Commands by mjb (0)

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An alias to select a portion of your desktop and save it as an image.

Display the standard deviation of a column of numbers with awk

Export a directory to all clients via NFSv4, read/write.
This exports a directory to the world in read/write mode. It is useful for quick, temporary NFS exports. Consider restricting the clients to a subnet or to specific hosts for security reasons (the client can be specified before the colon). On the client: mount -t nfs4 hostname:/ /mountpoint To terminate all of the exports (after unmounting on the client): exportfs -u -a Leave out the fsid=0 option if you don't want NFSv4. This works under recent versions of Linux.

back ssh from firewalled hosts
host B (you) redirects a modem port (62220) to his local ssh. host A is a remote machine (the ones that issues the ssh cmd). once connected port 5497 is in listening mode on host B. host B just do a ssh 127.0.0.1 -p 5497 -l user and reaches the remote host'ssh. This can be used also for vnc and so on.

Get MX records for a domain

Watch Network Service Activity in Real-time

Sort files by size

Create a persistent connection to a machine
Create a persistent SSH connection to the host in the background. Combine this with settings in your ~/.ssh/config: Host host ControlPath ~/.ssh/master-%r@%h:%p ControlMaster no All the SSH connections to the machine will then go through the persisten SSH socket. This is very useful if you are using SSH to synchronize files (using rsync/sftp/cvs/svn) on a regular basis because it won't create a new socket each time to open an ssh connection.

Monitor incoming connections of proxies and balancers.
Maybe this will help you to monitor your load balancers or reverse proxies if you happen to use them. This is useful to discover TIME OUTS and this will let you know if one or more of your application servers is not connected by checking.

Show errors in the kernel ring buffer
Much more useful then parsing syslog


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