Cascading Stylesheets are a brilliant and now ubiquitous mechanism for styling webpages. Draw borders, add colors, arrange the content, and make the whole site look presentable. Of course, CSS is not perfect.

The major annoyance for me has been the lack of support for variables. I’d like to say, “I want the same color on this border, this text, and this background,” or, “I want this padding to be the same as this margin and that border width.”

Sass solves this problem by extending the CSS language. Any valid CSS file is already valid SCSS, but in an SCSS file you can do a lot more. Whenever you change your SCSS file, sass automatically recompiles it into a valid CSS file. Browsers are indifferent, since they’re just getting standard CSS all along, but web authors get a much better development experience.

Variables are of particular interest to me, and sass supports them:

$color = #efefef;
.something { border-color: $color; }
.something-else { background: $color; }

And that’s only the beginning. Variables can also be used in mathematical expressions (e.g., width: $standard-width - 10px; to account for some padding, perhaps), and even in functions that generate CSS rules with slight variations.

I also particularly like the ability to add “parent references”:

#some .lengthy .selector a {
    color: black;
    &:hover { text-decoration: underline; }
    &:visited { color: purple; }
}

I just started using SCSS, and I already love it.

Whitson Gordon at Lifehacker just revealed the most exciting thing I’ve ever learned about Mac OS X: the secret to opening two instances of the same application simultaneously.

Unlike Windows, Mac OS X normally only opens each application one time. Then as you try to open new files the application just creates a new window for each one. This is ordinarily no problem at all — you can still have as many PDFs open in Preview as you want; there will just be only one Preview icon in the dock or in the ⌘→ switcher.

But what if you want to open the same file twice? That’s not possible! And what about applications like VLC that only open one window at a time? There, each new video you start playing replaces the previous one.

Opening a file with open -n changes all that. And my life is now happier for it.

Clifford Stoll wrote The Cuckoo’s Egg in 1989, telling the true story of how he started investigating 75¢ of computer time nobody had paid for and ended up catching an international hacker passing through his computers to gain access to military secrets. The classic story is a fascinating mix of technical detail and the thrilling action of hunting an invisible criminal through the phone lines.

My favorite passage, though, comes at the very end. After the overseas spy is caught and brought to justice, another hacker slips into Stoll’s system and for a moment the whole process starts over again. Stoll writes:

He got in through an unprotected astronomy computer run by a couple of infrared astronomers. They didn’t care about security . . . they just needed to connect to the network. Because I exchange programs with them, we’d set up our systems to work as one—you didn’t need a password to move from their computer to mine.

…

A couple days later the SOB called me. Said his name was Dave. From Australia. “I broke in to show that your security isn’t very good.”

“But I don’t want to secure my computer,” I replied. “I trust other astronomers.”

And that’s the moral, as true today as in the 1980s. We don’t want to secure most systems. Certainly I wouldn’t want my online bank account accessible to common thieves, but a database of research or a casual blog shouldn’t require elaborate protective measures.

This is just as true in the physical world. I wouldn’t put my valuables in a bank vault with no lock, but the classroom doors where I went to college were always open.

Unfortunately, in software0 leaving any door unlocked can grant access to resources beyond the application itself, so we sink a fortune into securing even the most trivial of software against all imaginable attacks. That’s a high price to pay for protection against the pranks of mischievous hackers.

I recently tried creating a new database table only to learn a table with that name exists already.

[me@mysql db] > CREATE TABLE log_search (
log_search_id BIGINT UNSIGNED AUTO_INCREMENT NOT NULL
, search VARCHAR(255)
, created_by VARCHAR(128), created_on DATETIME)
 ENGINE=InnoDB CHARSET=utf8;
ERROR 1050 (42S01): Table 'log_search' already exists
[me@mysql db] > DESC log_search;
+---------------+---------------------+------+-----+---------------------+----------------+
| Field         | Type                | Null | Key | Default             | Extra          |
+---------------+---------------------+------+-----+---------------------+----------------+
| log_search_id | bigint(20) unsigned |      | PRI | NULL                | auto_increment | 
| search        | varchar(255)        |      |     |                     |                | 
| created_on    | datetime            |      |     | 0000-00-00 00:00:00 |                | 
| created_by    | varchar(128)        |      |     |                     |                | 
+---------------+---------------------+------+-----+---------------------+----------------+
4 rows in set (0.00 sec)

I love naming conventions!  My favorite part of programming is when I start to write a routine only to learn I already wrote it months ago in preparation for what I knew I’d be doing now.