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Full Discussion: Need help on for loop inside ssh
Operating Systems AIX Need help on for loop inside ssh Post 302908884 by bakunin on Friday 11th of July 2014 05:28:35 AM
Old 07-11-2014
Quote:
Originally Posted by sumanthupar
when I run the below comamnd locally it will work fine,

Code:
IFS=$'\n'; for i in $(cat file) ;do echo "HI $i" ; done

But when i run the same command inside ssh,

Code:
ssh root@IPaddress "IFS=$'\n'; for i in $(cat file) ;do echo "HI $i" ; done"

Think it over: when you do a "ssh machine command", then "command" will be executed on the remote host, not your local one. If "command" is something like "for x in $(cat file) ...", then you are referring to a remote file, not a local one!

if you want to process a file locally and start ssh-sessions remotely using the content of the file you have to do the loop locally. The following sketch shows how:

Code:
while read LINE ; do
     ssh user@host "do_something_with $LINE"
done < /path/to/some/file

A second problem is your use of double quotes. You see, a shell maintains a simple switch "inside/outside a double quote" and once it encounters such a character this switch is flipped. Therefore double quotes cannot be nested. You will have to escape the inner pair to make your command work:

Code:
ssh root@IPaddress "IFS=$'\n'; for i in $(cat file) ;do echo \"HI $i\" ; done"

(which will - as explained above - still not work, but for a different reason)

I hope this helps.

bakunin
 

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LEARN ABOUT FREEBSD

ssh-keysign

SSH-KEYSIGN(8)						    BSD System Manager's Manual 					    SSH-KEYSIGN(8)

NAME

     ssh-keysign -- ssh helper program for host-based authentication

SYNOPSIS

     ssh-keysign

DESCRIPTION

     ssh-keysign is used by ssh(1) to access the local host keys and generate the digital signature required during host-based authentication with
     SSH protocol version 2.

     ssh-keysign is disabled by default and can only be enabled in the global client configuration file /etc/ssh/ssh_config by setting
     EnableSSHKeysign to ``yes''.

     ssh-keysign is not intended to be invoked by the user, but from ssh(1).  See ssh(1) and sshd(8) for more information about host-based authen-
     tication.

FILES

     /etc/ssh/ssh_config
	     Controls whether ssh-keysign is enabled.

     /etc/ssh/ssh_host_dsa_key
     /etc/ssh/ssh_host_ecdsa_key
     /etc/ssh/ssh_host_ed25519_key
     /etc/ssh/ssh_host_rsa_key
	     These files contain the private parts of the host keys used to generate the digital signature.  They should be owned by root, read-
	     able only by root, and not accessible to others.  Since they are readable only by root, ssh-keysign must be set-uid root if host-
	     based authentication is used.

     /etc/ssh/ssh_host_dsa_key-cert.pub
     /etc/ssh/ssh_host_ecdsa_key-cert.pub
     /etc/ssh/ssh_host_ed25519_key-cert.pub
     /etc/ssh/ssh_host_rsa_key-cert.pub
	     If these files exist they are assumed to contain public certificate information corresponding with the private keys above.

SEE ALSO

     ssh(1), ssh-keygen(1), ssh_config(5), sshd(8)

HISTORY

     ssh-keysign first appeared in OpenBSD 3.2.

AUTHORS

     Markus Friedl <markus@openbsd.org>

BSD
								 December 7, 2013							       BSD
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