Add FileMD5 function.

utils/md5.go

@@ -3,6 +3,8 @@ package utils
 import (
     "crypto/md5"
     "encoding/hex"
+    "io"
+    "os"
 )
 
 func MD5Hash(s string) string {
@@ -16,18 +18,32 @@ func MD5HashExt(s string, seps ...int) (string, []string) {
     hasher.Write([]byte(s))
     ss := []rune(hex.EncodeToString(hasher.Sum(nil)))
     var ret []string
-    if len(seps) >0 {
+    if len(seps) > 0 {
         var pos = 0
         for _, x := range seps {
-            if (pos+x) > len(ss) {
+            if (pos + x) > len(ss) {
                 panic("overload length of hex string length")
             }
             ret = append(ret, string(ss[pos:pos+x]))
             pos += x
         }
-        if pos<(len(ss)) {
+        if pos < (len(ss)) {
             ret = append(ret, string(ss[pos:]))
         }
     }
     return string(ss), ret
 }
+
+func FileMD5(filename string) (string, error) {
+    if f, e := os.Open(filename); nil != e {
+        return "", e
+    } else {
+        defer f.Close()
+        h := md5.New()
+        if _, e := io.Copy(h, f); nil != e {
+            return "", e
+        } else {
+            return hex.EncodeToString(h.Sum(nil)), nil
+        }
+    }
+}