	github.com/rivo/uniseg v0.4.4 // indirect
-	golang.org/x/sys v0.15.0 // indirect
-)

go.sum

@@ -1,19 +0,0 @@
-github.com/VividCortex/ewma v1.2.0 h1:f58SaIzcDXrSy3kWaHNvuJgJ3Nmz59Zji6XoJR/q1ow=
-github.com/VividCortex/ewma v1.2.0/go.mod h1:nz4BbCtbLyFDeC9SUHbtcT5644juEuWfUAUnGx7j5l4=
-github.com/acarl005/stripansi v0.0.0-20180116102854-5a71ef0e047d h1:licZJFw2RwpHMqeKTCYkitsPqHNxTmd4SNR5r94FGM8=
-github.com/acarl005/stripansi v0.0.0-20180116102854-5a71ef0e047d/go.mod h1:asat636LX7Bqt5lYEZ27JNDcqxfjdBQuJ/MM4CN/Lzo=
-github.com/corona10/goimagehash v1.1.0 h1:teNMX/1e+Wn/AYSbLHX8mj+mF9r60R1kBeqE9MkoYwI=
-github.com/corona10/goimagehash v1.1.0/go.mod h1:VkvE0mLn84L4aF8vCb6mafVajEb6QYMHl2ZJLn0mOGI=
-github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZgg3U=
-github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
-github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 h1:zYyBkD/k9seD2A7fsi6Oo2LfFZAehjjQMERAvZLEDnQ=
-github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646/go.mod h1:jpp1/29i3P1S/RLdc7JQKbRpFeM1dOBd8T9ki5s+AY8=
-github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
-github.com/rivo/uniseg v0.4.4 h1:8TfxU8dW6PdqD27gjM8MVNuicgxIjxpm4K7x4jp8sis=
-github.com/rivo/uniseg v0.4.4/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
-github.com/steakknife/hamming v0.0.0-20180906055917-c99c65617cd3 h1:njlZPzLwU639dk2kqnCPPv+wNjq7Xb6EfUxe/oX0/NM=
-github.com/steakknife/hamming v0.0.0-20180906055917-c99c65617cd3/go.mod h1:hpGUWaI9xL8pRQCTXQgocU38Qw1g0Us7n5PxxTwTCYU=
-github.com/vbauerster/mpb/v8 v8.7.0 h1:n2LTGyol7qqNBcLQn8FL5Bga2O8CGF75OOYsJVFsfMg=
-github.com/vbauerster/mpb/v8 v8.7.0/go.mod h1:0RgdqeTpu6cDbdWeSaDvEvfgm9O598rBnRZ09HKaV0k=
-golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
-golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

main.go

@@ -2,20 +2,17 @@ package main
 
 import (
 	"bufio"
+	"crypto/sha256"
+	"encoding/base64"
 	"encoding/json"
 	"flag"
 	"fmt"
+	"io"
 	"io/ioutil"
-	"log"
 	"os"
 	"path/filepath"
-	"runtime"
-	"runtime/pprof"
+	"strconv"
 	"strings"
-	"sync"
-
-	"github.com/vbauerster/mpb/v8"
-	"github.com/vbauerster/mpb/v8/decor"
 )
 
 var fromFile = flag.String("from-file", "", "Load results file from <path>")
@@ -23,174 +20,144 @@ var toFile = flag.String("to-file", "", "Save results to <path>")
 var deleteDupesIn = flag.String("delete-dupes-in", "", "Delete duplicates if they are contained in <path>")
 var promptForDelete = flag.Bool("delete-prompt", false, "Ask which file to keep for each dupe-set")
 var moveToFolder = flag.String("move-files", "", "Move files to <path> instead of deleting them")
-var minSize = flag.Int64("min-size", -1, "Ignore all files smaller than <size> in Bytes")
 var force = flag.Bool("force", false, "Actually delete files. Without this options, the files to be deleted are only printed")
 var verbose = flag.Bool("verbose", false, "Output additional information")
-var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file")
+
+func Delete(path string) {
+	if !*force {
+		return
+	}
+
+	if *moveToFolder == "" {
+		os.Remove(path)
+		return
+	}
+
+	MoveButDontOvewrite(path, *moveToFolder)
+}
+
+func MoveButDontOvewrite(path string, targetPath string) {
+	num := 0
+
+	filename := filepath.Base(path)
+
+	target := filepath.Join(targetPath, filename)
+
+	for {
+		_, err := os.Stat(target)
+		if os.IsNotExist(err) {
+			os.Rename(path, target)
+			return
+		}
+
+		target = filepath.Join(targetPath, filename+"."+strconv.Itoa(num))
+		num++
+	}
+}
 
