Which command would you use to run a Fortran code?

Answer 1

Fortran is a programming language, which means you write a program in Fortran, and COMPILE it to an EXECUTABLE program. The compiler you use differs depending on which operating system platform you intend to run the program on. If you wish to run the program on a PC using Windows XP, you must first compile it using a specific Fortran-compiler for Windows XP. The result after compiling will be an executable file (with the file-ending .exe). To find a suitable compiler, check out download.com, for instance.

Given that you know it is Fortran Code, we can assume that you do not have a compiled one, but just raw Frotran Source code.

To compile it, you need a Fortan compiler suitable for both your operating system as well as the version of Fortran the code was written for.

There is a free Fortran Compiler for Fortran77 from the GNU Project:

For Windows: http://www.geocities.com/Athens/Olympus/5564/

For Unix: http://www.gnu.org/software/fortran/fortran.HTML

The above is correct assuming your question is "Given the Fortran source code, how do I run it?" However if your question is "Given the Fortran executable (ProgName.exe) how do I run it?", the is that you run it like any other program. You either: 1 - Double-click on the file name OR 2 - Open a DOS window, go to the directory where the file is and type in the filename with or without the extension .exe OR 3 - You can select Start and Run and type in the filename.

Like any "compilable" language it can be used to build an exe or a dll. But a dll MUST be called by another program to run, you can only run a .exe directly.

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In addition the workflow for running a Fortran program on a *nix platform (such as Unix, Linux, or Mac OSx) would be as such:

1) Write given Fortran code with proper extension

a) Fortran 77 - *.fb) Fortran 90 - *.f90c) Fortran 95 - *.f95

2) Compile using your compiler suite (showing examples for a few different cases)

a) for gfortran as mentioned abovegfortran myfile.f90 -o myExecutableg77 myfile.f77 -o myExecutableb) for OpenMPImpif90 myfile.f90 -o myExecutablempif77 myfile.f77 -o myExecutablec) for Intel Fortranifort myfile.f90 -o myExecutable

3) To run the executable first make sure it is marked as executable, this can by going to the folder in which it was compiled then typing:

ls -l

You will then see the myExecutable file marked with permissions. Check to see if the executable permission is there. If it is not, you must change permissions to allow it to be executed. This is done by typing:

chmod a+x myExecutable

4) Finally to actually run the code you simple add the execution prefix:

./myExecutable

This will cause the file to run with output in the current terminal session. Note that if you terminate the terminal/ssh session, the code execution will halt. If you want to execute a large piece of code on lets say a remote computer (or a cluster for scientific computing) then you do the following step instead of 4

4*) To run the executable in backround and log terminal output (if you don't want to keep the terminal window open) you use the following command:

nohup ./myExecutable > terminalOuput.txt &

This will cause the executable to run in the background, it will the tell terminal not to hang up (nohup) if you close the window, and it will append the terminal output to the file terminalOutput.txt