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# 1  
Old 08-19-2014
Remote while IFS
Hello masters of scripting,

I've been working to develop some basic monitoring scripts. I have solved one problem, but want to know how to solve the other.

I have a script that runs locally to create an output file with the Linux system kernel paramters, preceeded by the system name:

Local Script:
Code:
HOST="$(/bin/hostname)"
KPARMS=$(sysctl -a)
OUTFILE=/var/tmp/sysctl.txt

while IFS= read
do
  echo "${HOST} : ${REPLY}"
done <<< "${KPARMS}" > ${OUTFILE}

An example snippet of the output from the local /var/tmp/sysctl.txt is as follows:


Code:
server1 : sunrpc.max_resvport  =  1023
server1 : sunrpc.min_resvport  =  665
server1 : sunrpc.tcp_slot_table_entries  =  16
server1 : sunrpc.udp_slot_table_entries  =  16

The problem is that I want to turn this into a remotely-executed script. So far I have the following
Code:
#!/bin/ksh

#HOST="$(/bin/hostname)"
HOST="server1"
KPARMS=$(/sbin/sysctl -a)
OUTFILE=/var/tmp/sysctl.txt

ssh -B ${HOST} "while IFS= read ; do echo \"${HOST} : ${REPLY}\"; done <<< \"${KPARMS}\" > ${OUTFILE} ; cat ${OUTFILE}"

Here is the output from /var/tmp/sysctl.txt on the remote server:
Code:
server1 :

How can I correct this?

Thanks in advance for any insight you can provide.
Last edited by rbatte1; 08-19-2014 at 01:45 PM..
# 2  
Old 08-19-2014
I think what you have done here is to execute the command /sbin/sysctl -a in your script before calling the ssh to run this on the remote server.

Try this (untested) adjustment:-
Code:
#!/bin/ksh

#HOST="$(/bin/hostname)"
HOST="server1"
KPARMS="\$(/sbin/sysctl -a)"
OUTFILE=/var/tmp/sysctl.txt

ssh -B ${HOST} "while IFS= read ; do echo \"${HOST} : ${REPLY}\"; done <<< \"${KPARMS}\" > ${OUTFILE} ; cat ${OUTFILE}"

Does that help?



Robin
# 3  
Old 08-19-2014
Hello rbattle,

That helps a little. It seems instead of getting one line of:

Code:
server1 :

I got a line for every variable, but no output from sysctl -a:

Code:
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :
server1 :

etc...

---------- Post updated at 12:34 PM ---------- Previous update was at 12:07 PM ----------

I came up with this and it seems to have worked:

Code:
#!/bin/ksh

OUTFILE=/output/sysctl.txt

for HOST in $(head -14 /server_list | sort)
 do
   KPARMS="$(ssh -B ${HOST} '/sbin/sysctl -a')"
   while IFS= read
    do
      echo "${HOST} : ${REPLY}"
   done <<< "${KPARMS}"
done > "${OUTFILE}"

This User Gave Thanks to LinuxRacr For This Post:
rbatte1
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