Configuring OS X for chemoinformatics


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This blog includes instructions on how to build and install RDKit, OpenBabel, MySQL, MySQLdb and Mychem, and PostgreSQL. In addition, with OS X 10.7, Apple continues to ship PHP 5.3 with PEAR and Apache out of the box. This is how to set it up from a clean install of OS X 10.7 and OS X 10.8.

The procedure as described here has been tested on a MacBook Pro with four Intel i7 cores, and OS X Lion 10.7.3 installed from scratch, and later updated to OS X 10.8.

Creating the right environment

Root password and installation directory

By default, OS X does not enable you a root password, so it is important to fix this first.

You can easily achieve this from the System Preferences ‣ Users & Groups menu page, select your login name and click the Login Options tab (you might need to unlock first), then select Join... for accessing the Network Account Server, followed by Open Directory Utility.... From the Edit menu in the Finder menu bar, select Enable Root User and enter your desired password.

Second, if not already existing, create a /usr/local directory and change ownership in order to avoid having to do a sudo each time:

> if [ ! -f /usr/local ] ; then sudo mkdir -p /usr/local ; fi
> sudo chown `whoami`:`id -g -n` /usr/local

Create a number of subdirectories in /usr/local:

> if [ ! -f /usr/local/include ] ; then mkdir -p /usr/local/include ; fi
> if [ ! -f /usr/local/bin ] ; then mkdir -p /usr/local/bin ; fi
> if [ ! -f /usr/local/lib ] ; then mkdir -p /usr/local/lib ; fi
> if [ ! -f /usr/local/Cellar ] ; then mkdir -p /usr/local/Cellar ; fi
> if [ ! -f /usr/local/man/man1 ] ; then mkdir -p /usr/local/man/man1 ; fi

Update your PATH environment variable so that it points to this directory:

> export PATH="$PATH:/usr/local"
> echo "export PATH=\"\$PATH:/usr/local\"" >> ~/.bash_profile


Install XCode from the App-store and start it up. Under Xcode ‣ Preferences ‣ Downloads, install the Command Line Tools (you’ll need an Apple Developer account which you can get free of charge). This will install all required compilers.

Command Line Tools under OS X 10.8

Since OS X 10.8, the Command Line Tools need to be installed directly from the Apple Developer site - there is no way anymore to install them from XCode.

The following compilers and preprocessors should now have been installed on your system:

        <- /usr/bin/c++
        <- /usr/bin/clang++
        <- /usr/bin/cc

        <- /usr/bin/llvm-g++-4.2
        <- /usr/bin/g++

        <- usr/bin/llvm-gcc-4.2
        <- /usr/bin/gcc

        <- /usr/bin/i686-apple-darwin11-llvm-g++-4.2

        <- i686-apple-darwin11-llvm-gcc-4.2


        <- /usr/bin/llvm-cpp-4.2


Open a terminal window, type java at the shell-prompt and follow installation instructions if required.


Homebrew is an easy and flexible way to install UNIX tools on OS X. We need Homebrew to install RDKit in a subsequent phase:

> /usr/bin/ruby -e "$(/usr/bin/curl -fksSL"
> brew doctor

Follow the suggestions and run brew doctor to check all is working fine. Very likely you will have to configure Xcode with the correct path:

> sudo xcode-select -switch /Applications/
> brew update


Pkg-config is a tool that provides a unified interface for querying installed libraries. It is required by CMake when installing Openbabel:

> brew install pkg-config


Eigen version 2 is required when using the language bindings in the release. Download Eigen2 (make sure to select version 2 and not 3). It doesn’t need to be compiled or installed. Just unzip it and specify its location when configuring cmake (see below) using -DEIGEN2_INCLUDE_DIR=location. In the example below, we define a EIGEN environment variable to specify the location:

> cd /usr/local/src
> mv ~/Downloads/eigen-eigen-b23437e61a07.tar .
> tar -xvf eigen-eigen-b23437e61a07.tar
> export EIGEN="/usr/local/src/eigen-eigen-b23437e61a07"



Use the Homebrew formula of Eddie Cao to install RDKit:

> brew tap edc/homebrew-rdkit
> brew install rdkit

Create the required environment variables:

> export RDBASE="/usr/local/Cellar/rdkit/2012.03.1"
> echo "export RDBASE=\"/usr/local/Cellar/rdkit/2012.03.1\"" >> ~/.bash_profile
> export PYTHONPATH="$PYTHONPATH:/usr/local/lib/python2.7/site-packages"
> echo "export PYTHONPATH=\"\$PYTHONPATH:/usr/local/lib/python2.7/site-packages\"" >> ~/.bash_profile

Now test the binding by launching Python:

