1 files changed, 100 insertions, 0 deletions
diff --git a/dedup.go b/dedup.go
new file mode 100644
index 0000000..a6b4549
--- /dev/null
+++ b/dedup.go
@@ -0,0 +1,100 @@
+package main
+
+import (
+	"crypto/sha256"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// sha256Sum Takes an io.Reader and computes the checksum returning it as a
+// formatted string and an error if any
+func sha256Sum(rdr io.Reader) (string, error) {
+	h := sha256.New()
+	if _, err := io.Copy(h, rdr); err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%X", h.Sum(nil)), nil
+}
+
+// Takes a filepath and returns the sha256sum and an error if any
+func getChecksum(fileName string) (string, error) {
+	fh, err := os.Open(fileName)
+	if err != nil {
+		return "", err
+	}
+	defer fh.Close()
+
+	return sha256Sum(fh)
+}
+
+func main() {
+	fl := flag.NewFlagSet("deduplicator", flag.ExitOnError)
+
+	path := fl.String("path", ".", "Path to deduplicate files in")
+	all := fl.Bool("a", false, "Scan hidden files as well")
+	script := fl.Bool("s", false, "Output format sutiable for scripts")
+
+	_ = fl.Parse(os.Args[1:])
+
+	// checksum -> filepaths
+	checksums := make(map[string][]string)
+
+	err := filepath.Walk(*path, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if !*all {
+			if strings.Contains(path, "/.") {
+				return nil
+			}
+		}
+
+		if info.IsDir() {
+			return nil
+		}
+
+		sum, err := getChecksum(path)
+		if err != nil {
+			return err
+		}
+
+		if _, ok := checksums[sum]; !ok {
+			checksums[sum] = []string{path}
+		} else {
+			checksums[sum] = append(
+				checksums[sum],
+				path)
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+	}
+
+	for sum, list := range checksums {
+		if len(list) == 1 {
+			continue
+		}
+
+		switch {
+		case *script:
+			for _, path := range list {
+				fmt.Printf("%s::%s\n", sum, path)
+			}
+		default:
+			fmt.Println(sum)
+			for _, path := range list {
+				fmt.Println("\t" + path)
+			}
+		}
+	}
+
+}