Myles Carrick

Unzipping massive files on OSX

OSX Snow Leopard has a command line zip/unzip utility…

Today I needed to unzip a MASSIVE (10GB) zip file (for Adobe LiveCycle - but that’s another story)… and got this response:

unzip LiveCycleES2.5-0.0.5.zip 
Archive:  LiveCycleES2.5-0.0.5.zip
skipping: LiveCycleES2.5-0.0.5/LiveCycleES2.5.x86_64-0.0.5.vmdk  need PK compat. v4.5 (can do v2.1)
creating: LiveCycleES2.5-0.0.5/
inflating: LiveCycleES2.5-0.0.5/LiveCycleES2.5.x86_64-0.0.5.vmx 

So what’s PK compat. v4.5 ? The standard zip libraries don’t let you unzip really big files. The PKZip libraries have evolved with myriad different versions and capabilities - including (in 4.5) the addition of Zip64 - with support for huge (>4.5 GB) files.

To get it to work, we need p7zip the Linux/Unix port of the 7-zip libraries.

I use homebrew - and you should too.

brew install p7zip

then use the 7z utility (with a magic ‘x’ for extract like so:

7z x LiveCycleES2.5-0.0.5.zip

…and we’re cookin with gas.

Rails3, Compass and the Heroku read-only filesystem

I use Compass with Blueprint for all projects these days.

When deploying on Heroku, the read-only filesystem has trouble with the conditional around the IE stylesheet - leading to something like this;

Errno::EROFS (Read-only file system - /disk1/home/slugs/.../mnt/public/stylesheets/compiled/ie.css - Heroku has a read-only filesystem.  See http://docs.heroku.com/constraints#read-only-filesystem)

I get around it by asking Compass / SASS to not bother trying to regenerate my sass/scss files in production:

in config/environments/production.rb:

Sass::Plugin.options[:never_update] = true

Turning off “Upload a single file” Assignment type in Moodle

Among the various things we’re doing for UNE’s move to Moodle, one thing we thought would be cool would be to remove the ancient option Assignment type that allows only one student file per submission (and no teacher “response” files).

This gives us a stack of simple benefits:

• we only have to hook up online marking to one type
• we can hook our funky new print and scanning system up to one type
• teachers never get stuck having allowed one file and then wanting to allow more
• teachers don’t have to remember that the more limited type doesn’t allow them to provide responses

Making the changes is really simple:

First, add a config setting (in config.php):

$CFG->assignment_hide_uploadsingle = true;

Then tweak mod/assignment/lib.php as per the commit at https://github.com/une/moodle/commit/cf89f14ffc36cae22175874f6f737f4e773cfd74

The change is basically:

-    $standardassignments = array('upload','online','uploadsingle','offline');
+    $standardassignments = array('upload','online','offline');

It doesn’t break any existing assignments of that type - just means your teachers won’t go creating new ones.