>>> from rdkit.Chem import AllChem
>>> from rdkit import Chem
>>> mol = Chem.MolFromSmiles('c1ccccc1')
>>> mol
<rdkit.Chem.rdchem.Mol object at 0x102395210>
>>> mol.GetNumAtoms()


Start by downloading the source files of version 2.3.1. Assuming that the source files were downloaded in the ~/Downloads directory, the following procedure installs it:

> cd /usr/local/src
> mv ~/Downloads/openbabel-2.3.1.tar.gz .
> tar -xvf openbabel-2.3.1.tar.gz
> cd openbabel-2.3.1
> mkdir build
> cd build
> cmake -DCMAKE_INSTALL_PREFIX=/usr/local/openbabel -DEIGEN2_INCLUDE_DIR=$EIGEN ..
> make

Test the installation. It should pass all tests with failures:

> make test

and after everything has completed without errors, install:

> sudo make install

According the procedure as described above, Openbabel gets installed in the /usr/local/openbabel/ directory:

> ls -A /usr/local/openbabel
bin/            include/        lib/            share/

It might be useful to create some additional links:

> cd /usr/local/bin
> for i in /usr/local/openbabel/bin/*; do ln -s $i; done

and update your .bash_profile file with essential environment variables:

> echo "export BABEL_DATADIR=\"/usr/local/openbabel/share/openbabel/2.3.1\"" >> ~/.bash_profile
> echo "export BABEL_LIBDIR=\"/usr/local/openbabel/lib/openbabel/2.3.1\"" >> ~/.bash_profile
> echo "export BABEL_INCLUDEDIR=\"/usr/local/openbabel/include/openbabel-2.0\"" >> ~/.bash_profile
> echo "export DYLD_LIBRARY_PATH=\"\$DYLD_LIBRARY_PATH:/usr/local/openbabel/lib\"" >> ~/.bash_profile

Start up a new shell and test the installation:

> which obabel
> obabel -V
Open Babel 2.3.1 -- Apr 21 2012 -- 00:38:28



Download PostgreSQL 9.1.3 and untar the file into your /usr/local/src directory. Move into the created /usr/local/src/postgresql-9.1.3 directory and start the installation:

> cd /usr/local/src/postgresql-9.1.3
> mkdir build
> cd build
> ../configure
> make world
> make check
> sudo make install-world
> echo "export PATH=\"\$PATH:/usr/local/pgsql/bin\"" >> ~/.bash_profile
> echo "export DYLD_LIBRARY_PATH=\"/usr/local/pgsql/lib:\$DYLD_LIBRARY_PATH\"" >> ~/.bash_profile

Now create the database cluster:

> cd /usr/local/pgsql
> initdb -D /usr/local/pgsql/data

In order to facilitate startup of the server without having to specify the database cluster, you can set an environment variable in your ~/.bash_profile file:

> echo "export PGDATA=\"/usr/local/pgsql/data\"" >> ~/.bash_profile

You can now start and stop the server from the command line:

> pg_ctl start -l logfile
> pg_ctl stop

If you want to start the server automatically each time when you start up your computer, you should add some items into your /Library/StartupItems folder:

> cd /Library/StartupItems
> sudo mkdir PostgreSQL
> cd PostgreSQL
> sudo touch PostgreSQL
> sudo chmod +x PostgreSQL
> sudo touch StartupParamaters.plist

Use your favorite text editor to add the following lines to the PostgreSQL file (with username replaced by your own username):

> cat PostgreSQL

sudo -u username /usr/local/pgsql/bin/pg_ctl -D /usr/local/pgsql/data -l /usr/local/pgsql/logfile start

and to the StartupParameters.plist file:

> cat StartupParameters.plist
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist SYSTEM "file://localhost/System/Library/DTDs/PropertyList.dtd">
<plist version="0.9">
               <string>Starting PostgreSQL</string>
               <string>Stopping PostgreSQL</string>

RDKit cartridge for PostgreSQL

RDKit provides a PostgreSQL cartridge. In order this to be installed, you’ll have to download the RDKit source code in addition to the Homebrew installation of Eddie Cao.

