Debian GNU/Linux 2.2 flunky.example.com
flunky login:
You should then be able to log in as normal and run a session. The output sent by the server will be written straight to your command prompt window, which will most likely not interpret terminal control codes in the way the server expects it to. So if you run any full-screen applications, for example, you can expect to see strange characters appearing in your window. Interactive connections like this are not the main point of Plink.
In order to connect with a different protocol, you can give the command line options -ssh, -telnet, -rlogin or -raw. To make an SSH connection, for example:
Z:\sysosd>plink -ssh login.example.com
login as:
If you have already set up a PuTTY saved session, then instead of supplying a host name, you can give the saved session name. This allows you to use public-key authentication, specify a user name, and use most of the other features of PuTTY:
Z:\sysosd>plink my-ssh-session
Sent username "fred"
Authenticating with public key "fred@winbox"
Last login: Thu Dec 6 19:25:33 2001 from :0.0
fred@flunky:~$
(You can also use the -load command-line option to load a saved session; see
section 3.8.3.1
. If you use -load, the saved session
exists, and it specifies a hostname, you cannot also specify a host or user@host argument - it will be treated as part of the remote command.)
7.2.2 Using Plink for automated connections
More typically Plink is used with the SSH protocol, to enable you to talk directly to a program running on the server. To do this you have to ensure Plink is using the SSH protocol. You can do this in several ways:
•Use the -ssh option as described in
section 7.2.1
.
•Set up a PuTTY saved session that describes the server you are connecting to, and that also specifies the protocol as SSH.
•Set the Windows environment variable PLINK_PROTOCOL to the word ssh.
Usually Plink is not invoked directly by a user, but run automatically by another process. Therefore you typically do not want Plink to prompt you for a user name or a password.
Next, you are likely to need to avoid the various interactive prompts Plink can produce. You might be prompted to verify the host key of the server you're connecting to, to enter a user name, or to enter a password.
To avoid being prompted for the server host key when using Plink for an automated connection, you should first make a manual connection (using either of PuTTY or Plink) to the same server, verify the host key (see
section 2.2
for more information), and
select Yes to add the host key to the Registry. After that, Plink commands connecting to that server should not give a host key prompt unless the host key changes.
To avoid being prompted for a user name, you can:
•Use the -l option to specify a user name on the command line. For example, plink login.example.com -l fred.
•Set up a PuTTY saved session that describes the server you are connecting to, and that also specifies the username to log in as (see
section 4.14.1
).
To avoid being prompted for a password, you should almost certainly set up public-key authentication. (See
chapter 8
for a general
introduction to public-key authentication.) Again, you can do this in two ways:
•Set up a PuTTY saved session that describes the server you are connecting to, and that also specifies a private key file (see
section 4.21.8
). For this to work without prompting, your private key will need to have no passphrase.
•Store the private key in Pageant. See
chapter 9
for further information.