# Run Fortran Applications from the Command Line

For programs run from the command line, the operating system searches directories listed in the PATH environment variable to find the requested executable file.

The program can also be run by specifying the complete path of the executable file. On Windows, any DLLs you are using must be in the same directory as the executable or in one specified in the path.

## Multithreaded Programs

If the program is multithreaded, each thread starts on whichever processor is available at the time. On a computer with one processor, the threads all run in parallel, but not simultaneously; the single processor switches among them. On a computer with multiple processors, the threads can run simultaneously.

## Using the -fpscomp filesfromcmd Option

If you specify the -fpscomp option with keyword filesfromcmd, the command line that executes the program can include additional file names to satisfy `OPEN` statements in the program for which the file name field (`FILE` specifier) has been left blank. The first file name on the command line is used for the first `OPEN` statement executed, the second file name for the second `OPEN` statement, and so on.

Each file name on the command line must be separated from the names around it by one or more spaces, or tab characters. You can enclose each name in quotation marks ("<filename>"), but this is not required unless the argument contains spaces or tabs. A null argument consists of an empty set of quotation marks with no file name enclosed ("").

The following example runs the program MYPROG.EXE from the command line:

    MYPROG "" OUTPUT.DAT

Because the first file name argument is null, the first `OPEN` statement with a blank file name field produces the following message:

    File name missing or blank - please enter file name
    UNIT number  ?

The number is the unit number specified in the `OPEN` statement. The file name OUTPUT.DAT is used for the second `OPEN` statement executed. If additional `OPEN` statements with blank file name fields are executed, you will be prompted to add more file names.

Instead of using the -fpscomp option with keyword filesfromcmd, you can:

- Call the `GETARG` library routine to return the specified command-line argument. To execute the program in the Microsoft Visual Studio IDE, provide the command-line arguments to be passed to the program using Project > Properties. Choose the Debugging category and enter the arguments in the Command Arguments text box.

- On Windows, call the GetOpenFileName Windows API routine to request the file name using a dialog box.

Parent topic: Use the Command Line

## See Also

-fpscomp option