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Full Discussion: Strange result of eval, how does eval really work with ssh?
Top Forums Shell Programming and Scripting Strange result of eval, how does eval really work with ssh? Post 302519466 by summer_cherry on Wednesday 4th of May 2011 05:22:54 AM
Old 05-04-2011
Strange result of eval, how does eval really work with ssh?
Hi all,

some small script with eval turned me to crazy.

my OS is linux
Code:
Linux s10-1310 2.6.16.53-0.8.PTF.434477.3.TDC.0-smp #1 SMP Fri Aug 31 06:07:27 PDT 2007 x86_64 x86_64 x86_64 GNU/Linux

below script works well
Code:
#!/bin/bash
eval ssh remotehost date
eval ssh remotehost ls

below script works also well
Code:
echo "ls
ls -l" | while read line;do
eval $line
done

then below script has issue that only first line of command got executed
Code:
echo "ssh remotehost date
ssh remotehost ls" | while read line;do
eval $line
done

i was thinking maybe eval break the loop, but below script do print out the "-----" line

Code:
echo "ssh remotehost date
ssh remotehost ls" | while read line;do
eval $line
echo "----"
done

so what wrong here, please kindly help.
Last edited by summer_cherry; 05-04-2011 at 06:26 AM.. Reason: wrong title
 

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LEARN ABOUT MOJAVE

ssh-argv0

SSH-ARGV0(1)                                                BSD General Commands Manual                                               SSH-ARGV0(1)

NAME

     ssh-argv0 -- replaces the old ssh command-name as hostname handling

SYNOPSIS

     hostname | user@hostname [-l login_name] [command]

     hostname | user@hostname [-afgknqstvxACNTX1246] [-b bind_address] [-c cipher_spec] [-e escape_char] [-i identity_file] [-l login_name]
     [-m mac_spec] [-o option] [-p port] [-F configfile] [-L port:host:hostport] [-R port:host:hostport] [-D port] [command]

DESCRIPTION

     ssh-argv0 replaces the old ssh command-name as hostname handling.  If you link to this script with a hostname then executing the link is
     equivalent to having executed ssh with that hostname as an argument.  All other arguments are passed to ssh and will be processed normally.

OPTIONS

     See ssh(1).

FILES

     See ssh(1).

AUTHORS

     OpenSSH is a derivative of the original and free ssh 1.2.12 release by Tatu Ylonen.  Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos,
     Theo de Raadt and Dug Song removed many bugs, re-added newer features and created OpenSSH.  Markus Friedl contributed the support for SSH
     protocol versions 1.5 and 2.0.  Jonathan Amery wrote this ssh-argv0 script and the associated documentation.

SEE ALSO

     ssh(1)

Debian Project                                                   September 7, 2001                                                  Debian Project
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