Article

Changing Drupal 7's built-in jQuery UI theme

Samat Jain — Tue, 23 Aug 2011 05:08:45 +0000

jQuery UI, a Javascript widget framework built upon jQuery, comes built-in Drupal 7 core. One of jQuery UI’s nicer features is that you can switch themes by changing out a CSS file.

There are some nice jQuery UI themes out there (unfortunately, not enough!), like Tait Brown’s port of Aristo to jQuery UI (see demo).

But since jQuery UI is in Drupal core, which internally keeps track of CSS files, how do you switch the jQuery UI theme in use?

The Seven theme, including with Drupal core, provides inspiration on the “one true Drupal way” of doing this, by providing hook_css_alter(). Place into your theme’s template.php:

function MYTHEME_css_alter(&$css) {
  if (isset($css['misc/ui/jquery.ui.theme.css'])) {
    $css['misc/ui/jquery.ui.theme.css']['data'] = drupal_get_path('theme', 'MYTHEME') . '/jquery.ui.theme.css';
  }
}

Replace “MYTHEME” with the name of your theme, and adjust the path to your jQuery UI theme’s CSS file accordingly (the above assumes you place jquery.ui.theme.css in the root folder of your theme).

With this magic in hand, I now have the Aristo jQuery UI theme running on this blog. Looks quite a bit better!

This post was inspired by an answer I posted on StackExchange.

Topic:

jQuery

Drupal

I'm Flattr'ed!

Samat Jain — Wed, 20 Jul 2011 04:06:51 +0000

2011 Flattr widget

I conducted an experiment back when I wrote my HP N36L review: I added affiliate links to both Amazon and Newegg, hopefully to get some revenue without polluting my site with advertisements.

It was successful; I earned enough to pay for a few cups of espresso, at least.

Many authors have PayPal-powered “tip jars” or links to their Amazon wishlist. I’ve now setup the same, but I think it’s unrealistic visitors spend the requisite time or money to use them.

Enter Flattr, a new “social micropayments” platform, a tip jar evolved to work on Web scale. Flattr is a quick and easy way to give back to content creators—including myself. Rather than trying to explain it, watch Flattr’s introductory video. I love the cake analogy.

If you want to get an item from my Amazon wish list, please do! But what if you wanted to contribute less? And why would anyone else want to use Flattr over PayPal?

Well, one, it’s simpler. Users need only click a single button (the Flattr widget) to Flattr me. Also, users don’t need to worry about figuring out how much to give me—Flattr’s “cake cutting” algorithm does it for you. Nothing stops you from donating more, of course.

Second, Flattr’s rates are better. Say you’ve decided to add $10/month to your Flattr account, and you’ve Flattr’ed 10 people, including me. Each of those people will be entitled to $1. With Flattr’s 10% commission, I’d get 90¢; with PayPal’s default fee schedule, I’d get 67.1¢ ($1-($1×2.9%+$0.30)). Big difference. Flattr works well when you’re dealing with small amounts (called micropayments), exactly the niche market they’re trying to fill.

Imagine you’re walking down the street and hear a great musician, to whom you’d like to donate some small change. It’s easy to do in the real world. With conventional payment systems oriented around transactions, this model doesn’t translate. With Flattr, however, the model does—it brings a donation system and ethic present within the real world onto the Web.

PayPal has its own little-known micropayments platform with a better fee schedule, but it requires the receiver to go through a manual approval process to receive a special account. It’s only available in a few countries and has been a “beta” product for years, implying PayPal does not care much about it. Why should they? PayPal, making money on high-value transactions, has little incentive to develop micropayments—not until there’s marketshare and mindshare to steal, something Flattr is building.

Third, with free culture luminaries like Peter Sunde of The Pirate Bay fame behind it, Flattr seems less likely to “censor” recipients, holding funds hostage and even confiscating them, something for which PayPal is notorious. While I’m not worried about anyone censoring my overly-politically correct blog, should I be OK with organizations unfairly censoring others? *cough* WikiLeaks *cough*

Flattr is so nascent, it’s unlikely I earn a significant amount of money. And the meager money I do earn I will probably use to Flattr others. But it’s easy to use, low-risk for myself and visitors, and most importantly I believe in its ethos—so why not?

