Data commit

Task/Find-duplicate-files/Go/find-duplicate-files.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+    "fmt"
+    "crypto/md5"
+    "io/ioutil"
+    "log"
+    "os"
+    "path/filepath"
+    "sort"
+    "time"
+)
+
+type fileData struct {
+    filePath string
+    info     os.FileInfo
+}
+
+type hash [16]byte
+
+func check(err error) {
+    if err != nil {
+        log.Fatal(err)
+    }
+}
+
+func checksum(filePath string) hash {
+    bytes, err := ioutil.ReadFile(filePath)
+    check(err)
+    return hash(md5.Sum(bytes))
+}
+
+func findDuplicates(dirPath string, minSize int64) [][2]fileData {
+    var dups [][2]fileData
+    m := make(map[hash]fileData)
+    werr := filepath.Walk(dirPath, func(path string, info os.FileInfo, err error) error {
+        if err != nil {
+            return err
+        }
+        if !info.IsDir() && info.Size() >= minSize {
+            h := checksum(path)
+            fd, ok := m[h]
+            fd2 := fileData{path, info}
+            if !ok {
+                m[h] = fd2
+            } else {
+                dups = append(dups, [2]fileData{fd, fd2})
+            }
+        }
+        return nil
+    })
+    check(werr)
+    return dups
+}
+
+func main() {
+    dups := findDuplicates(".", 1)
+    fmt.Println("The following pairs of files have the same size and the same hash:\n")
+    fmt.Println("File name                 Size      Date last modified")
+    fmt.Println("==========================================================")
+    sort.Slice(dups, func(i, j int) bool {
+        return dups[i][0].info.Size() > dups[j][0].info.Size() // in order of decreasing size
+    })
+    for _, dup := range dups {
+        for i := 0; i < 2; i++ {
+            d := dup[i]
+            fmt.Printf("%-20s  %8d    %v\n", d.filePath, d.info.Size(), d.info.ModTime().Format(time.ANSIC))
+        }
+        fmt.Println()
+    }
+}