UNIX for Advanced & Expert Users

Im trying to transfers a file from one unix server to another , make some changes and then send it back to the original server. All this using modems.

I've been using "cu" and i can "get" the file but i can't "put" it. Besides I need to do this using a shell script. I can write a script to get te file but i can´t do it for put the file. Is there another way to move files than cu?

In cu, instead of "get", which is not a command that "cu" knows, you need to use "take". Same concept, just a different name from the command.

With "expect", a popular public domain package, you can automate cu.

There is also uucp, which will work great once it's set up. And if have cu running, you're part way there. The learning curve to setting up uucp is a little steep. And getting help may be hard...it's been over 10 years since I last worked with uucp and I can't imagine that many people are still using it. The O'Rielly book on uucp was a big help, but I'm not sure if it's still in print.

There are packages like SLIP and PPP that can run tcp/ip over modems, but I get the impression that tcp/ip is not an option?

How about using SCP: secure copy?

I dont know if it will work, could you explain a little more

Secure Copy can transfer files like the 'rcp' command but uses an encrypted 'tunnel' to send the data through. It is thus safe from intruders and snoopers. You need SSH software for it (OpenSSH) and a set of SSH keys (1 public and 1 private key) that are used to authenticate your scp or ssh (secure shell).