 func main() {
 	flag.Parse()
 
-	if *cpuprofile != "" {
-		f, err := os.Create(*cpuprofile)
-		if err != nil {
-			log.Fatal(err)
-		}
-		pprof.StartCPUProfile(f)
-		defer pprof.StopCPUProfile()
-	}
-
 	if *verbose {
 		printConfiguration()
 	}
 
-	var countFiles int64 = 0
 	filesMap := newFilesMap()
 	if *fromFile != "" {
+		fmt.Println("Loading file", *fromFile)
+
 		byteValue, _ := ioutil.ReadFile(*fromFile)
-		err := json.Unmarshal(byteValue, &filesMap.FilesByHash)
+		err := json.Unmarshal(byteValue, &filesMap.FilesBySize)
 		if err != nil {
 			panic(err)
 		}
 	} else {
-		filesMap.incomingBar = filesMap.progress.AddSpinner(0,
-			mpb.PrependDecorators(
-				decor.Name("Finding files  "),
-				decor.Elapsed(decor.ET_STYLE_HHMMSS),
-			),
-			mpb.AppendDecorators(
-				decor.AverageSpeed(0, "%8.2f"),
-				decor.Name("   "),
-				decor.CurrentNoUnit("%5d"),
-			),
-		)
-		filesMap.fileHashingBar = filesMap.progress.AddBar(0,
-			mpb.PrependDecorators(
-				decor.Name("Hashing files  "),
-				decor.Elapsed(decor.ET_STYLE_HHMMSS),
-			),
-			mpb.AppendDecorators(
-				decor.AverageSpeed(decor.SizeB1024(0), "%23.2f"),
-				decor.Name("   "),
-				decor.CurrentKibiByte("%5d"),
-			),
-		)
-		filesMap.imageHashingBar = filesMap.progress.AddBar(0,
-			mpb.PrependDecorators(
-				decor.Name("Hashing images "),
-				decor.Elapsed(decor.ET_STYLE_HHMMSS),
-			),
-			mpb.AppendDecorators(
-				decor.AverageSpeed(decor.SizeB1024(0), "%23.2f"),
-				decor.Name("   "),
-				decor.CurrentKibiByte("%5d"),
-			),
-		)
-		done := make(chan bool)
-		wg := sync.WaitGroup{}
-		for i := 0; i < runtime.GOMAXPROCS(0); i++ {
-			wg.Add(2)
-			go filesMap.ImageHashingWorker(&wg)
-			go filesMap.FileHashingWorker(&wg)
+		for _, path := range flag.Args() {
+			filepath.Walk(path, func(path string, info os.FileInfo, err error) error {
+				filesMap.Add(path, info)
+				return nil
+			})
 		}
-
-		go filesMap.HashedWorker(done)
-
-		countFiles = filesMap.WalkDirectories()
-
-		wg.Wait()
-		close(filesMap.FilesHashed)
-		close(filesMap.ImagesHashed)
-		<-done
 	}
 
 	if *toFile != "" && *fromFile == "" {
-		json, _ := json.MarshalIndent(filesMap.FilesByHash, "", "  ")
-		ioutil.WriteFile(*toFile, json, 0644)
-	}
-
-	for hash, duplicateFiles := range filesMap.FilesByHash {
-		if len(duplicateFiles) > 1 {
-			continue
-		}
-
-		delete(filesMap.FilesByHash, hash)
+		json, _ := json.MarshalIndent(filesMap.FilesBySize, "", "  ")
+		ioutil.WriteFile(*toFile, json, 644)
 	}
 
