2022年python与常用文件传输协议 .pdf

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1、金枫 Intra net网安实验室作者：枫无眠版权所有 欢迎转载1/17python 与常用文件传输协议枫无眠关键词 ：python,linux,Ylmfos,Ubuntu,ftp,sftp,samba.0 引言文件操作在我们测试和开发当中都有用到，本文总结了最常见的文件传输的方式。ftp 互联网中使用广泛的协议Sftp linux 系统中使用最广泛的协议Samba-liunux 和 windows 这间使用最广泛的协议。1 ftp 协议ftp 全称文件传输协议，是在互联网中使用广泛的协议。基于tcp协议，缺省端口 21.1.1 ftplib- FTP protocolclientThismo

2、dule definesthe classFTPand a few relateditems.TheFTPclassimplements the clientsideof the FTP protocol.You can usethisto writePython programs thatperforma varietyof automated FTPjobs,such as mirroringotherftpservers.Itisalsoused by themoduleurllibto handle URLs thatuse FTP. For more informationon FT

3、P(FileTransferProtocol),see InternetRFC959.Heresa sample sessionusingtheftplibmodule:fromftplibimportFTPftp= FTP(ftp.cwi.nl)# connecttohost,defaultportftp.login()# useranonymous,passwdanonymousftp.retrlines(LIST)# listdirectorycontentstotal24418drwxrwsr-x5 ftp-usrpdmaint1536Mar2009:48.dr-xr-srwt105f

4、tp-usrpdmaint1536Mar2114:32.-rw-r-r-1 ftp-usrpdmaint5305Mar2009:48INDEX.名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 1 页，共 17 页 - - - - - - - - - 金枫 Intra net网安实验室作者：枫无眠版权所有 欢迎转载2/17.ftp.retrbinary(RETRREADME,open(README,wb).write)226Transfercomplete.ftp.quit()The

5、module definesthe followingitems:classFTP(host, user,passwd, acct)Return a new instance oftheFTPclass. When hostisgiven, the method callconnect(host)ismade. When useris given, additionally themethodcalllogin(user,passwd,acct)is made (where passwd and acctdefault to the empty string when notgiven).1.

6、2 APISeveralmethods are availableintwo flavors:one forhandlingtextfilesand anotherforbinaryfiles.These are namedforthecommandwhich isused followedby lines forthe textversionorbinary forthe binaryversion.FTPinstanceshave the followingmethods:set_debuglevel(level)Setthe instance sdebugging level. This

7、 controls the amountof debuggingoutput printed.Thedefault,0, producesno debugging output. A value of1producesamoderateamountof debuggingoutput,generally a single line per request.A value of2or higher producesthe maximum amountof debugging output, logging eachline sentand received on thecontrol conne

8、ction.connect(host, port)Connectto the given host and port. The default port number is21, asspecified by theFTP protocol specification. It is rarely needed to specify a different port number. Thisfunction should be calledonly once for each instance;it shouldnot be calledat all if ahostwasgiven when

9、the instancewas created.All other methodscanonly beusedafteraconnectionhasbeenmade.getwelcome()Return the welcomemessagesent by the server in reply to the initial connection.(Thismessagesometimescontains disclaimersor help information that may be relevantto theuser.)login(user, passwd, acct)Log in a

10、sthe given user. The passwd and acctparametersareoptional and default to theempty string.Ifno useris specified,itdefaultstoanonymous.Ifuseris名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 2 页，共 17 页 - - - - - - - - - 金枫 Intra net网安实验室作者：枫无眠版权所有 欢迎转载3/17anonymous, the

11、 default passwd isanonymous. This function should be calledonly once for each instance,after a connectionhasbeen established;it should not becalled at all if a host and user were given when the instancewas created.Most FTPcommandsareonly allowedafter theclient hasloggedin.abort()Abort a file transfe

12、rthat is in progress.Using thisdoesnot alwayswork, but its worth atry.sendcmd(comm and)Sendasimple commandstring totheserverandreturn theresponsestring.voidcmd(comm and)Sendasimple commandstring to theserver andhandlethe response.Returnnothing if aresponsecodein therange200-299isreceived.Raiseanexce

