Question

On windows machine(with Windows 7 running, x86-64) is it possible to open ‘etc/hosts’ file which is in system32/drivers/etc, modify it and save from ruby?

I get “not opened for writing(IOError)” error
The code is very simple

file = File.open("C:/Windows/System32/drivers/etc/hosts")
file << "new line"

Answer 1

Instead of trying to acquire privileges from code ( which maybe won’t be portable across different windows OS’es ), do like this:

• open a command prompt as an administrator
• run your script from there

By doing like this, all the programs you’re executing will have administrative privileges as well.

EDIT: This is your problem:

file = File.open("C:/Windows/System32/drivers/etc/hosts","w")
file << "new line"

You have to open the file in write mode.