I have desktop computer and a notebook where I work modifying the same files with the same programs. I want to automatically synchronize the changes I make in any of those.
I'm wondering if there exists some already coded script that makes this job or, if there isn't any, the commands to compare the creation of the files of interests in both computers via ssh and replaces the older ones with the newer ones.
Example:
I modify /home/text.txt file in the notebook and before shutting it off I want to execute a script that automatically saves the text.txt file into my desktop computer /home/text.txt becoase one is newer than the other
The bi-directional synchronizer unison comes to mind, and doesn't require internet access (although it does require a network connection between your two systems).
The easiest solution would be to use Dropbox.
Install it on both, create an account, and login. Problem solved.
Related
I'm only partially familiar with shell and my command line, but I understand the usage of * when uploading and downloading files.
My question is this: If I have updated multiple files within my website's directory on my local device, is there some simple way to re-upload every file and directory through the put command to just update every single file and place files not previously there?
I'd imagine that i'd have to somehow
put */ (to put all of the directories)
put * (to put all of the files)
and change permissions accordingly
It may also be in my best interests to first clear the directory to I have a true update, but then there's the problem of resetting all permissions for every file and directory. I would think it would work in a similar manner, but I've had problems with it and I do not understand the use of the -r recursive option.
Basically such functionality is perfected within the rsync tool. And that tool can also be used in a "secure shell way"; as lined out in this tutorial.
As an alternative, you could also look into sshfs. That is a utility that allows you to "mount" a remote file system (using ssh) in your local system. So it would be completely transparent to rsync that it is syncing a local and a remote file system; for rsync, you would just be syncing to different directories!
Long story short: don't even think about implementing such "sync" code yourself. Yes, rsync itself requires some studying, as many unix tools it is extremely powerful; thus you have to be very diligent when using it. But thing is: this is a robust, well tested tool. The time required to learn about it will pay out pretty quickly.
My task is to sync folders between two computers. One which acts as a windows server which is the host and the other one is a linux based server. The file transfer has to be secure and encrypted. Are there are any free softwares which will help me do this task.
Additionally the syncing should automatically happen after every pre decided interval.
I have a recollection that WinSCP can be invoked through command line. There, you have the option to synchronize folders (and the whole hierarchy there in). It may be worth trying.
Total Commander also has FTP/SFTP capabilities, but I'm not sure you can invoke it through command line.
One point to consider: If the process is to run automatically, you need to hard-code the username and password for the connection. There your security becomes compromised.
I am trying to make an application that runs submitted scripts, and would like to try to sandbox the submitted scripts. The scripts need to be able to be able to read in a certain directory (and in all of its subdirectories), but shouldn't be able to write at all, and, other than being able to read, should not be able to do anything that could not be done in a browser (ie download files using http). How would I go about doing this?
I don't think Node has this capability built in, but you should be able to run an "unsandboxed" Node on a *nix operating system as a severely restricted user (might be possible in other OSes too, I'm not sure). You might also want to look at Node's VM module.
Eventually, I decided on using the vm node module. I basically just made a namespace that the script running in the sandbox could use that would filter out malicious requests / requests that ought to be out of the bounds of the sandbox. The namebox included fs methods that would be necessary, but failed to execute any of the ones that would modify any directory other than the certain one that I wished the script to be able to modify.
We have a set of Mac machines (mostly PPC) that are used for running Java applications for experiments. The applications consist of folders with a bunch of jar files, some documentation, and some shell scripts.
I'd like to be able to push out new version of our experiments to a directory on one Linux server, and then instruct the Macs to update their versions, or retrieve an entire new experiment if they don't yet have it.
../deployment/
../deployment/experiment1/
../deployment/experiment2/
and so on
I'd like to come up with a way to automate the update process. The Macs are not always on, and they have their IP addresses assigned by DHCP, so the server (which has a domain name) can't contact them directly. I imagine that I would need some sort of daemon running full-time on the Macs, pinging the server every minute or so, to find out whether some "experiments have been updated" announcement has been set.
Can anyone think of an efficient way to manage this? Solutions can involve either existing Mac applications, or shell scripts that I can write.
You might have some success with a simple Subversion setup; if you have the dev tools on your farm of Macs, then they'll already have Subversion installed.
Your script is as simple as running svn up on the deployment directory as often as you want and checking your changes in to the Subversion server from your machine. You can do this without any special setup on the server.
If you don't care about history and a version control system seems too "heavy", the traditional Unix tool for this is called rsync, and there's lots of information on its website.
