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clone an USB stick using dd + see its process
The following command will clone usb stick inside /dev/sdc to /dev/sdd Double check you got the correct usb sticks (origional-clone)with fdisk -l.

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

Find last reboot time
Specific to OSX.

List the binaries installed by a Debian package
GNU grep's perl-compatible regular expression(PCRE).

Getting started with tcpdump
At some point you want to know what packets are flowing on your network. Use tcpdump for this. The man page is obtuse, to say the least, so here are some simple commands to get you started. -n means show IP numbers and don't try to translate them to names. -l means write a line as soon as it is ready. -i eth0 means trace the packets flowing through the first ethernet interface. src or dst w.x.y.z traces only packets going to or from IP address w.x.y.z. port 80 traces only packets for HTTP. proto udp traces only packets for UDP protocol. Once you are happy with each option combine them with 'and' 'or' 'not' to get the effects you want.

get a process list by listen port

get ip of all running docker containers
pretty self explanitory

DVD ripping with ffmpeg
To rip DVD movie to ogg format using ffmpeg, follow these steps. 1) find the vob files on the mounted video DVD in VIDEO_TS that stores the movie itself. There would be a few other VOB files that stores splash screen or special features, the vob files for the movie itself can be identified by its superior size. You can verify these vob files by playing them directly with a player (e.g. mplayer) 2) concatenate all such vob files, pipe to ffmpeg 3) calculate the video size and crop size. The ogg video size must be multiple of 16 on both width and height, this is inherit limitation of theora codec. In my case I took 512x384. The -vcodec parameter is necessary because ffmpeg doesn't support theora by itself. -acodec is necessary otherwise ffmpeg uses flac by default.

Look up a unicode character by name
No need for further filedes or substitution for splitting. Simply use read a b

Quickly find a count of how many times invalid users have attempted to access your system


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