Script to conditionally copy from network

Peterken · 08-13-2013, 05:42 PM

Hi guys,

Currently I'm using the autostart file to get a few things done but this is to restricted.
One of the commands is to copy some files from a networklocation so the local version of these files are always up-to-date and the system is not depending on the network.
Of course this should have gone wrong once because of network not available so now I would like to have a script that checks the availability of the network.
If present, the system should delete the local version of a few files.
If network source is not present, no files have to be deleted and just continue.
My scripting knowledge is mainly wintel based and if someone could pull this out of his sleeve, I would appreciate it big time (have no time/energy to figure this out right now)
I do know about the first line in scripts + how to make the script executable.

One other question regarding on how to create a script: is it not possible on linux to run a script by typing the commands just like in windows?

If there is a better way to synchronize a folder in one direction, that's more then welcome. I have searched for this but didn't find a way to get this done.

TIA!

Ser Olmy · 08-13-2013, 06:00 PM

Quote:

Originally Posted by Peterken

If there is a better way to synchronize a folder in one direction, that's more then welcome.

There is: rsync

You didn't say what sort of network protocol is used to communicate with the network server, nor what kind of server it is, so rsync may or may not be a feasible solution. If it's not, more details about the setup are needed in order to make a recommendation or write a sample script.

But yes, scripts can be just a set of commands as typed on the command line, and you can run any script from the command line. It's just like in Windows, only about an order of magnitude better.

Firerat · 08-13-2013, 06:03 PM

two words

man rsync

Kustom42 · 08-13-2013, 06:06 PM

So LQ just wiped my post out. awesome.

Im not going to retype everything I did because im a little PO'ed at LQ for doing that lol, use Puppet. Its designed to be a configuration management utility will work well for this and many other things you may need down the road.

Here is an example manifest of how you would declare a file that is required:

Code:

 file {'testfile':
      path    => '/tmp/testfile',
      ensure  => present,
      mode    => 0640,
      content => "I'm a test file.",
    }

http://docs.puppetlabs.com/learning/index.html

Even has a pre-packaged VM with it already installed you can just deploy and play with.

---------- Post added 08-13-13 at 04:06 PM ----------

Quote:

Originally Posted by Ser Olmy

There is: rsync

You didn't say what sort of network protocol is used to communicate with the network server, nor what kind of server it is, so rsync may or may not be a feasible solution. If it's not, more details about the setup are needed in order to make a recommendation or write a sample script.

But yes, scripts can be just a set of commands as typed on the command line, and you can run any script from the command line. It's just like in Windows, only about an order of magnitude better.

Rsync can work and the update option works sometimes but I have had experiences where rsynd did not pick up changes and update the files correctly due to file locks and other possible issues.

Peterken · 08-13-2013, 06:24 PM

Thanks a lot for your suggestions guys!

@Ser Olmy: it's a linux server but since all the clients are win boxes, the share is mounted with cifs.

To add some more details about the situation:
the files in just one folder on the server can be modified/erased/new ones added and the local version should match that.
It's for a kind of kiosk/digital signage that works independently from the network.

I'm using geeqie to diplay jpg files but apparently I have to restart the program to load the new files.
On top of that, the screens go on standby so by rebooting I check for new files & get the standby issue resolved. Maybe not very neat but it works well and I'm always open for improvements. ;-)

Firerat · 08-13-2013, 06:46 PM

Quote:

Originally Posted by Peterken

Thanks a lot for your suggestions guys!

@Ser Olmy: it's a linux server but since all the clients are win boxes, the share is mounted with cifs.

ok..

Quote:

Originally Posted by Peterken

To add some more details about the situation:
the files in just one folder on the server can be modified/erased/new ones added and the local version should match that.

who is local?
the win boxes?

Quote:

Originally Posted by Peterken

It's for a kind of kiosk/digital signage that works independently from the network.

independent, yet requires a network for 'updates'

Quote:

Originally Posted by Peterken

I'm using geeqie to diplay jpg files but apparently I have to restart the program to load the new files.

looks like geegie is 'unix'

Quote:

Originally Posted by Peterken

On top of that, the screens go on standby so by rebooting I check for new files & get the standby issue resolved. Maybe not very neat but it works well and I'm always open for improvements. ;-)

standby ?
what like a screensaver?
turn that feature off

OK, I think I understand..

you have linux boxes dotted around, they are remotes.
you have clients who want to push jpg images to your remotes
the clients use windows
when they buy a remote from you.
you add a cifs mount, so they can push content ??

hmm, second thoughts I don't understand..

anyway, cron on your remote(s) to get updates
look at power management for the standby issue
display of image?. eog will do that, and I think it will see file changes
client changes, some web interface on your server, they upload and you push