UNIX: Fifty Years and Counting
The UNIX Operating System has a long and influential history in computing and Brian Kernighan’s new book, UNIX: A History and a Memoir tells that story. I started teaching UNIX (and C programming) for Learning Tree back in 1984. A lot has changed since then including the advent of Linux, the move to PCs, and […]
How I Was Wrong About Kerberos
Microsoft’s Active Directory includes a version of Kerberos that has had a bad reputation. There were problems several years ago, but the criticisms are now outdated. What was the problem, and how has it been fixed? Origins of Active Directory Windows 2000 was originally going to be called Windows NT 5.0. It was released in […]
More Unexpected Applications of grep
Quentin Tarantino said “I steal from everything. Great artists steal, they don’t do homages.” He stole that from Pablo Picasso, who said “When there’s anything to steal, I steal,” and “Good artists copy, great artists steal.” In that frame of mind, let’s see a very elegant use of grep that, believe it or not, I […]
Stored passwords, eggs and bread dough?
All three of these share the need for one thing: salt. So what is a password salt and why do we need them? In the early days of the UNIX timesharing system the file containing the users’ passwords was readable by all users (that began in version 6, in the mid 1970’s). The file had […]