Shaun's Place

Wireless Perceptions

It has come to my attention that wireless is still considered somewhat amorphous and, as a result, I’ve seen some pretty interesting misconceptions.

How does our wireless work?

Small radios have a limited range so we have many of them all over campus. Sometimes they are in visible locations and sometimes they are hidden in closets or above ceilings. But, if you are receiving MUSTANG or MORNINGSIDE wireless networks, one must be nearby.

Every radio on campus is configured centrally to handle both MUSTANG and MORNINGSIDE networks.

In fact, MORNINGSIDE and MUSTANG share a number of features:

Both run on 5Ghz and 2.4Ghz spectrum, allowing both bands to connect.
Both run on every radio on campus.

What is the difference between MUSTANG and MORNINGSIDE?

MORNINGSIDE encrypts traffic passed through the air. MUSTANG does not.
MORNINGSIDE is authenticated. Because you log in with your Morningside credentials, Staff and Faculty are given more access than they would be on MUSTANG.
MORNINGSIDE will be faster. MORNINGSIDE has “High throughput” features of 802.11n enabled, while MUSTANG does not.

MORNINGSIDE is faster?

Yes. Sitting in my office, I benchtest 15.8Mbps on MUSTANG and 58.1Mbps on MORNINGSIDE. Everything is the same except for changing from MUSTANG to MORNINGSIDE.

How to attach to a remote emacs session

I was away from my workstation which was running an emacs with several open files (some potentially unsaved!) when I wanted to access some of those files.

My emacs is always configured to run the server process. This means I can start an emacs process and edit any file with `emacsclient $file`. Instead of a new emacs process, the file is opened by my original emacs.

I was curious if I could use emacsclient to connect remotely to a running frame: I can. By ssh’ing in I can run `emacsclient -nw` (no-window) and get a new frame of that emacs client in the terminal which has all my buffers open and ready to go.

Alternatively, if you’re forwarding X connections, using `ssh -X` for instance, `emacsclient -c` will fire up a new emacs frame on your local machine which shares the same emacs process.

More information: http://www.emacswiki.org/emacs/EmacsClient

Naive Programming

I think that may always be the case, especially when the resulting program is a function of what I’m asked to do! I was instead considering how, give experience in mathematical reasoning and programming, one writes increasingly concise code.

Because of the intense usefulness of Maths in programming, I cannot grok my fellow students’ disapproval of the subject. One of the major ways my code has grown less naive is in the borrowing of mathematical concepts.

Naive:

// print the sum of numbers x through y.
int sum(int x, int y) {
  int s = 0;
  for (int i = x; i <= y; i++)
    s += i;

  return s;
}

Insightful:

// print the sum of numbers x through y.
int sum(int x, int y) {
  return y*(y+1)/2 - x*(x+1)/2; 
}

I cannot remember a time when a working insightful function has been worse then the naive equivalent. Even in my contrived example above the naive_sum() has inputs which would yield undefined output such as the case where y <= x while the insightful_sum() would degrade more gracefully.

In the naive style, we’d have to add conditionals to validate inputs that the maths would accept, meaning increased line count, reduced legibility, increased chance of errors, and increased nativity. The only advantage I can see to the naive style is the reduction in mathematically cluttered code.

FreeBSD on the Desktop: How much are we giving up?

I’ve been running FreeBSD for awhile now. Looking back at my posts, it appears that I hammed up my Slackware installation right around the turn of the new year so near abouts three-and-a-half months.

FreeBSD on the desktop, if you’ve experienced it, is a learning experience. So much that at times I feel like I’m being punished for not knowing everything about my system.

To clarify on my desktop history you should know that a few months ago I switched to xmonad for my window management from Fluxbox. I went from an already minimal window-manager to an an even more minimal window-manager.

I don’t want my desktop to do everything for me all the time. On the other side of the coin, I don’t want to have to do everything for it.

I was reminded of this disconnect when I fired up Fedora 16 on a machine at home (it was running FreeBSD but I was sick of compiling packages from ports. Yes, I know I can get packages in binary but I can’t understand how to keep my binary packages and ports in sync for cherry picking every other source.) Everything just worked together.

After installing emacs and copying my global .emacs.d/ things are just working. After a `yum install xmonad` I am able to login under xmonad. I see they’ve even included a .xmonad/ in my home.

The Fedora developers must have a picture in mind of how the system should be and it appears that all packages have been designed with this picture in mind.

I don’t know what this means for FreeBSD. The craftsmanship of the FreeBSD project never ceases to amaze me. I love just setting my variables in rc.conf. However, it seems to me that more work needs to be done to integrate binary and source versions.

Some ports build against the kernel source. Why is my /usr/src not updated by freebsd-update? (Update: yes, it can update /usr/src.)

If FreeBSD could solve the Package vs Ports dilemma, and if packagers provided more apparent defaults for settings then FreeBSD would be a very strong desktop. I’m sorry that everything I plug in isn’t automagically configured, but doing that is complex and what is convenient for me may be inconvenient for the masses.

In the coming days, I do see myself spending some time contemplating the differences in experiences. FreeBSD truly is the unknown giant.

Mp3’s and blog posts.

Word on the street is that Morningsiders would like to embed MP3 files in their posts.

This sounds like a cool idea, so I’ve sat down and see that WordPress can already do something like this:

brobob

Sounds good. How to do it?

Step 1, have a mp3 file. =) That’s easy.

Step 2, choose “Upload/insert” from the post screen.

Step 3, choose your mp3. Enter some details about it and select enter into post.

Step 4, enjoy.