980afad15c
* S'utilise avec un context manager, le but est de faire un fichier temporaire de backup, et de s'assurer qu'on ferme bien le fichier dans lequel on écrit au fur et à mesure du temps
81 lines
2.1 KiB
Python
81 lines
2.1 KiB
Python
#!/usr/bin/env python
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# -*- coding: utf-8 -*-
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#
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# Library designed to write in config files data
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# safely.
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#
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# Author : Pierre-Elliott Bécue <becue@crans.org>
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# License : GPLv3
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# Date : 30/05/2014
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import tempfile
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import shutil
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import sys
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import time
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class ConfFile(object):
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"""Class handling ConfigFiles
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"""
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def __init__(self, filename):
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self._name = filename
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self._backup = None
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self._fd = None
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def __enter__(self):
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"""This file is used in context manager
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In case of syntax "with ConfFile("blop") as troll,
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troll will bind on self
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"""
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self.safe_open()
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return self
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def __exit__(self, etype, evalue, etraceback):
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"""Closes file, and, if there is any traceback, restores
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the backup
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"""
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self._fd.close()
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if etype:
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# In case of exception, cleans the mess.
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self.restore()
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def safe_open(self):
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"""Open a file in writemode but backups it before.
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"""
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self._backup = tempfile.NamedTemporaryFile()
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try:
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shutil.copyfile(self._name, self._backup.name)
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except IOError:
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self._backup = None
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self._fd = open(self._name, 'w')
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def write(self, data):
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"""Writes data into file
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"""
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self._fd.write(data)
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def restore(self):
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"""Restores the tempfile
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"""
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if self._backup is not None:
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shutil.copyfile(self._backup.name, self._name)
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def header(self, comment="#"):
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myHeader = """********************************************************************************************
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This file was generated automatically using the software %s.
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You should not modify it directly if you don't know what you are doing.
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Date : %s
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********************************************************************************************""" % (sys.argv[0].split("/")[-1], time.strftime("%d/%m/%Y - %H:%M:%S", time.localtime()))
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myHeader = comment + myHeader.replace("\n", "\n%s" % (comment,))
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myHeader += "\n\n"
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self.write(myHeader)
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