macOS Cheatsheet - Commonly used commands for my macOS Setup

macOS.txt

-- Automate your macOS a bit more, schedule Safari to open your favourite sites regularly at 7am to save a few seconds each morning.

# In terminal, type the following command which will allow you to edit current scheduled jobs with nano editor
# You might need to grant cron full disk access for this to work. https://osxdaily.com/2020/04/27/fix-cron-permissions-macos-full-disk-access/

env EDITOR=nano crontab -e

# Then copy and paste the following lines. Control-X to exit nano. The new jobs will be schedulled.
# The samples below are to open Safari at 7am each morning with the specified URL. It should placed them in new tab if that's how your safari is setup. It's good to wake up each morning saving a few seconds loading the sites you read daily. You can also use similar schedule to download files, open apps, etc. To learn more about how to specify the time, check out http://www.thegeekstuff.com/2009/06/15-practical-crontab-examples/
$ crontab -r where the -r flag removes current crontab configuration.
$ crontab -l where the -l to list crontab configuration
https://crontab.guru/ is helpful if you can't remember the schedule format

0 7 * * *  open -a Safari http://www.bbc.com/news
0 7 * * *  open -a Safari http://money.cnn.com
0 7 * * *  open -a Safari https://flipboard.com/section/technology-c5o31di9kg9ea7p6
0 7 * * *  open -a Safari https://www.macrumors.com

0 7 * * *  open -a 'Brave Browser' http://www.bbc.com

-- If you want it to open in a new window, you can do it with Chrome/Brave with the following
open -na "Google Chrome" --args --new-window "https://www.bbc.com"
open -na "Brave Browser" --args --new-window "https://www.bbc.com"



-- macOS screenshot files location, stop cluttering your desktop folder
-- With current release of macOS, you don't need to do this, just open the screenshot app, select the folder to save to, that will become the default
# Make a new "Screenshots" folder inside your home folder to store all your new screenshots.
# Then run the following command in Terminal.


defaults write com.apple.screencapture location ~/Screenshots; killall SystemUIServer

-- Fixing disk issues
# Find the disk number with the following command
diskutil list
# Then use the following command on HFS disk
sudo /sbin/fsck_hfs -drfy /dev/disk2s3

-- SSH Keys Ref: https://gist.github.com/grenade/6318301
chown root:root ~/.ssh/id_rsa*

chown user:user ~/.ssh/id_rsa*
chmod 600 ~/.ssh/id_rsa
chmod 644 ~/.ssh/id_rsa.pub

-- To merge many .ts videos
cd ts_files_directory
echo {1..500}.ts | tr " " "\n" > tslist
while read line; do cat $line >> combined.ts; done < tslist

-- To Install MongoDB with tools using homebrew
brew tap mongodb/brew
brew install mongodb-community
brew install mongodb-database-tools

-- To download thousands of URLs using CURL, make a long list of urls.txt
cat urls.txt | xargs -0 curl -O

-- Sometimes, I want to give a particulr app the full process priority
sudo renice -20 $(pgrep FaceTime)

-- To merge some AVI files without re-encoding, install mencoder, then
brew install mplayer
mencoder -oac copy -ovc copy 1.avi 2.avi 3.avi 4.avi 5.avi 6.avi -o final.avi

-- To loop through directories
for dir in *; do
echo $dir;
done

-- To loop through files in a directory
for file in *.avi; do
echo $file;
done

-- To delete all files (including subfolder from .) with .flac extension.
find . -name '*.flac' -delete

-- To open 2 copies of WeChat
nohup /Applications/WeChat.app/Contents/MacOS/WeChat > /dev/null 2>&1 &
nohup /Applications/企业微信.app/Contents/MacOS/企业微信 > /dev/null 2>&1 &

-- Using osascript to send imessage, please change your full international phone number with country code and the + sign, no, not with the squid game phone number. also, if you really need it, "pip install osascript"
osascript -e 'tell application "Messages" to send "Hello World!" to buddy "+1192182919191"'

-- Counting how many sub-subfolders are over 1mb in size, change max/mindepth to have different folder levels
find . -maxdepth 2 -mindepth 2 -type d -exec du -hs {} \; | grep "M\t" | wc -l

-- Copy files with certain extensions (pdf, jpg in this example) to a new folder preserving folder structure
rsync -a --include '*/' --include '*.pdf' --include '*.jpg' --exclude '*' source_folder/ destination_folder/

