Installation

Dependencies

CMake (version ≥ 3.16)¹.
The NetCDF-C library (version ≥ 4.6).
The NetCDF-Fortran library (version ≥ 4.5).
The Fortran compiler that was used to compile your installed NetCDF-Fortran library.
Git (optional, the easiest way to download NetCDF95).

Under Ubuntu ≥ 20.04 or Linux Mint ≥ 20, you can install all these dependencies with the following command:

sudo apt install libnetcdff-dev gfortran cmake git

Get NetCDF95 from Github. As the Git repository contains a submodule, the easiest way is to type:
```
git clone --recurse-submodules https://github.com/lguez/NetCDF95.git
```
If you prefer to download a ZIP file then you will also have to download the cmake subdirectory.
Create a build subdirectory in the NetCDF95 directory you have just downloaded:
```
cd NetCDF95
mkdir build
cd build
```
Decide in which directory you want to install NetCDF95 after compilation and type the command below with your choice after -DCMAKE_INSTALL_PREFIX= (enter an absolute path). For example:
```
cmake .. -DCMAKE_INSTALL_PREFIX=~/.local
```
Type:
```
make install
```

You do not need to keep the downloaded directory NetCDF95 (nor the build directory) after installation.

Most users should not need these advanded instructions.

You can choose any name and any location for the build directory. You have to refer to the source directory when you run cmake from the build directory:
```
mkdir /wherever/any/name
cd /wherever/any/name
cmake /where/I/downloaded/NetCDF95 -DCMAKE_INSTALL_PREFIX=~/.local
```
NetCDF95 assumes that the Fortran default character kind is the same as the C character kind (the official NetCDF-Fortran interface makes the same assumption). You can test this by running the command ctest in the build directory. If this test fails then the procedures nf95_inq_grpname, nf95_inq_grpname_full, nf95_inq_grp_full_ncid and nf95_get_att_text are not reliable.
You do not have to install. You can just use the compiled library in the build directory. So you do not have to specify the option -DCMAKE_INSTALL_PREFIX= and you can just type make instead of make install.
You can compile with debugging options by adding the option -DCMAKE_BUILD_TYPE=Debug to the command cmake.

If your installation of NetCDF or NetCDF-Fortran is in a non-standard location, and CMake does not find it, then re-run cmake setting the variable CMAKE_PREFIX_PATH to the directory containing it. CMake will then search ${CMAKE_PREFIX_PATH}/lib, ${CMAKE_PREFIX_PATH}/include, etc. For example, if you want to use the parallel-enabled version of NetCDF-C on Ubuntu or Linux Mint:
```
cmake . -DCMAKE_PREFIX_PATH:PATH=/usr/lib/x86_64-linux-gnu/netcdf/mpi
```
If you have several Fortran compilers on your machine, it is possible that CMake does not choose the one you want. Note that when you run cmake, it prints a line telling which compiler it is going to use. For example :
```
-- The Fortran compiler identification is GNU 11.3.0
```
So if you want another compiler, remove everything in the build directory and run cmake again setting the variable FC to the compiler you want. For example:
```
rm -r * # in the build directory!
FC=ifort cmake .. -DCMAKE_INSTALL_PREFIX=~/.local
```

On Mac OS, after downloading the application from the CMake web site, run it, then click on “How to Install For Command Line Use” in the Tools menu. ↩