Entries for January 2008
January 1, 2008 at 5:03AM Happy 2008!
Hey, everyone! Happy 2008!
Sorry to everyone who texted me and who I didn’t text back. The battery in my phone was almost dead, so I turned it off earlier. I’m just about to plug it back in, so to anybody who reads this before I text them, a happy new year to you!
January 2, 2008 at 6:00AM Death Cab for Cutie: The New Year
January 7, 2008 at 4:04PM Whenever I’m pulling data from a database in PHP...
...I keep wishing this stupid language supported lazy lists or would let me implement them in a non-sucky way.
January 8, 2008 at 11:37AM Is your Rails app giving the error “uninitialized constant ApplicationController::AuthenticatedSystem”?
If so, then you’re having problems with the acts_as_authenticated plugin. One of our customers here at work was having problems with this.
The first thing to do is to check if the plugin’s been installed. You can do this by checking the lib directory to make sure it contains the files authenticated_system.rb and authenticated_test_helper.rb, and the vendor directory to make sure it contains the acts_as_authenticated exists within it.
If they don’t, execute the following within your application’s root directory:
$ script/plugin install http://svn.techno-weenie.net/projects/plugins/acts_as_authenticated $ script/generate authenticated user account
And answer ‘N’ to all the questions the second command asks.
You should make sure that you upload the lib and vendor folders with your app.
January 14, 2008 at 3:32PM On the direct election of the Taoiseach
Bernie raises the idea of a directly elected Taoiseach. I posted the following comment (which appears to have ended up in /dev/null somehow) explaining why I don’t think this is either practical or desirable.
I have to say, while I agree with the idea of making mayors directly electable, the idea of making the office of Taoiseach directly electable seems somewhat, well, unworkable. The job of the US president is somewhat different from that of a head of state in a parliamentary democracy. While in a congressional democracy the head of the executive branch doesn’t need to have a power block in the upper and lower houses to do their job (though it helps), the head of government in a parliamentary democracy does. This is because the head of the executive branch in a congressional democracy combines most of the powers of the head of state with those of the head of government, meaning they have powers of veto, and so on, which heads of governments in parliamentary democracies don’t have.
Still, I’d say the election of the Taoiseach is at least a little more direct than that of the US President. They’re directly elected by their constituents, and then confirmed in the office by local delegates that have been directly elected to the Oireachtas.
[Aside: Yes, I know the Taoiseach is appointed by the President according to the constitution, but in reality, the President just confirms the selection of the Oireachtas.]
January 16, 2008 at 10:31PM Building an RPM package: a guide for the unwilling
This post has moved to http://stereochro.me/ideas/rpm-for-the-unwilling.
January 18, 2008 at 9:41PM The Cube
A rather odd, hour-long teleplay by Jim Henson.
This philosophical teleplay covers many themes such as, the nature of reality, individual versus scientific perception, self-reference, man’s relation to others and society, insanity, social projections, and race relations. It originally aired on NBC’s weekly anthology television show NBC Experiment in Television February 23, 1969. The production was produced and directed by Jim Henson, and was one of several experiments with the live-action film medium which he conducted in the 1960s, before focusing entirely on the Muppets and other puppet works. The screenplay was co-written by long-time Muppet writer Jerry Juhl (who also appears in a cameo).
[Wikipedia page for ‘The Cube’]
January 21, 2008 at 1:34PM Port management tools from my ~/bin directory
Here’s two small tools I have in my ~/bin directory. The first one, check-deps, checks the upwards and downwards dependencies for each package are consistent:
#!/usr/bin/env python
from __future__ import with_statement
import os
PKG_DB = '/var/db/pkg'
def each_dep(lines):
"""Extracts the package dependencies from the iterable."""
return (line[8:-1] for line in lines if line.startswith('@pkgdep '))
# Figure out from the dependencies which packages are required by which.
reqs = {}
for pkg in os.listdir(PKG_DB):
path = os.path.join(PKG_DB, pkg, "+CONTENTS")
if os.path.isfile(path):
with open(path) as f:
for dep in each_dep(f):
if dep not in reqs:
reqs[dep] = set()
reqs[dep].add(pkg)
# Check that the currently recorded ones are valid.
for pkg in reqs.keys():
path = os.path.join(PKG_DB, pkg, "+REQUIRED_BY")
if os.path.isfile(path):
with open(path) as f:
for line in f:
line = line[:-1]
if line in reqs[pkg]:
reqs[pkg].remove(line)
else:
print "===>\tErroneous dep '%s' in '%s'" & (line, pkg)
if len(reqs[pkg]) == 0:
del reqs[pkg]
else:
print "===>\t%s does not record:\n%s" % (pkg, "\n".join(reqs[pkg]))
if len(reqs) == 0:
print "All clean!"
