ITworld - Unix as a Second Language

How to enforce password complexity on Solaris

Sandra Henry-Stocker — Sat, 12 May 2012 23:44:20 +0000

Solaris 10 is the first version of Solaris to provide a complex set of variables for controlling password strength. The /etc/default/passwd file contains a series of parameters -- most commented out when a system is first installed -- that allow you to exercise some fairly rigorous constraints on the passwords your users may select.

How to enforce password complexity on Linux

Sandra Henry-Stocker — Mon, 07 May 2012 00:17:32 +0000

Enforcing password complexity involves making decisions about how long passwords need to be and whether they must contain a mix of characters -- such as digits, a mix of uppercase and lowercase, or special characters. In general, the rules are not hard to set up, but you need to know both the syntax and the rules to get the outcome you expect.

What makes a good password?

Sandra Henry-Stocker — Sun, 29 Apr 2012 21:02:38 +0000

Sound advice against the use of bad passwords has been around for decades. Yet I still find people electing to use passwords like pa55w0rd and login123 as if they'd never heard about password cracking programs. Even technical professionals -- programmers, help desk techs and systems administrators -- sometimes assign really weak passwords to their own and other important accounts. It's become painfully obvious to me that telling people to use good passwords isn't enough. We need to clearly define what a good password is -- and never imply that short or predictable passwords are ever OK.

A better way to learn Unix

Sandra Henry-Stocker — Sun, 22 Apr 2012 15:35:50 +0000

If you are still learning Unix or have any involvement in helping others master the command line, here's the book you have been waiting for. The Linux Command Line: A Complete Introduction (no starch press, 2012) will take you from 0 to 100 in 36 pain-free chapters.

What is access governance?

Sandra Henry-Stocker — Sun, 15 Apr 2012 22:04:11 +0000

Access governance is more than just the coolest concept since virtualization and cloud computing. It's likely to change the way you manage accounts on your servers. Designed to add clarity and control to questions like "Who has access to the recipe for our secret sauce?", it may be the answer to some of your biggest problems.

Fun with shell $ arguments

Sandra Henry-Stocker — Mon, 09 Apr 2012 14:19:16 +0000

How many special shell $ arguments do you use in your daily work? There may be a lot more of them than you think. Let's look over a bunch of them and examine how they can streamline your scripts.

How to keep yourself from losing important files on a Unix system

Sandra Henry-Stocker — Mon, 02 Apr 2012 21:45:15 +0000

If you haven't made the mistake of accidentally removed important files, you probably haven't worked with Unix very long. Here are some creative ways of keeping you from making that mistake.

Why I Love Unix

Sandra Henry-Stocker — Wed, 27 Oct 2010 12:48:34 +0000

Sandra Henry-Stocker's long-standing and largely happy relationship with Unix has been an interesting and rewarding trek. If she hasn't helped you to love Unix, let her try just once more.

Checking Your arp Entries

Sandra Henry-Stocker — Wed, 20 Oct 2010 20:45:26 +0000

One useful tool for diagnosing network troubles is the arp command -- a tool which allows
you to display the IP address to hardware (MAC) address mappings that a system has built so that it doesn't have to fetch the same information repeatedly for systems it communicates with.

Unix How-To: Checking on Collisions

Sandra Henry-Stocker — Wed, 13 Oct 2010 21:04:39 +0000

One metric that helps gauge how well your network is holding up to the strain of busy users and applications is the number of packets that slam into other packets, generating what is called a "collision". Let's check out an easy tool for calculating the collision rate for a particular network interface.

Unix How-To: Nifty One-Liners

Sandra Henry-Stocker — Wed, 06 Oct 2010 16:27:58 +0000

Today's collection of one-liners are sure to win some converts. There's nothing like a quick command that saves you a lot of trouble and just might impress your boss and coworkers that you're the cleverest person around.

Unix How-To: More Alias Quickies to Save You Time

Sandra Henry-Stocker — Wed, 29 Sep 2010 19:50:51 +0000

Today's column is a grab bag of useful aliases that will save you some precious typing time. The sysadmins I know like to type as few characters as possible, so many of these are especially terse

Unix How-To: Making Better Use of Find

Sandra Henry-Stocker — Wed, 22 Sep 2010 20:58:37 +0000

Find is not just useful for locating files, but also for doing things with the files once it finds them. You can find files based on numerous criteria -- their names, their owners, their size, etc. -- and you can then perform some operation on the files from simply listing them to changing permissions or analyzing their contents. You can also make the operation that you specify to occur only if you confirm that you want it to happen after you are prompted. Let's see how this works.

Unix How-To: Counting Anything

Sandra Henry-Stocker — Wed, 15 Sep 2010 15:23:15 +0000

A reader recently asked whether it was possible on Unix systems to count how many times a particular character appears on each line of text. "On Unix", I answered, "not only is just about anything possible, but there are usually half a dozen ways to do it".

Unix How-To: Quotes to Live By

Sandra Henry-Stocker — Thu, 09 Sep 2010 15:10:27 +0000

One of the things that really throws new Unix users is when to use quotes and which kind of quotes. Between single quotes, double quotes and back ticks, a person can start to feel that Unix is unnecessarily tricky.