Pexpect+pxssh 对长字符串的处理

Question

我正在使用 pexpect+pxssh 与远程服务器通信。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，它创建了一个超时。命令 'echo 1234567890 >log.txt 2>&1' 完全没有问题。在长路径位置使用短命令也会出现此问题，例如

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

如果 folder1/folder2/.../folder 的长度太长，expect 也不会工作，因为显示当前路径的 'prompt' 的长度。

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

如能解决此问题，我们将不胜感激。

SebE

Answer 1

自己找到了答案。因为我认为这与pexpect打开的命令行window的长度有关。默认为 80 个字符。您可以在创建后立即使用 channel.setwinsize(24, channel.maxread)

配置它

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

Answer 2

接受的答案不正确。

您必须在登录后添加对 setwinsize 的调用。

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()

登录前调用setwinsize会报错'pxssh'对象没有属性'ptyproc'

Pexpect+pxssh 对长字符串的处理

Pexpect+pxssh handling of long strings

python

pexpect

pxssh