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Logging in and logging out of a server in a script

Hi everyone,

I would like to be able to:
login to an execution node from a headnode of a cluster
have my job done there
logout back to the head node
scp output file to some storage server
repeat the proces in a loop

The problem is, if I put a 'logout' command in a script, I get an error "not a login shell, use 'exit'". If I use 'exit' then this command is interpreted by the shell as exiting the loop and stopping the execution of the script. Is there a way around this?
Maybe using trap to trap a signal or something? I am out of options
- my bash scripting skills are not very refined.

Thanks.

Code:

for i in true;

do

  ssh user@node -C "command; command2; ... " >> node.out 2>&1

done

No need to log-in and out, all very tidy.

Cheers,
Tink

Tinkster,

Thanks for the reply. No disrespect, but your suggestion kinda screwed me over. Putting my commands in the quotations deleted all my data files. Fortunately I backed them up beforehand. I ended up using your suggestion for the quotes (thanks for that), but I put all the stuff from inside the quotes in another script and run it that way. It worked.

I have no idea how did I manage to erase everything, and actually, I'd appreciate if someone could explain to me what went wrong.

This is what happened: I have 20 directories called
anneal_1 to anneal_20. Each one has different number of data files called si.001 to si.0** (stars are some nubers). I needed to pick up an si.0** file (from each anneal_* directory) that has the highest number in its name, and then execute simulation on that file. So this is the beginning of the unsuccesfull script - the part that messed me up:

Code:

for i in `seq 1 20`

do

  rsh node10 "

  cd /to/the/appropriate/directory

  max=anneal_$i/si.001

  for j in anneal_$i/si.0*

  do

        if [ $j > $max ]

        then

                max=$j

        fi

  done

  ... " #rest of the simulation run on the node10

I get the error message

Code:

bash: line 8: [: missing `]'

twenty times. After that, all the files si.0** were empty except for the highest-numbered one, and get this: an empty file with the name " ] " showed up in the directory where script is executed (!?!?). How that happened is a great mistery to me :scratch: . Some weird redirection was done by the '>' character. Actually, without the quotation marks that I use to submit job to the execution node, it works as it's supposed to.

Sorry about your loss of data ... I never said I knew what
you're doing, and that my approach was safe for that.

What is your users default shell on the remote node?

Cheers,
Tink

it's bash, version 3.00. I don't know if I made it clear, but,
when I regularly log in the exec. node and run this script bit, it works fine.