topic Getting remote variables more efficiently in Operating System - HP-UX

Getting remote variables more efficiently

Patrick Ware_1 — Mon, 12 Jul 2010 15:15:08 GMT

Hello all,

I have a script that has to get variables remotely. Rather than having the script login to the remote server 3 separate times, is there a faster way to get each variable?

CODE
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##Server comes from input or list##

CHKINSTALL=`ssh server "swlist | grep -i program" | grep -v Running | awk '{print $1}'`
CHKVERSION=`ssh server "swlist | grep -i program" | grep -v Running | awk '{print $2}'`
CFEPROCESS=`ssh server "ps -ef | grep -i program > /dev/null ; echo $?" | grep -v -e grep -e Running`

Re: Getting remote variables more efficiently

James R. Ferguson — Mon, 12 Jul 2010 15:45:42 GMT

Hi:

Perhaps (by example):

# ssh myserver -n 'MODEL=$(model);HOST=$(echo $(hostname));UNAME=$(uname -a);echo "${MODEL}:${HOST}:${UNAME}"'

Regards!

...JRF...

Re: Getting remote variables more efficiently

Bill Hassell — Tue, 13 Jul 2010 01:23:07 GMT

Variables (shells such as ksh and HP's POSIX sh) can hold megabytes of data. Put everything in one variable and then parse locally at memory speeds:

SWLISTOUT=$(ssh server /usr/sbin/swlist)
CHKINSTALL=$(echo "$SWLISTOUT" | grep -i program | grep -v Running | awk '{print $1}')
CHKVERSION=$(echo "$SWLISTOUT" | grep -i program | grep -v Running | awk '{print $2}')

Grave accents `` are obsolete and deprecated in the man pages. Use $(command...) instead.

ps|grep is full of mistakes. Use ps to locate programs by name using the UNIX95 variable to activate -C and -o features:

CFEPROCESS=$(ssh server UNIX95=1 ps -C program -o pid= -oargs=)

Re: Getting remote variables more efficiently

Patrick Ware_1 — Fri, 16 Jul 2010 18:27:33 GMT

Thanks for the replies.

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CFEPROCESS=$(ssh server UNIX95=1 ps -C program -o pid= -oargs=

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Bill, I've never used the UNIX95 command. I noticed the flags you used for the pid and other arguments. Is the "-o pid=" required?

Re: Getting remote variables more efficiently

Steven E. Protter — Fri, 16 Jul 2010 18:44:25 GMT

Shalom,

Bill's UNIX95 argument is required for values on his recommended ps command.

Without setting the variable, you won't get the data.

First time I saw this, I got all excited and set UNIX95 in my /etc/profile . That was a bad idea, as it broke several things on the system.

You need UNIX95 for the command Bill recommends.

SEP

Re: Getting remote variables more efficiently

Bill Hassell — Fri, 16 Jul 2010 18:55:31 GMT

> Bill, I've never used the UNIX95 command. I noticed the flags you used for the pid and other arguments. Is the "-o pid=" required?

UNIX95 is a variable, not a command. It is an underutilized feature of the shell that you can temporarily assign a variable for the duration of the command by making the assignment in front of a command. UNIX95 (when defined) enables 3 VERY useful options:

-C exact-process-name
-H show hierarchy of parents and children
-o make your own customized ps command

-C is the only way to stop grep failures -- let ps find the process in the kernel's process table. So ps -C sh and ps -C ksh will get exact matches.

-o allows you to choose the columns you want in the output. The optional = sign says use this label instead of the default, and with nothing following the two option= arguments, ps removes the title line completely, perfect for scripting.