Hash MD5

.gitignore

@@ -35,3 +35,4 @@ longest-word/longest-word
 statecsv/statecsv
 go-financial/go-financial
 my-fnv/my-fnv
+my-md5/my-md5

my-md5/main.go

@@ -0,0 +1,23 @@
+package main
+
+import "fmt"
+import "crypto/md5"
+import "io"
+import "log"
+import "os"
+
+func main() {
+	if len(os.Args) < 2 {
+		log.Fatalln("Usage my-md5 file")
+	}
+	f, err := os.Open(os.Args[1])
+	if err != nil {
+		log.Fatalln(err)
+	}
+	defer f.Close()
+
+	h := md5.New()
+
+	io.Copy(h, f)
+	fmt.Printf("%x\n", h.Sum(nil))
+}