Keep your Mac awake (disable lid and idle sleep) (how to)

A lot of people were using a convenient little application called InsomniaX to disable temporarily the sleep feature on MacOS that is activated due to inactivity after a few minutes or when you close your laptop's lid (screen). 

However, a security vulnerability was identified in the software and after that point in time it is considered a legacy software as it is no longer actively being developed. 

There are alternatives depending on what you want to do. The easiest way to keep the mac from going to sleep is to use a terminal window with the built-in command: caffeinate

However, this does not help when you change focus from that particular terminal window or need to temporarily close your laptop's lid without going into sleep mode. 

youtube-dl (how to) - best guide to get you started

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###        youtube-dl - the best guide to get you started        ###

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>> Installing

[Note]: Before you start; 

If you have upgraded to Catalina (on never have installed xcode and gcc before), then you will need to:

install Xcode (from Apple's App Store), then run the command: xcode-select --install 

then install gcc, and then install youtube-dl

[TIP]: You must run brew update first. Then you can either use the brew upgrade to update all packages, or, run brew upgrade youtube-dl to update only youtube-dl

//To install youtube-dl [1] under MacOS use:
brew install youtube-dl

//Once it is installed, update the application:
sudo youtube-dl -U

Re-encode screen recordings to work in iMovie

There was a case where I did some screen recordings but iMovie refused to see the video files .mp4 format. Video captures can be very useful as proof-of-concept and/or evidence of actions performed, for example during a security assessment, such as penetration testing sessions. 

In my case, it was showing only a "green screen" instead of what it was actually captured during the screen recording. Bear in mind that VLC could play the video file without any issues, but when loaded in iMovie, the same video file was failing to show properly.

If you have ffmpeg installed on your MacOS, you can very easily fix this problem, by re-encoding e.g. from an .mp4 file to a .mov file. 

Keep in mind, simply changing the "container" from an .mp4 video to .avi/.mov in most cases won't fix your problem. Hence, doing something like the following, as many others advice online, it will simply not work for you:
- ffmpeg -i Video.mp4 -c copy Video.mp4
- ffmpeg -i Video.mp4 -acodec copy -vcodec copy -f mov Video.mov


Re-encoding however, will fix your problem and ensure that iMovie can see the video as they were captured:

ffmpeg -i ScreenRec.mp4 -c:v libx264 -preset fast -profile:v baseline outRec.mov 

Of course, if you want to keep the same format, you can do:

ffmpeg -i ScreenRec.mp4 -c:v libx264 -preset fast -profile:v baseline outRec.mp4

Xcode update is stuck at waiting

This is something that happens often and I wanted to make sure you are going to fix this the right away, without causing any problems to your system and save you some time. 

This was written for Xcode 8.3 (but it has worked for previous versions as well) and it is confirmed that it works on:
OS X 10.10 Yosemite, OS X 10.11 El Capitan, and macOS 10.12 Sierra.

I am assuming that you are at your Updates screen and Xcode is stuck at "waiting". Click on Xcode (the actual name/caption of the pending update) and the relevant page of Xcode on App Store will show (see below). 

When you click the Update button (beneath the application icon on App Store), a little progress bar appears beneath it, and it usually tells you "less than a minute" (but it is stuck there forever). 

Don't navigate away from this screen on App Store, because we want this little progress bar to be our indicator on what is happening. 

• Open a new Finder window and click Applications (top left hand side). 
• Scroll down to the Xcode application and drag the application to Trash.
• You will be asked to confirm your password before moving Xcode to Trash.
• Once you enter your password, there will be a prompt asking you if you want to cancel the update or delete the app. Choose delete. 
• You will notice that immediately after clicking delete, xcode starts downloading the updated version, and you can see/confirm that at the progress bar (as discussed earlier on) and it will tell you how long it will take (it can take an hour, depending on your Internet connection).
• (optional) If you want to save some space on your disk, go to Trash, right-click on xcode, and delete it completely from the system. It will ask you again to confirm your password. 

Don't forget to plug-in your computer, as the whole process takes a while, and the computer might go to sleep and suspend the download and/or the installation.