 	if *deleteDupesIn != "" {
 		deleteIn := filepath.Clean(*deleteDupesIn)
-		for hash := range filesMap.FilesByHash {
-			duplicateFiles := filesMap.FilesByHash[hash]
-			hasDupesInFolder := false
-			hasDupesOutsideFolder := false
-			for _, file := range duplicateFiles {
-				fileIsInFolder := strings.HasPrefix(filepath.Clean(file), deleteIn)
-				hasDupesOutsideFolder = hasDupesOutsideFolder || !fileIsInFolder
-				hasDupesInFolder = hasDupesInFolder || fileIsInFolder
-			}
-
-			if !hasDupesInFolder || !hasDupesOutsideFolder {
-				if !hasDupesOutsideFolder {
-					fmt.Println("Not deleting one of the following files, since all would be deleted")
-				}
-				if !hasDupesInFolder {
-					fmt.Println("Not deleting one of the following files, since none are in the selected directory")
+		for size := range filesMap.FilesBySize {
+			for hash := range filesMap.FilesBySize[size] {
+				duplicateFiles := filesMap.FilesBySize[size][hash]
+				if len(duplicateFiles) <= 1 {
+					continue
 				}
 
 				for _, file := range duplicateFiles {
-					fmt.Println("-", file)
-				}
-				fmt.Println()
-				continue
-			}
-
-			for _, file := range duplicateFiles {
-				if strings.HasPrefix(filepath.Clean(file), deleteIn) {
-					fmt.Println("Would delete ", file)
-					if *force {
-						remove(file)
+					if strings.HasPrefix(filepath.Clean(file), deleteIn) {
+						fmt.Println("Would delete ", file)
+						if *force {
+							Delete(file)
+						}
 					}
 				}
 			}
 		}
 	} else if *promptForDelete {
 		reader := bufio.NewReader(os.Stdin)
-		for hash := range filesMap.FilesByHash {
-			duplicateFiles := filesMap.FilesByHash[hash]
-			promptForDeletion(reader, duplicateFiles)
+		for size := range filesMap.FilesBySize {
+			for hash := range filesMap.FilesBySize[size] {
+				duplicateFiles := filesMap.FilesBySize[size][hash]
+				if len(duplicateFiles) <= 1 {
+					continue
+				}
+
+				fmt.Print("\033[H\033[2J")
+				for i, file := range duplicateFiles {
+					fmt.Println(i+1, file)
+				}
+
+				fmt.Printf("Which file to keep? ")
+				input, err := reader.ReadString('\n')
+				if err != nil {
+					fmt.Println("Invalid input")
+					continue
+				}
+
+				input = strings.TrimRight(input, "\n\r")
+				intInput, err := strconv.Atoi(input)
+				if err != nil || intInput > len(duplicateFiles) || intInput < 1 {
+					fmt.Println("Invalid input")
+					continue
+				}
+
+				for i, file := range duplicateFiles {
+					if i+1 == intInput {
+						continue
+					}
+
+					if *force {
+						Delete(file)
+					}
+				}
+
+			}
 		}
 	} else {
-		countInstances := 0
-		countDupeSets := 0
+		for size := range filesMap.FilesBySize {
+			for hash := range filesMap.FilesBySize[size] {
+				duplicateFiles := filesMap.FilesBySize[size][hash]
+				if len(duplicateFiles) <= 1 {
+					continue
+				}
 
