The modification date the script reported was correct, but the creation date the script reported was different from the creation date that doing “Get Info” in the OS X Finder reported. Hmm. Not good. I did some investigating.

Let’s look at a test file. The Finder reports the following creation and modification dates:
Created: Monday, April 10, 2006 17:04
Modified: Thursday, April 13, 2006 15:54

Python reports a different creation date and the same modification date:

>>> import os.path
>>> import time
>>> stamp = os.path.getctime('datetest.txt')
>>> time.ctime(stamp)
'Fri Apr 10 15:51:10 2009'
>>> stamp = os.path.getmtime('datetest.txt')
>>> time.ctime(stamp)
'Thu Apr 13 15:54:43 2006'

Hmmm. What does “ls” in the Terminal report? The standard “ls -l” reports creation date. Adding “-T” makes it report the full date in all cases. And “-c” counter-intuitively means “display modification date.”

$ ls -lT datetest.txt
-rwxr-xr-x@ 1 schof  schof  2448091 Apr 13 15:54:43 2006 datetest.txt
$ ls -lcT datetest.txt
-rwxr-xr-x@ 1 schof  schof  2448091 Apr 10 15:51:10 2009 datetest.txt

The plot thickens. The modification date matches the Finder and Python, but both Python and ls are reporting an incorrect (according to the Finder) creation date.

Quite a bit of Googling showed me the “mdls” tool — or “metadata ls.” Very useful. This shows the complete set of metadata for a file. Including the OS X creation date. Actually, two creation dates, one for the file, and one for the file content. (I’m not sure what circumstances would make those creation dates differ. The documentation I’ve been able to find has been unclear and contradictory.)


$ mdls datetest.txt
kMDItemContentCreationDate     = 2006-04-10 17:04:34 -0700
kMDItemContentModificationDate = 2006-04-13 15:54:43 -0700
...
kMDItemFSContentChangeDate     = 2006-04-13 15:54:43 -0700
kMDItemFSCreationDate          = 2006-04-10 17:04:34 -0700
...
kMDItemLastUsedDate            = 2009-04-11 11:48:03 -0700
kMDItemUsedDates               = (
2009-04-11 00:00:00 -0700
)


Now that we’ve got all that information, what does it tell us? The Unix/Linux standard for “creation date” is to show you the date on which a particular file was created. If you copy file “a” to file “b,” those are two different files, and the “creation date” for file “b” will be the date you made the copy.

OS X metadata travels with the file, so if you copy file “a” to file “b” using ditto on the command-line or using the Finder, the Unix creation date will be the date the copy was done, but the OS X creation date of file “b” will be the same as file “a.”

There’s good arguments for handling “creation date” the Unix way, and there are good arguments for doing “creation date” the OS X way, but mixing them as OS X does is kind of frustrating.

I’ve written a quick-and-dirty Python example script that reports the Unix creation date and the OS X creation date for any particular file. Since it’s released under the open-source MIT license, feel free to use it in your own programs. You can download it here: http://www.sudosu.net/getcreationdate.safe.

(Shortest review I’ve ever written.)

While I don’t agree with everything Joel has written, I find most of what he writes to be a clear exposition of common-sense approaches to managing software development. No BS, just simple stuff that works. A small percentage of “Joel On Software” is mind-changing, opening your eyes to new ways of doing things or new ways of thinking about old software.

Highly recommended.

First, lose the headphones. That didn’t affect our decision at all, but I could imagine it affecting it at other companies.

Second, you’re obviously intelligent and capable. You messed up on the unit test, but I’m attributing that to interview nerves – I’m reasonably certain you could handle the technical demands of the job. But that’s only the first hurdle.

The next is personality and fit with the company — and this is a sticky one. In an interview, I’ve got about an hour to decide if you’re the kind of person I want to spend the next three or more years with, in relatively close quarters. Can you argue a position strongly, but lose gracefully? You may be right about the technical merits of something, but the business reality means we have to do something else — can you live with that? On a good day, we go two steps forward and one step back — bad days it’s one step forwards and two steps back. Can you deal with that frustration? I received certain cues from you — interrupting, hitting the table during the coding test, etc. — that you might have been hard to work with. Is that true? I can’t tell in an hour. But saying “no” to a candidate who would have been terrific is a smaller risk than saying “yes” to a candidate who turns out to be a bad hire.

I hope you appreciate my honesty in writing this, rather than brushing you off with “not a good fit.” I did so because I think your question about your interview performance is sincere, and I’m hoping my answer helps.

If it’s not obvious from reading the e-mail, Rands has been a big influence on my management style.