Start by downloading the source code of RDKit version 2012.03.1 and install it under /usr/local/src. Start the installation by creating a symbolic ink from the source code directory into /usr/local/Cellar:

> cd /usr/local/Cellar/rdkit/2012.03.1
> ln -s /usr/local/src/RDKit_2012_03_1/Code

Make sure that the following environment variables are defined (I’m not sure that all of these are required):

> export RDBASE="/usr/local/Cellar/rdkit/2012.03.1"
> export PYTHONPATH="$PYTHONPATH:/usr/local/lib/python2.7/site-packages"

Change directory to /usr/local/src/RDKit_2012_03_1/Code/PgSQL/rdkit and remove the static linking directive from the Makefile by replacing the 3rd line (STATIC_LINK=1) into STATIC_LINK=0. Then start the installation:

> make
> sudo make install

Now you can install the extension from within psql, assuming that you have launched psql as superuser:

=> create extension "rdkit";

=> show rdkit.tanimoto_threshold;
(1 row)

=> select 'c1ccccc1O'::mol;
(1 row)


By adding the shared_preload_libraries = 'rdkit' line to your /usr/local/pgsql/data/postgresql.conf file, configuration variables provided by the cartridge will be available since server startup and you could avoid errors like this:

=> show rdkit.tanimoto_threshold;
ERROR:  unrecognized configuration parameter "rdkit.tanimoto_threshold"


Download the latest 64-bit DMG archive (in this example it’s the 5.5.24 version; you can skip the registration form). Mount the disk image and install the MySQL server by following the on-screen instructions. The installation script installs the MySQL server in /usr/local. Update your ~/.bash_profile file by adding /usr/local/mysql/bin to your path and by modifying the DYLD_LIBRARY_PATH:

> echo "export PATH=\"\$PATH:/usr/local/mysql/bin\"" >> ~/.bash_profile
> echo "export DYLD_LIBRARY_PATH=\"/usr/local/mysql/lib:\$DYLD_LIBRARY_PATH\"" >> ~/.bash_profile

The disk image you downloaded also contains a Startup Package & Preferences Pane which allows you to start/stop MySQL server from the Mac’s System Preferences and automatically start MySQL server at startup. Install this by double-clicking the MySQLStartupItem.pkg and MySQL.prefPane files. MySQL will be added to your System Preferences:


Make sure to start up the server and check the installation by launching the MySQL client and log in as root (a password is asked for but simply press ‘enter’):

> mysql -u root -p

By default, if you have never set a password for the root account, the server does not require a password at all for connecting as root. It is however advisable to install this:

> mysqladmin -u root password yourpassword

(with yourpassword as the chosen password).


It is advisable to install Python drivers for MySQL. Do this downloading MySQL-python 1.2.3 and install:

> cd ~
> tar xfz MySQL-python-1.2.3.tar.gz
> cd MySQL-python-1.2.3
> python build
> sudo python install

Where are my site-packages stored?

The location of the site-packages directory depends on the operating system and the location in which Python was installed. To find out your system’s site-packages location, execute the following from the command line (note that this should be run from a shell prompt, not a Python interactive prompt):

> python -c "from distutils.sysconfig import get_python_lib; print get_python_lib()"

Test the installation by launching Python and issue the following commands:

>>> import MySQLdb as mysql
>>> db = mysql.connect('localhost', 'root', 'password')
>>> cur = db.cursor()
>>> cur.execute("select version()")
>>> print cur.fetchone()

Mychem cartridge for Openbabel

Mychem is a nice chemoinformatics extension for MySQL and OpenBabel. The tool has been developed by Jerome Pansanel and provides a set of functions to manipulate chemical data that are stored within a MySQL database. These functions permit you to search, analyze and convert chemical data. More information is available on the Mychem website.

Download Mychem 0.9.1 and untar the file into your /usr/local/src directory. Start the Mychem installation by creating a build directory and call cmake:

> cd /usr/local/src
> tar -xvf ~/Downloads/mychem-0.9.1.tgz
> cd /usr/local/src/mychem-0.9.1
> mkdir build
> cd build
> cmake ..
> make
> make install

The installation copies the shared library into your /usr/local/lib directory and creates symbolic links:

> ls -1 /usr/local/lib/libmychem*

You should now be able to install the SQL functions:

> cd /usr/local/src/mychem-0.9.1
> mysql -u root -p < src/mychemdb.sql

Inspect the feedback well. A typical error could be about not finding the shared library:

> mysql -u root -p < src/mychemdb.sql
Enter password:
ERROR 1126 (HY000) at line 10: Can't open shared library '' (errno: 2 dlopen(/usr/local/mysql/lib/plugin/, 2): image not found)

You can fix this error by creating a symbolic link to the correct directory:

> cd /usr/local/mysql/lib/plugin
> sudo ln -s /usr/local/lib/libmychem.dylib

This should at least fix the location error, but changes are realistic that a second type of error will occur:

> mysql -u root -p < src/mychemdb.sql
Enter password:
ERROR 1126 (HY000) at line 10: Can't open shared library '' (errno: 2 dlopen(/usr/local/mysql/lib/plugin/, 2): Library not loaded: libmysqlclient.18.dylib
  Referenced from: /usr/local/m)

