I installed vsftpd on my server using this and this link. But due to this error I followed the solution and tried to update the vsftpd.
But because of some configuration problem it was not functioning and I decided to reinstall it using this problem's solutions.
But now after installing it again when I type:
sudo service vsftpd restart or sudo /etc/init.d/vsftpd restart it shows me:
vsftpd: unrecognized service. and
sudo: /etc/init.d/vsftpd: command not found
How to solve this?