### 18.3.2. Default Fortran Compilers

The `cfx5mkext` command requires a Fortran compiler to be in your path. The commands given in the following table are the defaults used to execute the compiler on each platform.

Platform | Command
--- | ---
winnt-amd64 | ifort
linux-amd64 | ifort

If the commands shown do not execute the Fortran compiler on your platform, then you will have to manually edit a copy of the `CFXROOT`/etc/cfx5mkext.ccl file and place it in the working directory. The `cfx5mkext` command looks for a copy of cfx5mkext.ccl in the current working directory first. Further instructions are provided at the top of the file cfx5mkext.ccl file.

The required compiler versions are given in Compiler Requirements for All Windows Versions in the Installation and Licensing Documentation and Compiler Requirements for All Linux Versions in the Installation and Licensing Documentation.

Release 18.2 - © ANSYS, Inc. All rights reserved.