13、ptionotherwise.retrbinary(comm and, callback, maxblocksize, r est)Retrieve a file in binary transfer mode. comm andshould be an appropriate RETRcommand:RETRfilename. The callbackfunction is called for each block of datareceived, witha single stringargument givingthe data block.The optionalmaxblocksi

14、ze argumentspecifiesthemaximum chunksize to readon the low-level socketobject createdto do the actual transfer (which will alsobe the largestsize of the datablocks passedto callback). A reasonable default ischosen.r est meansthesamething asinthetransfercmd()method.retrlines(command, callback)Retriev

15、e a file or directory listing in ASCIItransfer mode. comm andshould be anappropriateRETR command(seeretrbinary() or a LIST command(usually justthe stringLIST). The callbackfunction is calledfor each line, with the trailing CRLFstripped.The defaultcallbackprints the line tosys.stdout.set_pasv(boolean

16、)Enablepassive mode if booleanis true, other disablepassivemode. (In Python2.0 andbefore,passivemode wasoff by default; in Python2.1 andlater,it is onby default.)storbinary(comm and, file,blocksize)Storeafile in binary m andshouldbeanappropriateSTOR command:STORfilename. fileis an open file object w

17、hich is read until EOF using itsread()method in blocks of size blocksizeto provide the data to be stored. Theblocksizeargumentdefaultsto8192.Changedin version2.1:default for blocksizeadded.storlines(command, file)Storea file in ASCII transfermode. commandshouldbean appropriateSTOR command(seestorbin

18、ary(). Lines are read until EOF from theopen file object fileusing itsreadline()methodtoprovide thedatato bestored.transfercmd(cmd,rest)Initiate a transfer over the data connection.If the transfer is active,send a EPRT orPORT commandandthe transfercommandspecifiedby cmd, andaccepttheconnection.If th

19、eserver is passive,send a EPSV or PASV command,connectto it, and start thetransfercommand.Either way,return thesocketfor theconnection.Ifoptionalrest isgiven,a REST commandissentto the名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 3 页，共 17 页 - - - - - - - - - 金枫 Intr

20、a net网安实验室作者：枫无眠版权所有 欢迎转载4/17server,passingrest as an argument.rest isusuallya byteoffsetintothe requestedfile,tellingthe serverto restartsendingthe filesbytesat the requestedoffset,skippingoverthe initialbytes.Note however thatRFC959 requiresonlythatrest be a stringcontainingcharactersinthe printab

21、lerangefrom ASCII code 33 to ASCII code 126. Thetransfercmd()method,therefore,convertsrest to a string,but no check isperformedon the stringscontents.Ifthe serverdoes not recognizetheREST command,anerror_replyexceptionwillbe raised.Ifthishappens, simplycalltransfercmd()withouta rest argument.ntransf

22、ercmd(cmd,r est)Liketransfercmd(), but returnsa tuple of the dataconnection andtheexpectedsizeof the data. If the expectedsize could not be computed,Nonewill be returnedas theexpectedsize.cmd andrest meansthesamething asintransfercmd().nlst(argument,.)Return a list of files asreturned by the NLST co

23、mmand.The optional argumentis adirectory to list (default is the currentserverdirectory). Multiple argumentscanbe usedto passnon-standardoptions to theNLST command.dir(argument,.)Producea directory listing asreturned by the LIST command,printing it to standardoutput.Theoptional argumentis adirectory

24、 to list (default is thecurrentserver directory).Multiple argumentscanbeused to passnon-standardoptions to theLISTcommand.Ifthe lastargumentis afunction, it is usedasacallbackfunction asforretrlines(); thedefault prints tosys.stdout. Thismethod returnsNone.rename(fromname,toname )Renamefile fromname

25、on theserver totoname.delete(filename)Remove the file named filename from the server. If successful, returns the text of theresponse,otherwiseraiseserror_permon permissionerrorsorerror_replyon othererrors.cwd(pathname )Setthe currentdirectory on theserver.mkd(pathname )Createanewdirectory on theserv

