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Question

注意：我在同一个.rb文件中有两个代码块（见下文）。第一次ftp.getbinaryfile（）工作，然后它抛出错误。

注意： file变量是用于调试目的的文件的静态路径。

我在ruby 2.0.0p481 (2014-05-08) [x64-mingw32]

中有这段代码

file = "/Filetrack/E-mail_Gateway/_Installer/GA/E-mail Gateway_10.0_Changes_PUBLIC.pdf"

list = ftp.list('*')
list.each{|item| 

  counter=counter+1
  counter++
  ftp.getbinaryfile(file, where_to_save+File.basename(file)+counter.to_s, 1024)
  puts "downloaded - .each used"
}

然后在同一个.rb文件中我得到了这段代码

ftp.list('*') { |item| 
  puts "downloading using .list('*') {"
  counter++
  ftp.getbinaryfile(file, where_to_save+File.basename(file)+counter.to_s, 1024)

  puts "downloaded #{file}"
}

并且该代码会抛出此错误

Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:974:in `parse227': 200 Type set to I. (Net::FTPReplyError)
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:394:in `makepasv'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:406:in `transfercmd'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:487:in `block (2 levels) in retrbinary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:199:in `with_binary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:485:in `block in retrbinary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:484:in `retrbinary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:617:in `getbinaryfile'

ftp会话由

创建

ftp = Net::FTP.new('ftp.***.***.net')
ftp.passive = false
ftp.debug_mode = true
ftp.login(ftp_username, ftp_password)

有人可以解释为什么第二个版本有效吗？

更新

添加了ftp调试日志：

put: USER r.***
get: 331 Password required for r.***.
put: PASS ************
get: 230-Welcome to FTP
get: 230 User r.****logged in.
put: TYPE I
get: 200 Type set to I.
put: CWD /Filetrack/E-mail_Gateway/_Installer/GA/010_000_003_000/
get: 250 CWD command successful.
put: TYPE A
get: 200 Type set to A.
put: PASV
get: 227 Entering Passive Mode (194,212,10,23,195,92).
put: LIST *
get: 125 Data connection already open; Transfer starting.
get: 226 Transfer complete.
put: TYPE I
get: 200 Type set to I.
put: PASV
get: 227 Entering Passive Mode (194,212,10,23,195,93).
put: RETR /Filetrack/E-mail_Gateway/_Installer/GA/010_000_003_000/E-mail Gateway_10.0_Changes_PUBLIC.pdf
get: 125 Data connection already open; Transfer starting.
get: 226 Transfer complete.
downloaded - .each used
put: TYPE A
get: 200 Type set to A.
put: PASV
get: 227 Entering Passive Mode (***,***,10,23,195,97).
put: LIST *
get: 125 Data connection already open; Transfer starting.
downloading using .list('*') {
put: TYPE I
get: 226 Transfer complete.
put: PASV
get: 200 Type set to I.
put: TYPE A
get: 227 Entering Passive Mode (***,***,10,23,195,98).
put: TYPE I
get: 200 Type set to A.
d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:974:in `parse227': 200 Type set to I. (Net::FTPReplyError)
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:394:in `makepasv'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:406:in `transfercmd'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:487:in `block (2 levels) in retrbinary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:199:in `with_binary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:485:in `block in retrbinary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:484:in `retrbinary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:617:in `getbinaryfile'
        from download2 - debugging.rb:41:in `block in <main>'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:518:in `block (3 levels) in retrlines'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:515:in `loop'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:515:in `block (2 levels) in retrlines'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:199:in `with_binary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:512:in `block in retrlines'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:511:in `retrlines'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:760:in `list'
        from download2 - debugging.rb:38:in `<main>'

UPDATE2

如果使用ftp.passive = false则记录

downloading using .list('*') {
put: TYPE I
get: 226 Transfer complete.
put: PORT ***,***,20,102,235,136
get: 200 Type set to I.
put: RETR /Filetrack/E-mail_Gateway/_Installer/GA/010_000_003_000/Email Gateway_10.0_Changes_PUBLIC.pdf
get: 200 PORT command successful.
put: TYPE A
put: TYPE I
d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/protocol.rb:211:in `write': An existing connection was forcibly closed by the remote host. (Errno::ECONNRESET)
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/protocol.rb:211:in `write0'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/protocol.rb:185:in `block in write'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/protocol.rb:202:in `writing'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/protocol.rb:184:in `write'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:283:in `putline'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:360:in `block in voidcmd'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:359:in `voidcmd'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:183:in `send_type_command'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:172:in `binary='
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:201:in `ensure in with_binary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:201:in `with_binary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:512:in `block in retrlines'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:511:in `retrlines'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:760:in `list'
        from download2 - debugging.rb:39:in `<main>'

UPDATE3

我尝试在ftp活动模式下运行相同的代码几次，实际上所有文件都已下载，但脚本完成时出现错误。

downloading using .list('*') {
put: TYPE I
get: 200 Type set to I.
put: PORT **,**,20,102,197,73
get: 200 PORT command successful.
put: RETR /Filetrack/E-mail_Gateway/_Installer/GA/010_000_003_000/E-mail Gateway_10.0_Changes_PUBLIC.pdf
get: 150 Opening BINARY mode data connection for /Filetrack/E-mail_Gateway/_Installer/GA/010_000_003_000/E-mail Gateway_10.0_Changes_PUBLIC.pdf(
60911 bytes).
get: 226 Transfer complete.
put: TYPE A
get: 200 Type set to A.
downloaded /Filetrack/E-mail_Gateway/_Installer/GA/010_000_003_000/E-mail Gateway_10.0_Changes_PUBLIC.pdf
put: TYPE I
get: 200 Type set to I.
d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/protocol.rb:158:in `rescue in rbuf_fill': Net::ReadTimeout (Net::ReadTimeout)
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/protocol.rb:152:in `rbuf_fill'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/protocol.rb:134:in `readuntil'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:1108:in `readline'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:289:in `getline'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:300:in `getmultiline'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:318:in `getresp'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:338:in `voidresp'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:526:in `block (2 levels) in retrlines'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:199:in `with_binary'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:512:in `block in retrlines'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:511:in `retrlines'
        from d:/prog/Ruby200-x64/lib/ruby/2.0.0/net/ftp.rb:760:in `list'
        from download2 - debugging.rb:39:in `<main>'

Answer 1

`200 Type设置为I.（Net :: FTPReplyError）`

的原因

您的连接使用PASSIVE模式。由于您没有显示创建FTP对象的代码部分，因此我假设您明确将模式设置为passive。

ftp = Net::FTP.new('example.com')
ftp.passive = true

根据异常的堆栈跟踪，可以看到方法makepasv发出PASV命令时发生问题，但是得到的响应不是227 Entering Passive Mode (194,212,10,23,195,93).，而是获得响应200 Type set to I.

makepasv和parse227的实施（稍后在帖子中提及参考1 ＆amp; 参考2 ）表明代码专门寻找回报代码227如果不是这样，它将抛出一个FTPError。

这是给定方案中发生的事情。

为什么`parse227`收到错误的回复？

这可归因于下面显示的语法 _{这很可能不是那么理解的行为（正如我自己在回答这篇文章的过程中发现的那样）}

ftp.list('*') { |item| 
  ftp.getbinaryfile(file, where_to_save+File.basename(file)+counter.to_s, 1024)
}

在上面的代码中，LIST *发出ftp.list('*')命令。此命令的典型响应如下：

put: LIST *
get: 125 Data connection already open; Transfer starting.
get: 226 Transfer complete.

可以看出，LIST *会产生两行结果。这个事实对于理解这个问题至关重要。

传递给ftp.list('*')的块使用getbinaryfile方法下载二进制文件。

getbinaryfile通常会发出以下命令：

TYPE I将连接置于图像（二进制）模式
PASV进入被动模式
RETR /path/of/file/to/download

当块执行ftp.list('*')的第一个结果，并开始发出与getbinaryfile相关的命令时，在该时间点，只读取LIST *的第一行响应 - 第二行尚未阅读。这是第二行，显示为对块中发出的下一个命令的响应。

因此，当发出第一个命令TYPE I时，代码将LIST *的第二行作为响应读取（在调试日志中显而易见）

put: TYPE I
get: 226 Transfer complete.

