IO.popen and ssh

[Paul Lynch]

I've been having some trouble using IO.popen to control an ssh process
(and also mysqldump) on Linux. My understanding is that if I do:
p = IO.popen('ssh mymachine')
then the input and output of the ssh subprocess should be accessible via
p. However, when I try that in an irb shell, the ssh process
immediately takes over the standard input and output of irb, and I get
an "Enter password:" prompt. I have to hit control-c to get back to the
irb prompt.

Is there a workaround for this? Or should I be doing this a different
way? Thanks,
--Paul

 

[Edwin Van leeuwen]

Is there a workaround for this? Or should I be doing this a different
way?

Why not use Net::SSH to connect directly from ruby?
http://net-ssh.rubyforge.org/chapter-2.html#s1

 

[Paul Lynch]

That looks much better-- thanks!

Why not use Net::SSH to connect directly from ruby?
http://net-ssh.rubyforge.org/chapter-2.html#s1

 

[Konrad Meyer]

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Quoth Edwin Van leeuwen on Tuesday 11 September 2007 08:59:39 am:

=20
Why not use Net::SSH to connect directly from ruby?
http://net-ssh.rubyforge.org/chapter-2.html#s1

Because at least in my experience, it doesn't work?

=2D-=20
Konrad Meyer <[email protected]> http://konrad.sobertillnoon.com/

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[ara.t.howard]

I've been having some trouble using IO.popen to control an ssh process
(and also mysqldump) on Linux. My understanding is that if I do:
p = IO.popen('ssh mymachine')
then the input and output of the ssh subprocess should be
accessible via
p. However, when I try that in an irb shell, the ssh process
immediately takes over the standard input and output of irb, and I get
an "Enter password:" prompt. I have to hit control-c to get back
to the
irb prompt.

Is there a workaround for this? Or should I be doing this a different
way? Thanks,

ssh requires a pty to read the password. note that this is NOT the
same as STDIN, which is what you get with IO.popen. you need to use
the built-in pty lib to control ssh that way and it's still fraught
with peril. it's much, much, much, much better to setup ssh keys for
password-less access (no passwords in scripts), and to spawn a simple
command, such as /bin/sh, on the remote end to read pre-generated
commands (a script).

regards.

a @ http://drawohara.com/