diff -Nur pkgship-2.2.0/packageship/application/core/compare/validate.py pkgship-2.2.1/packageship/application/core/compare/validate.py
--- pkgship-2.2.0/packageship/application/core/compare/validate.py	2021-08-16 03:27:41.000000000 +0000
+++ pkgship-2.2.1/packageship/application/core/compare/validate.py	2021-11-18 03:44:09.566149890 +0000
@@ -1,81 +1,81 @@
-#!/usr/bin/python3
-# ******************************************************************************
-# Copyright (c) Huawei Technologies Co., Ltd. 2020-2020. All rights reserved.
-# licensed under the Mulan PSL v2.
-# You can use this software according to the terms and conditions of the Mulan PSL v2.
-# You may obtain a copy of Mulan PSL v2 at:
-#     http://license.coscl.org.cn/MulanPSL2
-# THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR
-# PURPOSE.
-# See the Mulan PSL v2 for more details.
-# ******************************************************************************/
-"""
-Validate args of compare command
-"""
-import os
-import shutil
-
-from packageship.application.common.constant import SUPPORT_QUERY_TYPE
-from packageship.application.query import database
-
-# Maximum number of supported databases
-MAX_SUPPORT_DB = 4
-
-
-def validate_args(depend_type, dbs, output_path):
-    """
-    validate args of compare command
-    :param depend_type:
-    :param dbs: input databases
-    :param output_path:
-    :return:
-    """
-    if not all((depend_type, dbs, output_path)):
-        raise ValueError('[ERROR] Parameter error, please check the parameter and query again.')
-    # verify depend type
-    if depend_type not in SUPPORT_QUERY_TYPE:
-        raise ValueError(f'[ERROR] Dependent type ({depend_type}) is not supported, please enter again.')
-    # verify dbs
-    _validate_dbs(dbs)
-    # verify output_path
-    if not os.path.isdir(output_path) or not _is_writable(path=output_path):
-        raise ValueError(f'[ERROR] Output path ({output_path}) not exist or does not support user pkgshipuser writing.')
-
-
-def _validate_dbs(dbs):
-    """
-    Verify that the input database is supported
-    :param dbs: input dbs
-    :return: None
-    """
-    if len(dbs) > MAX_SUPPORT_DB:
-        raise ValueError(f'[ERROR] Supports up to four databases.')
-
-    if len(dbs) != len(set(dbs)):
-        raise ValueError(f'[ERROR] Duplicate database entered.')
-
-    support_dbs = database.get_db_priority()
-    for db in dbs:
-        if db not in support_dbs:
-            raise ValueError(f'[ERROR] Database ({db}) is not supported, please enter again.')
-    if len(dbs) == 1:
-        print('[WARNING] There is only one input database, '
-              'and only dependent information files will be generated without data comparison.')
-
-
-def _is_writable(path):
-    """
-    Verify whether run user has write permission to the output path
-    :param path: cvs save path
-    :return: True False
-    """
-    tmp_path = os.path.join(path, 'tmp_compare')
-    try:
-        os.mkdir(tmp_path)
-    except PermissionError:
-        return False
-    finally:
-        if os.path.isdir(tmp_path):
-            shutil.rmtree(tmp_path)
-    return True
+#!/usr/bin/python3
+# ******************************************************************************
+# Copyright (c) Huawei Technologies Co., Ltd. 2020-2020. All rights reserved.
+# licensed under the Mulan PSL v2.
+# You can use this software according to the terms and conditions of the Mulan PSL v2.
+# You may obtain a copy of Mulan PSL v2 at:
+#     http://license.coscl.org.cn/MulanPSL2
+# THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR
+# PURPOSE.
+# See the Mulan PSL v2 for more details.
+# ******************************************************************************/
+"""
+Validate args of compare command
+"""
+import os
+import shutil
+
+from packageship.application.common.constant import SUPPORT_QUERY_TYPE
+from packageship.application.query import database
+
+# Maximum number of supported databases
+MAX_SUPPORT_DB = 4
+
+
+def validate_args(depend_type, dbs, output_path):
+    """
+    validate args of compare command
+    :param depend_type:
+    :param dbs: input databases
+    :param output_path:
+    :return:
+    """
+    if not all((depend_type, dbs, output_path)):
+        raise ValueError('[ERROR] Parameter error, please check the parameter and query again.')
+    # verify depend type
+    if depend_type not in SUPPORT_QUERY_TYPE:
+        raise ValueError(f'[ERROR] Dependent type ({depend_type}) is not supported, please enter again.')
+    # verify dbs
+    _validate_dbs(dbs)
+    # verify output_path
+    if not os.path.isdir(output_path) or not _is_writable(path=output_path):
+        raise ValueError(f'[ERROR] Output path ({output_path}) not exist or does not support user pkgshipuser writing.')
+
+
+def _validate_dbs(dbs):
+    """
+    Verify that the input database is supported
+    :param dbs: input dbs
+    :return: None
+    """
+    if len(dbs) > MAX_SUPPORT_DB:
+        raise ValueError(f'[ERROR] Supports up to four databases.')
+
+    if len(dbs) != len(set(dbs)):
+        raise ValueError(f'[ERROR] Duplicate database entered.')
+
+    support_dbs = database.get_db_priority()
+    for db in dbs:
+        if db not in support_dbs:
+            raise ValueError(f'[ERROR] Database ({db}) is not supported, please enter again.')
+    if len(dbs) == 1:
+        print('[WARNING] There is only one input database, '
+              'and only dependent information files will be generated without data comparison.')
+
+
+def _is_writable(path):
+    """
+    Verify whether run user has write permission to the output path
+    :param path: cvs save path
+    :return: True False
+    """
+    tmp_path = os.path.join(path, 'tmp_compare')
+    try:
+        os.mkdir(tmp_path)
+    except PermissionError:
+        return False
+    finally:
+        if os.path.isdir(tmp_path):
+            shutil.rmtree(tmp_path)
+    return True

