It’s pretty common for me to execute the same commands on a remote machine everyday. I usually do something like:
$ ssh <machine.domain.com>
$ screen -x # reattach to irssi screen session
The most obvious optimization to make is to edit the ~/.ssh/config file to
alias machine.domain.com to something easier to type, like just machine.
Now I can just type:
$ ssh machine
$ screen -x
Of course, it would be nice if I didn’t have to type screen -x each time as
well. We can solve this by passing the commands to run on the remote maching
as arguments to the ssh command. So we try:
$ ssh machine 'screen -x '
Must be connected to a terminal.
Uh oh. The remote machine is unable to start screen because, by default, a tty
(a pseudoterminal), isn’t created when we execute remote commands. To work
around this we need to pass the magic -t option. This forces the remote
machine to create a tty for us.
$ ssh machine -t 'screen -x '
Voila! Worked like a charm. And this is useful for a bunch of typical commands you’d like to run on a remote server, for example:
$ ssh machine -t 'top' # grab stats
$ ssh machine -t 'watch ps -eaf | grep <blah>'
The final optimization we can make is to alias the whole command to something
easier to type. Since I like to keep my aliases in a separate
~/.bash_aliases file, I’d run:
$ echo alias irc='ssh machine -t "screen -x"' >> ~/.bash_aliases
Now, all I have to do is type irc each morning and I’m right back into my IRC
session.