diff --git a/ProxyBuilder/builder.py b/ProxyBuilder/builder.py
index 9a5fcb7..bfc1ac7 100644
--- a/ProxyBuilder/builder.py
+++ b/ProxyBuilder/builder.py
@@ -36,12 +36,18 @@ def __checkPortAvailable(port): # 检测端口可用性
         return True # IPv4 TCP / IPv4 UDP / IPv6 TCP / IPv6 UDP 均无占用
     except:
         return False
-    finally:
-        try: # 关闭socket
-            if ipv4_tcp: ipv4_tcp.close()
-            if ipv4_udp: ipv4_udp.close()
-            if ipv6_tcp: ipv6_tcp.close()
-            if ipv6_udp: ipv6_udp.close()
+    finally: # 关闭socket
+        try:
+            ipv4_tcp.close()
+        except: pass
+        try:
+            ipv4_udp.close()
+        except: pass
+        try:
+            ipv6_tcp.close()
+        except: pass
+        try:
+            ipv6_udp.close()
         except: pass
 
 def __genTaskFlag(length = 16): # 生成任务代号
@@ -63,11 +69,28 @@ def __getAvailablePort(rangeStart, rangeEnd): # 获取一个空闲端口
             return port
         time.sleep(0.1) # 100ms
 
-def build(proxyInfo, configDir): # 构建代理节点连接
-    taskFlag = __genTaskFlag()
-    socksPort = __getAvailablePort(1024, 65535) # Socks5测试端口
-    if not 'type' in proxyInfo:
-        return None
+def build(proxyInfo, configDir, portRangeStart = 1024, portRangeEnd = 65535):
+    '''
+    创建代理节点客户端
+
+        程序内部错误:
+            return None, {reason}
+
+        代理节点无效:
+            return False, {reason}
+
+        代理工作正常:
+            return True, {
+                'flag': taskFlag,
+                'port': socksPort,
+                'file': configFile,
+                'process': process
+            }
+    '''
+    taskFlag = __genTaskFlag() # 生成测试标志
+    socksPort = __getAvailablePort(portRangeStart, portRangeEnd) # 获取Socks5测试端口
+    if not 'type' in proxyInfo: # 未指定节点类型
+        return False, 'Proxy type not specified'
     proxyType = proxyInfo['type'] # 节点类型
     proxyInfo.pop('type')
 
@@ -77,19 +100,16 @@ def build(proxyInfo, configDir): # 构建代理节点连接
     elif proxyType == 'ssr': # ShadowsocksR节点
         startCommand, fileContent = ShadowsocksR.load(proxyInfo, socksPort, configFile)
     else: # 未知类型
-        print("Unknown proxy type")
-        return None
+        return False, 'Unknown proxy type'
     if startCommand == None: # 格式出错
-        print("Format error with " + proxyType)
-        return None
+        return False, 'Format error with ' + str(proxyType)
     try:
         with open(configFile, 'w') as fileObject:
             fileObject.write(fileContent) # 保存配置文件
-    except:
-        print("Unable write to file " + configFile)
-        return None # 配置文件写入失败
+    except: # 配置文件写入失败
+        return None, "Unable write to file " + str(configFile)
 
-    try:
+    try: # 子进程形式启动
         for libcPath in libcPaths:
             if os.path.exists(libcPath): # 定位libc.so文件
                 break
@@ -99,37 +119,68 @@ def build(proxyInfo, configDir): # 构建代理节点连接
             stderr = subprocess.DEVNULL,
             preexec_fn = exitWithMe) # 子进程跟随退出
     except:
-        print("WARNING: Subprocess may become a Orphan Process")
-        process = subprocess.Popen(startCommand,
-            stdout = subprocess.DEVNULL,
-            stderr = subprocess.DEVNULL) # prctl失败 回退正常启动
+        try:
+            process = subprocess.Popen(startCommand,
+                stdout = subprocess.DEVNULL,
+                stderr = subprocess.DEVNULL) # prctl失败 回退正常启动
+        except: pass
+    if not 'process' in vars(): # 启动失败
+        return None, 'Subprocess start failed by `' + ' '.join(startCommand) + '`'
 
-    return { # 返回连接参数
+    return True, { # 返回连接参数
         'flag': taskFlag,
         'port': socksPort,
         'file': configFile,
-        'process': process,
-        'pid': process.pid,
+        'process': process
     }
 
