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fpp(1)			    General Commands Manual			fpp(1)

NAME
       fpp - the Fortran language preprocessor for FORTRAN 77 and Fortran 90.

SYNOPSIS
       fpp [ options ] [ input-file [ output-file ] ]

DESCRIPTION
       fpp is the  preprocessor	 for FORTRAN 77	and Fortran  90.  fpp option-
       ally  accepts  two  filenames  as   arguments.  input-file and output-
       file  are, respectively,	the  input file	read and the output file writ-
       ten by the preprocessor.	 By default standard input and output are
       used.  fpp should be used instead of the	cpp preprocessor with the Sun
       FORTRAN 77 compiler.

OPTIONS
       -c_com={yes|no}
	      By default, C style comments are recognized. Turn	this off by
	      specifying -c_com=no

       -Dname Define the preprocessor variable name as 1 (one).	This is	the
	      same as if a -Dname=1 option appeared on the fpp command line,
	      or as if a

		     #define name 1

	      line appeared in the source file,	which is processed by fpp.

       -Dname=def
	      Define name as if	by a #define directive.	 This is the same as
	      if a

		     #define name def

	      line appeared in the source file that fpp	is processing.	The -D
	      option has lower precedence than the -U option.  That is,	if the
	      same name	is used	in both	a -U option and	a -D option, the name
	      will be undefined	regardless of the order	of the options.

       -fixed Assumes fixed format input source.

       -free  Assumes free format input	source.

       -Idirectory
	      Insert directory into the	search path for	#include files with
	      names not	beginning with `/'.  directory is inserted ahead of
	      the standard list	of ``include'' directories.  Thus, #include
	      files with names enclosed	in double-quotes (") are searched for
	      first in the directory of	the file with the #include line, then
	      in directories named with	-I options, and	lastly,	in directories
	      from the standard	list.  For #include files with names enclosed
	      in angle-brackets	(<>), the directory of the file	with the #in-
	      clude line is not	searched.

       -M     Generate a list of makefile dependencies and write them to the
	      standard output. This list indicates that	the object file	which
	      would be generated  from the input file depends on the input
	      file  as	well  as  the  include	files referenced.

       -macro={yes|no_com|no}
	      By default, macros are expanded everywhere.  Turn	off macro ex-
	      pansion in comments by specifying	-macro=no_com and turn off
	      macro expansion all together by specifying -macro=no

       -P     Do not put line numbering	directives to the output file. This
	      directive	appears	as
	      #line-number file-name

       -Uname Remove any initial definition of name, where name	is a fpp vari-
	      able that	is predefined by a particular preprocessor.  Here is a
	      partial list of symbols that may be predefined, depending	upon
	      the architecture of the system:

		     Operating System:	 unix, __unix, and__SVR4
		     Hardware:		 sun, __sun, sparc, and__sparc

       -undef Remove initial definitions for all predefined symbols.

       -w0    Don't output warnings from fpp to	stderr.

       -Xu    Convert upper-case letters to lower-case,	except within charac-
	      ter-string constants. The	default	is to not convert upper-case
	      letters  to  lower-case.

       -Xw    For fixed	form source files (See below) fpp assumes that the
	      symbol ' ' (space) is insignificant.  By default for this	form
	      the 'space' symbol is the	delimiter of tokens.

       -Ydirectory
	      Use the specified	 directory in place of the standard list of
	      directories when searching for files.

       fpp    also understands some FORTRAN 77 compiler	options	(See f77(1)):

       -e     Accept extended source lines, up to 132 characters long.

       -w     Do not output warnings to	stderr.

USAGE
   Source files
       fpp operates on both fixed and free form	source files. Files with '.F'
       extension are assumed to	be in fixed form, and files with '.F90'	exten-
       sions (and all others) are assumed to be	in free	form by	default. There
       is the '-fixed' option for using	fixed form in Fortran 90.  fpp recog-
       nizes the tab format of a source	line when in fixed mode.

       A source	file may contain fpp tokens.  fpp tokens are close to those of
       Fortran.	They are:

	      -	     fpp directive names.

	      -	     symbolic names including Fortran keywords.	fpp permits
		     all symbols in names that Fortran does.

