Initialization in #include files

[der Mouse]

In article <8046 at brl-smoke.ARPA>, gwyn at brl-smoke.ARPA (Doug Gwyn ) writes:
> In article <5776 at chinet.UUCP> les at chinet.UUCP (Leslie Mikesell) writes:
>> But the variables are very likely to be used in every source file,
> I do hope you people know better than to design software with lots of
> pathological inter-module connections like this.

Let's pick an example.  I wrote a dvi-to-printer program for our
printers here.  Here's the list of global variables (the .h file which
every file includes).  What would you recommend I do with each one?
All of them hold stuff which is conceptually global, ie, which should
be available to any module which cares to refer to it.

[#include blather (type definitions, eg) deleted]

	extern PAGENO veryfirst;
	extern PAGENO verylast;
These are the lowest and highest possible page numbers.  PAGENO is a
non-simple type, so these are initialized data rather than #defines.
Under ANSI they would be declared const.

	extern char *inclexcl[MAX_INCL_EXCL];
	extern int n_inclexcl;
	extern PAGENO ie_pgs[MAX_INCL_EXCL][2];
	extern int default_is_excl;
	extern int is_excl[MAX_INCL_EXCL];
These variables describe the results of parsing the command-line
options to select what pages of the dvi file to print.

	extern int debugging;
This variable turns on debugging information from various modules.

	extern char dvifile[256];
	extern FILE *dvif;
Variables describing the dvi file: name and FILE pointer.

	extern SIXVALUES *stack;
	#define h stack->H
	#define v stack->V
	#define hh stack->HH
	#define vv stack->VV
	#define w stack->W
	#define x stack->X
	#define y stack->Y
	#define z stack->Z
The stack of positions (see the dvi file format documentation).

	extern FONT *fonts;
	extern FONT *curfont;
The list of all fonts and the current font.

	extern int numerator;
	extern int denominator;
	extern double trueconv;
	extern int mag;
	extern double conv;
These hold global information obtained from the dvi file, things like
conversion ratios between dvi file units and pixels.

	extern int dvilength;
	extern int postamble;
	extern int firstbackpointer;
Stuff to help find the dvi file administrivia.

	extern int maxh;
	extern int maxv;
Maximum values of h and v (see the dvi format documentation).

	extern int npages;
	extern long int *pg_begins;
Number of pages and locations at which they begin in the dvi file.

	extern int startloc;
Set but never used (historical artifact).

	extern PRINTER *printer;
Pointer through which printer-specific routines are accessed.

	extern int Fflag;
	extern int Xflag;
Two command-line flags, to be used by the printer routines.

	extern int nfontdirs;
	extern char **fontdirs;
	extern int maxfdlen;
The results of parsing the path for font files.

	extern char defaultfontpath[];
	extern char fontpath_env[];
Initialized strings for the font file path.

	extern int missingfonts;
Indication of whether there were any fonts for which the bitmap files
could not be located.

					der Mouse

			uucp: mouse at mcgill-vision.uucp
			arpa: mouse at larry.mcrcim.mcgill.edu