26、er.pwd()Return thepathnameof thecurrentdirectory ontheserver.rmd(dirname)Removethedirectorynameddirnameon theserver.size(filename)Requestthesize of thefile namedfilenameon theserver.Onsuccess, thesizeof thefile isreturnedasan integer,otherwiseNoneis returned.Note that theSIZE commandis notstandardiz

27、ed,but is supportedby manycommonserverimplementations.quit()名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 4 页，共 17 页 - - - - - - - - - 金枫 Intra net网安实验室作者：枫无眠版权所有 欢迎转载5/17SendaQUIT commandto theserverandclose theconnection.This is thepolite wayto close a connection,

28、but it may raiseanexceptionof theserverrepondswith anerror tothe QUIT command. This implies a call to theclose()method which renders theFTPinstanceuselessfor subsequentcalls(seebelow).close()Close the connection unilaterally. This should not be applied to an already closedconnection such as after a

29、successful call toquit(). After this call theFTPinstanceshouldnot be usedanymore (after a call toclose()orquit()you cannotreopentheconnectionby issuinganotherlogin()method).2 sftp 协议（ ssh）ssh在 linux/unix 上最流行的远程控制方式，几乎所有的远程控制都是通过ssh进行的。ssh还有一个附属协议就是 sftp 协议，可以用来在网络上传输文件，而且是加密的。如果在linux/unix 之间传输文件，通

30、过 sftp 无疑是最安全，最方便的方式。2.1 安装 paramikoparamiko包给我们提供了 ssh的访问接口，使用非常方便。安装：sudoapt-getinstallpython-paramiko即可。2.2 编程主要介绍了几个客户端对像，来操作和获取服务器上的文件。2.2.1SSHClient 对象SSHClinet 对象用来描述与 server这间的连接，建立时需要提供ip,port，用户名密码等信息。一个简单的例子：名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 5

31、 页，共 17 页 - - - - - - - - - 金枫 Intra net网安实验室作者：枫无眠版权所有 欢迎转载6/17SSHClient 对象主要的方法：connectconnect(self,hostname,port=22,username=None,password=None,pkey=None,key_filename=None,timeout=None,allow_agent=True,look_for_keys=True)sourcecodeConnect to an SSH server and authenticateto it. The servers host k

32、ey ischecked against the system host keys (see load_system_host_keys)and anylocal host keys(load_host_keys).If theservers hostnameis not found in eithersetofhostkeys,themissinghostkeypolicyisused(seeset_missing_host_key_policy).The default policy is to reject thekey and raiseanSSHException.Authentic

33、ation is attemptedin thefollowing order of priority:Thepkey or key_filenamepassedin (if any)Any key we canfind throughanSSHagentAny id_rsa orid_dsa key discoverablein /.ssh/Plainusername/password auth,if apasswordwasgivenIf a private key requiresa passwordto unlock it, and a passwordis passedin,that

34、passwordwill beusedto attempttounlock thekey.Parameters:hostname(str) - theservertoconnecttoport (int) - theserverport toconnecttousername(str) - the usernameto authenticateas(defaults to the current localusername)password(str) - a passwordtousefor authenticationor for unlocking aprivatekeypkey (PKe

35、y) - anoptional privatekey to usefor authenticationkey_filename (str or list(str) - the filename, or list of filenames, of optionalprivatekey(s) to try for authenticationtimeout(float) - anoptional timeout (in seconds)for theTCPconnectallow_agent(bool) - set toFalsetodisable connectingto theSSHagent

36、look_for_keys (bool) - set to Falsetodisablesearchingfor discoverableprivatefrom paramikoimport *client = SSHClient()client.load_system_host_keys()client.connect( 192.168.19.134,22,test2010,123456)stdin,stdout,stderr = client.exec_command( ls-l)print stdout.read()client.close()名师资料总结 - - -精品资料欢迎下载 -

37、 - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 6 页，共 17 页 - - - - - - - - - 金枫 Intra net网安实验室作者：枫无眠版权所有 欢迎转载7/17key files in /.ssh/Raises:BadHostKeyException- if theservershostkey could notbeverifiedAuthenticationException- if authenticationfailedSSHException- if therewas anyother error c

38、onnectingor establishingan SSHsessionsocket.error- if asocketerror occurredwhile connectingexec_command exec_command(self,command,bufsize=-1)sourcecodeExecutea command on the SSH server. A new Channel is opened and therequestedcommandis executed.The command s input and output streamsarereturnedaspyt

