Install (source code)
Introduction and requirements
Here we describe the compilation and installation procedure for OpenBabel 2.0.2. For a different release, the version number will be different and you should take this in account when reading the instructions below.
The following are required to compile Open Babel:
- The latest version of the Open Babel source code
- A C++ compiler (like g++)
- A makefile system (like GNU make)
The following are optional when compiling Open Babel, but if not installed, it may restrict the features available:
- Python is required to compile the Python bindings
- Perl is required to compile the Perl bindings
- SWIG is required to recreate the Python/Perl bindings (this is only necessary for developers...see Advanced Notes for more info)
- libxml2 development headers are required to read/write CML files (the libxml2-dev package in Ubuntu)
- zlib.h is required to support reading gzipped files (the zlib1g-dev package in Ubuntu)
If you want to install globally on your system, you will need root access, and should follow these instructions. If you don't have root access or if you simply wish to install in your 'home' area, see Installing locally without root access.
Installing globally with root access
(A1) Open a command window, and decompress the downloaded file with following command:
tar zxvf openbabel-2.0.2.tar.gz
This will create a folder called 'openbabel-2.0.2'.
(A2) You now need to configure and compile openbabel. To do this, change directory into 'openbabel-2.0.2'. Run the following commands, one after the other
./configure | tee configure.out make | tee make.out
If there are any errors at this point, send an email to the openbabel-discuss mailing list and attach the files 'configure.out' and 'make.out'.
If you look at the output of 'configure' you can see whether CML and gzip support will be included in openbabel (see Optional Libraries above).
... checking for libxml - version >= 2.6.5...yes (version 2.6.21) ... checking for zlib.h... yes
(A3) If you have root permissions, you can install openbabel globally. As root, run the following command:
Install the Python bindings globally
(B1) If you want to use OpenBabel from Python, you now need to compile the python extension. This may require an extra Python package depending on your Linux distribution. For example, for Debian you need the 'python-dev' package (installed using 'apt-get'); for SUSE, you need 'python-devel' (installed using YaST).
Change directory to 'openbabel-2.0.2/scripts/python' and run:
python setup.py build
(B2) To install the python interface globally, as root type:
python setup.py install
(B3) You may need to add the location of libopenbabel.so.1 (on my system, the location is /usr/local/lib) to the environment variable LD_LIBRARY_PATH if you get the following error when you try to import the OpenBabel library at the Python prompt:
$ python >>> import openbabel Traceback (most recent call last): File "<stdin>", line 1, in ? File "/usr/lib/python2.4/site-packages/openbabel.py", line 9, in ? import _openbabel ImportError: libopenbabel.so.1: cannot open shared object file: No such file or directory
Install the Perl bindings globally
(C1) If you want to use OpenBabel from Perl, you now need to compile the Perl extension.
Change directory to 'openbabel-2.0.2/scripts/perl' and run:
perl Makefile.PL make make test # (Optional - this runs a few standard tests)
(C2) To install the Perl bindings globally, as root type:
(C3) You may need to add the location of libopenbabel.so.1 (on my system, the location is /usr/local/lib) to the environment variable LD_LIBRARY_PATH if you get an error when you try to import the OpenBabel library in a Perl script.
Installing locally without root access
If you don't have root access, you can still compile and use Open Babel.
(D1) Follow Step A1 above
(D2) Make a local directory to install everything into. In this example, I will use the folder "tree" in my home directory:
(D3) Instead of Step A2 above, use the 'prefix' option of configure as follows:
./configure --prefix=/home/noel/tree | tee configure.out make | tee make.out
(D4) You can now install without root permissions using the following command:
This installs the babel executable (and related tools) to /home/noel/tree/bin so you need to add this directory to your PATH in your startup scripts (that is, .bashrc, or whatever):
Install the Python bindings locally
(E1) To compile the Python extension, follow Step B1 above.
(E2) To install the Python extension, instead of Step B2 above, use the 'prefix' option to setup.py:
python setup.py install --prefix=/home/noel/tree
This installs the Python extension into something like /home/noel/tree/lib/python2.3/site-packages, so you need to add this directory to your PYTHONPATH in your startup scripts (that is, .bashrc, or whatever):
(E3) As described in Step B3 above, you will probably also have to edit the variable LD_LIBRARY_PATH as follows:
Install the Perl bindings locally
(F1) To compile the Perl extension, instead of Step C1 above, use the 'PREFIX' option to Makefile.PL to specify an install location:
perl Makefile.PL PREFIX=/home/noel/tree make make test # (Optional - this runs a few standard tests)
(F2) To install the Perl extension, run the following:
This installs the extension into something like /home/noel/tree/lib/perl/5.8.7, so you need to add "/home/noel/tree/lib/perl" to your PERL5LIB environment variable or specify this location in your Perl scripts as follows:
use lib "/home/noel/tree/lib/perl"; # Must come before "use Chemistry::OpenBabel;"
(F3) As described in Step C3 above, you will probably also have to edit the variable LD_LIBRARY_PATH as follows:
- When compiling the Python extension, if you want to link to a version of Open Babel that is not in ../../src (relative to setup.py), /usr/local or /usr (this is the order in which these locations are searched), you should set OPENBABEL_INSTALL to point to the alternative location. There should be an "include/openbabel-2.0" and a "lib" directory at the location pointed to by OPENBABEL_INSTALL.
- If you need to recompile the SWIG bindings for the openbabel module, make sure you have the latest version of SWIG installed, and at Step A2 above, run configure as follows: