sudo – what is it?

If you’ve been following my posts for a while, you will have also noticed the use of the sudo command in a lot of the Unix/Linux configuration and setup instructions. This is because of the security model used by these operating systems. Users generally have limited access, and only the ‘root’ or admin accounts has greater access. A common convention is to use the sudo command to allow for temporary (usually 5 minutes at a time) permission to make changes, using escalated rights for an existing non root user.

It’s often best to think of “sudo” as “mother may I”, as the server administrator can give users access to some (but not all) commands.

Permissions are stored in a file that can be edited in a variety of manners (do so carefully):
/etc/sudoers

To give an existing user permission to use sudo…

sudo adduser USERNAME sudo

REFERENCES:

Killing hung, frozen or zombie programs

As a web developer, I’m often doing new (and interesting) things to stretch the boundaries of the browser. Sometimes, in doing so, the browser can hang or freeze, remaining in a state that makes it unresponsive.

Here are a few simple methods to force-close the browser on Windows and Linux, they can be expanded for other software executables as needed.

Windows:
taskkill /f /im iexplore.exe
taskkill /f /im firefox.exe
taskkill /f /im chrome.exe
taskkill /f /im safari.exe

Linux/Unix:
for i in `ps -A | grep firefox | awk '{print $1}'`; do kill -9 $i; done

Free Antivirus Software

So, a family member has recently approached me about virus scan products for Windows. It seems that, while he runs a commercial product, it’s a little dated and he does not keep up on the frequent updates, unfortunately this has put him into a position where his computer was infected and has become almost unusable. Using the same commercial products he’s unable to clean up the mess and has already lost many files.

I’ve been a convert to Avast for several years and even run it on my servers to scan for malicious content, it’s both free for non-commercial use and updates automatically.

Other products worth considering:

For Windows:

Unix/Linux:

Mac OS/X:

Cheers!