I was unable to make screencasts in wmii using Istanbul. So here’s how I installed xvidcap. Unfortunately I cannot come up with a way for wget retrieval of the sourceball, so some manual labour is needed. Retrieve the sourceball and put it in /tmp. Then follow the instructions below. Also see the snippet for an alias for the make command first.

Note that I put the binaries in /usr/local/stow/xvidcap because the package comes from outside package management. I then use xstow to manage the symlinks in /usr/local/bin.

   1  sudo apt-get install libxml-parser-perl libxmu-dev libglade2-dev libgtk2.0-dev
   2  cd /tmp
   3  tar zxvf xvidcap*.tar.gz
   4  cd xvidcap*
   5  ./configure --prefix /usr/local/stow/xvidcap
   6  make
   7  sudo make install
   8  cd /usr/local/stow
   9  sudo xstow xvidcap

To remove xvidcap follow these steps

   1  cd /usr/local/xstow
   2  xstow -D xvidcap
   3  sudo rm -rf /usr/local/stow/xvidcap

Simple usage of a here document in Linux.

   1  marko@x61s:~$ cat << EOF > /tmp/hubbabubba
   2  > hubba
   3  > EOF
   4  marko@x61s:~$ cat /tmp/hubbabubba 
   5  hubba

I run this nat.sh script whenever I need to share my 3g connection to other computers in the switch I’m plugged into. Please note that it resets existing iptables rules.

   1  #!/bin/bash
   2  iptables --flush            
   3  iptables --table nat --flush
   4  iptables --delete-chain
   5  iptables --table nat --delete-chain
   6  
   7  echo 1 > /proc/sys/net/ipv4/ip_forward
   8  
   9  internal=eth0
  10  external=ppp0
  11  /sbin/iptables -t nat -A POSTROUTING -o ${external} -j MASQUERADE
  12  /sbin/iptables -A FORWARD -i ${external} -o ${internal} -m state --state RELATED,ESTABLISHED -j ACCEPT
  13  /sbin/iptables -A FORWARD -i ${internal} -o ${external} -j ACCEPT

The stemmer4r gem is fubar. Warning draft snippet…

   1  # gem install stemmer4r
   2  Bulk updating Gem source index for: http://gems.rubyforge.org
   3  Building native extensions.  This could take a while...
   4  ERROR:  While executing gem ... (Gem::Installer::ExtensionBuildError)
   5      ERROR: Failed to build gem native extension.
   6  
   7  ruby extconf.rb install stemmer4r
   8  
   9  Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/stemmer4r-0.6 for inspection.
  10  Results logged to /usr/lib/ruby/gems/1.8/gems/stemmer4r-0.6/ext/stemmer4r/gem_make.out
  11  
  12  
  13  1. Change path of Ruby executable
  14  
  15  cd /usr/lib/ruby/gems/1.8/gems/stemmer4r-0.6/ext/stemmer4r/
  16  vim extconf.rb
  17  
  18  #!/usr/bin/ruby -w
  19  
  20  to
  21  
  22  #ruby -w
  23  
  24  2. Compile libstemmer_c
  25  
  26  cd /usr/lib/ruby/gems/1.8/gems/stemmer4r-0.6/ext/stemmer4r/libstemmer/
  27  make
  28  
  29  3. Compile stemmer4r
  30  
  31  cd /usr/lib/ruby/gems/1.8/gems/stemmer4r-0.6/ext/stemmer4r/
  32  
  33  Change path:
  34  /usr/local/ruby/lib/ruby/1.8/i686-linux/
  35  To:
  36  /usr/lib/ruby/1.8/x86_64-linux/
  37  
  38  Or wherever you have it installed
  39  
  40  ruby extconf.rb
  41  
  42  
  43  4. Build stemmer4r gem
  44  
  45  
  46  gem build stemmer4r.gemspec
  47  
  48  gem install stemmer4r-0.6.gem
  49  
  50  
  51  Problems
  52  
  53  gcc -shared -rdynamic -Wl,-export-dynamic   -L"/usr/lib" -o stemmer4r.so stemmer4r.o libstemmer_c/libstemmer.o  -lruby1.8  -lpthread -ldl -lcrypt -lm   -lc
  54  /usr/bin/ld: libstemmer_c/libstemmer.o(libstemmer.o): relocation R_X86_64_32 against `a local symbol' can not be used when making a shared object; recompile with -fPIC
  55  libstemmer_c/libstemmer.o: could not read symbols: Bad value
  56  collect2: ld returned 1 exit status
  57  make: *** [stemmer4r.so] Error 1
  58  
  59  
  60  Add CFLAGS:
  61  
  62  root@aktagon:/usr/lib/ruby/gems/1.8/gems/stemmer4r-0.6/ext/stemmer4r/libstemmer_c# make
  63  include mkinc.mak
  64  CFLAGS   =  -fPIC
  65  libstemmer.o: $(snowball_sources:.c=.o)
  66          $(AR) -cru $@ $^
  67  

Git is a good alternative to Mercurial, and of course SVN or CVS if you’re still using stone age tools, so in this post I’ll show you how to compile, install and use git with Rails.

