Input and Output Files

You can use the DF command to process multiple files. These files can be source files, object files, or object libraries.

When a file is not in your path or working directory, specify the directory path before the file name.

The file extension determines whether a file gets passed to the compiler or to the linker. The following types of files are used with the DF command:

• Files passed to the compiler: .f90, .for, .f, .fpp, .i, .i90, .inc, .fi, .fd, .f77

  Typical Fortran (DF command) source files have a file extension of .f90, .for, and .f. When editing your source files, you need to choose the source form, either free-source form or fixed-source form (or a variant of fixed form called tab form). You can either use a compiler option to specify the source form used by the source files (see /fixed or /free), or you can use the following file extensions when creating or renaming your files:

  • The compiler assumes that files with an extension of .f90, .F90, or .i90 are free-form source files.
  • The compiler assumes that files with an extension of .f, .for, .FOR, or .i are fixed-form (or tab-form) files.
  
  
• Files passed to the linker: .lib, .obj, .o, .exe, .res, .rbj, .def, .dll

  For example, object files usually have a file extension of .obj. Files with extensions of .lib are usually library files.

The output produced by the DF command includes:

• An object file (.OBJ) if you specify the /compile_only, /keep, or /object option on the command line.
• An executable file (.EXE) if you do not specify the /compile_only option
• A dynamic-link library file (.DLL) if you specify the /dll option and do not specify the /compile_only option
• A module file (.MOD) if a source file being compiled defines a Fortran 90 module (MODULE statement)
• A program database file (.PDB) if you specify the /pdbfile or /debug:full (or equivalent) options
• A listing file (.LST) if you specify the /list option
• A browser file (.SBR) if you specify the /browser option

You control the production of these files by specifying the appropriate options on the DF command line. Unless you specify the /compile_only option or /keep option, the compiler generates a single temporary object file from one or more source files. The linker is then invoked to link the object file into one executable image file.

If fatal errors are encountered during compilation, or if you specify certain options such as /compile_only, linking does not occur.

When a path or file name includes an embedded space or a special character, enclose the entire file location name in double quotation marks ("). For example:

   DF "Project xyz\fortmain.f90"

For more information about naming input and output files, see:

• Naming Output Files
• Temporary Files