-def check(taskInfo): # 检查客户端是否正常
-    if taskInfo == None:
-        return False
-    process = taskInfo['process']
-    if process.poll() != None:
-        return False # 死亡
-    else:
-        return True # 正常
-
-def destroy(taskInfo): # 结束客户端并清理
-    if taskInfo == None:
-        return
-    process = taskInfo['process']
-    if process.poll() == None: # 未死亡
-        process.terminate() # SIGTERM
-        while process.poll() == None: # 等待退出
-            time.sleep(1)
-            process.terminate()
+def check(client):
+    '''
+    检查客户端是否正常运行
+
+        检测出错: return None
+
+        工作异常: return False
+
+        工作正常: return True
+    '''
+    if client == None:
+        return None
+    try:
+        if client['process'].poll() != None:
+            return False # 死亡
+        else:
+            return True # 正常
+    except:
+        return None # 异常
+
+def destroy(client):
+    '''
+    结束客户端并清理
+
+        销毁异常: return None
+
+        客户端退出: return True
+    '''
+    if client == None:
+        return None
     try:
-        os.remove(taskInfo['file']) # 删除配置文件
-    except: pass
+        process = client['process']
+        if process.poll() == None: # 未死亡
+            process.terminate() # SIGTERM
+            while process.poll() == None: # 等待退出
+                time.sleep(1)
+                process.terminate()
+    except:
+        return None
+
+    try:
+        file = client['file']
+        if os.path.exists(file) and os.path.isfile(file):
+            os.remove(file) # 删除配置文件
+        else:
+            return None
+    except:
+        return None
+
+    return True # 销毁完成
diff --git a/demo.py b/demo.py
index ea3941c..4266aa8 100644
--- a/demo.py
+++ b/demo.py
@@ -1,50 +1,81 @@
 #!/usr/bin/python
 # -*- coding:utf-8 -*-
 
+import os
 import time
-import socket
-import requests
 
 import ProxyBuilder as Builder
 import ProxyChecker as Checker
 
-testInfo = {
-    'type': 'ss',
-    'server': '127.0.0.1',
-    'port': 12345,
-    'password': 'dnomd343',
-    'method': 'aes-256-ctr',
-    'plugin': '',
-    'pluginParam': '',
+workDir = '/tmp/ProxyC'
+
+ssTest = {
+    'tag': 'f43c9bae21ae8693',
+    'check': [
+        'http'
+    ],
+    'info': {
+        'type': 'ss',
+        'server': '127.0.0.1',
+        'port': 12345,
+        'password': 'dnomd343',
+        'method': 'aes-256-ctr',
+        'plugin': '',
+        'pluginParam': '',
+    }
+}
+
+ssrTest = {
+    'tag': 'f43c9bae21ae8693',
+    'check': [
+        'http'
+    ],
+    'info': {
+        'type': 'ssr',
+        "server": "127.0.0.1",
+        "port": 23456,
+        "password": "dnomd343",
+        "method": "table",
+        "protocol": "auth_aes128_md5",
+        "protocolParam": "",
+        "obfs": "tls1.2_ticket_auth",
+        "obfsParam": ""
+    }
 }
 
-# testInfo = {
-#     'type': 'ssr',
-#     "server": "127.0.0.1",
-#     "port": 23456,
-#     "password": "dnomd343",
-#     "method": "table",
-#     "protocol": "auth_aes128_md5",
-#     "protocolParam": "",
-#     "obfs": "tls1.2_ticket_auth",
-#     "obfsParam": ""
-# }
-
-print("start")
-print(testInfo)
-task = Builder.build(testInfo, '/tmp/ProxyC')
-print(task)
-time.sleep(1)
-if Builder.check(task) == False:
-    print("error exit")
-    Builder.destroy(task)
-else:
-    print("http check")
-    health, delay = Checker.httpCheck(task['port'])
+def loadDir(folderPath): # 创建文件夹
+    try:
+        if os.path.exists(folderPath): # 文件 / 文件夹 存在
+            if not os.path.isdir(folderPath): # 文件
+                return False # 无法创建
+        else: # 不存在
+            os.makedirs(folderPath) # 递归创建文件夹
+        return True # 文件夹正常
+    except:
+        return False
+
+def proxyTest(rawInfo, startDelay = 1, destroyDelay = 0.5):
+    if loadDir(workDir) == False: # 工作文件夹无效
+        return None
+    if not 'info' in rawInfo:
+        return None
+    status, client = Builder.build(rawInfo['info'], workDir)
+    if status != True:
+        print(client)
+        return None
+    time.sleep(startDelay)
+    if Builder.check(client) != True:
+        print("client error")
+        return None
+    health, httpDelay = Checker.httpCheck(client['port'])
     print("health = " + str(health))
-    if delay < 0:
-        print("error")
+    if httpDelay < 0:
+        print("http error")
     else:
-        print("delay = " + format(delay, '.2f') + 'ms')
-    Builder.destroy(task)
+        print("delay = " + format(httpDelay, '.2f') + 'ms')
+    if Builder.destroy(client) != True:
+        print("client destroy error")
+    time.sleep(destroyDelay)
     print("done")
+
+proxyTest(ssrTest)
diff --git a/test.py b/test.py
index 8fbf9e6..88520af 100644
--- a/test.py
+++ b/test.py
@@ -23,9 +23,9 @@ def startTest(testList):
             print("server unexpected exit")
             continue
         print(field['caption'] + ' => ', end = '')
-        client = Builder.build(field['proxyInfo'], '/tmp/ProxyC')
+        status, client = Builder.build(field['proxyInfo'], '/tmp/ProxyC')
         time.sleep(0.5) # 等待初始化完成
-        if not Builder.check(client):
+        if Builder.check(client) != True:
             print("client unexpected exit") # 客户端启动失败
         else:
             print(format(Checker.httpPing(client['port']), '.2f') + 'ms')