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Full Discussion: Why this script is not working as 'expected' when doing ssh with while read ... really confused?
Top Forums UNIX for Beginners Questions & Answers Why this script is not working as 'expected' when doing ssh with while read ... really confused? Post 303035057 by RudiC on Monday 13th of May 2019 07:39:58 AM
Old 05-13-2019
My first guess is that the while read opens the input and reads the first line, then ssh consumes all the residual lines from the input file. Try ssh -n.


But - the approach to loop through the input file and opening an ssh session for every single entry is resource hungry and far from optimal. How about creating a "search" file and running the grep from it in a single session?
 

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LEARN ABOUT DEBIAN

knife-ssh

KNIFE-SSH(1)							    Chef Manual 						      KNIFE-SSH(1)

NAME

       knife-ssh - Run a command or interactive session on multiple remote hosts

SYNOPSIS

       knife ssh QUERY COMMAND (options)

       -a, --attribute ATTR
	      The attribute to use for opening the connection - default is fqdn

       -C, --concurrency NUM
	      The number of concurrent connections

       -m, --manual-list
	      QUERY is a space separated list of servers

       -P, --ssh-password PASSWORD
	      The ssh password

       -x, --ssh-user USERNAME
	      The ssh username

       -i, --identity-file IDENTITY_FILE
	      The SSH identity file used for authentication

       -p, --ssh-port PORT
	      The ssh port

       --[no-]host-key-verify
	      Verify host key, enabled by default.

DESCRIPTION

       The  ssh  sub-command  opens  an  ssh  session  to each of the nodes in the search results of the QUERY. This sub-command requires that the
       net-ssh-multi and highline Ruby libraries are installed. On Debian systems, these are the libnet-ssh-multi-ruby and libhighline-ruby  pack-
       ages. They can also be installed as RubyGems (net-ssh-multi and highline, respectively).

TERMINAL MULTIPLEXING AND TERMINAL TAB SUPPORT

       knife  ssh integrates with several terminal multiplexer programs to provide a more convenient means of managing multiple ssh sessions. When
       the COMMAND option matches one of these, knife ssh will create multiple interactive ssh sessions running locally  in  the  terminal  multi-
       plexer instead of invoking the command on the remote host.

       The available multiplexers are:

       interactive
	      A built-in multiplexer. interactive supports running commands on a subset of the connected hosts in parallel

       screen(1)
	      Runs ssh interactively inside screen. ~/.screenrc will be sourced if it exists.

       tmux(1)
	      Runs ssh interactively inside tmux.

       macterm (Mac OS X only)
	      Opens  a	Terminal.app  window and creates a tab for each ssh session. You must install the rb-appscript gem before you can use this
	      option.

SEE ALSO

       knife-search(1)

AUTHOR

       Chef was written by Adam Jacob adam@opscode.com with many contributions from the community.

DOCUMENTATION

       This manual page was written by Joshua Timberman joshua@opscode.com. Permission is granted to copy, distribute and / or modify  this  docu-
       ment under the terms of the Apache 2.0 License.

CHEF

       Knife is distributed with Chef. http://wiki.opscode.com/display/chef/Home

Chef 10.12.0							     June 2012							      KNIFE-SSH(1)
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