»
Upgraded to WordPress 3.6. The admin bar went missing on the front end…

Blockquoted code blocks

Written in the mid-afternoon in English • Tags: , ,

I’ve been writing in Markdown for nine years now, because it allows me to spend more time on content as opposed to formatting. Using it with WordPress has required a couple of bug-hunt sessions, but overall I feel it has been a time-saver.

This week I spent a little bit of time experimenting with formatting code snippets. While looking into my earlier writing I realized I’ve had an issue with code snippets repeatedly. Today I took the time to fix the problem by changing the Markdown parser slightly. (more…)

Wheezy upgrades

Written late in the evening in English • Tags: , , , , , , ,

Debian 7.0 “wheezy” was officially released about a week ago. I’ve been running it on a couple of systems for a few months already because of the more recent software versions available on it. Today I upgraded one of the shell servers, a couple of days ahead of the originally posted schedule due to security updates to MySQL (DSA-2667). As usual for Debian, the upgrade process is well documented1 and robust. However, here are some notes for upgrading the next instance. (more…)

Two-factor authentication for WordPress

Written late in the morning in English • Tags: , , ,

Content management systems are being targeted by brute-force password attacks. Improve the security of your self-hosted WordPress blog by installing the Google Authenticator plugin. (more…)

File Vault volumes cannot be resized

Written late in the evening in English • Tags: ,

Turns out one has to turn off File Vault to resize the underlying partition. However, resizing does not work when running off of the recovery partition (which you might be doing to run fsck on the primary partition). (more…)

Time to upgrade Asterisk

Written late in the evening in English • Tags: , ,

SIP appears to be broken in the Asterisk 1.6 packages released to address DSA-2550. I resorted to a hasty upgrade to Asterisk 1.8 from backports. (more…)

Troubleshooting USB Audio 2.0 on a Mac

Written in the wee hours in English • Tags: ,

I noticed my Cambridge Audio DacMagic Plus was no longer recognized by my iMac and music was coming out of the built-in speakers instead. I had no idea when the DAC had disappeared, as I hadn’t listened to music in the office for a while (and had been traveling for a week as well). I moved it to another USB port and it was recognized, but the signal it received was at 48 kHz instead of 192 kHz.

I tried:

  • connecting a USB headset to the problem port: it was not recognized.
  • connecting the DAC to a Macbook Air: the DAC indicated a 192 kHz signal.
  • an SMC reset: no change.
  • a PRAM reset: I got the USB port back, but still at 48 kHz.

My searches on Google weren’t turning up anything useful about the sample rate on USB Audio. Then I happened to search for just “imac usb audio 2.0” and started reading the top hit: USB Audio on the Mac. It has a section on Clock Entities showing the Audio Midi Setup tool.

For some reason the Mac had the clock for the external DAC set at 48 kHz. Using the dropdown menu I could set it at 192 kHz and all was instantly back to normal.

Bring back audio after Asterisk 1.6 upgrade

Written in the mid-afternoon in English • Tags: , ,

I upgraded to Asterisk 1.6 some time ago, but didn’t think anything was wrong until recently. Calls coming in from Callcentric didn’t work: I received no audio. Everything had been working fine with Asterisk 1.4. I don’t get many calls, so initially I dismissed this as a temporary problem. Calls from my other four carriers kept working fine.

After some research, I noticed the following settings suggested by Callcentric:

session-timers=refuse
session-expires=180
session-minse=90
session-refresher=uas

I’ve placed this in the [general] section of sip.conf, because calls from Callcentric arrive from multiple servers and the way Asterisk handles SRV records, only one of the servers ends up mapping into the per-carrier context at any given time. It doesn’t seem to have an adverse effect on calls from other carriers. (It is just turning off functionality new to 1.6, and setting some sensible defaults.)

Perl on the Mac

Written early in the evening in English • Tags: , ,

Mac OS X comes with Perl installed — that’s good. But it doesn’t come with all the modules you may want. On Ubuntu this is no problem: most modules can be found with aptitude as packaged by Ubuntu and their friends. I was trying to think how to manage Perl modules on my Mac in a similar way, so I could track what is installed. What I didn’t think of was the fact that no software is tracked on the Mac anyway, so why should I care.

Thus I should happily use CPAN to add any modules I might need. Maybe not the most secure thing in the world to run as root, but that’s the expected way to do it…

Turns out there is still a hiccup, but apparently just with Xcode 4: there is no ppc assembler on the system, but Perl is configured to expect one. Fortunately others have already figured this out — the full problem and a fix are presented in Perl and Xcode 4.

I guess I should be backing up the list of installed Perl modules somehow.