How to place a watermark in the corner of an image with ImageMagick.

ImageMagick(1) can be used to put a watermark on an image easily. The command below will place a TV styled watermark on an image in the lower left corner. This is very useful to watermark images you place on the Internet. convert pripyat.jpg ABCTV2005.png -gravity southeast -composite output.pngconvert pripyat.jpg ABCTV2005.png…

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Very useful Linux shell tips and tricks.

Add a new directory to the PATH to allow running an application from it without typing the full path every time you wish to run it. PATH=$PATH:/usr/local/binPATH=$PATH:/usr/local/bin Or you may have something like this in your .bashrc to add this every time you log in. PATH="/home/jason/perl5/bin${PATH:+:${PATH}}"; export PATH;PATH="/home/jason/perl5/bin${PATH:+:${PATH}}"; export PATH;…

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Very useful resources for learning penetration testing and Linux commands.

CysCA hacking challenge penetration testing results, how students overcame a few vulnerable network servers and successfully captured flags. Students Write-ups. A number of write-ups submitted by the students on the day, this is a document of their solutions for the challenge. https://www.cyberchallenge.com.au/pdf/CySCA2018-Students.pdf. Active Defense pentest. https://www.cyberchallenge.com.au/pdf/CySCA2018-Active_Defence_Questions.pdf. These resources might give…

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Broadband in Australia is worse than Uganda.

The Australian Broadband Network is the envy of no one. This is terrible. Constant dropouts, and slow speeds are the norm in Australia. We could have had super fast Internet in Australia, but we got copper wires combined with some fiber connections. But the presence of a 1000 Mega Bits…

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Digital TV on Linux really works well.

Using Digital TV on Linux is possible, but it depends on the adapter whether it will work or not. I had a Compro DVB T-300 digital TV card in my old PC. And the digital TV support will only work on Windows, I have to use a USB device to…

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Fun with sed on Linux.

The sed command can be used to reverse text. This is a very interesting feature. Provide a text string, and it will be reversed. jason@jason-Virtual-Machine:~$ sed ‘/\n/!G;s/\(.\)\(.*\n\)/&\2\1/;//D;s/./Hello. /’ <<< ‘This is a long sentence in reverse. This is a lot of fun.’ Hello. .nuf fo tol a si sihT .esrever…

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Get information about users on your Linux system easily.

A Linux system can have a lot of users in the /etc/passwd file. But it is easy to keep track of your users with the command line. The lslogins command will print a listing of known users on your Linux system. An example of the usage. jason@jason-Virtual-Machine:~$ lslogins UID USER…

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How to fix the annoying narrow Firefox scrollbar on Ubuntu.

The Firefox scrollbar is very narrow on Ubuntu. This is very annoying. But since I am using the MATE desktop and GTK 3.0, I can fix this easily. Add this line to the ~/.config/gtk-3.0/settings.ini file, and this will force Firefox to use the scrollbar defined by the theme instead. gtk-primary-button-warps-slider=falsegtk-primary-button-warps-slider=false…

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Windows still having issues with updates in 2019.

Linux and Windows are continually in a state of competition, but the problem with Windows 10 is the update methods that create many and varied problems that should never even happen in the first place. The Linux and Macintosh operating systems do not have that many problems when upgrading. I…

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Overlay two videos on top of another with ffmpeg.

Overlaying two other video files on to another is very easy with ffmpeg. I had two video files that are 640×360 pixels, and one that is 1920×1080. I used this command line with ffmpeg to overlay them. ffmpeg -i controller_agroprom.mp4 -vf "movie=dbz120.mp4 [a]; movie=dbz121.mp4 [b]; [in][a] overlay=0:32 [c]; [c][b] overlay=0:448"…

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Play movies with mpv and scale the output to a certain size.

The mpv media player can scale the output, just as mplayer does. This can be useful. Use this parameter to scale the video. -vf scale=960:720-vf scale=960:720 This is how this is done. This will scale the output to 960×720 pixels. 4.4 Mon Jul 08 jason@Yog-Sothoth 0: $ mpv -vf scale=960:720…

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