Root user/sudo equivalent in Cygwin?

I answered this question on SuperUser but only after the OP disregarded the unhelpful answer that was at the time the only answer to the question.

Here is the proper way to elevate permissions in Cygwin, copied from my own answer on SuperUser:

I found the answer on the Cygwin mailing list. To run command with elevated privileges in Cygwin, precede the command with cygstart --action=runas like this:

$ cygstart --action=runas command

This will open a Windows dialogue box asking for the Admin password and run the command if the proper password is entered.

This is easily scripted, so long as ~/bin is in your path. Create a file ~/bin/sudo with the following content:

#!/usr/bin/bashcygstart --action=runas "$@"

Now make the file executable:

$ chmod +x ~/bin/sudo

Now you can run commands with real elevated privileges:

$ sudo elevatedCommand

You may need to add ~/bin to your path. You can run the following command on the Cygwin CLI, or add it to ~/.bashrc:

$ PATH=$HOME/bin:$PATH

Tested on 64-bit Windows 8.

You could also instead of above steps add an alias for this command to ~/.bashrc:

# alias to simulate sudoalias sudo='cygstart --action=runas'

You probably need to run the cygwin shell as Administrator. You can right click the shortcut and click run as administrator or go into the properties of the shortcut and check it in the compatability section. Just beware.... root permissions can be dangerous.

Building on dotancohen's answer I'm using an alias:

alias sudo="cygstart --action=runas"

Works as a charm:

sudo chown User:Group <file>

And if you have SysInternals installed you can even start a command shell as the system user very easily

sudo psexec -i -s -d cmd