Get off my lawn.

Tuesday, June 27, 2006

Screwing oneself on a secure OS

Here's today's commandment in system administration when dealing with a secure OS:

"Thou shalt Know what commands do before thou doest execute them."

I added a group to my Linux box, intending to add my own userid to that group to give myself access to certain functions on the machine. So, I typed the following command:

/usr/sbin/usermod -G (groupname) (username)

...where "(groupname)" and "(username)" are, of course, not the actual values I used.

The important thing is that "-G" switch. My meaning was "Add the specified userid to the specified group". Which it did. What it also did was to remove the specified userid from every other group." I forgot the "-a".

The effects are many and immediately noticeable. Playing audio is suddently out of the question. So is accelerated video, or plugging USB devices in, or (worst of all) fixing the aforementioned problems, since this system doesn't have a discrete "root" user for things like that, and I just kicked myself out of the A/V club called the "admin" group. If I try to do any of those things, the velvet rope comes up, and I'm kicked out of the party going on in my own house. I'm free to stand in the entry way, and think about how cool it would be to go elsewhere, but that's about it.

This is the second time I've screwed something up on a *nix machine while running as "root" (not couning the time that SuSE wiped out my wife's partition table while installing alongside Windows. I wasn't "root" then, anyway.).

The first time, I was young and reckless, and I deleted /etc/passwd, intending to replace it with a backup (but forgetting to do so). I logged out, and got a prompt that said "I don't know you." I tried logging in elsewhere. "I don't know you." I talked to the computer like Scotty on Star Trek, yelling directly into the mouse, microphone-style, and got the same response.

I think it's kind of interesting that, in both cases, the computer came out of the knife fight just fine. It just sits there fending off my attempts to log in. If I were to reboot my Linux system without fixing the problem, it would continue to just work like it does now (kind of like a plane on auto-pilot).

Well, it's not that interesting. I guess I better fix it.

Saturday, June 24, 2006

Delorean's drummer

Andrew is going to start band practice for school soon, so he and I went to Guitar Center today to pick up a snare drum for him.

Saturdays being what they are, Guitar Center was overrun by a crowd of teenagers beating on the various drumsets around the place. Andrew eventually took a turn, so I went over to look at the snare drums. A red-haired girl standing there said that I ought to look at the piccolo snares, since they sound good in a marching band. Talking to her further, I came to find out she played drums. She was really helpful and unassuming. I thought, "How nice. A nice girl. Playing drums. " Eventually, she got a turn at a drumset. It's hard to describe what happened next.

Imagine lighting one of those little ladyfinger firecrackers, expecting to hear a sound like someone snapping their fingers. Then, it explodes hard enough to knock your house over, kill your pets, and leave a 100ft. crater in the ground. (Dang. Wasn't expecting that...)

She played with a skill level and ferocity I've rarely seen in top-tier drummers, and have definitely never seen from some kid hanging out a GC on a Saturday. Andrew was standing there wide-eyed, giggling, and I was too. It was kind of a cool mix of styles, too. Complicated beats, jazzy-sounding high-speed fills, and double-bass work that would cripple Danny Carey. It was not only technically good, it sounded like music. Seriously. I'm a Rush fan. If I saw Neil Peart do what she was doing, I would have said "Wow. After all this time, he's still the man!"

It turns out she's in a band called DeLorean, and they're playing around the KC area. They have a myspace site, There appear to be downloads available there, so I'm going to check them out. I haven't heard them yet, so I don't know if Delorean is collectively as good as their drummer. But she's good!

Tuesday, June 13, 2006

Good news

My buddy Cooper went into the hospital a couple of days ago for brain surgery.

He has had persistent headaches for the past few years, and finally had something done about it a couple of weeks ago. He underwent an operation where they used some kind of router to clear out his sinus cavities. (Kind of like getting your head ported and polished.)

He came out of that with a voice that sounded kind of like Dennis Leary, and he still didn't appear to feel very well.

Last Saturday, he started getting dizzy and sick. He went to the emergency room where a scan was done, and they found a brain tumor. (By the way, hearing that one of your best friends has a brain tumor is about like getting hit in the stomach with a baseball bat. Not cool.)

Doctors were 85% sure that the tumor was benign, and were confident they could get the tumor out. His family was pretty upbeat, considering the situation.

Yesterday he went into surgery, while a lot of people prayed for him. It apparently went well. The latest word is that the tumor is gone, and that Cooper is hungry, wants some coffee, his iPod, his Blackberry, and to go home.

Some (including Cooper) were concerned about possible after-effects of the surgery. Motor skills can be affected by brain operations, as can higher functions. Cooper seems to be okay, with the following notables:

  1. He is now left-handed.
  2. He can calculate pi out to 243,182 digits in his head.
  3. He is terrified of clouds.
  4. He has lost awareness of 2 letters of the alphabet: "K" and "L", and words containing them.
  5. No matter where you are in the world, if you tune your FM radio to 88.5, you can hear his thoughts (in French).

#1 can be remedied with intense therapy.
#2 is a handy thing to be able to do, especially if you're an architect.
#3 and #5 can be accounted for by wearing a metal hat.
#4 is not really an issue since he's known only by the name "Cooper" (kind of like Cher is only known by one name) and it contains neither of the lost letters.

The good news is that after so long having headaches, he's likely to feel really good now. The clean sinus cavities he has now are a bonus.