If you like this post or my blog, please flattr it!

Topic:

Flattr

Free Culture

Following Firefox's New Development Channels with Ubuntu

Samat Jain — Tue, 31 May 2011 20:29:49 +0000

Shortly after Firefox 4’s release, Mozilla announced the move to a channel development model, à la Chrome. On Windows and Mac, builds from these channels update themselves; what about on Linux, where both self-updating software and software outside management of the package manager (i.e. manually installed) is taboo?

If you use Debian, Mike Hommey and the Debian Mozilla Team’s mozilla.debian.net provides packages for the Firefox Stable, Beta, Aurora, and Nightly channels. Be aware that these packages are still labeled Iceweasel, i.e. they lack the official Firefox branding. These packages work on Ubuntu should you want to use them.

What if you want something more Ubuntu-specific? PPAs following each of the channels exist, but they’re not obvious to find.

Nightly builds of Firefox trunk, formerly known as “Minefield” builds, are available in the Ubuntu Mozilla Daily PPA. Remember, Nightly builds receive little testing (e.g. can they build without errors?) and thus may crash frequently. Start using these builds by pasting the following into your terminal:

sudo add-apt-repository ppa:ubuntu-mozilla-daily/ppa
sudo apt-get update && sudo apt-get install firefox-trunk

Firefox’s new build channel, Aurora, has builds that have had more testing than those from Nightly. Builds from the Aurora channel are available from the firefox-aurora PPA, which you can use with:

sudo add-apt-repository ppa:ubuntu-mozilla-daily/firefox-aurora
sudo apt-get update && sudo apt-get install firefox

The Beta channel, containing builds that received more testing than Aurora and are (mostly) ready to be released, is available in the firefox-next PPA:

sudo add-apt-repository ppa:mozillateam/firefox-next
sudo apt-get update && sudo apt-get install firefox

Lastly, if you want to follow the Stable channel, consider sticking with what’s available in Ubuntu’s normal repositories. Ubuntu has a (new) policy to bring stable Firefox updates to Ubuntu releases more quickly. If you really want to be testing the next Firefox release, try the Beta channel above. If you still want the “bleeding edge” of stable, there’s the firefox-stable PPA, which will go away soon, and Ubuntu’s Mozilla Security Team PPA, within which packages only remain until they are moved into the main archive.

Notice that the Aurora, Beta, and Stable channels contain packages of the same name: “firefox”; this means:

You can only install Firefox from one channel at a time.
They all will use the same profile and profile registry. You’ll need to manually switch profiles or alter shortcuts to launch the desired profile if you desire different.

Packages in the Nightly channel, however, are named firefox-trunk and can be co-installed alongside builds from another channel.

To switch to another channel, disable the source with Ubuntu’s Software Properties or delete the appropriate file in /etc/apt/sources.list.d/:

sudo rm /etc/apt/sources.list.d/ubuntu-mozilla-team-firefox-aurora*list
sudo rm /etc/apt/sources.list.d/mozillateam*list

Then re-add the appropriate repository to switch to a desired channel.

Hopefully, with easy-to-use PPAs available for each of Firefox’s build channels, more people, including you, will test these builds. Go forth and test!

Topic:

Firefox

Linux

Ubuntu

Why I use Firefox 4 Mobile

Samat Jain — Thu, 19 May 2011 23:16:29 +0000

A couple weeks ago, Mozilla released Firefox 4 Mobile (née Fennec) for both Android and Maemo.

I’ve had an Android phone since 2008 and honestly, I’ve never browsed the web on my phone as much as I have in the past few months when I started using Firefox 4 Mobile. It really is that much better! Here are my thoughts (focused on the Android version) on why.

Topic:

Firefox

Android

Using my Creative Commons-licensed photos

Samat Jain — Fri, 13 May 2011 06:34:05 +0000

Since I’ve become a photobug and licensed those photos under the Creative Commons, I’ve been getting a lot of requests for reuse. After all, that’s what CC-licensed content is for!

