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dS )a4 This class extends pexpect.spawn to specialize setting up SSH connections.
This adds methods for login, logout, and expecting the shell prompt.
PEXPECT LICENSE
This license is approved by the OSI and FSF as GPL-compatible.
http://opensource.org/licenses/isc-license.txt
Copyright (c) 2012, Noah Spurrier <noah@noah.org>
PERMISSION TO USE, COPY, MODIFY, AND/OR DISTRIBUTE THIS SOFTWARE FOR ANY
PURPOSE WITH OR WITHOUT FEE IS HEREBY GRANTED, PROVIDED THAT THE ABOVE
COPYRIGHT NOTICE AND THIS PERMISSION NOTICE APPEAR IN ALL COPIES.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
� )�ExceptionPexpect�TIMEOUT�EOF�spawnN�ExceptionPxssh�pxsshc @ s e Zd ZdZdS )r z!Raised for pxssh exceptions.
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This class extends pexpect.spawn to specialize setting up SSH
connections. This adds methods for login, logout, and expecting the shell
prompt. It does various tricky things to handle many situations in the SSH
login process. For example, if the session is your first login, then pxssh
automatically accepts the remote certificate; or if you have public key
authentication setup then pxssh won't wait for the password prompt.
pxssh uses the shell prompt to synchronize output from the remote host. In
order to make this more robust it sets the shell prompt to something more
unique than just $ or #. This should work on most Borne/Bash or Csh style
shells.
Example that runs a few commands on a remote server and prints the result::
from pexpect import pxssh
import getpass
try:
s = pxssh.pxssh()
hostname = raw_input('hostname: ')
username = raw_input('username: ')
password = getpass.getpass('password: ')
s.login(hostname, username, password)
s.sendline('uptime') # run a command
s.prompt() # match the prompt
print(s.before) # print everything before the prompt.
s.sendline('ls -l')
s.prompt()
print(s.before)
s.sendline('df')
s.prompt()
print(s.before)
s.logout()
except pxssh.ExceptionPxssh as e:
print("pxssh failed on login.")
print(e)
Example showing how to specify SSH options::
from pexpect import pxssh
s = pxssh.pxssh(options={
"StrictHostKeyChecking": "no",
"UserKnownHostsFile": "/dev/null"})
...
Note that if you have ssh-agent running while doing development with pxssh
then this can lead to a lot of confusion. Many X display managers (xdm,
gdm, kdm, etc.) will automatically start a GUI agent. You may see a GUI
dialog box popup asking for a password during development. You should turn
off any key agents during testing. The 'force_password' attribute will turn
off public key authentication. This will only work if the remote SSH server
is configured to allow password logins. Example of using 'force_password'
attribute::
s = pxssh.pxssh()
s.force_password = True
hostname = raw_input('hostname: ')
username = raw_input('username: ')
password = getpass.getpass('password: ')
s.login (hostname, username, password)
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ignore_sighup�echo�encoding� codec_errorsz<pxssh>z\[PEXPECT\][\$\#] zPS1='[PEXPECT]\$ 'zset prompt='[PEXPECT]\$ 'z-o'RSAAuthentication=no'z -o 'PubkeyAuthentication=no'Fz5-o'RSAAuthentication=no' -o 'PubkeyAuthentication=no')
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zpxssh.__init__c C s� t |�t |� }}||kr.|| }}|| }}t|d �}x�td|d �D ]�}||gdg| }}xptd|d �D ]^}|| d ||d d } }
||d } ||d ||d kr�| d } t| |
| �||< qtW qJW || S )zBThis calculates the Levenshtein distance between a and b.
� r )�len�range�min) r" �a�b�n�mZcurrent�iZprevious�j�add�deleteZchanger r r
�levenshtein_distance� s
zpxssh.levenshtein_distancec C s� |d }|d }|d }| j � }tj� }d}|}xJ||k rzy&|| jd|d�7 }tj� | }|}W q2 tk
rv P Y q2X q2W |S )aX This facilitates using communication timeouts to perform
synchronization as quickly as possible, while supporting high latency
connections with a tunable worst case performance. Fast connections
should be read almost immediately. Worst case performance for this
method is timeout_multiplier * 3 seconds.
g �?g�������?g @g r# )�sizer )Z string_type�timeZread_nonblockingr ) r" Ztimeout_multiplierZfirst_char_timeoutZinter_char_timeoutZ
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�try_read_prompt� s
zpxssh.try_read_prompt� �?c C s� | j � tjd� y| j|� W n tk
r4 Y nX | j � | j|�}| j � | j|�}| j � | j|�}| j||�}t|�}|dkr�dS t|�| dk r�dS dS )a� This attempts to find the prompt. Basically, press enter and record
the response; press enter again and record the response; if the two
responses are similar then assume we are at the original prompt.