当发出第二个命令PASV时，代码会读取TYPE I的响应（从调试日志中可以看出）

put: PASV
get: 200 Type set to I.

makepasv的实现是这样的，它希望响应的响应代码为227（参见参考文献1和参考文献2中的第394和973行）。在这种情况下抛出异常Net::FTPReplyError，因为parse227传递了TYPE I命令的响应。

总之，在使用passive模式时，似乎不可能在给予ftp.list（＆＃39; *＆＃39;）的块中执行其他FTP操作

为什么`ftp.list（＆＃39; *＆＃39;）。每个都工作？

在这种情况下，ftp.list('*')在没有块的情况下被调用，因此它返回字符串数组作为输出。在该数组上使用each不会产生类似的情况 - 因此，没有观察到任何问题。

解决方案

FTP#list的作者似乎希望以下两种变体以同等方式运作：

ftp.list('*') { |f| } # block given to list ftp.list('*').each { |f| } # block given to enum returned by list

根据list API的official documentation：


list（* args）{| line | ......}

返回。中的文件信息数组   目录（输出类似于ls -l）。如果给出一个块，它   遍历列表。

如果我们查看list的实现，那么，我们会看到，当给出一个块时，从ftp.list('*')读取的每一行都将逐一产生到块中。使用被动模式时，如果该块尝试执行任何其他FTP命令，则会导致上述情况。

754 def list(*args, &block) # :yield: line 755 cmd = "LIST" 756 args.each do |arg| 757 cmd = cmd + " " + arg.to_s 758 end 759 if block 760 retrlines(cmd, &block) 761 else 762 lines = [] 763 retrlines(cmd) do |line| 764 lines << line 765 end 766 return lines 767 end 768 end

我们可以通过首先将ftp.list('*').each响应中的所有行收集到数组中来将实现更改为等同于LIST *变量来解决此问题，并且如果块是块则将该数组传递给块给出。我们仍将坚持API文档。

def list(*args, &block) # :yield: line cmd = "LIST" args.each do |arg| cmd = cmd + " " + arg.to_s end # First lets fetch all the lines lines = [] retrlines(cmd) do |line| lines << line end if block lines.each { |l| yield l } else return lines end end

我已报告bug in Ruby Bug Tracker建议在FTP＃list方法的实施方面发生上述变化。

参考1 - makepasv
的实施
391 # sends the appropriate command to enable a passive connection 392 def makepasv # :nodoc: 393 if @sock.peeraddr[0] == "AF_INET" 394 host, port = parse227(sendcmd("PASV")) 395 else 396 host, port = parse229(sendcmd("EPSV")) 397 # host, port = parse228(sendcmd("LPSV")) 398 end 399 return host, port 400 end

参考2 - parse227
的实施
968 # handler for response code 227 969 # (Entering Passive Mode (h1,h2,h3,h4,p1,p2)) 970 # 971 # Returns host and port. 972 def parse227(resp) # :nodoc: 973 if resp[0, 3] != "227" 974 raise FTPReplyError, resp 975 end 976 if m = /\((?<host>\d+(,\d+){3}),(?<port>\d+,\d+)\)/.match(resp) 977 return parse_pasv_ipv4_host(m["host"]), parse_pasv_port(m["port"]) 978 else 979 raise FTPProtoError, resp 980 end 981 end

源代码摘要取自ftp.rb.

更新时间：2015年9月13日 对于这个问题，Ruby核心团队已经The proposed change accepted。

为什么我将“200 Type设置为I.（Net :: FTPReplyError）”

更新

1 个答案:

`200 Type设置为I.（Net :: FTPReplyError）`

为什么`parse227`收到错误的回复？

为什么`ftp.list（＆＃39; *＆＃39;）。每个都工作？

解决方案

list（* args）{| line | ......}