Python 实现文件的全备份和差异备份详解,

来源:http://www.sh-fengwen.com 作者:家常菜谱 人气:70 发布时间:2019-09-04
摘要:Python实现网站文件的全备份和差异备份, 之前有写利用md5方式来做差异备份,但是这种md5方式来写存在以下问题: •md5sum获取有些软连接的MD5值存在问题 •不支持对空目录进行备份,

Python实现网站文件的全备份和差异备份,

之前有写利用md5方式来做差异备份,但是这种md5方式来写存在以下问题:

•md5sum获取有些软连接的MD5值存在问题
•不支持对空目录进行备份,因为md5sum无法获取空目录的md5值
•权限的修改md5sum无法判断

解决方案:

利用文件的mtime ctime

mtime(Modified time)是在写入文件时随文件内容的更改而更改的
ctime(Create time)是在写入文件、更改所有者、权限或链接设置时随Inode的内容更改而更改的
废话不多说直接上代码:

#!/usr/bin/env python
import time,os,sys,cPickle

fileInfo = {}

def logger(time,fileName,status,fileNum):
  f = open('backup.log','a')
  f.write("%st%st%stt%sn" % (time,fileName,status,fileNum))

def tar(sDir,dDir,fileNum):
  command = "tar zcf %s %s >/dev/null 2>&1" % (dDir + ".tar.gz",sDir)
  if os.system(command) == 0:
    logger(time.strftime('%F %X'),dDir + ".tar.gz",'success',fileNum)
  else:
    logger(time.strftime('%F %X'),dDir + ".tar.gz",'failed',fileNum)

def fullBak(path):
  fileNum = 0
  for root,dirs,files in os.walk(path):
    for name in files:
      file = os.path.join(root, name)
      mtime = os.path.getmtime(file)
      ctime = os.path.getctime(file)
      fileInfo[file] = (mtime,ctime)
      fileNum += 1
  f = open(P,'w')
  cPickle.dump(fileInfo,f)
  f.close()
  tar(S,D,fileNum)

def diffBak(path):
  for root,dirs,files in os.walk(path):
    for name in files:
      file = os.path.join(root,name)
      mtime = os.path.getmtime(file)
      ctime = os.path.getctime(file)
      fileInfo[file] = (mtime,ctime)

  if os.path.isfile(P) == 0:
    f = open(P,'w')
    f.close()

  if os.stat(P).st_size == 0:
    f = open(P,'w')
    cPickle.dump(fileInfo,f)
    fileNum = len(fileInfo.keys())
    f.close()
    print fileNum
    tar(S,D,fileNum)
  else:
    f = open(P)
    old_fileInfo = cPickle.load(f)
    f.close()
    difference = dict(set(fileInfo.items())^set(old_fileInfo.items()))
    fileNum = len(difference)
    print fileNum

    difference_file = ' '.join(difference.keys())
    print difference_file

    tar(difference_file,D,fileNum)
    f = open(P,'w')
    cPickle.dump(fileInfo,f)
    f.close()

def Usage():
  print '''
    Syntax: python file_bakcup.py pickle_file model source_dir filename_bk
      model: 1:Full backup 2:Differential backup

    example: python file_backup.py fileinfo.pk 2 /etc etc_$(date +%F)
      explain: Automatically add '.tar.gz' suffix
  '''
  sys.exit()

if len(sys.argv) != 5:
  Usage()

P = sys.argv[1]
M = int(sys.argv[2])
S = sys.argv[3]
D = sys.argv[4]

if M == 1:
  fullBak(S)
elif M == 2:
  diffBak(S)
else:
  print "33[;31mDoes not support this mode33[0m"
  Usage()

测试:

$ python file_backup.py data.pk 1 data data_$(date +%F) #全备份
$ > data/www.jb51.net #测试创建文件,修改文件权限
$ chmod 777 data/py/eshop_bk/data.db
$ python file_backup.py data.pk 2 data data_$(date +%F)_1 #备份改变的文件
2
data/py/eshop_bk/data.db data/www.jb51.net

看了博主的代码,很受启发,但是有一个问题,如果我完成完整备份之后,删除了其中某个文件,再做差异备份,可以检测出被删除的文件,但是执行tar就会出错,因为这个文件已经是不存在的了,所以在执行tar之前,最好用os.path.exists()判断一下差异文件路径是否存在,如果不存在则不执行tar, 反馈一条文件删除信息。

之前有写利用md5方式来做差异备份,但是这种md5方式来写存在以下问题: md5sum获取有些软连接的...