39、honfile-like objects representingstdin, stdout,andstderr.Parameters:command(str) - the commandtoexecutebufsize (int) - interpreted thesame way asby the built-in file() function inpythonReturns:tuple(ChannelFile,ChannelFile,ChannelFile)thestdin,stdout, andstderrof theexecutingcommandRaises:SSHExcepti

40、on- if theserver fails to executethecommandinvoke_shellinvoke_shell(self,term=vt100, width=80, height=24)sourcecodeStartan interactiveshell sessionon theSSH server.A newChannel is openedandconnectedto apseudo-terminalusing therequestedterminal typeandsize.Parameters:term(str) - the terminaltypeto em

41、ulate(for example,vt100)width (int) - thewidth (in characters)of theterminal windowheight (int) - theheight (in characters)of theterminal windowReturns:Channelanewchannelconnectedto theremoteshellRaises:SSHException- if theserver fails to invokeashellopen_sftpopen_sftp(self)sourcecodeOpenanSFTPsessi

42、onon theSSHserver.Returns:SFTPClientanewSFTPsessionobject名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 7 页，共 17 页 - - - - - - - - - 金枫 Intra net网安实验室作者：枫无眠版权所有 欢迎转载8/172.2.2SFTPClient 对象SSHClient 对象建立后，可以建立一个SFTPClient会话来进行文件相关的操作。具体如下：SFTPClient的主要方法：chmodchmod(sel

43、f,mode)sourcecodeChangethe mode (permissions)of this file. The permissions are unix-styleandidentical to thoseusedbypythonsos.chmodfunction.Parameters:mode(int) - newpermissionschdirchdir(self,path)Changethepathfor remotesession.closeclose(self)sourcecodeClosetheSFTPsessionanditsunderlyingchannel.Si

44、nce:1.4filefile(self, filename,mode=r, bufsize=-1)sourcecodeOpena file on theremoteserver.The argumentsarethesameasfor pythonsbuilt-in file (aka open). A file-like object is returned,which closely mimicsimport timefrom paramikoimport *client = SSHClient()client.load_system_host_keys()client.connect(

45、 192.168.19.134,22,test2010,123456)sftp = client.open_sftp()#建立一个 SFTPClient对象sftp.mkdir(test)print sftp.listdir()begin= time.time()sftp.get(src/1.data,./1.jpg)print time.time()-begin名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 8 页，共 17 页 - - - - - - - - - 金枫 Intra

46、 net网安实验室作者：枫无眠版权所有 欢迎转载9/17thebehaviorof anormal python file object.Themode indicateshow thefile is tobeopened:rfor reading,w for writing(truncatinganexisting file), a for appending,r+ for reading/writing, w+ forreading/writing (truncating an existing file), a+ for reading/appending.Thepython b fla

47、g is ignored,since SSHtreatsall files asbinary. The U flag issupportedin acompatible way.Since1.5.2, an x flag indicatesthat theoperationshould only succeedif thefile was createdand did not previously exist. This hasno direct mapping topythons file flags,but is commonlyknown asthe O_EXCL flag in pos

48、ix.Thefile willbe buffered in standardpython styleby default, but canbealteredwith the bufsize parameter.0 turns off buffering, 1 usesline buffering, andanynumbergreaterthan1 (1) usesthatspecific buffer size.Parameters:filename (str) - nameof thefile toopenmode(str) - mode(python-style) toopen inbuf

49、size(int) - desiredbuffering (-1 = defaultbuffer size)Returns:SFTPFileafile objectrepresentingtheopenfileRaises:IOError - if thefile couldnot be opened.getget(self,remotepath,localpath,callback=None)sourcecodeCopy a remote file (remotepath)from the SFTPserver to the local host aslocalpath. Any excep

50、tion raised by operations will be passedthrough. Thismethodis primarily provided asaconvenience.Parameters:remotepath(str) - theremotefile tocopylocalpath(str) - thedestinationpathon thelocal hostcallback(function(int, int) - optional callback function that acceptsthe bytestransferredsofar andthetot