What does 'bash -c' do?

Question

I followed the following tutorial: http://davidtsadler.com/archives/2012/06/03/how-to-install-magento-on-ubuntu/

At some point it told me to execute the following command:

sudo bash -c "cat >> /etc/apache2/sites-available/magento-store.com <<EOF <VirtualHost *:80>    ServerName  localhost.magento-store.com   ServerAlias www.localhost.magento-store.com    DocumentRoot /home/dev/public_html/magento-store.com/public    LogLevel warn   ErrorLog  /home/dev/public_html/magento-store.com/log/error.log   CustomLog /home/dev/public_html/magento-store.com/log/access.log combined  </VirtualHost> EOF" 

What did this command do, and how I can cancel that?

I restarted the computer, and it seems that it is still running. I looked in .bashrc and .profile, but I did not find it inside.

Answer 1

Quoting from man bash:

-c string If the -c option is present, then commands are read from string.
If there are arguments after the string, they are assigned to the positional parameters, starting with $0.

The command quoted by you would append the text in heredoc (i.e. the text in VirtualHost tag) to the file /etc/apache2/sites-available/magento-store.com.

Answer 2

The manual page for Bash (e.g. man bash) says that the -c option executes the commands from a string; i.e. everything inside the quotes.