맥북을 사용중이며 터미널로 'EC2 한방에 세팅하기' 코드스니펫 실행 문제 확인 요청드립니다!

sudo chmod 400/Users/hongdakyung/Desktop/sparta_ddoqikey.pem

를 실행하고

컴퓨터 비밀번호를 입력하였습니다!

코드스니펫 복사하여 아래처럼 첫 줄을 실행하려고 했는데,

sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 10

sudo: update-alternatives: command not found

라는 문구가 나와 질문드립니다 ㅠㅠ

Last login: Wed Oct 19 20:25:10 on ttys000

hongdakyung@hongdagyeong-ui-MacBookAir ~ % sudo chmod 400/Users/hongdakyung/Desktop/sparta_ddoqikey.pem

Password:

usage:	chmod [-fhv] [-R [-H | -L | -P]] [-a | +a | =a  [i][# [ n]]] mode|entry file ...

	chmod [-fhv] [-R [-H | -L | -P]] [-E | -C | -N | -i | -I] file ...

hongdakyung@hongdagyeong-ui-MacBookAir ~ % sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 10

Password:

sudo: update-alternatives: command not found

hongdakyung@hongdagyeong-ui-MacBookAir ~ % sudo chmod 400/Users/hongdakyung/Desktop/sparta_ddoqikey.pem

usage:	chmod [-fhv] [-R [-H | -L | -P]] [-a | +a | =a  [i][# [ n]]] mode|entry file ...

	chmod [-fhv] [-R [-H | -L | -P]] [-E | -C | -N | -i | -I] file ...

hongdakyung@hongdagyeong-ui-MacBookAir ~ % sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 10

sudo: update-alternatives: command not found

hongdakyung@hongdagyeong-ui-MacBookAir ~ % sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 10

sudo: update-alternatives: command not found

hongdakyung@hongdagyeong-ui-MacBookAir ~ %