find ~ -name *.plist -or -name *Photo*
find ~ -name *.plist -and -name *Photo*
([] ? *)		[Not Regular Expression]

date
uptime
df -h 		--Disk free space of the system	
du -ah		--Disk usage statistics
sort -frub	--ignore-case --reverse --unique --ignore-leading-blanks


!123	The history command #123
!-2		The last seconde history command (2 command-back)
!cat	The most recent command beginning with "cat"
!!		The last command
!$ 		The last command argument

cat file1.txt file2.txt > joined.txt

grep
-i  Case insensitive
-w  Word
-v 	Reverse (Only show the not matched)
-n  Show the line number
-c  Count of the matched
-R  Recursive (For folder)
-l  Only list matched file names (with -R)
-L  Reverse of -l (NOT matched file names)

tr  Translating characters

sed 's/[aeiou]/_/g' 
control+v = \t = tab

cut -c 2-10,30-36 file.txt				Characters
cat file.txt | cut -f 2,6 -d ","     	Delimiter and column

man -t emacs | open -fa Preview
man -t bash | open -fa Preview

cut -f 2,6 students.tsv | pbcopy		Copy the the pasteboard (Send it)
pbcopy < something.txt
pbpaste
alias pbsort='pbpaste | sort | pbcopy'

screencapture -v filename				Capture the screen video
mdls file  								Get the meta data of the file
mdfind -onlyin ./ 'kMDItemFSName == "*lisp*"'		In recent 2 days
mdfind -onlyin ./ 'kMDItemFSCreationDate >= $time.today(-2)'		In recent 2 days [$time.yesterday $time.this_week(-1) ]
mdfind -onlyin ./ 'kMDItemFSCreationDate >= $time.iso(2019-02-12 12:35:11 -0800)'				Create since that time!
mdfind -onlyin ./ 'kMDItemFSCreationDate >= $time.now(-100000) && kMDItemFSName == "*lisp*"'	In recent 100000 seconds AND file name ...

sudo defaults write com.apple.loginWindow DesktopPicture "/Library/Desktop Pictures/El Capitan 2.jpg"