1 Introduction

This page is dedicated to explaining how to install OpenFOAM in Fedora.

If you do not yet feel comfortable using Linux, then perhaps you better first read the page Working with the Shell and train a bit with the shell/terminal environments, so you can have a better perception of the steps shown below.

2 Copy-Paste steps

A few notes before you start copy-pasting:

Lines that start with # don't have to be copy-pasted. They are just comments to let you know what's going on.
One wrong character is enough for breaking this guide, so make sure you can read the characters properly or that the installed language system does not break the copied characters!

2.1 Fedora 23

Discussion thread where you can ask questions about these steps: OpenFOAM 3.0.x on Fedora 23

Steps:

Switch to root mode (administrator), to install the necessary packages:
```
sudo -s
```
- If the 'sudo' command tells you're not in the sudoers list, then run:
```
su -
```

Install the necessary packages:

dnf groupinstall 'Development Tools' 
dnf groupinstall 'C Development Tools and Libraries'
dnf install git openmpi openmpi-devel qt-devel qtwebkit-devel zlib-devel wget CGAL-devel \
boost-devel gmp-devel mpfr-devel patch readline-devel ncurses-devel python python-devel

Now exit from the root mode:
```
exit
```
Start a new terminal. This is because you'll need a fully refreshed shell.
Download and unpack (here you can copy-paste all in single go):
```
#OpenFOAM downloading and installation
cd ~
mkdir OpenFOAM
cd OpenFOAM
git clone https://github.com/OpenFOAM/OpenFOAM-3.0.x.git
git clone https://github.com/OpenFOAM/ThirdParty-3.0.x.git
```
But we will now have to download a few more of the necessary packages for the ThirdParty-3.0.x folder:
1. First, we need to prepare for the downloads:
```
cd ThirdParty-3.0.x
mkdir download
```
2. Now, we need to download the essential source code packages for these instructions you are following (the links are from the file README.org):
```
wget -P download http://www.paraview.org/files/v4.4/ParaView-v4.4.0-source.tar.gz
wget -P download https://gforge.inria.fr/frs/download.php/file/34099/scotch_6.0.3.tar.gz
```
3. Next, we need to unpack the packages we've downloaded:
```
tar -xzf download/ParaView-v4.4.0-source.tar.gz
tar -xzf download/scotch_6.0.3.tar.gz
```
4. And we need to correct some folder names... in this case, it's just ParaView:
```
mv ParaView-v4.4.0-source ParaView-4.4.0
```
5. Last but not least, the final command on this sub-list is to go back to the main OpenFOAM folder:
```
cd ..
```
Since we are going to use CGAL 4.7 that comes with Fedora, we are going to configure accordingly by running:
```
sed -i -e 's/^$cgal_version=$.*/\1cgal-system/' OpenFOAM-3.0.x/etc/config/CGAL.sh
```
For building OpenFOAM itself, it depends on whether you have installed the i386 or x86_64 architecture of CentOS/SL/RHEL. To check this, run:
```
uname -m
```
Now, accordingly:
- For i386:
```
#forcefully load Open-MPI into the environment
#the export command has been reported as needed due to the 
#module not being available in a clean installation
module load mpi/openmpi-i386 || export PATH=$PATH:/usr/lib/openmpi/bin
 
#ignore any error messages given by the command above
 
source $HOME/OpenFOAM/OpenFOAM-3.0.x/etc/bashrc foamCompiler=ThirdParty WM_COMPILER=Gcc48 WM_ARCH_OPTION=32 FOAMY_HEX_MESH=yes
```
  Also, save an alias in the personal .bashrc file, simply by running the following command:
```
echo "alias of30x='module load mpi/openmpi-i386; source \$HOME/OpenFOAM/OpenFOAM-3.0.x/etc/bashrc $FOAM_SETTINGS'" >> $HOME/.bashrc
```
  Note: This last line means that whenever you start a new terminal window or tab, you should run the alias command associated to the OpenFOAM 3.0.x shell environment. In other words, whenever you start a new terminal, you should run:
```
of30x
```
  For more information on this topic, read section Using aliases to help manage multiple OpenFOAM versions in the page Installation/Working with the Shell.
- For x86_64, it depends on whether you need 64-bit integer support or not. But first, common to both, we will forcefully load Open-MPI into the environment (the export command has been reported as needed due to the module not being available in a clean installation):
```
module mpi/load openmpi-x86_64 || export PATH=$PATH:/usr/lib64/openmpi/bin
```
  Note: Ignore any error messages given by the command above.
  Now, depending on whether you need 64-bit integer support or not:
  - For building with the normal 32-bit integer support (maximum 2.147×10⁹ cells, faces or points):
```
source $HOME/OpenFOAM/OpenFOAM-3.0.x/etc/bashrc FOAMY_HEX_MESH=yes
```
  - For building with the normal 64-bit integer support (maximum 9.22×10¹⁸ cells, faces or points):
```
source $HOME/OpenFOAM/OpenFOAM-3.0.x/etc/bashrc WM_LABEL_SIZE=64 FOAMY_HEX_MESH=yes
```
  Also, save an alias in the personal .bashrc file, simply by running the following command:
```
echo "alias of30x='module load mpi/openmpi-x86_64; source \$HOME/OpenFOAM/OpenFOAM-3.0.x/etc/bashrc $FOAM_SETTINGS'" >> $HOME/.bashrc
```
  Note: This last line means that whenever you start a new terminal window or tab, you should run the alias command associated to the OpenFOAM 3.0.x shell environment. In other words, whenever you start a new terminal, you should run:
```
of30x
```
  For more information on this topic, read section Using aliases to help manage multiple OpenFOAM versions in the page Installation/Working with the Shell.

