How to get the for loop output from a remote server in UNIX shell scripting?

Shell Programming and Scripting
1

Hi,

I am using ksh , when i try to use for loop i am getting the expected output.

$for variable in $(ps -fu user | grep -i something/ | grep -i something | grep -v grep | awk '{print $2}');do
> grep $variable /tmp/some_path/*/*
> done

when tried the below to remote server, getting the entire content rather than the expected output.

$for variable in $(ssh server_name "ps -fu user | grep -i something/ | grep -i something | grep -v grep | awk '{print $2}'");do
> grep $variable /tmp/some_path/*/*
> done

I tried the below to remote server , but getting the below error.

$ssh server_name "for variable in $(ps -fu user | grep -i something/ | grep -i something | grep -v grep | awk '{print $2}');do
> grep $variable /tmp/some_path/*/*;
> done"

/bin/ksh: syntax error at line 2: `31656' unexpected

I am not sure what is the syntax mistake i did in the above script.

Please advise.

Thanks,
Regards,
karthikram

2

If you have pgrep then you can probably do

pgrep -u user something

and no problem to run that as ssh argument.
If you insist in your complex commands, save them in a script command.sh
And run it remotely with

ssh -qx server_name ksh < command.sh

By passing via a stream the script commands are only interpreted by one shell (the ksh at the remote server).

1 Like
3

Thanks you very much , i came across pgrep many times but it didnt strick.

I am able to learn that if we need to run such kind of script better to save and run.

By passing via a stream the script commands are only interpreted by one shell (the ksh at the remote server).

Thanks,
Regards,
karthikram

4

You'll need to fiddle around with some serious escaping, like (and eventually more)

$ssh server_name 'for variable in $(ps -fu user | grep -i something/ | grep -i something | grep -v grep | awk "{print\ \$2}");do  grep "$variable" /tmp/some_path/*/*; done'
1 Like
5

Thank you very much , you are all great, it worked perfectly.

i made only this change to work in ksh

$ssh server_name 'for variable in $(ps -fu user | grep -i something/ | grep -i something | grep -v grep | awk "{print \$2}");do  grep "$variable" /tmp/some_path/*/*; done'

Thanks,
Regards,
karthikram