The “BY” bit in CC licenses, which stands for attribution, means authors/creators must be attributed if you decide to use a work. It does not specify how a work should be attributed or cited (though, there are some guidelines in CC’s FAQ), leaving it up to the owner of the work—which is the way it should be, of course.

Flickr does a terrible job letting people know how to attribute works. If you’re reading this, I’ve probably directed you here asking how I’d like you to cite or attribute any of my photos.

If you’re just using a photo, simple add a line like this somewhere near the photo, with the appropriate hyperlinks:

Name of photo, linked to Flickr photo page © Samat Jain, used CC BY-SA 2.0.

If you’re creating a derived work (that is, you modified the photo in some way), please use:

Derived from Name of photo, linked to Flickr photo page © Samat Jain, used CC BY-SA 2.0.

Summarized in an example:

Hyperthyroidism the morning (with zits!) © Samat Jain, used CC BY-SA 2.0.

Now, a rant on why I ask all for all this. There are just two reasons:

I have a philosophical agenda to promote open source and free culture. I’m hoping the explicit wording and hyperlinks do so.
I’m putting photos I took time to take and process on the web, for your free use… asking for a little credit (in exchange for link-fu) is not much to ask! Linking to Flickr fulfills Flickr’s ToS; linking to my homepage makes me happy; and linking to the appropriate license hopefully promotes free culture, informing users of their rights. To that end, if you can, avoid creating hyperlinks with nofollow.

Lastly, if you decide to use a photo, please let me know! I like to keep track of these things, and may link back to your use of my photo. Thanks!

Topic:

Free Culture

Monitoring Intel SSD lifetime with S.M.A.R.T.

Samat Jain — Mon, 09 May 2011 23:49:22 +0000

The Internet is abuzz with talk about solid state reliability right now (see a recent article by Jeff Atwood). Random, catastrophic failures aside, how can you know how much life you’ve eaten into your SSD?

If you’ve an Intel SSD, it’s pretty easy; they export a S.M.A.R.T. attribute “Media Wearout Indicator”. Starting at 100 (new), the attribute decreases to, well, zero. Forget how to do that on Linux? It’s easy:

$ sudo smartctl -a /dev/sda | grep Media_Wearout_Indicator
233 Media_Wearout_Indicator 0x0032   098   098   000    Old_age   Always       -       0

The SSD in my laptop is at 98, and my oldest SSD in another system (from mid-2009) is at 97. Yours?

On to the real news: the OpenStreetMap project has switched their tile rendering server to an SSD (hopefully making tile renders much, much faster). A newer, consumer-grade MLC-based Intel 320 Series 600 GB SSD, in fact. Conveniently, OpenStreetMap monitors their servers with Munin, which by default graphs all S.M.A.R.T. attributes, including Media Wearout Indicator.

Other than the initial import of the tile rendering database, OSM tile rendering does not consume many write cycles. But it definitely hammers the disk to death on reads. Keep a lookout on these graphs to see how their SSD ages over time. Don’t forget to contribute to OpenStreetMap yourself so we can see that number go down a bit quicker (I’m pretty sure OSM doesn’t mind!).

Note: Toby mentioned to me that all the values appear to be pegged at 100. Most of these attributes are dummy values—only “Media Wearout Indicator” and “Available Reserved Space” appear to change with normal use.

Topic:

OpenStreetMap

Computer Hardware

Linux

What does the "BY" in Creative Commons' license names mean?

Samat Jain — Fri, 15 Apr 2011 23:27:38 +0000

Have you ever wondered what the “BY” in Creative Commons’ licenses (e.g. CC-BY, CC-BY-SA, and CC-BY-SA NC) stands for?

The other bits in the license name are obvious, for the most part:

CC – Creative Commons
NC – Non-Commercial
ND – No Derivatives
SA – Share-Alike

“BY” is confusing because it’s not an acronym, shortening of a word, or anything otherwise obvious. But buried in the Creative Commons FAQ, it’s mentioned it stands for attribution.

If all Creative Commons require attribution (except CC0), why is it included in the license names (especially the abbreviations) at all?

