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Convert .flv to .3gp
Download YouTube videos as .flv and convert them to .3gp for your mobile phone.

Watch Al Jazeera Livestream directly in mplayer #jan25
One cannot call the high quality livestream directly, but command this gives you a session ID and the high quality stream. #egypt #jan25

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"

Check if a machine is online
PING parameters c 1 limits to 1 pinging attempt q makes the command quiet (or silent mode) /dev/null 2>&1 is to remove the display && echo ONLINE is executed if previous command is successful (return value 0) || echo OFFLINE is executed otherwise (return value of 1 if unreachable or 2 if you're offline yourself). I personally use this command as an alias with a predefined machine name but there are at least 2 improvements that may be done. Asking for the machine name or IP Escaping the output so that it displays ONLINE in green and OFFLINE in red (for instance).

mix video and audio
-map 0.0:0 map the video of video.mp4 to the video of mix.mp4 -map 1.0:1 map the audio of audio.mp3 to the audio of mix.mp4 make sure that video.mp4 and audio.mp3 have the same duration

scan folder to check syntax error in php files

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.

Watch the progress of 'dd'
dcfldd is a forensic version of dd that shows a process indicator by default.

Display which distro is installed

List total available upgrades from apt without upgrading the system
This let's you find out the total packages that have available upgrades. Usefull if you want to check or show the total available upgrades on your system.


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