diff --git a/android-interact.sh b/android-interact.sh
index fc4867a..113d502 100755
--- a/android-interact.sh
+++ b/android-interact.sh
@@ -1,4 +1,4 @@
-#!/bin/bash -e
+#!/bin/bash
 # File: android-interact.sh
 # Date: Fri Jun 26 10:38:07 2015 +0800
 # Author: Yuxin Wu <ppwwyyxxc@gmail.com>
@@ -18,7 +18,7 @@ adb root
 
 if [[ $1 == "uin" ]]; then
 	adb pull $MM_DIR/shared_prefs/system_config_prefs.xml 2>/dev/null
-	uin=$($GREP 'default_uin' system_config_prefs.xml | $GREP -o 'value="-\?[0-9]*' | cut -c 8-)
+	uin=$($GREP 'default_uin' system_config_prefs.xml | $GREP -o 'value="\-?[0-9]*' | cut -c 8-)
 	[[ -n $uin ]] || {
 		>&2 echo "Failed to get wechat uin. You can try other methods, or report a bug."
 		exit 1
@@ -26,7 +26,7 @@ if [[ $1 == "uin" ]]; then
 	rm system_config_prefs.xml
 	echo "Got wechat uin: $uin"
 elif [[ $1 == "imei" ]]; then
-	imei=$(adb shell dumpsys iphonesubinfo | $GREP 'Device ID' | $GREP -o '[0-9]\+')
+	imei=$(adb shell dumpsys iphonesubinfo | $GREP 'Device ID' | $GREP -o '[0-9]+')
 	[[ -n $imei ]] || {
 		>&2 echo "Failed to get imei. You can try other methods, or report a bug."
 		exit 1
@@ -78,7 +78,7 @@ elif [[ $1 == "db" || $1 == "res" ]]; then
 	fi
 elif [[ $1 == "db-decrypt" ]]; then
 	echo "Getting uin..."
-	$0 uin | tail -n1 | $GREP -o '-\?[0-9]*' | tee /tmp/uin
+	$0 uin | tail -n1 | $GREP -o '\-?[0-9]*' | tee /tmp/uin
 	echo "Getting imei..."
 	$0 imei | tail -n1 | $GREP -o '[0-9]*' | tee /tmp/imei
 	echo "Getting db..."
diff --git a/compatibility.sh b/compatibility.sh
index 9565876..0f99b4a 100755
--- a/compatibility.sh
+++ b/compatibility.sh
@@ -13,7 +13,7 @@ if [ `uname` = 'Darwin' ]; then
   MD5SUM='md5'
 else
   REALPATH='readlink -f'
-  GREP=grep
+  GREP='grep -E'
   MD5SUM='md5sum'
 fi
 
diff --git a/wechat/avatar.py b/wechat/avatar.py
index 5cb2b7e..5e78cbf 100644
--- a/wechat/avatar.py
+++ b/wechat/avatar.py
@@ -25,16 +25,21 @@ class AvatarReader(object):
         filename = os.path.join(dir1, dir2,
                                 "user_{}.png.bm".format(filename))
 
-        index_avatar = self.query_index(filename)
-        if index_avatar == -1:
-            logger.warn("Avatar not found for {}".format(username))
+        try:
+            index_avatar = self.query_index(filename)
+            if index_avatar == -1:
+                logger.warn("Avatar not found for {}".format(username))
+                return None
+            else:
+                img = self.read_bm_block(index_avatar)
+                return img
+        except:
+            logger.warn("Failed to retrieve avatar!")
             return None
-        else:
-            img = self.read_bm_block(index_avatar)
-            return img
+
 
     def read_bm_block(self, pos):
-        file_idx = pos >> 32 
+        file_idx = pos >> 32
         fname = os.path.join(self.avt_dir,
                 'avatar.block.' + '{:05d}'.format(file_idx))
         # 16 is unknown prefix
@@ -45,8 +50,8 @@ class AvatarReader(object):
             f.seek(start_pos)
             size = (96, 96, 3)
             img = np.zeros(size, dtype='uint8')
-            for i in range(96):
-                for j in range(96):
+            for i in xrange(96):
+                for j in xrange(96):
                     r, g, b, a = map(ord, f.read(4))
                     img[i,j] = (r, g, b)
         return img
diff --git a/wechat/libchathelper.py b/wechat/libchathelper.py
index cfe9014..febce1c 100644
--- a/wechat/libchathelper.py
+++ b/wechat/libchathelper.py
@@ -19,7 +19,7 @@ class LibChatHelper(object):
     """ Build LibChat messages from WeChat Msg"""
 
     """ Types of message whose contents are fully parsed.
-    No need to save extra data for them. """
+        No need to save extra data for them. """
     FullyParsed = [TYPE_MSG, TYPE_SPEAK, TYPE_EMOJI,
                     TYPE_CUSTOM_EMOJI, TYPE_IMG]
 
diff --git a/wechat/msg.py b/wechat/msg.py
index 96c2bfa..50e5a0a 100644
--- a/wechat/msg.py
+++ b/wechat/msg.py
@@ -67,7 +67,7 @@ class WeChatMsg(object):
                 pass
             return "LOCATION:" + label + " ({},{})".format(loc['x'], loc['y'])
         elif self.type == TYPE_LINK:
-            pq = PyQuery(self.content_xml_ready, parser='xml')
+            pq = PyQuery(self.content_xml_ready)
             url = pq('url').text()
             if not url:
                 title = pq('title').text()