Topic:

Wiki

Free Culture

Increase file descriptors for Transmission on Linux

Samat Jain — Tue, 05 Apr 2011 23:31:11 +0000

Have you run out of file descriptors for Transmission? The torrent will be stopped (for no apparent reason), and when you examine it, you’ll see an error similar to:

$ transmission-remote -t 1 -i | grep -i 'open files'
Unable to save resume file. Too many open files.

Time to increase the number of file descriptors available. This article is tailored towards Debian and Ubuntu.

It’s unlikely you’ll need to raise your system’s global limit. Check with:

$ cat /proc/sys/fs/file-max
397460

The OS needs a couple thousand file descriptors for itself. Make sure to make space for them with whatever numbers to choose below. In my case, I’ve more than enough.

If you still need to raise your system’s limit, you can easily; to set it to a million (which will be remembered across reboots):

sudo sh -c "echo fs.file-max=$(dc -e '2 20 ^ p') > /etc/sysctl.d/file-descriptors-max.conf
sudo service procps restart

While you may not need to change your system’s global limit, you probably will need to change the limit for your users. Check that limit with:

$ ulimit -Sn
1024
$ ulimit -Hn
1024

If you’re working with hundreds of torrents (each with dozens to hundreds of files) with Transmission, this isn’t enough. To let a user have a few thousand (in the below example, 16,384, with 128 more for the hard limit), create a new file /etc/security/limits.d/debian-transmission.conf:

sudo sh -c "echo debian-transmission soft nofile $(dc -e '2 14 ^ p')" > /etc/security/limits.d/debian-transmission.conf
sudo sh -c "echo debian-transmission hard nofile  $(dc -e '2 14 ^ 2 7 ^ + p')" >> /etc/security/limits.d/debian-transmission.conf

Replace “debian-transmission” with the user that is running Transmission.

For the changes to go into effect, you need to logout completely (e.g. close multiplexed SSH connections, etc), and log back in again. Or to be sure, just reboot to make sure changes kick in. You’ll see you have many more file descriptors available:

$ ulimit -Sn
16384
$ ulimit -Hn
16512

Now, we need to configure Transmission to use this many. In /etc/transmission-daemon/settings.json, find the open-file-limit option and set to a larger number (e.g. 16000 or so). When done, restart transmission-daemon:

sudo service transmission-daemon restart

If you’re not running Transmission as a system user, edit the right settings.json and restart the daemon appropriately.

That’s it. Have fun!

Topic:

Linux

Debian

Ubuntu

High-resolution text console with uvesafb and Debian

Samat Jain — Wed, 10 Nov 2010 00:08:29 +0000

While you may rarely use the console on your server, it’s nice to have a high-resolution display just to see that many more columns and rows. Linux’s vesa module (via the vga= parameter) has been around for a while and made this possible, provided you kept up with what VGA mode number to use and don’t mind the spotty hardware compatibility.

While KMS is the way to do this in the future, it doesn’t help us with the drivers and hardware we have now. A new kernel module, uvesafb, mainlined in 2.6.24, is another, new option. In addition to specifying modes in a more user-friendly way (e.g. 1280x1024-32 for 32-bit color, with a 1280x1024 resolution), hardware compatibility is better—in particular, you can now get a high-resolution text console with NVIDIA display adapters.

In the following, I describe how to use uvesafb on Debian and derivative distributions (e.g. Ubuntu). The instructions assume kernel 2.6.27 or higher (Debian 6.0 (squeeze) and Ubuntu 8.10 (Intrepid Ibex), or later).

Topic:

Quick and easy network bandwidth benchmarking on Linux and MacOS X

Samat Jain — Sun, 15 Mar 2009 20:55:14 +0000

A couple years ago, I setup my first gigabit Ethernet network. I wanted to test just how fast it could go with the equipment I gave it (that is, the NICs, cabling, and switches it operated on). Gigabit Ethernet, theoretically, can operate at 1000 Mbit/sec. This translates to 119.209 MiB/sec, units your OS typically displays when doing downloads (1000 Mbit/sec / 8 / 2^20). How close is your network setup to that maximum? Copying files between PCs, while being a very “real world” test, will be limited by how fast your disks can read or write. A specialized tool is needed.

