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("%s\t%s\t%s\t\t%s\n" % (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 "\033[;31mDoes not support this mode\033[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。
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