This can be a slow function. Worst case with the default sync_multiplier
can take 12 seconds. Low latency connections are more likely to fail
with a low sync_multiplier. Best case sync time gets worse with a
high sync multiplier (500 ms with default). g�������?r Fg�������?T)�sendliner1 Zsleepr3 r r/ r$ �float)r" �sync_multiplier�xr' r( ZldZlen_ar r r
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g�}|dk�rf| j� t d��|dk�r�| j� t d��n�|dk�r�n�|dk�r�| j� t d��np|dk�r�| j� t d ��nT|dk�r�| j� t d ��n8|d k�r�n,|d k�r
| j� t d ��n| j� t d!��| j| ��s6| j� t d"��|�rb| j� �sb| j� t d#| j| jf ��d$S )%a4 This logs the user into the given server.
It uses
'original_prompt' to try to find the prompt right after login. When it
finds the prompt it immediately tries to reset the prompt to something
more easily matched. The default 'original_prompt' is very optimistic
and is easily fooled. It's more reliable to try to match the original
prompt as exactly as possible to prevent false matches by server
strings such as the "Message Of The Day". On many systems you can
disable the MOTD on the remote server by creating a zero-length file
called :file:`~/.hushlogin` on the remote server. If a prompt cannot be found
then this will not necessarily cause the login to fail. In the case of
a timeout when looking for the prompt we assume that the original
prompt was so weird that we could not match it, so we use a few tricks
to guess when we have reached the prompt. Then we hope for the best and
blindly try to reset the prompt to something more unique. If that fails
then login() raises an :class:`ExceptionPxssh` exception.
In some situations it is not possible or desirable to reset the
original prompt. In this case, pass ``auto_prompt_reset=False`` to
inhibit setting the prompt to the UNIQUE_PROMPT. Remember that pxssh
uses a unique prompt in the :meth:`prompt` method. If the original prompt is
not reset then this will disable the :meth:`prompt` method unless you
manually set the :attr:`PROMPT` attribute.
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<listcomp> s z pxssh.login.<locals>.<listcomp>z -qz) -o'NoHostAuthenticationForLocalhost=yes'� Nz -p %sz private ssh key does not existz -i %szssh %s -l %s %sz0(?i)are you sure you want to continue connectingz((?i)(?:password:)|(?:passphrase for key)z(?i)permission deniedz(?i)terminal typez$(?i)connection closed by remote host)r r �yes� � � z&Could not establish connection to hostz-Weird error. Got "are you sure" prompt twice.r# zpassword refused� zpermission deniedz.Weird error. Got "terminal type" prompt twice.� � zconnection closedzunexpected login responsez*could not synchronize with original promptz8could not set shell prompt (received: %r, expected: %r).T)�joinr! �itemsr r �str�os�path�isfiler r Z_spawn�expectr r r5 �closer9 �set_unique_promptZbeforer )r" ZserverZusernameZpasswordZ
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login_timeoutZportZauto_prompt_resetZssh_key�quietr7 Zcheck_local_ipZ ssh_options�cmdr+ r r r
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z pxssh.loginc C s@ | j d� | jtdg�}|dkr4| j d� | jt� | j� dS )zuSends exit to the remote shell.
If there are stopped jobs then this automatically sends exit twice.
�exitz(?i)there are stopped jobsr# N)r5 rP r rQ )r" �indexr r r
�logout[ s
z pxssh.logoutc C s2 |dkr| j }| j| jtg|d�}|dkr.dS dS )a� Match the next shell prompt.
This is little more than a short-cut to the :meth:`~pexpect.spawn.expect`
method. Note that if you called :meth:`login` with
``auto_prompt_reset=False``, then before calling :meth:`prompt` you must
set the :attr:`PROMPT` attribute to a regex that it will use for
matching the prompt.
Calling :meth:`prompt` will erase the contents of the :attr:`before`
attribute even if no prompt is ever matched. If timeout is not given or
it is set to -1 then self.timeout is used.
:return: True if the shell prompt was matched, False if the timeout was
reached.
r# )r FT���)r rP r r )r" r r+ r r r
r2 g s z pxssh.promptc C sb | j d� | j | j� | jt| jgdd�}|dkr^| j | j� | jt| jgdd�}|dkr^dS dS )a} This sets the remote prompt to something more unique than ``#`` or ``$``.
This makes it easier for the :meth:`prompt` method to match the shell prompt
unambiguously. This method is called automatically by the :meth:`login`
method, but you may want to call it manually if you somehow reset the
shell prompt. For example, if you 'su' to a different user then you
will need to manually reset the prompt. This sends shell commands to
the remote host to set the prompt, so this assumes the remote host is
ready to receive commands.
Alternatively, you may use your own prompt pattern. In this case you
should call :meth:`login` with ``auto_prompt_reset=False``; then set the
:attr:`PROMPT` attribute to a regular expression. After that, the
:meth:`prompt` method will try to match your prompt pattern.
zunset PROMPT_COMMANDr= )r r FT)r5 r rP r r r )r" r+ r r r
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