Now, in order to build ParaView 4.4.0 that comes with OpenFOAM:

For building ParaView 4.4.0 with Python and MPI, run:

cd $WM_THIRD_PARTY_DIR
 
#We need to apply a fix for a problem with reading multiple solids in an STL
wget https://raw.githubusercontent.com/Kitware/VTK/40937e934308e5009e80769dc0c451ee4f157749/IO/Geometry/vtkSTLReader.cxx -O ParaView-4.4.0/VTK/IO/Geometry/vtkSTLReader.cxx 
 
#this will take a while... somewhere between 30 minutes to 2 hours or more
./makeParaView4 -qmake $(which qmake-qt4) -mpi -python > log.makePV 2>&1

Once the makeParaView4 script is finished running, make sure to check the contents of the file log.makePV and check if there are any errors.
Finally, update the shell environment:
```
wmSET $FOAM_SETTINGS
```

Now let's build OpenFOAM:
1. First let's simply create empty folders for the Boost and CGAL installation paths:
```
mkdir -p $CGAL_ARCH_PATH
mkdir -p $BOOST_ARCH_PATH
```
2. Go into OpenFOAM's main source folder:
```
cd $WM_PROJECT_DIR
```
3. This next command will take a while... somewhere between 30 minutes to 3-6 hours:
```
./Allwmake -j 4 > log.make 2>&1
```
  Note: The "4" refers to the number of cores to be used for building in parallel. In addition, the amount of RAM needed for building scales with the number of cores used, something like 1GB of RAM per core; a minimum of 1.5GB is needed for linking the libraries, which is not done in parallel.
4. Run it a second time for getting a summary of the installation:
```
./Allwmake -j 4 > log.make 2>&1
```
  Note: Technically, the build will stop as soon as the first error is found. Running a second time only makes it easier to sort through between what's already been built and where the crash occurred.
To check if everything went well:
1. Check if icoFoam is working, by running this command:
```
icoFoam -help
```
  which should tell you something like this:
```
Usage: icoFoam [OPTIONS]
options:
  -case <dir>       specify alternate case directory, default is the cwd
  -noFunctionObjects
                    do not execute functionObjects
  -parallel         run in parallel
  -roots <(dir1 .. dirN)>
                    slave root directories for distributed running
  -srcDoc           display source code in browser
  -doc              display application documentation in browser
  -help             print the usage
```
  Note: And keep in mind that you need to be careful with the letter case of the command. It's icoFoam, not icoFOAM.
2. If the previous command failed to work properly, then edit the file log.make and check if there are any error messages. A few examples on how you can edit this file:
  - By using kwrite:
```
kwrite log.make
```
  - By using gedit:
```
gedit log.make
```
  - By using nano:
```
nano log.make
```
    You can then exit by using the key combination Ctrl+X and following any instructions it gives you.
  Note: It's the first error message that matters.
3. If you don't understand the output, then please compress the log-file log.make and attach the compressed file to a post in the designated thread.
  If you do not know how to create a compressed file, then try one of the following examples:
  - You can compress the file with gzip by running this command:
```
gzip < log.make > log.make.gz
```
    Then attach the resulting package file named log.make.gz to a post in the designated thread.
  - Or you can compress one or more log-files into a tarball package file, by running this command:
```
tar -czf logs.tar.gz log.*
```
    Then attach the resulting package file named logs.tar.gz to a post in the designated thread.
4. Instructions on how to further diagnose the issue yourself, have a look at the section Common errors when building OpenFOAM from source code in the page FAQ/Installation and Running.
Now you can go read the User Guide, where you may have more than one choice:
1. Which you can find a local copy of the User Guide by running the following command:
```
ls -A1 $WM_PROJECT_DIR/doc/Guides*/*UserGuide*.pdf
```
  - You should see two available formats: A4 and US-Letter.
  - But if it instead tells you that there is No such file or directory, then the OpenFOAM environment is possibly not properly activated.
2. You can also find the more recent OpenFOAM Foundation User Guides online at the following page: official OpenFOAM User Guide - but be careful if you use the version that is too much ahead of the version you are currently using, given that some features have changed overtime.

Reminder: Whenever you start a new terminal window or tab, you should run the alias command associated to the OpenFOAM 3.0.x shell environment. In other words, run the following command whenever you start a new terminal:

of30x

For more information on this topic, read section Using aliases to help manage multiple OpenFOAM versions in the page Installation/Working with the Shell.