How to auto login ssh server and run some command to modify a file.

Question

Here is the limitations:

1. No public key file uploaded to server (since this may be run at different target machine), this is just for an automatic testing program, so security is not a concern.
2. It's automatically program run background, so no user input.
3. I do not want to use "expect" which require user to install.
4. I have know the root user's password.

So I wonder is that a lightweight expect tool or a ssh library I can easily use to do such work.

Answer 1

The only properly secure way is with an exported SSH public key file, where every client and every server have been verified - otherwise, what's to stop Mr. Havingabadday from exploiting the system?

Answer 2

libssh http://www.libssh.org/ can help for a C project. Using Perl, there is a module which can be used: Net::SSH (I use it for +/- the same kind of purposes)