Fix this by modifying the shared library so that all dependent libraries contain the correct path information:

> otool -L
        /usr/local/lib/libmychem.0.dylib (compatibility version 0.0.0, current version 0.9.1)
        /usr/local/lib/libopenbabel.4.dylib (compatibility version 4.0.0, current version 4.0.1)
        libmysqlclient.18.dylib (compatibility version 18.0.0, current version 18.0.0)
        /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 159.1.0)
        /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 52.0.0)
> sudo find / -name 'libmysqlclient.18.dylib' -print
> sudo install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql-5.5.24-osx10.6-x86_64/lib/libmysqlclient.18.dylib
> cd /usr/local/src/mychem-0.9.1
> mysql -u root -p < src/mychemdb.sql

Test the installation by launching MySQL and running:

|                                 78.046950 |
1 row in set (0.02 sec)

|                      1.6865999999999999 |
1 row in set (0.02 sec)

|                                                                                         1 |
1 row in set (0.00 sec)



Create a /etc/php.ini file so that the mysql.sock file can be found by PHP:

> cd /etc
> sudo cp php.ini.default php.ini
> sudo chmod u+w php.ini

Use a text editor program to edit the php.ini file and replace all instances of /var/mysql/mysql.sock into /tmp/mysql.sock, since the latter is the actual location of this file on OS X 10.7 and OS X 10.8. Also, make sure to set the error reporting level to error_reporting = E_ALL | E_STRICT. Finally, after saving, reset the php.ini write permissions back to the original ones:

> sudo chmod u-w php.ini


Give write permission to the httpd.conf:

> cd /etc/apache2
> sudo chmod u+w httpd.conf

Now edit this httpd.conf file using your favorite editor:

  • Find #LoadModule php5_module libexec/apache2/ and remove the leading #.
  • Find AllowOverride None within the <Directory "/Library/WebServer/Documents"> section and change to AllowOverride All so that .htaccess files will work.

In order to specify that files ending with .htm or .html are also interpreted as potentially containing PHP code, one should tweak the setup a little further. On OS X 10.7, one should look for the entry containing <IfModule php5_module> in the /etc/apache/httpd.conf and modify the AddType application/x-httpd-php .php line into AddType application/x-httpd-php .php .html .htm. On OS X 10.8 however, the PHP settings are stored in the /private/etc/apache2/other/php5.conf file rather than in /etc/apache/httpd.conf. Modify this /private/etc/apache2/other/php5.conf file by changing the AddType application/x-httpd-php .php line into AddType application/x-httpd-php .php .html .htm:

> sudo chmod u+w /private/etc/apache2/other/php5.conf
> sudo vi /private/etc/apache2/other/php5.conf
> sudo chmod u-w /private/etc/apache2/other/php5.conf

Change the permissions of /etc/apache/httpd.conf back to the original state:

> sudo chmod u-w httpd.conf

The Apache server now needs to be (re)started. The procedure for this is different between OS X 10.7 and OS X 10.8. Under OS X 10.7, one should start Apache by ticking the Web Sharing checkbox in System Preferences ‣ Sharing:


However, in the case of OS X 10.8, the Apache server needs to be enabled via the command line. To start it, type:

> sudo apachectl start

and to stop it:

> sudo apachectl stop

As an alternative to stooping and then starting again, one can restart using a single command:

> sudo apachectl restart

After starting Apache, test to see if the webserver is working in the browser by navigating to localhost. You should see the “It Works!” text.

Under both OS X 10.7 and OS X 10.8, one can test the webserver by creating a info.php file in the /Library/Webserver/Documents directory with <?php phpinfo(); ?> written into it:

> cd /Library/Webserver/Documents
> sudo vi info.php

Use Safari to navigate to localhost/info.php and check that the PHP version is displayed (5.3.10 in our case for OS X 10.7 and 5.3.15 for OS X 10.8). Also verify that mysql.default_socket, which can be found under the mysql heading of the output, is pointing to /tmp/mysql.sock:



For some reason, PEAR is not set up ready to on OS X 10.7 and OS X 10.8, but the install phar file is here, so we just need to run it:

> cd /usr/lib/php
> sudo php install-pear-nozlib.phar
> cd /etc
> sudo chmod u+w php.ini

Edit php.ini with your editor and find the line ;include_path = ".:/php/includes". Change it into include_path = ".:/usr/lib/php/pear" (make sure to remove the leading ;). Reset the php.ini write permissions and update the PEAR settings:

> sudo chmod u-w php.ini
> cd /usr/lib/php
> sudo pear channel-update
> sudo pecl channel-update
> sudo pear upgrade-all
> sudo pear install Mail
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