Hello all,

I'm new to the forums, so if this is the wrong place to post this, please let me know. I've also done a few searches and didn't get an answer, so I do apologize if this has been covered.

Here's what I'm trying to do...

We use a compute farm to calculate and process the request from a main application...Basically this means sometimes having to make the same add/change/delete to a whole bunch of machines.

What I usually do is terminal into 1 box, and then ssh into the subsequent boxes to make the changes...As you can guess, it's tedious.

I've tried to script the process of ssh'ing to the boxes and the commands, but I'm doing something wrong...I'm doing something like:

------------
#!/bin/bash

SERVERS=`cat /usr/servers.txt` #has list of the machines to be updated

for i in $SERVERS
do

ssh $i
cd /directory
rm file.txt
exit

done
-------------

The commands aren't making their way to each of the boxes I'm ssh'ing to. What am I doing wrong?

thanks much!

Welcome to LQ.

All of the commands that you place in your bash script will be run on the local box so it is trying to cd and rm on your machine. To run a command on a remote box you can use the syntax:
ssh user@host command

If you want to run a whole script on a remote box then a good technique is to upload the script that is to be run remotely to a web server. Then when you execute the ssh command - use:
ssh user@host "wget -qO - http://www.yourhost.com/script.sh | sh"

This will download "script.sh" and run it on the server that you ssh to. This is also quite useful for automatic updates as you can schedule the wget command using cron.

Thanks for the reply,

One of the local gurus here helped me out with this, he said to use a 'here' redirect? something like this...

-------------
SERVERS=`cat servers.txt`

for i in $SERVERS
do
ssh i$ <<-EOF
command
EOF
done