How to download and instal Open Babel from source code on CentOS computers? I want to build the binary programs by myself.

If you want to build the Open Babel binary programs from source code yourself, you can follow this tutorial.

1. Go to Open Babel Code Repository at https://sourceforge.net/projects/openbabel/.

2. Open "Files > openbabel / 2.4.1" folder. And download openbabel-2.4.1.tar.gz.

3. Unzip and untar the download file. You should see a directory ~/openbabel-2.4.1 with all source code.

4. Create a "build" sub-directory and configure the build system.

fyicenter$ cd openbabel-2.4.1/

fyicenter$ mkdir build 
fyicenter$ cd build 

fyicenter$ cmake .. 
-- The C compiler identification is GNU 8.3.1
-- The CXX compiler identification is GNU 8.3.1
...
-- Checking for module 'cairo'
--   Package 'cairo', required by 'virtual:world', not found
-- Could NOT find Cairo (missing: CAIRO_LIBRARIES CAIRO_INCLUDE_DIRS) 
-- Could NOT find Cairo. PNG output will NOT be supported.
-- Looking for getopt
-- Looking for getopt - found
-- Attempting to build the GUI
--    wxWidgets not found => GUI will not be built
-- Found PythonInterp: /usr/bin/python3.6 (found version "3.6.8") 
-- Configuring done
-- Generating done
-- Build files have been written to: /home/fyicenter/openbabel-2.4.1/build

5. Run the build process.

fyicenter$ make -j2 
Scanning dependencies of target inchi
Scanning dependencies of target openbabel
[  0%] Building CXX object src/CMakeFiles/openbabel.dir/alias.o
[  0%] Building C object src/formats/libinchi/CMakeFiles/inchi.dir/ichi_bns.o
[  0%] Building C object src/formats/libinchi/CMakeFiles/inchi.dir/ichi_io.o
[  0%] Building C object src/formats/libinchi/CMakeFiles/inchi.dir/ichican2.o
[  1%] Building CXX object src/CMakeFiles/openbabel.dir/atom.o
...
[ 99%] Building CXX object test/CMakeFiles/test_runner.dir/smartstest.o
[ 99%] Building CXX object test/CMakeFiles/test_runner.dir/smartsparse.o
[ 99%] Building CXX object test/CMakeFiles/test_runner.dir/smilesmatch.o
[100%] Building CXX object test/CMakeFiles/test_runner.dir/unitcell.o
[100%] Building CXX object test/CMakeFiles/test_runner.dir/obtest.o
[100%] Linking CXX executable ../bin/test_runner
[100%] Built target test_runner

6. Run tests on the build result. You may see some failures.

fyicenter$ make test 
Running tests...
Test project /home/fyicenter/openbabel-2.4.1/build
        Start   1: test_automorphism_1
  1/151 Test   #1: test_automorphism_1 ..............   Passed    0.01 sec
        Start   2: test_automorphism_2
  2/151 Test   #2: test_automorphism_2 ..............   Passed    0.01 sec
        Start   3: test_automorphism_3
  3/151 Test   #3: test_automorphism_3 ..............   Passed    0.01 sec
        Start   4: test_automorphism_4
        ...
150/151 Test #150: pytest_kekule ....................   Passed    0.32 sec
        Start 151: pytest_pdbformat
151/151 Test #151: pytest_pdbformat .................***Failed    0.03 sec

94% tests passed, 9 tests failed out of 151

Total Test time (real) =  21.85 sec

The following tests FAILED:
   42 - test_gzip_1 (Failed)
   53 - test_isomorphism_5 (Failed)
   54 - test_isomorphism_6 (Failed)
   57 - test_multicml_1 (Failed)
   64 - test_rotor_2 (Failed)
   65 - test_rotor_3 (Failed)
   66 - test_rotor_4 (Failed)
  146 - pytest_sym (Failed)
  151 - pytest_pdbformat (Failed)
Errors while running CTest
make: *** [Makefile:73: test] Error 8

7. Build final installation targets and install them to the default system location.

fyicenter$ sudo make install 
[ 14%] Built target openbabel
[ 16%] Built target plugin_descriptors
[ 20%] Built target plugin_ops
[ 21%] Built target plugin_fingerprints
[ 22%] Built target plugin_forcefields
...
[ 88%] Built target test_inchiwrite
[100%] Built target test_runner
[100%] Built target roundtrip
Install the project...
-- Install configuration: "RelWithDebInfo"
-- Installing: /usr/local/include/openbabel-2.0/openbabel/babelconfig.h
-- Installing: /usr/local/lib/pkgconfig/openbabel-2.0.pc
-- Installing: /usr/local/lib/cmake/openbabel2/OpenBabel2_EXPORTS.cmake
-- Installing: /usr/local/lib/cmake/openbabel2/OpenBabel2_EXPORTS-relwithdebinfo.cmake
-- Installing: /usr/local/lib/cmake/openbabel2/OpenBabel2Config.cmake
-- Installing: /usr/local/lib/cmake/openbabel2/OpenBabel2ConfigVersion.cmake
-- Installing: /usr/local/include/inchi/inchi_api.h
...
-- Installing: /usr/local/bin/obthermo
-- Set runtime path of "/usr/local/bin/obthermo" to "/usr/local/lib"
-- Installing: /usr/local/bin/obspectrophore
-- Set runtime path of "/usr/local/bin/obspectrophore" to "/usr/local/lib"
-- Installing: /usr/local/bin/obgrep
-- Set runtime path of "/usr/local/bin/obgrep" to "/usr/local/lib"
-- Installing: /usr/local/bin/roundtrip
-- Set runtime path of "/usr/local/bin/roundtrip" to "/usr/local/lib"

7. Verify installation.

fyicenter$ babel -V
Open Babel 2.4.1 -- May 25 2020 -- 08:24:13

Open Babel command line tools are ready to use.

Note that the building process requires you to have building tools: GCC compiler, CMake, and make.

You can also download Open Babel source code from github.com as https://github.com/openbabel/openbabel

⇒ Running Open Babel on macOS

⇐ Install Open Babel CLI RPM Package for CentOS

⇑ Running Open Babel on CentOS

⇑⇑ Open Babel Tutorials