	      -	     constants.	Integer, real, double and quadruple precision,
		     binary, octal, hexadecimal	including alternate notation,
		     character and hollerith.

	      -	     comments. There are Fortran comments and fpp comments.

	      -	     others. Special characters, space,	tab, newline, etc.

   Output
       Output consists of a modified copy of the input,	plus lines of the
       form:

	    #line_number  file_name

       inserted	to indicate the	original source	line number and	filename of
       the output line that follows.  There is the '-P'	option (See above)
       which disables the generation of	these lines.

   Directives
       Syntax and semantics of fpp directives are the same as cpp directives
       (See cpp(1)).

       All fpp directives  start with the hash symbol (#)  as the first	char-
       acter on	a line.	White space (SPACE or TAB characters) can  appear af-
       ter the initial '#' for proper indentation.  The	 directives can	be di-
       vided  into the following groups:

       - macro definitions;

       - conditional source code selection;

       - inclusion of external files;

       - line control.

   Macro definition.
       The #define directive is	used to	define both simple string variables
       and more	complicated macros:

       #define name  token-string

       This is the definition of a fpp variable. Wherever 'name' appears in
       the source lines	following the definition, 'token-string' will be sub-
       stituted	for 'name'.

       #define name(argument [,	argument] ...  )  token-string

       This is the definition of a function-like macro.	 Occurrences of	the
       macro 'name' followed by	the comma-separated list of arguments within
       parentheses are substituted by the token	string produced	from the macro
       definition. Every occurrence of an argument identifier from the macro
       definition's arguments list is substituted by the token sequence	repre-
       senting the corresponding macro actual argument.

       In these	definitions, spaces between the	macro name and the '(' symbol
       are prohibited to prevent the directive being interpreted as a fpp
       variable	definition with	the rest of the	line beginning with the	'('
       symbol being interpreted	as a token-string.

       #undef name

       Remove any definition for 'name'	(produced by 'D' options, #define di-
       rectives	or by default).	No additional tokens are permitted on the di-
       rective line after the name.

   Including External Files.
       There are two forms of file inclusion:

       #include	"filename"

       #include	<filename>

       Read in the contents of filename	at this	location.  The lines read in
       from the	file are processed by fpp as  if it were a part	of the current
       file.

       When the	 <filename> notation is	 used, filename	is only	searched for
       in the standard ``include'' directories.	 See the 'I' and 'Y' options
       above for more detail.  No additional tokens are	permitted in the di-
       rective line after the final  `"'  or `>'.

   Line	control.
       #line-number "filename"

       Generate	line control information for the next  pass of the compiler.
       The integer-constant is	interpreted as the line	number of  the next
       line and	the filename is	 interpreted  as the name of the file from
       where it	comes.	If "filename" is not given, the	current	filename is
       unchanged.

   Conditional selection of source text.
       There are two forms of conditional selection of source text

       1)
		    #if	condition_1
			 block_1
		    #elif condition_2
			 block_2
		    #else
			 block_n
		    #endif

       2)
		    #ifdef name
			 block_1
		    #elif condition
			 block_2
		    #else
			 block_n
		    #endif

       or
		    #ifndef name
			 block_1
		    #elif condition
			 block_2
		    #else
			block_n
		    #endif

       else- and elif-part are optional.  There	may be more than one elif-
       part. Condition is an expression	involving fpp constants, macros	 and
       intrinsic  functions.  Condition	expressions are	similar	to  cpp	ex-
       pressions, and may contain any cpp operations and operands with the ex-
       ception of c long, octal	and hexadecimal	constants. Additionally, fpp
       will accept and evaluate	Fortran	logical	operations .NOT. .AND.	.OR.
       .EQV. .NEQV. .GT. .LT. .LE. .GE.	etc. and logical constants .TRUE.
       .FALSE.

Details
   Scope of macro or variable definitions.
       The scope of a definition begins	from the place of its definition and
       encloses	all the	source lines (and source lines from included files)
       from that definition line to the	end of the current file.

       There are the following exceptions to the scope effected	by an fpp def-
       inition:

       - files included	by Fortran INCLUDE statements;

       - fpp and Fortran comments;

       - IMPLICIT single letter	specifications;

       - FORMAT	specifications;

       - numeric, typeless and character constants.

