Why sudo cat gives a Permission denied but sudo vim works fine?

Question

I am trying to automate the addition of a repository source in my arch\'s pacman.conf file but using the echo command in my shell script. However, it fails like th

Answer 1

append files (sudo cat):

cat  | sudo tee -a 

append echo to file (sudo echo):

echo  | sudo tee -a 

(EXTRA) disregard the ouput:

echo >origin> | sudo tee -a  >/dev/null