Stan Angeloff’s blog

Not enough random bytes available.

Please do some other work to give the OS a chance to collect more entropy! (Need more bytes)

I decided to upgrade pacman on Arch Linux recently. I was advised to run [sudo] pacman-key --init after the update had finished. Sounds simple enough, just one extra command I need to copy -> paste to get me going again. Wrong. It turns out gpg will go about generating a very strong key (did not investigate the exact key size). On my not-so-busy machine it would just sit there doing (what would appear as) nothing for hours. To generate entropy, /dev/random is used. I started:

$ cat /dev/random

in a remote session and there was nothing printed on-screen, e.g., nothing was being generated, e.g., no entropy, e.g., no gpg joy. What follows is a very ugly hack to speed things up. Keep the above remote connection open and connect to the machine in a separate tab/window. Start pacman-key as instructed earlier. Leave the window/tab open and connect again, in a third, separate window/tab. Repeat (many) times:

$ ls -R /
$ [sudo] sync
$ sudo tee /proc/sys/vm/drop_caches <<< 3

Ugly, I know.

pacman -Syu barfs error: XYZ: signature is unknown trust

Things kept getting better and better. Following the recent pacman upgrade, I was now facing issues with regards to package signatures. I had already successfully completed the keyring initialisation and I was a bit stumbled as to what exactly I was doing wrong.

You remember all those /etc/config saved as /etc/config.new messages. Yes, as it turns out these are important. Given you haven’t modified your pacman configuration (perhaps added to the HoldPkg list recently?), you can safely accept the new values:

$ [sudo] mv /etc/pacman.conf /etc/pacman.conf.pacprev
$ [sudo] mv /etc/pacman.conf.pacnew /etc/pacman.conf

Re-run [sudo] pacman -Syu and you are on your way.

Ubuntu 11.10: Replace the Default (and Annoying) Orange Scheme

Switching to Ubuntu 11.10 is painful, ugly and time consuming… but more on that some other time.

I was quite surprised to see most of the theme control options are now gone. The Appearance panel has no colour tweaks and I hate the default orange scheme. Luckily, there is a way to change it in Gtk3:

$ sudo apt-get install dconf-tools
$ dconf-editor

Browse to org.gnome.desktop.interface. Locate gtk-color-scheme. Edit the property:

bg_color:#f0f1f2;selected_bg_color:#4677f0

Change the colours to your liking. You may need to re-launch some apps for changes to take effect.

…now if I could only get those Gnome Terminal tabs to look darker.

Compass Magick Tutorial - Part 2

There is more to Compass Magick than gradients and borders. In the second part of the tutorial series, we will go through the steps to create a simple 3-state button with an icon.

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Compass Magick Tutorial - Part 1

Introduction

We have all been there - you release a cool new website with all the goodies of CSS3 just to find several weeks later your Customer wants you to support Internet Explorer as well. It seems solid backgrounds don’t cut it.

There are also cases where CSS3 isn’t the right solution, whether you have custom shapes or other elements of your design you end up creating images for (SVG is a good solution for these cases, but there’s that big 10-year old elephant sitting in the middle of the room again).

Compass Magick tries to solve these issues by allowing you to dynamically generate images from your Compass projects taking full advantage of variables, mixins, etc.

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Yoke: a drop-in, quick and dirty alternative to Sprockets

In local development, I tend to create separate pieces of JavaScript for every controller, model, view, etc. I loved the idea of Sprockets — grab all these files and stitch them together. While it worked well for a while (on the command-line), I got fed up with how slow it runs, especially on Ruby under Cygwin.
So, what to do? Node.js of course. Why? It’s fast, it’s super-easy to install and writing a script on top of it is a breeze. Meet Yoke:

To use, copy the script above on $PATH and then:

yoke [-I path[ -I path]...] input.js > output.js

In most cases, you would just need to replace your existing sprocketize command with yoke. Both <file> and "file" requires are supported.

