SSH Bash Loop

m1ck · 01-31-2007, 08:26 AM

Hi All,

I'm trying to do a loop that will ssh onto a list of nodes and print to a file the current processes of that node. I currently have the following but for some reason its only doing the first node in my list. Is there something wrong with the ssh line? (I've cut the print statement down so its easier to read)

Any advice appreciated.

Code:

while read uplist

do

	ssh $uplist ps aux | awk '$1 != "root" {print $1}' >> processes

	
done < uplist

exit

matthewg42 · 01-31-2007, 09:27 AM

Can you show a section of the uplist file? The "while read" loop will want the input as one input per line of the file.

m1ck · 01-31-2007, 09:31 AM

Its a list of IP's one line after the other....

149.x.x.x
149.x.x.x
149.x.x.x
149.x.x.x
149.x.x.x
149.x.x.x
etc....

m1ck · 01-31-2007, 09:37 AM

I've worked it out after some googling...

I needed the -n in my ssh line so that ssh didn't read from standard input

.

Thanks

m1ck · 01-31-2007, 09:44 AM

One more quick questions -

How can I print $1 if its not equal to another username as well i.e.

ssh $uplist ps aux | awk '$1 != "root" && !="usera" {print $1}'

The above doesnt work I was just wondering is there an easy way to do it?

matthewg42 · 01-31-2007, 09:49 AM

Do it like this:

Code:

... | awk '{ if ( $1 != "root" && $1 != "usera" ) { print $1; } }'

matthewg42 · 01-31-2007, 09:52 AM

Or you could use grep to exclude lines based on a regular expression pattern. It might be cleaner if you have multiple patterns:

Code:

... | grep -v -e ^root -e ^usera -e ^userb ...

You can just add "-e pattern" clauses for each one you want to exclude. ^ just means "beginning of line"

m1ck · 01-31-2007, 10:03 AM

Thanks mate both work perfectly