Installing git on Mac OS X

First compile and install git:

   1  cd /usr/local/src
   2  wget http://kernel.org/pub/software/scm/git/git-1.5.4.4.tar.bz2
   3  tar jxvf git-1.5.4.4.tar.bz2
   4  cd git-1.5.4.4
   5  make prefix=/usr/local all
   6  make prefix=/usr/local test && echo $?
   7  sudo make prefix=/usr/local install

Installing git on Debian

On a Debian installation install git by first executing the following commands:

$ sudo apt-get install git-core

Note that the package name is git-core not git.

If you want the latest and greatest version, you first need to install the dependencies (note that you can leave out tk and expat):

   1  sudo apt-get install curl
   2  sudo apt-get install libcurl3
   3  sudo apt-get install libcurl3-dev
   4  sudo apt-get install tk8.4
   5  sudo apt-get install cpio expat
   6  sudo apt-get install zlib
   7  sudo apt-get install build-essential
   8  sudo apt-get install zlib1g-dev 
   9  sudo apt-get install asciidoc
  10  sudo apt-get install xmlto

Then compile and install:

   1  NO_EXPAT=yes NO_SVN_TESTS=yes NO_IPV6=yes NO_TCLTK=yes make -j2 prefix=/usr all
   2  NO_EXPAT=yes NO_SVN_TESTS=yes NO_IPV6=yes NO_TCLTK=yes make -j2 prefix=/usr install

Configuring git

Run these commands to tell git your name and email:

   1  git config --global user.name "u name"
   2  git config --global user.email x@x.com

Otherwise, you might get this error:

   1  *** Environment problem:
   2  *** Your name cannot be determined from your system services (gecos).
   3  *** You would need to set GIT_AUTHOR_NAME and GIT_COMMITTER_NAME
   4  *** environment variables; otherwise you won't be able to perform
   5  *** certain operations because of "empty ident" errors.
   6  *** Alternatively, you can use user.name configuration variable.
   7  
   8  fatal: empty ident  <........@........com> not allowed
   9  fatal: The remote end hung up unexpectedly

If you like colorized command output execute these commands:

   1  git config --global color.diff auto
   2  git config --global color.status auto
   3  git config --global color.branch auto

Using git

If all goes well, change to your project directory and run the following commands:

   1  git init

This creates the git repository, so we’re now ready to start adding files to it, but first we need to create the git ignore file, which tells git to ignore certain files completely:

   1  cat <<EOF<<EOF > .gitignore 
   2  config/database.yml
   3  db/*.sqlite3
   4  log/*.log
   5  tmp/**/*
   6  .DS_Store
   7  doc/api
   8  doc/app
   9  EOFEOF

By default git doesn’t add empty directories—sucks if you ask me—so we’ll create a dummy file in all empty directories with the find and touch commands:

   1  find . \( -type d -empty \) -and \( -not -regex ./\.git.* \) -exec touch {}/.gitignore \; 

Importing files

We’re now ready to start adding and commiting files, so without thinking execute:

   1  git add .
   2  git commit -m 'initial import'

This creates the git repository, adds and commits all files that are in the current folder.

Using remote repositories

If you’re like me you’ll want to use a remote repository, so let’s continue the exercise by creating the repository folder on the remote server (Note that commands are executed on the remote server from now on):

   1  mkdir /var/lib/git/repositories/project_name

We want the folder to be accessible by users belonging to the git group only:

   1  addgroup git
   2  chown root.git /var/lib/git/repositories/project_name
   3  chmod 770 /var/lib/git/repositories/project_name

Now add yourself—or the user you’ll be using to connect to the remote server—to the git group:

   1  usermod -a -G git your_username

Alternatively create a new user:

   1  useradd -g git your_username

Now we’re finally ready to copy the local repository to the remote server, which is done with the scp command (Note that commands are executed locally again from now on):

   1  scp -rp .git user@server://var/lib/git/repositories/project_name

To let git know that this repository exists we’ll use the git remote command:

   1  git remote add project_name ssh://server/var/lib/git/repositories/project_name

This adds the information to .git/config, which might be good to have a quick look at.

Note that if you’re using a non-standard SSH port you need to add the following to your ~/.ssh/config file:

   1  Host server
   2    Port 1234

Commit files and push them to the remote server

Now change a file and commit and push the changes to the remote server:

   1  git commit -m "Me be sleepy"
   2  git push project_name

If you get an error such as this it means you need to install git:

   1  $ git push project_name
   2  username@server's password: 
   3  sh: git-receive-pack: command not found
   4  fatal: The remote end hung up unexpectedly

That’s all…

Miscellaneous problems

error: unable to create temporary sha1 filename ./objects/obj_FUu2jb: Permission denied

Resources

http://jointheconversation.org/railsgit

http://devblog.michaelgalero.com/2007/12/17/my-git-notes-for-rails/

http://railscasts.com/episodes/96

http://groups.google.com/group/rails-oceania/browse_thread/thread/2c8611dc93917952/e175f72310823547

http://www.kernel.org/pub/software/scm/git/docs/tutorial.html

http://scie.nti.st/2007/11/14/hosting-git-repositories-the-easy-and-secure-way