A quick and dirty way to use namespaces in CoffeeScript

There you have it — should work both in the browser and on the server.

Extract changed files from Git and prepare a deployment (Bash script)

So, you have moved over to Git. Well done! You have big plans for your future deployment process — it is going to be automated and thoroughly tested… but you still have to support your existing legacy products. If you are like me, you most likely started with simple FTP copies (oh, this takes me back). I moved over from SVN and TortoiseSVN was my primary choice for a desktop client. After each deployment, I would create an SVN tag so next time I can get a list of all changed files. In TortoiseSVN it’s as simple as selecting two revisions while holding down the Shift key and doing a Compare Revisions. From the new window you can export all changed files to a new location. If your project in 100MB in size, you only ever have to deal with modified files on subsequent updates. Simple (or so I thought back then).

Moving over to Git has thought me many things. I used to love my Cygwin console even before the switch and I’ve learnt to do pretty much every daily task in it. But the one thing I really needed and didn’t have with Git was an option to copy modified files from the working tree between two commits. It wasn’t available on the command line, nor in any of the clients I’ve tried so far. So having been playing with shell scripts for a few weeks, I decided to put one together which would do just that:

Paste the above in a script on your $PATH. Using gitk or another tool find the first commit you want to include in your extract. Invoke the script as below:

$ git-extract initial_hash_of_first_commit_to_include..HEAD
Do you wish to remove '.deployments' first? [Y/n]
  Purging '.deployments'...
  Done.
Processing 10 files... 100.00%
Done.

A new directory .deployments will be created with all files that have changed in the given commits range. If files were deleted, a .delete file will be generated and you have to handle these manually.

I haven’t found a better solution yet, but I am sure there is a Git way to do just what I am after. This script is a hack to get the job done.

Leave a comment if you found this post useful. Fork the Gist and modify it to suit your needs.

Vim 7 on Red Hat Enterprise Linux (RHEL)

Following my last post I moved on to installing Vim 7.x as the one that comes with RHEL 4 is pretty outdated (6.x).

Vim 7.2 from SVN

Tested on RHEL 4 i386:

$ cd ~
$ svn co https://vim.svn.sourceforge.net/svnroot/vim/vim7
$ cd vim7
$ ./configure --prefix=/usr --with-features=huge --disable-gui --without-x --enable-rubyinterp --enable-cscope --enable-multibyte
$ make && make install
$ vim --version
VIM - Vi IMproved 7.2 (2008 Aug 9)

Vim 7.3 from Mercurial

Tested on RHEL 5 x86_64:

$ cd ~
$ yum install hg ncurses-devel
$ hg clone https://vim.googlecode.com/hg/ vim
$ cd vim
$ ./configure --prefix=/usr --with-features=huge --disable-gui --without-x --enable-rubyinterp --enable-cscope --enable-multibyte
$ make && make install
$ vim --version
VIM - Vi IMproved 7.3 (2010 Aug 15)

RHEL 4 comes with up2date. I tried -i mercurial and -i hg, but both failed. Vim offers an archived download so you can skip steps 3-4 above and instead use:

[..]
$ wget ftp://ftp.vim.org/pub/vim/unix/vim-7.3.tar.bz2
$ tar xjvf vim-7.3.tar.bz2
$ cd vim73
[..]

Let me know if this post helped you or if you had to install any additional libraries.

Git on Red Hat Enterprise Linux (RHEL) 4 i386

I have been struggling with this for a while now. There is no yum to begin with and up2date doesn’t help much either (no git-* packages). Here is a quick solution:

$ cd ~
$ wget http://packages.sw.be/git/git-1.7.3-1.el4.rf.i386.rpm
$ wget http://packages.sw.be/git/perl-Git-1.7.3-1.el4.rf.i386.rpm
$ rpm -ivh --nodeps git-1.7.3-1.el4.rf.i386.rpm perl-Git-1.7.3-1.el4.rf.i386.rpm
$ git --version

You can browse packages.sw.be/git/ for the latest packages and update the above accordingly.