CommandLineQuickTips

ls .  		      # files in current directory 
ls ..                 # files in parent directory 
tree > log.txt        # put the results of a command in a file (You must have tree installed. It's available via macports <sudo port install tree>)
ls >> log.txt         # append the results of a command in a file
mkdir -p one/two/     # create multiple directories in one step
env                   # print out environment variables in name value pair 

Control + a           # go to the beginning line
Control + e           # go to the end line
Control + k           # delete all to the right
Control + w           # delete previous word
Control + r           # search history interactively
Control + c           # force quit out of a program i.e. vi, vim, nano etc..
q,x,ctrl+q,ctrl+x or ESC # common escape commands for processes 
ESC + b               # go back a word
ESC + f               # go forward a word
!33		      # execute an item in the history index, in this case 33
!!                    # previously executed command
!$                    # last argument of previous command
!cd                   # will run the last command in history that started with the text, in this case cd
cat file.txt          # print contents of file
cat file.txt | pbcopy # put file contents into clipboard
pbpaste               # paste your clipboard
f                     # forward paging while in the man pages
b                     # backward paging while in the man pages
q                     # quit man page
Option + (Click)      # move the cursor to a specific position
man -k searchTerm     # search manual for search term results  
cd -                  # toggle back to previous directory
tail file.log         # print the end of a file
tail -f file.log      # follow changes at the end of a file
head file.log         # print beginning of a file
sudo chown user:group file.txt #change user and group permissions 
sudo chown -R user:group folder #change user and group permissions recursively on a folder
chmod ugo=rwx          #Give Read, Write and Execute access to User, Group and Other (short hand: chmod ugo+rwx or chmod a+rwx) using alpha notation
chmod u=rwx,g=rw,o=r   #Give Read, Write and Execute access to User,Read and Write to Group and Read only to Other using alpha notation
chmod o-wx file.txt #Remove permissions using alpha notation
chmod 777 file.txt  #Set permission on file with numeric notation. See alpha conversions: (r=4) (w=2) (e=1)
chmod -R 755 folder  #Set permission on folder with numeric notation
sudo                   #substitute user and do
sudo -k                #terminate session as substitute user
whereis                #get location information about a command
which                  #get location information about a command
whatis                 #get information about a command