umask determines what permissions any new files or directories will have by default. Like file permissions, it historically takes an octal value (e.g. ‘umask 002′), but can also symbolic values (e.g. ‘umask a=rx,ug+w’). I’m going to just focus on the octal values.
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FFmpeg is an open-source command line utility for performing audio/video file conversions. It can be used to simply convert straight from one video format to another, or to crop, pad, rescale, change bit-rates, merge or split out audio and video, and so on…
I only came across this command fairly recently. It’s a simple command, but immensely useful.
The watch command is used to run a given command at a predefined interval, and to monitor the output in real-time until the watch command is terminated. When run, it initially only displays the first output of the given command, and then only updates it if something in the output changes.
A remote Windows PC can easily be shutdown, assuming you have Samba installed on your Linux box, and you have a user account on the Windows PC that has the necessary rights.
Sometimes burning an ISO file to a CD-ROM just to access its contents is overkill, but there is another way.
Need a simple way to test the bandwidth between two hosts that you have access to? If so, then just drop Iperf onto both machines. Launch one instance as the server
iperf -s
and the other as the client
iperf -c <Server IP>
then after 10 seconds you’ll have your result.
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Ever tried to unmount a device in Linux, but can’t because it is apparently still being used by something? If so, then the ‘fuser’ command is what you want. Just type ‘fuser -m’ followed by the path that the device is currently mounted to (e.g. ‘fuser -m /home’), and then you’ll receive a list of all the processes that are currently using it.
The fuser command can also be used to kill the processes as well, just by adding the ‘-k’ option (e.g. ‘fuser -km /home’).