The second one, check-packing, checks that the file manifest for each port is correct and that all the files are intact by comparing them against their recorded MD5 hashes:
#!/usr/bin/env python
from __future__ import with_statement
import os
import hashlib
import sys
PKG_DB = '/var/db/pkg'
def each_file(f):
"""
Generates a list of tuples, the first element being an absolute file
path, and the second being its recorded hash, from a package manifest.
"""
cwd = ''
file = ''
try:
for line in f:
if line[0] != '@':
file = os.path.join(cwd, line.strip())
elif line.startswith('@cwd '):
new_cwd = line.split(' ', 2)[1].strip()
# This check is a hack for dealing with broken manifests.
# mysql-client-5.0, nss, pth, portupgrade and zsh are
# examples.
if new_cwd != '':
cwd = new_cwd
elif file != '' and line.startswith('@comment MD5:'):
digest = line.split(':', 2)[1].strip()
yield (file, digest)
file = ''
finally:
pass
def hash_matches(path, original_hash):
"""Checks if the given file matches a hash."""
with open(path) as f:
new_hash = hashlib.md5(f.read()).hexdigest()
return new_hash == original_hash
for pkg in sorted(os.listdir(PKG_DB)):
path = os.path.join(PKG_DB, pkg, "+CONTENTS")
if os.path.isfile(path):
print "===>\tChecking %s" % (pkg,)
with open(path) as f:
for (file_path, hash) in each_file(f):
try:
if not os.path.exists(file_path):
if os.path.islink(file_path):
print "Missing: %s -> %s" % (file_path, os.path.realpath(file_path))
else:
print "Missing: %s" % (file_path,)
elif not os.path.islink(file_path) and not hash_matches(file_path, hash):
print "Altered: %s" % (file_path,)
except KeyboardInterrupt:
raise
except:
print "Unchecked: %s" % (file_path,)
They might be useful to someone.
Update (Feb 12th): Removed some stupid inefficiencies in how the files are hashed.
January 22, 2008 at 10:25AM Audiosurf - Chemical Brothers’ Star Guitar
Audiosurf is insane:
Here’s the original Michel Gondry video:
January 25, 2008 at 11:52PM Merging .iso files on Debian, Ubuntu, and most likely Linux in general
I hardly ever have to do this, so I can never remember precisely how to do it. Hopfully by noting it here, I won’t forget again.
Specifically, I want to do this so that I can create a single DVD image from the FreeBSD 6.3 CD images I have. Here’s more-or-less how it goes:
mount -t iso9660 -o loop disc1-mountpoint mount -t iso9660 -o loop disc2-mountpoint mkisofs -l -J -R -o dvd.iso disc1-mountpoint disc2-mountpoint
Don’t forget to unmount those mountpoints afterwards.
Here’s a shell script to do the work. It assumes it’s in a directory with a subdirectory called isos, which contains the source .iso images. It has no error handling, so the usual caveats apply:
#!/bin/sh
rm -rf mnt contents
mkdir mnt contents
for i in isos/*.iso; do
mount -t iso9660 -o loop $i mnt
cp -av mnt/* contents
umount mnt
done
# This bit is specific to merging FreeBSD .isos.
sed -i -e 's/^CD_VOLUME = .$/CD_VOLUME = 1/' contents/cdrom.inf
sed -i -e 's/|.$/|1/' contents/packages/INDEX
mkisofs -l -J -R -o dvd.iso contents
rm -rf mnt contents
And here’s how you merge several .iso files into a single one on FreeBSD, and how to do it for FreeBSD .iso images.