       The scope of the	macro effect can be limited by means of	the #undef di-
       rective.

   End of macro	definition
       Macro definition	can be of any length and is limited only by the	'new-
       line' symbol. A Macro can be defined in multiple	lines. A Macro can be
       continued to the	next line with the insertion of	'\'. So, the occur-
       rence of	a 'newline' without a macro-continuation signifies the end of
       the macro definition.

       For example:
       #define long_macro_name(x,\
       y) x*y

   Function-like macro definition
       The number of macro call	arguments should be the	same as	the number of
       arguments in the	corresponding macro definition.	An error is flagged if
       they don't.

   Cancelling macro definitions	of both	kinds
       #undef name

       After this directive,  'name' would not interpreted by fpp as a macro
       or variable name. If this name has not been defined earlier as a	macro
       name, then the given directive has no effect

   Conditional source code selection
       - Constant-expression

       Subsequent lines	up to the matching #else, #elif, or #endif directive,
       appear in the output only if their constant-expression yields a true
       value.

       The lines following the #elif directive appear in the output only if
       all of the following conditions hold:

	      -	     The constant-expression  in the   preceding #if directive
		     evaluated to .FALSE.  or the name in the preceding	#ifdef
		     directive is not defined or the name in the preceding
		     #ifndef directive is defined.

	      -	     The constant-expression in	all intervening	#elif  direc-
		     tives  evaluated to .FALSE.

	      -	     The  current constant-expression	evaluates to .TRUE.

       If  the	constant-expression  evaluates to .TRUE., subsequent #elif
       and  #else directives are ignored up to the matching #endif.  Any  con-
       stant-expression	allowed	in an #if  directive is	allowed	in  an #elif
       directive.

       The intrinsic function `defined'	can be used in a constant-expression
       also.

       The following items are permitted:

	      -	     C language	operations: <, >, ==, !=, >=, <=, +, -,	/, *,
		     %,	<<, >>,	&,  ~, |, &&, || They are interpreted by fpp
		     in	accordance to the C language semantics (this facility
		     is	provided for compatibility with	"old" Fortran programs
		     using cpp)

	      -	     Fortran language operations: .AND., .OR., .NEQV., .XOR.,
		     .EQV., .NOT.  , .GT., .LT., .LE., .GE., .NE., .EQ., **
		     (power).

	      -	     Fortran logical constants:	.TRUE. , .FALSE.

	      Only these items,	integer	constants, and names can be used
	      within a constant-expression. Names which	have not been defined
	      with the help of the 'D' option, a #define directive or by de-
	      fault, get 0 as the value.  The C	operation '!=' (not equal) can
	      be used in #if or	#elif directive, but NOT in #define directive,
	      where the	symbol '!' is considered as the	Fortran	comment	sym-
	      bol.

       #ifdef name
	      Subsequent lines up to the matching  #else, #elif, or #endif ap-
	      pear in the output only if the name has been defined, either by
	      a	#define	directive or by	the 'D'	option,	and in the absence of
	      an intervening #undef directive. No additional tokens are	per-
	      mitted on	the directive line after name.

       #ifndef name
	      Subsequent lines up to the matching  #else,   #elif, or #endif
	      appear in	the output only	 if name has not been defined, or if
	      its definition has been removed with an #undef directive.	No ad-
	      ditional tokens  are permitted on	the directive line after name.

       #elif constant-expression .
	      Any number of #elif directives may  appear   between an #if,
	      #ifdef, or #ifndef directive and a matching #else	or #endif  di-
	      rective.

       #else  This inverts the sense of	the conditional	directive otherwise in
	      effect. If the preceding conditional would indicate that lines
	      are to be	included, then lines between the #else and the match-
	      ing #endif are ignored.  If the preceding	conditional indicates
	      that lines would be ignored, subsequent lines are	included in
	      the output.   Conditional	directives and corresponding #else di-
	      rectives can be nested.

       #endif End a section of lines begun by one of the conditional direc-
	      tives  #if, #ifdef, or #ifndef.  Each such directive must	have a
	      matching #endif.