But in general, I’m finding SPBS both challenging and a hell of a lot of fun. It’s turning into a bigger project than I expected — or perhaps, a better way of saying it is that SPBS is slowly revealing its complexity to me. I could get this done a lot fast by adapting pyBloxsom. But where’s the fun in that? {grin}

I’ve written an introduction to SPBS, and the reasons I’m writing it here, at http://code.google.com/p/spbs/wiki/SPBSIntroduction

python `python -c “import pimp; print pimp.__file__”` -i readline

Moral? If at first you don’t succeed, Google. If Google fails, try, try again.

Update: And to make forward-delete work, try this.

Some background: There’s a very useful website located at whatismyip.com, which reports the IP you used to connect to the site. If you’re on a computer behind a router which does NAT (Network Address Translation), you can’t find out what your external IP is by issuing commands on the computer. Your computer’s address is (for instance) 192.168.1.5, but when traffic reaches the router, the router translates (with NAT) your address to an external IP address, such as 34.23.64.9 (an IP address I just made up).

WhatIsMyIP.com (and other sites like it) sprang up to fill that void, and give you a simple way of finding out what external IP address you’re using.

Ubuntu Geek’s script fetches the whatismyip.com page with wget, parses it to find the IP address, and prints the IP address.

I tried it on my OS X box, and it didn’t work, because wget isn’t installed on OS X — but curl, a similar tool, is.

So I started modifying the script to use curl — and discovered an interesting comment in the source code to whatismyip.com’s page:

<!–Please set your code to scrape your IP from www.whatismyip.com/automation/n09230945.asp Please set your code to hit this page at a REASONABLE pace. For more info, please see our “What’s New” page.–>

Hitting that link gets you just your IP address, which has two benefits over Ubuntu Geek’s implementation — it means you have no parsing to do, and it gives a SIGNIFICANTLY lower load to WhatIsMyIP’s servers. (It’s rude to slam someone else’s servers with an automated script — even though a script that simply fetches a web page once doesn’t slam a server, 10,000 people running that script would.)

Here’s my take on Ubuntu Geek’s BASH script:

#!/bin/bash

echo -n “Your external IP Address is: ”
curl http://www.whatismyip.com/automation/n09230945.asp
echo “.”

For comparison’s here’s Ubuntu Geek’s original script:

#!/bin/bash

echo Your external IP Address is:
wget http://Www.whatismyip.com -O – -o /dev/null | \
grep ‘<TITLE>’ | sed -r ’s/<TITLE>WhatIsMyIP\.com \- //g’ | \
sed -r ’s/<\/TITLE>//g’
exit 0

Moral of the story? Always look for a simpler way of doing things.

Talking about a software development schedule more than a year out is like talking about where we go after we die.  Everyone has some idea where we’ll end up, but those ideas differ wildly, and there’s a lack of solid evidence to support any of them.

(Via)

You can remove all “.svn” directories starting below “~/svn/exampleproject” — change this to suit your system — with the following command:

find ~/svn/exampleproject -name “\.svn” -exec rm -rf {} \;

To make sure that the above command is going to do what you want it to do, you may want to first generate a list of what it will delete (I highly recommend it).

find ~/svn/exampleproject -name “\.svn” -exec echo “rm -rf {}” \;

Text editing is TextMate. I was trying to use vim, because it’s one editor I can use both on my OS X desktop and SSH’d across the network to linux boxes. I will continue to use vim remotely — though I may look at emacs as well. But for local editing, it’s TextMate for sure. Its functionality when dealing with large source code files and trees with many different files is impressive — I can see myself working significantly more efficiently with TextMate.

I’m used to working on the command-line with Subversion, but TextMate integrates with it, so I can commit changes by hotkey, etc.

And Python is rapidly becoming my system administration language of choice. All of this seems to fit together really well.

I found a different binary at Martin Ott’s site. I have no idea why his site isn’t linked from Subversion’s, but his binary is 1.4.3, the latest.

Simply run the installer in his package, and it will do ALMOST all that’s needed. However, you still won’t be able to run svn from the command-line, because the package installs it in /usr/local/bin, and that path isn’t in Apple’s default.

For those new to the terminal, the path variable is a list of directories where OS X should look for applications. This applies only to the command line. For instance, if you type “ls” on the command line, it will look for the “ls” program in each directory listed in the path. Since it finds it in /bin, it will run ls. The path is why running “ls” is the same as running “/bin/ls”.

To find out what your path is currently, enter the following command: “echo $PATH”

(Capitalization does matter.)

To add /usr/bin/local to your path, copy and paste the following line into your terminal:

echo “export PATH=$PATH:/usr/local/bin” >> ~/.profile

This will not affect the shell you’re running now, so type “exit” to leave the shell. Then hit CMD-N to get a new terminal, and type “svn”

You should get a message telling you to type “svn help” for more information. Success, svn is installed and configured properly.

I’ve been looking at the long list of technologies I need to master for work. (And quickly!) I’ve also been looking at the even longer list of technologies I’m interested in and would like to study in depth.

Clearly, I can’t do it all. Not immediately, at least. (And certainly not at the same time.) I need to be selective about what subjects I choose to tackle. But I also need to maximize my chances of being able to tackle these subjects.

As far as I can tell, that boils down to two main areas where I need work:

1) Time Management
2) Life Management

This was all brought about, by the way, by an excellent article I read by Steve Friedl about the process he went through penetration-testing a web app using SQL injection. Great article, but reading Steve’s site really brought home some areas where I need to update my skills.

Time Management

In poker, there’s the concept of “plugging leaks in your game.” Poker is a game of percentages, of making the best decisions possible given incomplete information, stress, and a variety of complicating factors. You can play well (even be a winning player) but have certain situations where you habitually don’t make the optimum choice. Maybe you don’t recognize the value of a certain pair of cards. Or you are easily bluffed when you’re short on chips. In any case, it’s a leak that, if plugged, can increase your overall win rate, sometimes significantly.

I feel I’m generally very productive, but I need to plug my leaks. I use NetNewsWire to keep up on a variety of tech news sites — and I’ll have to keep doing that, because knowing what’s coming (or what’s here right now) is vital to my current job performance and to my career in general. But I also have a number of non-tech-related feeds in NNW. Things like Slate.com. Warren Ellis. Others. I keep them segregated in an “Entertainment” folder, and don’t read them during work hours. But I want to maximize the return on effort I get while sitting at my computer — so I can use my non-computer time for things like hiking with K., my girlfriend. So all the non-workish feeds go. That’s a start.

I’ll have to work on disciplining my appetite for tech feeds, as well. Cutting out the less-vital ones, and making a list of the longer articles to read later, instead of reading an article on SQL Injection when I could be doing work with more of an immediate payoff.

In general, I’ll just have to be aware of how I’m spending my time.

Life Management

In terms of optimizing my life, I need to eat better, sleep better, and exercise more. Spend more time with my friends, as well. (Although right now much of my non-work time is spent with K. — I need to make an effort to keep my other relationships well fed as well.)

Right now I eat well on weekends with K., but my weekday diet is strictly bachelor-squalor — cheeseburgers, burritos, and sandwiches. (I’ll be sad if I have to give up Bay Cities Deli.) If I can make time to pick up some vegetables-in-a-bag before work, and perhaps some chicken or fish, I’ll be able to have nutritious lunches and dinners at work. (I’ll be sad again if I give up my bagel-and-cream-cheese breakfasts. Not sure what I’ll do there.)

I’ll need to get to sleep a little earlier too. I get home from work usually between 8:30 and 9:30 PM — and it often takes me a while to run down before I’m tired enough to sleep. I think exercise will help with that, though.

I love taking hikes when I get home from work (I live in the Santa Monica Mountains, and there’s lovely parks for hiking within walking distance of my house.) but I’m not crazy about hiking at night. I’ve done it, and it’s quite calm and peaceful — but sometimes a bit creepy, too. And even though I stick to fairly well-maintained trails, there is a slightly greater chance of losing my footing and breaking something, with nobody likely to come by until morning. And if I’m getting home from work at 9:30, there’s just no way I’m going for an hour’s hike.

So that leaves mornings. (Just hiking on weekends isn’t going to do much for my overall energy level. You need exercise 3-5 times a week for that.) I get up at 7:30 normally. Tonight I’ll set the alarm for 6:30, and get a short hike in before breakfast. If I can keep that up every morning (or at least most mornings) I’ll be in good shape for the rest of things I’m trying to do.

It’s a pretty ambitious plan I’ve set out for myself here. I’ll keep you posted on how I do. It took me almost two months to read a 5-page document on procrastination. Don’t hold your breath. But do cross your fingers for me.
UPDATE: I wrote this last night but didn’t post it until this morning. In the meantime, I went for an hour hike in my neighborhood — on a trail straight up a hill for 40 minutes, then 20 minutes back down to home. My calves are sore but I feel great! I’ll post more about my hikes and my general progress with the non-technical aspects of this plan.