topic Re: Running cmds via SSH in Operating System - HP-UX

Running cmds via SSH

PatRoy — Tue, 15 Aug 2006 14:12:21 GMT

Hello.

I'm trying to issue the following cmd via SSH.

ssh -n hostname /usr/sbin/ioscan -funC disk | while read a b; do [[ $b = /dev/rdsk/* ]] && /usr/sbin/diskinfo $b; done | sed '/vendor/d'

This doesn't work because instead of launching the 'diskinfo' on the remote host, it's launched in the localshell, trying to diskinfo devices that might not exist on localhost!

The fix is to put the entire cmd between quotes like so:

ssh -n hostname '/usr/sbin/ioscan -funC disk | while read a b; do [[ $b = /dev/rdsk/* ]] && /usr/sbin/diskinfo $b; done | sed '/vendor/d''

HOWEVER, this is where I've got a problem. My sed part already uses single quotes, and I cannot escape them. If I remove the sed part, all works exactly has expected!

I'm trying to see how this can be accomplised *without* the need to write a script on the remote servers...

P.s.: don't question on why that cmd.. I know it's pretty useless. It's just an example of some things I'd like to do...

Regards,
Patrick

Re: Running cmds via SSH

Patrick Wallek — Tue, 15 Aug 2006 14:16:21 GMT

Patrick,

Use double quotes instead.

ssh -n hostname "/usr/sbin/ioscan -funC disk | while read a b; do [[ $b = /dev/rdsk/* ]] && /usr/sbin/diskinfo $b; done | sed '/vendor/d'"

Re: Running cmds via SSH

PatRoy — Tue, 15 Aug 2006 14:20:23 GMT

I already thought of that and no that doesn't work either:

sh: Syntax error at line 1 : `/dev/rdsk/*' is not expected.

is what I get in return

Re: Running cmds via SSH

spex — Tue, 15 Aug 2006 14:20:42 GMT

Hi,

In the example you gave, the sed command works without quotes:

ssh -n hostname '/usr/sbin/ioscan -funC disk | while read a b; do [[ $b = /dev/rdsk/* ]] && /usr/sbin/diskinfo $b; done | sed /vendor/d'

PCS

Re: Running cmds via SSH

Steven E. Protter — Tue, 15 Aug 2006 14:21:15 GMT

Shalom Patrick,

Few things to look at.

Some systems don't provide environment properly, so make sure PATH and such is set.

Enclose commands in double quotes.

Example:

ssh root@hostname "ls -lrt *.iso"

For complex commands including say awk the \ for special characters will permit quotes within quotes.

SEP

Re: Running cmds via SSH

PatRoy — Tue, 15 Aug 2006 14:26:03 GMT

You're right! it does work.

But now, what if I wanted to add an

awk '{print $2}'

?

I need to do a bunch a little scripts which collects various server information from approx. 17-18 servers.. (i.e BDFs, vgdisplay, etc.). That's why I need a bunch of theses...

Re: Running cmds via SSH

PatRoy — Tue, 15 Aug 2006 14:30:00 GMT

Steven E. Protter, no in cannot use '\' to escape my quotes. I've already tried that...

and has for having double quotes and even trying to escape my single quote won't do:

ssh -n host "/usr/sbin/ioscan -funC disk | while read a b; do [[ $b = /dev/rdsk/* ]] && /usr/sbin/diskinfo $b; done | awk \'{print $2}\'"

gives me:
sh: 2: Parameter not set

Re: Running cmds via SSH

spex — Tue, 15 Aug 2006 14:39:16 GMT

Patrick,

Use double-quotes, then single-quotes, and escape special characters, such as $.

Also, I believe the error you reported in your second posting was caused by not escaping (\) the LF between lines.

PCS

Re: Running cmds via SSH

PatRoy — Tue, 15 Aug 2006 14:45:35 GMT

spex, you've got it.

the following worked:

ssh -n host "/usr/sbin/ioscan -funC disk | while read a b; do [[ \$b = /dev/rdsk/* ]] && /usr/sbin/diskinfo \$b; done | awk '{print \$1}'"

and so does something like:

ssh -n host "/usr/sbin/ioscan -funC disk | while read a b; do [[ \$b = /dev/rdsk/* ]] && /usr/sbin/diskinfo \$b; done | sed '/vendor/d'"

so basically, when using double quotes, it's only $ I need to escape, and not the ' single quotes.

thanks again!

Re: Running cmds via SSH

PatRoy — Tue, 15 Aug 2006 14:56:38 GMT

as per last msg.