   Including External Files
       Is the same as it is for	cpp.  Files are	searched as follows:

       for  #include "file_name":

	      -	     in	the directory, in which	the processed file has been
		     found;

	      -	     in	the directories	specified by the -I option;

	      -	     in	the default directory.

       for #include <file_name>:

	      -	     in	the directories	specified by the -I option;

	      -	     in	the default directory.

       fpp directives (beginning with the # symbol in the first	position of
       lines) can be placed anywhere in	a source code, in particular before a
       Fortran continuation line.  The only exception is the prohibition of
       fpp directives within a macro call divided on several lines by means of
       continuation symbols.

   Comments
       fpp permits comments of two kinds:

       1) Fortran language comments.  A	source line containing one of the sym-
       bols 'C', 'c', '*', 'd' or 'D' in the first position, is	considered as
       a comment line. Within such lines macro expansions are not performed.
       The '!' symbol is interpreted as	the beginning of a comment extending
       to the end of the line. The only	exception is the case when this	symbol
       occurs within a constant-expression in #if and #elif directives (See
       above).

       2) fpp comments enclosed	in the '/*' and	'*/' parasymbols.  They	are
       excluded	from the output	and macro expansions are not performed within
       these symbols.  fpp comments can	be nested and for each parasymbol '/*'
       there must be a corresponding parasymbol	'*/'.  fpp comments are	suit-
       able for	excluding the compilation of large portions of source instead
       of commenting every line	with Fortran comment symbols.

   Intrinsic functions
       The intrinsic function

       defined(name)   or defined name

       Returns:

	 .TRUE.	- if name is defined as	a macro.

	 .FALSE.- if the name is not defined.

   Macro expansion
       If, during expansion of a macro,	the column width of a line exceeds
       column 72 (for the fixed	format)	or column 132 (for the free format),
       fpp inserts appropriate continuation lines.

       In the fixed form there is limitation on	macro expansions in label
       fields (positions 1-5):

	      -	     a macro call (together with possible arguments) should
		     not extend	more than the column 5 position;

	      -	     a macro call whose	name begins with one of	the Fortran
		     comment symbols is	considered as a	part of	a comment;

	      -	     a macro expansion may produce a text extending beyond the
		     column 5 position.	In such	a case a warning will be is-
		     sued.

       In the fixed form when the '-Xw'	option has been	specified an ambiguity
       may appear if a macro call occurs in a statement	position and a macro
       name begins or coincides	with a Fortran keyword.	For example, in	the
       following text:

	 #define callp(x)   call f(x)
		 call p(0)

       fpp can not determine with certainty how	to interpret the 'call p' to-
       ken sequence. It	could be considered as a macro name.  The current im-
       plementation does the following:

	      -	     the longer	identifier is chosen (callp in this case);

	      -	     from this identifier the longest macro name or keyword is
		     extracted;

	      -	     if	a macro	name has been extracted	a macro	expansion is
		     performed.	If the name begins with	some keyword fpp out-
		     puts an appropriate warning;

	      -	     the rest of the identifier	is considered as a whole iden-
		     tifier.

       In the above example the	macro expansion	would be performed and the
       following warning would be output:

       warning:	possibly incorrect substitution	of macro callp

       It should be noted that this situation appears only when	preprocessing
       a fixed format source code and when the space symbol is not interpreted
       as a token delimiter.  It should	be said	also that if a macro name co-
       incides with a keyword beginning	part, as in the	following case:

	    #define INT	   INTEGER*8
		    INTEGER k

       then in accordance with the described algorithm,	the INTEGER keyword
       will be found earlier than the INT macro	name. Thus, there will be no
       warning when preprocessing such a macro definition.

DIAGNOSTICS
       There are three kinds of	diagnostic messages:

	      -	     warnings.	preprocessing of source	code is	continued and
		     the return	value remains to be 0.

	      -	     errors.  fpp continues preprocessing but sets the return
		     code to a nonzero value, namely number of errors.

	      -	     fatal error.  fpp cancels preprocessing and returns a
		     nonzero return value.

       The messages produced by	fpp are	intended to be self-explanatory.  The
       line number and filename	where the error	occurred are printed along
       with the	diagnostic.

SEE ALSO
       cpp(1), f77(1), f90(1)

				  19 Aug 1996				fpp(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | USAGE | Details | DIAGNOSTICS | SEE ALSO

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