Running a command with input from a file.

[bigb89]

Hi guys,

Here's what I'm trying to do:

I have a backup server in my network that has passwordless ssh connection to all the servers in the network. I have a script called "load_checker.sh" that I wanna use to monitor the load on all the servers. Now, I wanna copy load_checker.sh to all of the servers in the network.

I have a list of all of the servers in the network, so to make my job easier, it would be alot faster if I could just run the following command from the backup server:

scp load_checker.sh user@$serverlist:/some/directory/load_checker.sh

The variable $serverlist will be all of the servers that are listed in the serverlist file. That way, load_checker.sh will be sent to every server that's listed on the file. The serverlist file will have each server separated by a line, example:

server1
server2
server3
.....

So as you guys may have noticed, I know the concept what needs to be done, but I just don't know what I have to do.

Conclusion: What would be the best way to scp load_checker.sh to all of the servers that are listed in the serverlist file?

Kind regards,
--Bigb89

[phoenix]

Start a Bourne shell (sh, bash, zsh) and use the for loop:

# for server in $( cat /path/to/serverlist ); do
scp /path/to/load_checker.sh user@${server}:/some/directory/
done

The $( ) construct tells the shell to run the command(s) between the $( ) and to substitute the values in place of the $( ).

The for loop will replace ${I} with each value returned by $( ).

[bigb89]

Thanks Phoenix!

I'm gonna try that out and see how it goes.

Regards

[IdOp]

A minor correction to phoenix' solution: Replace ${I} with ${server} .

[phoenix]

D'oh! Can you tell how I usually setup my for loops?

Post has been corrected.