Pexpect+pxssh 处理长字符串

Question

我正在使用 pexpect+pxssh 与远程服务器进行通信。有些命令可能有点长，下面的代码不起作用：

import pxssh

channel = pxssh.pxssh()
channel.login('192.168.93.129', 'tester', 'tester', 22, auto_prompt_reset=False, quiet=False)
channel.PROMPT = 'tester' + "@[^#$]+[#$]"
channel.sendline('echo 1234567890abcdefghojklmnopqrstuvwxyzmyveryverylongaworkspaceaoneamoreafolder >log.txt 2>&1')
print channel
index = channel.expect(['echo 1234567890abcdefghojklmnopqrstuvwxyzmyveryverylongaworkspaceaoneamoreafolder >log.txt 2>&1'], timeout=10, )
print channel

由于 expect 函数，它会创建一个超时。命令'echo 1234567890 >log.txt 2>&1' 完全没有问题。问题也发生在长路径位置的短命令上，例如

sendline('cd folder1')
sendline('cd folder2')
...
sendline('cd foldern')
pexpect('cd foldern')

如果 folder1/folder2/.../folder 的长度太长，由于显示当前路径的“提示”的长度，expect 也不起作用。

这是代码产生的输出：

/usr/bin/python2.7 /data/eskenazi/stash/alb-tools/testing_framework/tests/build/remote_build_test.py
<pexpect.pxssh.pxssh object at 0x7f6402096990>
version: 3.1
command: /usr/bin/ssh
args: ['/usr/bin/ssh', '-l', 'tester', '192.168.93.129']
searcher: <pexpect.searcher_re object at 0x7f6402096a50>
buffer (last 100 chars): ' '
before (last 100 chars): ": \r\nWelcome to Ubuntu 14.04.2 LTS (GNU/Linux 3.16.0-30-generic x86_64)\r\n\r\n * Documentation:  https://help.ubuntu.com/\r\n\r\n517 packages can be updated.\r\n296 updates are security updates.\r\n\r\nNew release '16.04.1 LTS' available.\r\nRun 'do-release-upgrade' to upgrade to it.\r\n\r\nLast login: Mon Feb  6 16:56:30 2017 from 192.168.93.130\r\r\ntester@ubuntu:~"
after: '$'
match: <_sre.SRE_Match object at 0x7f640209a850>
match_index: 1
exitstatus: None
flag_eof: False
pid: 7004
child_fd: 3
closed: False
timeout: 30
delimiter: <class 'pexpect.EOF'>
logfile: None
logfile_read: None
logfile_send: None
maxread: 2000
ignorecase: False
searchwindowsize: None
delaybeforesend: 0.05
delayafterclose: 0.1
delayafterterminate: 0.1
Traceback (most recent call last):
  File "/data/eskenazi/stash/alb-tools/testing_framework/tests/build/remote_build_test.py", line 23, in <module>
    index = channel.expect(['echo 1234567890abcdefghojklmnopqrstuvwxyzmyveryverylongaworkspaceaoneamoreafolder >log.txt 2>&1'], timeout=10, )
  File "/usr/lib/python2.7/dist-packages/pexpect/__init__.py", line 1417, in expect
    timeout, searchwindowsize)
  File "/usr/lib/python2.7/dist-packages/pexpect/__init__.py", line 1431, in expect_list
    timeout, searchwindowsize)
  File "/usr/lib/python2.7/dist-packages/pexpect/__init__.py", line 1542, in expect_loop
    raise TIMEOUT(str(err) + '\n' + str(self))
pexpect.TIMEOUT: Timeout exceeded.
<pexpect.pxssh.pxssh object at 0x7f6402096990>
version: 3.1
command: /usr/bin/ssh
args: ['/usr/bin/ssh', '-l', 'tester', '192.168.93.129']
searcher: <pexpect.searcher_re object at 0x7f6402096a10>
buffer (last 100 chars): 'eaoneamoreafolder >log.                         \x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08txt 2>&1\r\ntester@ubuntu:~$ '
before (last 100 chars): ' echo 1234567890abcdefghojklmnopqrstuvwxyzmyveryverylongawork\r<67890abcdefghojklmnopqrstuvwxyzmyveryverylongaworks                         \x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08paceaoneamoreafolder >log\r\r<vwxyzmyveryverylongaworkspaceaoneamoreafolder >log.                         \x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08\x08txt 2>&1\r\ntester@ubuntu:~$ '
after: <class 'pexpect.TIMEOUT'>
match: None
match_index: None
exitstatus: None
flag_eof: False
pid: 7004
child_fd: 3
closed: False
timeout: 30
delimiter: <class 'pexpect.EOF'>
logfile: None
logfile_read: None
logfile_send: None
maxread: 2000
ignorecase: False
searchwindowsize: None
delaybeforesend: 0.05
delayafterclose: 0.1
delayafterterminate: 0.1

Process finished with exit code 1

我们将不胜感激任何帮助来解决这个问题。

SebE

Answer 1

接受的答案不正确。

1. 您必须在登录后添加对 setwinsize 的调用。

2. 调用setwinsize后必须匹配提示。

       s = pxssh.pxssh()
       hostname = ipaddress
       username = ssh_username
       password = ssh_pass
   
       print("############ Logging into remote machine ############")
       s.login(hostname, username, password)
       print("logged into host: " + hostname)
   
       print("setting winsize")
       s.setwinsize(100, 1000)
       s.prompt()
   

   在登录前调用 setwinsize 会给你错误信息 'pxssh' object has no attribute 'ptyproc'

Answer 2

自己找到了答案。我认为这与 pexpect 打开的命令行窗口的长度有关。默认值为 80 个字符。您可以在创建后立即配置它channel.setwinsize(24, channel.maxread)

import pxssh

channel = pxssh.pxssh()
channel.setwinsize(24, channel.maxread)
channel.login('192.168.93.129', 'tester', 'tester', 22, auto_prompt_reset=False, quiet=False)
channel.PROMPT = 'tester' + "@[^#$]+[#$]"
channel.sendline('echo 1234567890abcdefghojklmnopqrstuvwxyzmyveryverylongaworkspaceaoneamoreafolder >log.txt 2>&1')
print channel
index = channel.expect(['echo 1234567890abcdefghojklmnopqrstuvwxyzmyveryverylongaworkspaceaoneamoreafolder >log.txt 2>&1'], timeout=10, )
print channel