A file ending in ‘.f90’ or ‘.f95’ is taken to be a Fortran free-form source file, a file ending in ‘.f’, ‘.for’ or ‘.ftn’ is taken to be a Fortran fixed-form source file; these assumptions can be overridden with the -fixed or -free option. A file ending in ‘.ff90’ or ‘.ff95’ is taken to be a free-form file requiring preprocessing by fpp, and a file ending in ‘.ff’ is taken to be a fixed-form file requiring preprocessing by fpp. On Unix, a file ending in ‘.F90’ or ‘.F95’ is taken to be a free-form file requiring preprocessing by fpp, and a file ending in ‘.F’ is taken to be a fixed-form files requiring preprocessing by fpp. (Note that on Mac OS X and Windows, the file system is not case-sensitive so uppercase and lowercase letters are equivalent in filenames including in the suffixes.)
If a filename without a suffix is provided nagfor will look for a file with the suffix ‘.f95’, and if that does not exist, the suffix ‘.f90’.
A file ending in ‘.c’ is taken to be a C source file. In the =compiler mode, this is assumed to be the output from the compiler with the -S option, and the C compiler is passed -D and -I options suitable for compiling such a file. In the =C mode, it is assumed to be a file for the companion processor; no -D is passed, and only -I options specified by the user. In both cases, options are passed to the C compiler according to the ABI and compatibility mode options.
Non-intrinsic modules, INCLUDE files and #include files are expected to exist in the current working directory or in a directory named by an -I option.