While many system benchmark suites include network testing tools, most are not easily separate from their suites, and are not easy to install and use.

Enter NetStrain. It’s a very simple C application for Linux and MacOS X designed to stress network connections. Unfortunately, it’s not included in most Linux distributions or MacOS X, so you need to download and compile it yourself.

After compiling, use is simple. One machine acts as a server, and another machine acts as a client. Start the server first with:

netstraind -4 9999

This starts a server using IPv4 networking on port 9999 (use a different port if you know this is in use; remember to pick one above 1024 if you’re not running as root). On your client machine, start the client connect to the server (assumed to be running on IP 192.168.1.2 and port 9999):

netstrain -4 192.168.1.2 9999 send

NetStrain will then try to send as much over your network connection as it can as long as the client is running. NetStrain is very spartan, so there are not a lot of options. In addition to sending, you may want to test receiving, as well simultaneously sending and receiving. Check NetStrain’s README for details.

Most likely, you will not get anything near 119.209 MiB/sec—but hopefully, you’ll get better speeds than a normal 100 Mbit connection to make everything worthwhile.

What if you want to make things faster (without buying newer, better hardware)? There are many parameters you can tune on your operating system’s networking stack. However, in most modern operating systems, most of them are already set, or are automatically configured (e.g. TCP window scaling). The one major tunable is something called MTU (Maximum Transmission Unit).

Data is transferred over Ethernet in packets; the MTU defines the size of those packets. A larger packet size means fewer packets are needed to send the same amount of data, reducing the amount of processing that needs to be done by your computer, switches, and routers. Your computer’s NIC, switches, and routers need to support large-size MTUs, a feature often advertised as “Ethernet jumbo frames.” Jeff Atwood wrote an article on the promise and perils of jumbo frames that you may want to read if you’re interested.

Topic:

Linux

Computer Hardware

High Performance Computing

Mac OS X

Getting on the microblogging bandwagon

Samat Jain — Sun, 01 Mar 2009 04:47:41 +0000

I’m usually a luddite when it comes to the latest Internet fads. I technically did not start blogging until 2003. I didn’t create a Flickr account or a Facebook account until 2006. I never bothered with MySpace. I turned samat.org into my OpenID in 2008. Given those things, I still hate YouTube (and all web video in general), and have yet to create a podcast or upload a video. I usually don’t think lolcats are funny, either.

Joining in the past year’s latest fad, I’ve started microblogging. Also known as “twittering,” microblogging revolves around the publication of little 140-character notes. The idea is that you share via these little notes news, thoughts, ideas, or whatever you happen to be doing at the moment. These notes are also known as “twits,” “dents,” etc.

Believe it or not, you’ve probably been doing a form of microblogging for a while. If you use an IM service and set “Away” messages, you’re microblogging. If you set your status on Facebook or LinkedIn, you’re microblogging as well. The currently accepted notion of microblogging is, started by the start-up company Twitter, a little different. Instead of messages being available to a select group of friends, your messages are global. Anyone in the world can read and respond to what you’re doing (that if, of course, if you have something interesting to say). Microblogging, Twitter-style, could be considered a type of global instant messaging.

Twitter, however, is a closed service. Your posts, lists of friends, etc live in a silo owned and controlled by them, and it’s difficult to extract data from that silo. They dictate how and when you’ll use their service, most evidenced by the frequent downtimes (it’s been so bad they’ve started a new meme, “the fail whale”). They’re also, unfortunately, a company out to make out to profit, and at this point, it’s not clear how they will do that—what if they disappear tomorrow?

Because of these and many other reasons, I’ve eschewed using Twitter and gone with Identi.ca instead. In it’s most simple description, it is an open-source Twitter clone, oriented around a new openly-developed standard for microblogging. You can download the software that runs Identi.ca (called Laconica) and run it yourself. Your data is also available in open formats: you can easily take your posts and friends lists with you. Best of all, you can still interact with other open microblogging sites in a large, distributed network, hopefully making reliability problems things of the past.