Python 实现文件的全备份和差异备份详解,

Python实现文件的全备份和差异备份

之前有写利用md5方式来做差异备份,但是这种md5方式来写存在以下问题:

  • md5sum获取有些软连接的MD5值存在问题
  • 不支持对空目录进行备份,因为md5sum无法获取空目录的md5值
  • 权限的修改md5sum无法判断

解决方案:

利用文件的mtime ctime

mtime(Modified time)是在写入文件时随文件内容的更改而更改的

ctime(Create time)是在写入文件、更改所有者、权限或链接设置时随Inode的内容更改而更改的

废话不多说直接上代码:

#!/usr/bin/env python
import time,os,sys,cPickle
fileInfo = {}
def logger(time,fileName,status,fileNum):
  f = open('backup.log','a')
  f.write("%st%st%stt%sn" % (time,fileName,status,fileNum))
def tar(sDir,dDir,fileNum):
  command = "tar zcf %s %s >/dev/null 2>&1" % (dDir + ".tar.gz",sDir)
  if os.system(command) == 0:
    logger(time.strftime('%F %X'),dDir + ".tar.gz",'success',fileNum)
  else:
    logger(time.strftime('%F %X'),dDir + ".tar.gz",'failed',fileNum)
def fullBak(path):
  fileNum = 0
  for root,dirs,files in os.walk(path):
    for name in files:
      file = os.path.join(root, name)
      mtime = os.path.getmtime(file)
      ctime = os.path.getctime(file)
      fileInfo[file] = (mtime,ctime)
      fileNum += 1
  f = open(P,'w')
  cPickle.dump(fileInfo,f)
  f.close()
  tar(S,D,fileNum)
def diffBak(path):
  for root,dirs,files in os.walk(path):
    for name in files:
      file = os.path.join(root,name)
      mtime = os.path.getmtime(file)
      ctime = os.path.getctime(file)
      fileInfo[file] = (mtime,ctime)
  if os.path.isfile(P) == 0:
    f = open(P,'w')
    f.close()
  if os.stat(P).st_size == 0:
    f = open(P,'w')
    cPickle.dump(fileInfo,f)
    fileNum = len(fileInfo.keys())
    f.close()
    print fileNum
    tar(S,D,fileNum)
  else:
    f = open(P)
    old_fileInfo = cPickle.load(f)
    f.close()
    difference = dict(set(fileInfo.items())^set(old_fileInfo.items()))
    fileNum = len(difference)
    print fileNum
    difference_file = ' '.join(difference.keys())
    print difference_file
    tar(difference_file,D,fileNum)
    f = open(P,'w')
    cPickle.dump(fileInfo,f)
    f.close()
def Usage():
  print '''
    Syntax: python file_bakcup.py pickle_file model source_dir filename_bk
      model: 1:Full backup 2:Differential backup
    example: python file_backup.py fileinfo.pk 2 /etc etc_$(date +%F)
      explain: Automatically add '.tar.gz' suffix
  '''
  sys.exit()
if len(sys.argv) != 5:
  Usage()
P = sys.argv[1]
M = int(sys.argv[2])
S = sys.argv[3]
D = sys.argv[4]
if M == 1:
  fullBak(S)
elif M == 2:
  diffBak(S)
else:
  print "33[;31mDoes not support this mode33[0m"
  Usage()

测试:

$ python file_backup.py data.pk 1 data data_$(date +%F) #全备份
$ > data/www.linuxeye.com #测试创建文件,修改文件权限
$ chmod 777 data/py/eshop_bk/data.db
$ python file_backup.py data.pk 2 data data_$(date +%F)_1 #备份改变的文件
2
data/py/eshop_bk/data.db data/www.linuxeye.com

感谢阅读,希望能帮助到大家,谢谢大家对本站的支持!

实现文件的全备份和差异备份详解, Python实现文件的全备份和差异备份 之前有写利用md5方式来做差异备份,但是这种md5方式来写存在...

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