Trick requires various free third party utilities in order to function. All the following products are used by Trick and may already be installed as part of your OS distribution. **Install any missing dependencies with your operating system's [package manager](https://en.wikipedia.org/wiki/Package_manager).** For most operating systems, the default version of a dependency will be compatitable with Trick. Please check the specific OS instructions below for your operating system for more details.
Clang/LLVM can be installed and located manually should your package manager fail to acquire it. You can tell Trick where to find Clang/LLVM with the "--with-llvm" configuration option specified [below](TODO).
Trick runs on GNU/Linux and MacOSX, though any System V/POSIX compatible UNIX workstation should accept the Trick software with very little source code porting. Below are instructions for installing the prerequisites on popular operating systems here at NASA.
Trick requires the clang/llvm compiler to compile and link the Trick Interface Code Generator. clang/llvm is available through the [Extra Packages for Enterprise Linux](https://fedoraproject.org/wiki/EPEL) repository. Download and install the 'epel-release' package.
Trick makes use of several optional packages if they are present on the system. These include using the HDF5 package for logging, the GSL packages for random number generation, and google test (gtest) for Trick's unit testing. These are available from the EPEL repository. In order to access gtest-devel in the epel repository you need to enable the dnf option PowerTools
Trick requires the clang/llvm compiler to compile and link the Trick Interface Code Generator. clang/llvm is available through the [Extra Packages for Enterprise Linux](https://fedoraproject.org/wiki/EPEL) repository. Download and install the 'epel-release' package.
Trick makes use of several optional packages if they are present on the system. These include using the HDF5 package for logging, the GSL packages for random number generation, and google test (gtest) for Trick's unit testing. These are available from the EPEL repository
Trick makes use of several optional packages if they are present on the system. These include using the HDF5 package for logging, the GSL packages for random number generation, and google test (gtest) for Trick's unit testing. These are available from the EPEL repository
All packages required for Trick may be installed through apt-get. If your package manager cannot find these packages, try searching for alternatives, or your Ubuntu version may be too old.
Openmotif may install dependent packages that conflict with other installations, fontconfig and freetype. Use the following command to skip installing these packages if you encounter conflicts.
The following commands will clone the Trick repository into a folder named *trick* in your home directory. You can install multiple copies of Trick in different locations to isolate your simulation environments from one another.
```bash
cd ${HOME}
git clone https://github.com/nasa/trick
```
## 2.) Configure Trick
Navigate to the *trick* directory you just created and run the *configure* script.
```bash
cd ${HOME}/trick
./configure
```
The *configure* script will generate makefiles and locate project dependencies automatically. It may be necessary to specify dependency paths manually. Run the following command to see the possible options *configure* will accept.
```bash
./configure --help
```
## 3.) Compile Trick
Now that Trick has been configured and a makefile has been generated, we can run *make* to compile Trick. To build Trick in 32-bit mode, first set the `TRICK_FORCE_32BIT` environment variable to `1`.
```bash
make
```
## 4.) Optionally Update Your Environment
Gone are the days when you needed to set several environment variables to use Trick. Trick can now be used completely environmentlessly*. You no longer need to set `TRICK_HOME` and friends.
Trick still makes use of shell variables, but their existence is only required during simulation compilation and execution. If they are not set, Trick will infer them without polluting your environment. Furthermore, they will be available to any processes that are spawned as part of compilation or execution, so even your own tools may no longer need these variables to be manually set.
Similarly, Trick does not require its executables to be on your `PATH`, but you may find it convenient to add them if you prefer to not specify the full path to `trick-CP` every time you build a sim. They are located in `bin` under Trick's root directory. However, if you frequently work with multiple versions of Trick, it is often easier to use a full path than to keep changing an environment variable.
Finally, although setting `TRICK_CFLAGS` and `TRICK_CXXFLAGS` is not necessary, it can be useful to do so if you want a set of flags (`-g` or `-Wall`, for instance) to be applied to all simulation builds.
*The exception to this is if you're building in 32-bit mode, in which case the `TRICK_FORCE_32BIT` environment variable must be set to `1` before you build Trick or any simulation.
[Continue to Building A Simulation](../building_a_simulation/Building-a-Simulation)
If you intend to build Trick in 32-bit mode, you will need 32-bit versions of the libraries in the above table. If a 32-bit version of udunits is not available through your package manager, you can build it from [source](ftp://ftp.unidata.ucar.edu/pub/udunits/udunits-2.2.25.tar.gz):
