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Synchronize both your system clock and hardware clock and calculate/adjust time drift
Do not run this command if you already have ntpd running! This needs to run as root, for example with sudo: $ sudo ntpdate pool.ntp.org && sudo hwclock --systohc && sudo hwclock --adjust This command will fetch accurate time from NTP servers and synchronize your system clock, then it will use the system clock to synchronize your hardware clock, and will calculate the time drift.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Create a new file

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Cleanup Docker
# Delete all containers docker rm $(docker ps -a -q) # Delete all images docker rmi $(docker images -q)

Stage only portions of the changes to a file.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Find usb device in realtime
Using this command you can track a moment when usb device was attached.

Encode a file to MPEG4 format
Encode video.avi into newvideo.avi using the libav codec to produce an MPEG4 file with a bitrate of 800

Test I/O performance by timing the writing of 100Mb to disk
Write 200 blocks of 512k to a dummy file with dd, timing the result. The is useful as a quick test to compare the performance of different file systems.


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