The general syntax of the compiler command line is:
f77 [options] list_of_files [-lx] f90 [options] list_of_files [-lx]
Items in square brackets indicate optional parameters. The brackets are not part of the command. The options are a list of option keywords prefixed by dash (-). Some keyword options take the next item in the list as an argument. The list_of_files is a list of source, object, or library file names separated by blanks.