Initial commit

.gitignore

@@ -0,0 +1 @@
+b3sum

go.mod

@@ -0,0 +1,5 @@
+module git.wow.st/gmp/b3sum
+
+go 1.13
+
+require github.com/zeebo/blake3 v0.0.1

go.sum

@@ -0,0 +1,6 @@
+github.com/zeebo/assert v1.1.0/go.mod h1:Pq9JiuJQpG8JLJdtkwrJESF0Foym2/D9XMU5ciN/wJ0=
+github.com/zeebo/blake3 v0.0.1 h1:nZUbpoC0IddEMH+XSzRlqmLLpxg+knEXBx3b2u0kzWY=
+github.com/zeebo/blake3 v0.0.1/go.mod h1:+l01N1So4KnXR2QTSMaSH2H6dHCb16oZOLgyfN5AgDc=
+github.com/zeebo/wyhash v0.0.0-20191228005337-11a718112e35/go.mod h1:Ti+OwfNtM5AZiYAL0kOPIfliqDP5c0VtOnnMAqzuuZk=
+golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5 h1:LfCXLvNmTYH9kEmVgqbnsWfruoXZIrh4YBgqVHtDvw0=
+golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

main.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"encoding/hex"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/zeebo/blake3"
+)
+
+var (
+	help = flag.Bool("h", false, "Prints help information")
+	length = flag.Int("l", 32,  "The number of output bytes, prior to hex encoding (default 32)")
+)
+
+func main() {
+	flag.Parse()
+	if *help || len(flag.Args()) == 0 {
+		flag.Usage()
+		os.Exit(0)
+	}
+	buf := [65536]byte{}
+	for _, name := range flag.Args() {
+		file, err := os.Open(name)
+		if err != nil {
+			panic(err)
+		}
+		hasher := blake3.NewSized(*length)
+		for {
+			n, err := file.Read(buf[:])
+			hasher.Write(buf[:n])
+			if err == io.EOF {
+				break
+			} else if err != nil {
+				panic(err)
+			}
+		}
+		file.Close()
+		hash := hasher.Sum([]byte{})
+		fmt.Print(hex.EncodeToString(hash))
+		fmt.Print("  ")
+		fmt.Println(name)
+	}
+}