I’ve been microblogging since the beginning of the year. Most of my entries are about the same topics as this blog—Linux, open-source software, etc. I notice that I also tend to write a lot of things about New York City. If you care about any of these things, please subscribe to me on Identi.ca. If you use Twitter, you can look read my cross-postings on my Twitter account too.

Topic:

Web 2.0

Creating your own personal aspell dictionary

Samat Jain — Sun, 02 Nov 2008 23:23:44 +0000

Something that has bothered me forever is that applications that use GNU aspell for spell checking kept marking my name as a misspelling (I’m looking at you, KMail). Most front-end applications don’t provide a way for you to add your own custom words.

Apparently, creating your own personal dictionary is ridiculous easy with aspell.

If your language is English, create a file in your home directory called ”.aspell.en.pws”:

personal_ws-1.1 en 0
Samat
quasirhombicosidodecahedron

The first line is a required header. Every subsequent line is a word you want to add to your dictionary. I can’t believe I’ve let this sit for so long. Because it’s a nice text file, syncing this file between machines to take your dictionary with you is trivially easy.

Topic:

Linux

Software

Taking Drupal sites offline via mysql and the command line

Samat Jain — Sat, 01 Nov 2008 05:42:10 +0000

Drupal-powered websites can be put into an “offline mode.” This is much better than most alternatives (such as taking the web server offline), especially for search engines, as the message and HTTP status codes given to users and robots alike will tell them to patiently come back later.

I’ve found that putting the site into offline mode makes database backups go much faster on heavily trafficked sites (which is obvious). However, for a particular site I was working with, this needed to be done in an automated manner, and on a dedicated database server that did not have access to the Drupal installation.

Most people take their Drupal sites offline through Drupal’s web-based administration interface. They can also be put offline through the Drupal Shell. Neither were suitable for me: the former cannot be automated easily, and the latter requires access to the Drupal installation. Fortunately, Drupal sites can easily be taken offline by setting things in the database, which can easily be done via bash scripts and the command-line MySQL client.

Given your database user is my_db_user, password my_password, and database my_drupal_db, the backup script would look something similar to:

 #!/bin/bash

# Take site offline
mysql --user my_db_user --password=my_password my_drupal_db << EOF
UPDATE variable SET value='s:1:"1";' WHERE name = 'site_offline';
DELETE FROM cache WHERE CID = 'variables'; EOF

# Do stuff here while the site is offline (e.g. backup)

# Bring site online
mysql --user my_db_user --password=my_password my_drupal_db << EOF
UPDATE variable SET value='s:1:"0";' WHERE name = 'site_offline';
DELETE FROM cache WHERE CID = 'variables';
EOF

Update: The original version of this article had some problems on some setups with the variables table being cached. I added another SQL statement to make sure this cache is flushed so the site actually reflects its configuration.

Update: This method really doesn’t work that well, and the more I think about it, there isn’t a way to get around writing something that interacts with Drupal. I’m working on a script that will be more fool-proof.

Topic:

Linux

Drupal

Bash Shell

Python-like tuple unpacking for PHP

Samat Jain — Wed, 29 Oct 2008 21:55:47 +0000

Python provides a neat way for functions to return multiple arguments via “tuple unpacking”. For example:

def blah:
  return ('one', 'two')

rval_1, rval_2 = blah()

The same can be done in PHP relatively easily via the list construct:

function blah()
{
  return array('one', 'two'); }

list($rval_1, $rval_2) = blah();

Topic:

Programming

Python

PHP

Speeding up SpamAssassin rule processing on Debian and Ubuntu

Samat Jain — Thu, 02 Oct 2008 19:01:57 +0000

SpamAssassin is one of the most-used spam filtering systems in use today. Unfortunately, because there are so many different ways SpamAssassin can be used, SpamAssassin remains subject to many performance problems. Fortunately, there are several speed-ups and optimizations that can be applied to most SpamAssassin installations to speed up its rule processing, especially on Debian and Ubuntu GNU/Linux-based systems. These instructions can be adopted to other operating systems as well.

This article does not discuss configuring your mail filtering system (i.e. procmail, maildrop). This depends completely on your setup, and more than likely there are plenty of other articles that describe the best way to setup what you want.

Type:

Topic: