Joe Dog Software

The things Your JoeDog will do for you….

A couple weeks ago he complained about Valgrind (and probably a whole bunch of other stuff but we’re talking about Valgrind now). His snippet was leaking memory and valgrind was unable to identify the leak. The leak was manually identified in this function:

ARRAY
array_destroy(ARRAY this) 
{
  int i;

  for (i = 0; i < this->length; i++) {
    xfree(this->data[i]);  
  } 
  xfree(this->data);
  this = NULL;
  return this; 
}

While we freed the elements of the array, we never freed the array itself. The leak is fixed like this:

ARRAY
array_destroy(ARRAY this) 
{
  int i;

  for (i = 0; i < this->length; i++) {
    xfree(this->data[i]);  
  } 
  xfree(this->data);
  xfree(this);
  this = NULL;
  return this; 
}

Today Your JoeDog was coding on the train again.  Before he boarded, he downloaded the above code onto his snazzy Linux laptop.  He was turning caffeine into code when wouldn’t you know it? Another stinkin’ memory leak. “What the hell,” he thought. “Let’s give valgrind another try.” Unfortunately it wasn’t installed on snazzy Linux laptop. For some reason, Amtrak’s proxy won’t allow downloads larger than 10MB. Stupid Amtrak.

That’s easy to bypass. Your JoeDog established an ssh tunnel from his laptop to this webserver and proxied to the Ubuntu repository.

--2014-10-25 10:15:13--http://us.archive.ubuntu.com/ubuntu/pool/main/v/valgrind/valgrind_3.10~20140411-0ubuntu1_amd64.deb
Resolving localhost (localhost)... 127.0.0.1
Connecting to localhost (localhost)|127.0.0.1|:11111... connected.
Proxy request sent, awaiting response... 200 OK
Length: 15078790 (14M) [application/x-debian-package]
Saving to: ‘valgrind_3.10~20140411-0ubuntu1_amd64.deb’

100%[=============================================>] 15,078,790 290KB/s in 73s

2014-10-25 10:16:26 (202 KB/s) - ‘valgrind_3.10~20140411-0ubuntu1_amd64.deb’ saved [15078790/15078790]

ARRAY
array_destroy(ARRAY this) 
{
  int i;

  for (i = 0; i < this->length; i++) {
    xfree(this->data[i]);  
  } 
  xfree(this->data);
  //xfree(this);
  this = NULL;
  return this; 
}

There’s rumors on the Internets. “Oh, really? What do they say?” They claim your posting frequency affects Google’s crawling frequency. The more you update, the more often it crawls.

Your JoeDog wanted to scrutinize this hypothesis. He wanted to monitor his logs and compare Google’s crawl rate against his web site updates.

So he added this rule to fido.conf

/var/log/httpd/joedog-access_log {
 rules = Googlebot
 action = /home/jeff/bin/googler
}

With that config he produced this document: google.txt

“J!!!!!!!!” Funk shouted in IRC. “You need to verify Googlebot”

“You mean a lot people forge that User-agent?”

“I’ll bet forty percent is forged.”

“D’oh!”

Fido can’t validate an IP address, nor do I want it to. Still, it needs a new feature, namely the ability to interact with its action script. Your JoeDog will add support for regex capture to his rules. This will allow you to capture part of the match and send that text to your action script.

“I have no idea what you just said.”

Okay, let’s modify the rule above with its intended implementation:

/var/log/httpd/joedog-access_log {
 rules = ([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+).*Googlebot
 action = /home/jeff/bin/googler
}

The parentheses are highlighted in red because they represent the proposed feature.

On a match, fido will capture everything inside the parentheses and send it as argument 1 to the googler script. In this case it will be an IP address which googler can then verify as one that belongs to Google. If you have multiple captures, fido will send them as space separated arguments, i.e.,  /home/jeff/bin/googler  173.240.11.11 GET /index.php

For a sh script, $1 = 173.240.11.11, $2 = GET and $3 = /index.php

If all I wanted to do was solve this problem, I’d just write a script that parses the logs. However, I think this will be a valuable feature that will allow fido more flexibility to solve all the world’s problems.

Your JoeDog hasn’t spent much time blogging about Bitcoin but it does interest him for two reasons: 1.) He studied economics in college and 2.) The rogue currency has a technology/Internets angle. From an economics perspective, a successful currency must provide a medium of exchange and serve as a reasonably stable store of value. Bitcoin certainly provided the former but the latter was always in doubt.

And doubt won. Since its peak, Bitcoin has lost two-thirds of its value. Its bust was obviously not without victims. From Izabella Kaminska, we hear the story of one of those victims. Redditor Whattodobtc appears to have impoverished himself with bad bets on Bitcoins.  Izabella claims, “Some extremely wealthy libertarians have a lot to answer for if these sorts of ppl lose all due to believing in them.” Your JoeDog is certainly no libertarian but he feels the burden of risks should be placed on those who take them.

Certainly there have been influential libertarians who’ve been pushing Bitcoin as a hedge against fiat money. And if people like Whattodobtc better understood currency, they’d be less inclined to go long on a Libertarian pipe dream. But is this any different than the hucksters who shilled gold as a hedge against non-existent hyper-inflation? If you believed Glenn Beck back in 2012 and sunk your savings in gold, you lost 36% of your investment. That’s not as depressing as Whattodobtc’s story but it’s equally devoid of a happy ending.

Whattodobtc posted to Reddit because he wanted advice. Should he sell or weather the storm? He should have posted a similar inquiry before he sunk his savings in Bitcoin. Personally, I’d sell now before all I had left were some worthless binary numbers.