Perhaps you're looking for a solution that doesn't involve any polling; in that case, maybe you could have a process that runs on each Mac and registers a local network Bonjour service; DNS-SD libraries are probably available for your language of choice, and it's a pretty simple matter to get a list of active machines in this case. I wrote this script in Ruby to find local machines running SSH:
#!/usr/bin/env ruby
require 'rubygems'
require 'dnssd'
handle = DNSSD.browse('_ssh._tcp') do |reply|
puts "#{reply.name}.#{reply.domain}"
end
sleep 1
handle.stop
You can use AppleScript remotely if you turn on Remote Events on the client machines. As an example, you can control programs like iTunes remotely.
I'd suggest that you put an update script on your remote machines (AppleScript or otherwise) and then use remote AppleScript to trigger running your update script as needed.
If you update often then Jim Puls idea is a great one. If you'd rather have direct control over when the machines start looking for an update then remote AppleScript is the simplest solution I can think of.
I have several different locations in a fairly wide area, each with a Linux server storing company data. This data changes every day in different ways at each different location. I need a way to keep this data up-to-date and synced between all these locations.
For example:
In one location someone places a set of images on their local server. In another location, someone else places a group of documents on their local server. A third location adds a handful of both images and documents to their server. In two other locations, no changes are made to their local servers at all. By the next morning, I need the servers at all five locations to have all those images and documents.
My first instinct is to use rsync and a cron job to do the syncing over night (1 a.m. to 6 a.m. or so), when none of the bandwidth at our locations is being used. It seems to me that it would work best to have one server be the "central" server, pulling in all the files from the other servers first. Then it would push those changes back out to each remote server? Or is there another, better way to perform this function?
The way I do it (on Debian/Ubuntu boxes):
Use dpkg --get-selections to get your installed packages
Use dpkg --set-selections to install those packages from the list created
Use a source control solution to manage the configuration files. I use git in a centralized fashion, but subversion could be used just as easily.
An alternative if rsync isn't the best solution for you is Unison. Unison works under Windows and it has some features for handling when there are changes on both sides (not necessarily needing to pick one server as the primary, as you've suggested).
Depending on how complex the task is, either may work.
One thing you could (theoretically) do is create a script using Python or something and the inotify kernel feature (through the pyinotify package, for example).
You can run the script, which registers to receive events on certain trees. Your script could then watch directories, and then update all the other servers as things change on each one.
For example, if someone uploads spreadsheet.doc to the server, the script sees it instantly; if the document doesn't get modified or deleted within, say, 5 minutes, the script could copy it to the other servers (e.g. through rsync)
A system like this could theoretically implement a sort of limited 'filesystem replication' from one machine to another. Kind of a neat idea, but you'd probably have to code it yourself.
AFAIK, rsync is your best choice, it supports partial file updates among a variety of other features. Once setup it is very reliable. You can even setup the cron with timestamped log files to track what is updated in each run.
I don't know how practical this is, but a source control system might work here. At some point (perhaps each hour?) during the day, a cron job runs a commit, and overnight, each machine runs a checkout. You could run into issues with a long commit not being done when a checkout needs to run, and essentially the same thing could be done rsync.
I guess what I'm thinking is that a central server would make your sync operation easier - conflicts can be handled once on central, then pushed out to the other machines.
rsync would be your best choice. But you need to carefully consider how you are going to resolve conflicts between updates to the same data on different sites. If site-1 has updated
'customers.doc' and site-2 has a different update to the same file, how are you going to resolve it?
I have to agree with Matt McMinn, especially since it's company data, I'd use source control, and depending on the rate of change, run it more often.
I think the central clearinghouse is a good idea.
Depends upon following
* How many servers/computers that need to be synced ?
** If there are too many servers using rsync becomes a problem
** Either you use threads and sync to multiple servers at same time or one after the other.
So you are looking at high load on source machine or in-consistent data on servers( in a cluster ) at given point of time in the latter case
Size of the folders that needs to be synced and how often it changes
If the data is huge then rsync will take time.
Number of files
If number of files are large and specially if they are small files rsync will again take a lot of time
So all depends on the scenario whether to use rsync , NFS , Version control
If there are less servers and just small amount of data , then it makes sense to run rysnc every hour.
You can also package content into RPM if data changes occasionally
With the information provided , IMO Version Control will suit you the best .
Rsync/scp might give problems if two people upload different files with same name .
NFS over multiple locations needs to be architect-ed with perfection
Why not have a single/multiple repositories and every one just commits to those repository .
All you need to do is keep the repository in sync.
If the data is huge and updates are frequent then your repository server will need good amount of RAM and good I/O subsystem