-		fmt.Println("Files that are binary identical:")
-		for _, duplicateFiles := range filesMap.FilesByHash {
-			countDupeSets++
-			for _, file := range duplicateFiles {
-				countInstances++
-				fmt.Println(file)
+				for _, file := range duplicateFiles {
+					fmt.Println(file)
+				}
+				fmt.Println()
 			}
-			fmt.Println()
 		}
-
-		fmt.Println("Images that are similar:")
-		imageClusters := filesMap.getImageClusters()
-		for _, cluster := range imageClusters {
-			countDupeSets++
-			for _, image := range cluster.images {
-				countInstances++
-				fmt.Println(image.path, image.distance)
-			}
-
-			fmt.Println()
-		}
-
-		fmt.Println("Statistics:")
-		fmt.Println(countFiles, "Files")
-		fmt.Println(len(filesMap.FilesBySize), "Unique Sizes")
-		fmt.Println(len(filesMap.FilesByHash), "Unique Hashes")
-		fmt.Println(countInstances, "Duplicate Files")
-		fmt.Println(countDupeSets, "Duplicate Sets")
 	}
 }
 
@@ -207,3 +174,82 @@ func printConfiguration() {
 	fmt.Println()
 	fmt.Println()
 }
+
+// FilesMap is a struct for listing files by Size and Hash to search for duplicates
+type FilesMap struct {
+	FilesBySize map[int64]map[string][]string
+}
+
+// Add a file to the Map and calculate hash on demand
+func (fm *FilesMap) Add(path string, info os.FileInfo) error {
+	if info.IsDir() {
+		return nil
+	}
+
+	fileInfo := path
+
+	filesByHash := fm.FilesBySize[info.Size()]
+
+	// first file with same size
+	// => create new map for size
+	if filesByHash == nil {
+		filesByHash = map[string][]string{}
+		fm.FilesBySize[info.Size()] = filesByHash
+		filesByHash[""] = []string{fileInfo}
+		return nil
+	}
+
+	// second file with same size
+	// => calculate hashes for all entries
+	if _, hasEmptyHash := filesByHash[""]; hasEmptyHash {
+		err := appendByFileHash(filesByHash, fileInfo)
+		err2 := appendByFileHash(filesByHash, filesByHash[""][0])
+
+		delete(filesByHash, "")
+
+		if err != nil {
+			return err
+		}
+
+		return err2
+	}
+
+	// for later files always append by hash
+	return appendByFileHash(filesByHash, fileInfo)
+}
+
+func appendByFileHash(filesByHash map[string][]string, fileInfo string) error {
+	hash, err := calculateHash(fileInfo)
+
+	if err != nil {
+		return err
+	}
+
+	if _, ok := filesByHash[hash]; ok {
+		filesByHash[hash] = append(filesByHash[hash], fileInfo)
+	} else {
+		filesByHash[hash] = []string{fileInfo}
+	}
+	return nil
+}
+
+func newFilesMap() *FilesMap {
+	return &FilesMap{
+		FilesBySize: map[int64]map[string][]string{},
+	}
+}
+
+func calculateHash(path string) (string, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	h := sha256.New()
+	if _, err := io.Copy(h, f); err != nil {
+		return "", err
+	}
+
+	return base64.RawStdEncoding.EncodeToString(h.Sum(nil)), nil
+}

ui.go

@@ -1,49 +0,0 @@
-package main
-
-import (
-	"bufio"
-	"fmt"
-	"strconv"
-	"strings"
-)
-
-func promptForDeletion(reader *bufio.Reader, files []string) {
-	fmt.Print("\033[H\033[2J")
-	for i, file := range files {
-		fmt.Println(i+1, file)
-	}
-	fmt.Println(0, "Keep all")
-
-	fmt.Printf("Which file to keep? ")
-	input, err := reader.ReadString('\n')
-	if err != nil {
-		fmt.Println("Invalid input")
-		return
-	}
-
-	input = strings.TrimRight(input, "\n\r")
-	intInput, err := strconv.Atoi(input)
-	if err != nil {
-		fmt.Println("Invalid input")
-		return
-	}
-
-	if intInput == 0 {
-		return
-	}
-
-	if intInput > len(files) || intInput < 1 {
-		fmt.Println("Invalid input")
-		return
-	}
-
-	for i, file := range files {
-		if i+1 == intInput {
-			continue
-		}
-
-		if *force {
-			remove(file)
-		}
-	}
-}