CODEWITHSUNDEEP
pythonsshtelnetpexpect
vinod reddy
vinod reddy

Reputation: 133

logic in pexpect

Hi I am using pexpect in Python to read ssh device information.

expObject = pexpect.spawn('/usr/bin/ssh %s@%s' % (username, device))
expObject.sendline(password)

After giving the password I have show some device information and in command prompt it will ask press any key to continue; Once I press any key the info disappears.

I use below logic to capture other data coming after giving command like show version

    expObject.expect(CLI_PROMPT)
    data = expObject.before

So how do I capture the data which is displayed after giving password and before pressing any key to comtinue using "expObject".

Upvotes: 0

Views: 1145

Answers (2)

Ivo Bosticky
Ivo Bosticky

Reputation: 6408

I had a similar problem where I needed the handle the text output line by line. To get this to work, you have to be aware that pexpect configures regexp such that .* pattern includes linefeeds, so instead of .* you have to use [^\n]* . Something like this should work in your situation:

child = pexpect.spawn('ssh command goes here')
child.expect('password prompt text\r\n')
child.sendline(password)
data = ""
while True:
    i = child.expect(['press any key to continue', '[^\n]*\r\n'])
    if i == 0:
        break
    data += child.before
print data

This should work with a command that outputs the following:

password propt text
<start of data captured> - 1st line
a second line
a third line
last line <end of data that will be captured>
press any key to continue

Upvotes: 2

jdizzle
jdizzle

Reputation: 4154

http://ubuntuforums.org/showthread.php?t=220139

Is an excellent guide for exactly what you want to do. I suspect you do not actually need to use expect and can accomplish everything you want with just ssh command execution and ssh keys. For example:

hostA:~ jdizzle$ ssh hostB hostname
hostB

Here is another tutorial on ssh keys: http://pkeck.myweb.uga.edu/ssh/

Upvotes: 1

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