-- To remove node and start again. Lesson: avoid installing node with homebrew
-- https://gist.github.com/dotcomputercraft/b7283bd52f4b5389e748
-- Also check https://stackabuse.com/how-to-uninstall-node-js-from-mac-osx/
sudo rm /usr/local/bin/npm
sudo rm /usr/local/share/man/man1/node.1
sudo rm /usr/local/lib/dtrace/node.d
sudo rm -rf ~/.npm
sudo rm -rf ~/.node-gyp
sudo rm /opt/local/bin/node
sudo rm /opt/local/include/node
sudo rm –rf /usr/local/bin/node
sudo rm -rf /opt/local/lib/node_modules
sudo rm -rf /usr/local/bin/npm
sudo rm -rf /usr/local/share/man/man1/node.1 
sudo rm -rf /usr/local/lib/dtrace/node.d
sudo rm -rf /usr/local/lib/node_modules
-- check after the above with "which node"

—————
To cleanup system extensions.

sudo rm -rf /Library/Extensions/<kextname.kext>
sudo kextcache -i /
sudo kextcache --clear-staging
sudo reboot

—————
To convert all SVG to PNG of fixed 1200 height

brew install librsvg
find . -type f -name "*.svg" -exec bash -c 'rsvg-convert -h 1200 "$0" > "$0".png' {} \; 

—————
Too lazy to start another gist for now, just jotting down my frequently used regex patterns.

-- To strip HTML tags
\<[^\>]*\>

-- To merge a folder of mp4s, same quality, with ffmpeg (or brew install ffmpeg)
rm list.txt; for f in *.mp4 ; do echo file \'$f\' >> list.txt; done && sort -V list.txt > list-sort.txt && ffmpeg -f concat -safe 0 -i list-sort.txt -c copy stitched-video.mp4 ; rm list.txt list-sort.txt

-- To use socks in terminal
export http_proxy="127.0.0.1:7890"
export https_proxy="127.0.0.1:7890"

-- For Apple Silicon Macs
-- If you get "found architecture 'arm64', required architecture 'x86_64'" error
Recompile the library from source using x86_64 architecture
Add following line to CMakeLists.txt before running the CMake command
set(CMAKE_OSX_ARCHITECTURES "x86_64" CACHE INTERNAL "" FORCE)
-- Ref: https://stackoverflow.com/questions/69803659/what-is-the-proper-way-to-build-for-macos-x86-64-using-cmake-on-apple-m1-arm

-- For Apple Silicon Macs
-- If you get "zsh: bad CPU type in executable" error
Manually install Rosetta 2 with following command:
softwareupdate --install-rosetta

-- For Apple Silicon Macs
-- If you get misc error with Brew, and you used Migration Assistant from Intel to Apple Silicon, consider the following:
Migration Assistant from Intel to Apple Silicon would copy over all x86 based packages which might cause compile issues later. So I am sharing my answer wider to just homebrew.

Two options I recommend:

1) "Rebuild" your system. Back it up to Time Machine and then use Migration Assistant again, but only for your user folder (do not choose "Applications" and "Other Files & Folders") and maybe System & Network settings. Then reinstall all the software with Apple Silicon versions.
2) If you are sure that you ever only used homebrew to install packages, and not macport or direct pkg installers for python/go/etc,etc. Then you can use the following commands to clean out old homebrew and install it again from start. You might need to sudo rm a few stubborn folders after running these 2 commands (or if you are feeling brave, use sudo to run the uninstall.sh).

curl -O https://raw.githubusercontent.com/Homebrew/install/HEAD/uninstall.sh
/bin/bash uninstall.sh --path=/usr/local

-- AppleScript to open all tabs on current Brave window to Safari
tell application "Brave Browser"
	
	set tab_list to every tab in the front window
	
	repeat with the_tab in tab_list
		set the_url to the URL of the_tab
		tell application "Safari" to open location the_url
	end repeat
	
end tell

-- To generate 5 random passwords
for i in $(seq 1 5); do LANG=C && echo $(tr -dc 'A-Za-z0-9!"#$%&()*+,-./:;<=>?@[\\]^_`{|}~' < /dev/urandom | head -c 20); done 

-- To hide a user account from the login screen and settings
-- Useful for selling old computer to someone online, hide an account with Find My enabled. When they have accepted and paid, then remove the Find My lock online.
sudo dscl . create /Users/<hiddenuser> IsHidden 1

-- Find dupes and delete
brew install fdupes
-- Find dupes
fdupes -r .
-- Find and delete dupes, keeping first one
fdupes -rdN .

-- Delete pdfs under 1k in filesize
find . -type f -name "*.pdf" -size -1k -delete

-- iCloud Folders
iCloud Drive: $HOME/Library/Mobile\ Documents/com~apple~CloudDocs
Mobile Documents: $HOME/Library/Mobile\ Documents

-- To quarantine an app which you can't open, try
xattr -d com.apple.quarantine /Applications/Lepton.app

-- Split a folder with many files into subfolders of 1000 files in each
i=0; for f in *; do d=dir_$(printf %03d $((i/1000+1))); mkdir -p $d; mv "$f" $d; let i++; done