I got apt error during executing commands

Question

I tried to execute the following command but i got below error

sudo apt-get apt install -y ruby-dev nodejs postgresql-client redis-server wkhtmltopdf memcached

E: Invalid operation apt

Answer 1

You're using apt and apt-get together, which does not work. You should either use sudo apt or sudo apt-get.

So the correct command is:

sudo apt install -y ruby-dev nodejs postgresql-client redis-server wkhtmltopdf memcached` 

For more details about apt and apt-get check their manpages (man apt, man apt-get) and check this question too: what is the difference between apt and apt-get