Tag Archives: Mac OS X

Observing packets on the wire flying by

Posted on August 28, 2016 by Jacco

Anyone who has ever tried to install a modem or configure an Internet connection has almost certainly wondered if there’s any traffic flowing back and forth from networks. Observing network traffic that is generated by a PC or Mac is … Continue reading →

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Email and malware dissection, Part II

Posted on September 24, 2014 by Jacco

If you’re running a mail server on the Internet, you will surely be familiar with spam and malicious email. This post is the last part on how to identify and isolate malware in email while respecting your users’ email privacy. … Continue reading →

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Resizing multiple images

Posted on July 30, 2013 by Jacco

I’m sure there are easier ways, and better I assume, to reduce the size of multiple images at once. But there was some point in time where I couldn’t resist the urge of solving this myself using ImageMagick and Tcl/Tk. … Continue reading →

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Rotating photos automatically

Posted on November 28, 2011 by Jacco

Stuff you need to do that just sneaks up on you. I’m sure this has happened to the most of us. This article is about one of those that is really high on the list of the “things to fix” … Continue reading →

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Change the login background of Mac OS X

Posted on August 28, 2011 by Jacco

(This article needs verification for Mac OS X Lion) This story has a history. Way back in early 2000, I wrote a small shellscript that would set the background of the login-screen of XDM (It’s a Xwindows/Unix thing). You can … Continue reading →

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File integrity on Mac OS X

Posted on August 4, 2011 by Jacco

Recently the US-CERT released a documented titled “Security Recommendations to Prevent Cyber Intrusions“, which seems to add quite a few measurements to another US official document, but this time in more technical terms. I don’t live in the US, but … Continue reading →

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