#ifndef lintstatic char	*sccsid = "@(#)READ8.c	1.2	(ULTRIX)	1/27/86";#endif lint/************************************************************************ *									* *			Copyright (c) 1986 by				* *		Digital Equipment Corporation, Maynard, MA		* *			All rights reserved.				* *									* *   This software is furnished under a license and may be used and	* *   copied  only  in accordance with the terms of such license and	* *   with the  inclusion  of  the  above  copyright  notice.   This	* *   software  or  any  other copies thereof may not be provided or	* *   otherwise made available to any other person.  No title to and	* *   ownership of the software is hereby transferred.			* *									* *   This software is  derived  from  software  received  from  the	* *   University    of   California,   Berkeley,   and   from   Bell	* *   Laboratories.  Use, duplication, or disclosure is  subject  to	* *   restrictions  under  license  agreements  with  University  of	* *   California and with AT&T.						* *									* *   The information in this software is subject to change  without	* *   notice  and should not be construed as a commitment by Digital	* *   Equipment Corporation.						* *									* *   Digital assumes no responsibility for the use  or  reliability	* *   of its software on equipment which is not supplied by Digital.	* *									* ************************************************************************//**************************************************************************			Modification History**		David Metsky,	27-Jan-86** 001	Replaced old version with BSD 4.3 version as part of upgrade**	Based on:	READ8.c		1.9 (Berkeley)	11/6/83**************************************************************************/#include "h00vars.h"#include <errno.h>extern int errno;doubleREAD8(curfile)	register struct iorec	*curfile;{	double			data;	int			retval;	if (curfile->funit & FWRITE) {		ERROR("%s: Attempt to read, but open for writing\n",			curfile->pfname);		return;	}	UNSYNC(curfile);	errno = 0;	retval = readreal(curfile, &data);	if (retval == EOF) {		ERROR("%s: Tried to read past end of file\n", curfile->pfname);		return;	}	if (retval == 0) {		ERROR("%s: Bad data found on real read\n", curfile->pfname);		return;	}	if (errno == ERANGE) {		if (data == 0.0)			ERROR("%s: Underflow on real read\n", curfile->pfname);		else			ERROR("%s: Overflow on real read\n", curfile->pfname);		return;	}	if (errno != 0) {		PERROR("Error encountered on real read ", curfile->pfname);		return;	}	return (data);}/* *	given a file pointer, read a sequence of characters of the *	syntax of section 6.1.5 and form them into a double. * *	the syntax of a signed-real is: *	    [-|+] digit {digit} [ . digit {digit} ] [ e [+|-] digit {digit} ] * *	returns: *		1	for success (with value in *doublep) *		0	on error (with *doublep unchanged) *	       -1	on end-of-file during read (with *doublep unchanged) *	side effects: *	      errno	may be set to ERANGE if atof() sets it. */readreal(curfile, doublep)	struct iorec	*curfile;	double		*doublep;{	FILE	*filep = curfile->fbuf;	/* current file variable */	char	*sequencep;		/* a pointer into sequence */	int	read;			/* return value from fscanf() */	char	sequence[BUFSIZ];	/* the character sequence */	double	atof();#define PUSHBACK(curfile, sequencep) \	if (ungetc(*--(sequencep), (curfile)->fbuf) != EOF) { \		*(sequencep) = '\0'; \	} else if ((curfile)->funit & SYNC) { \		(curfile)->funit &= ~SYNC; \		*(curfile)->fileptr = *(sequencep); \		*(sequencep) = '\0'; \	} else { \		return (0); \	}#define	RETURN_ON_EOF(read) \	if (read == EOF) \		return (EOF); \	else \		/* void */;#define	PUSH_TO_NULL(sequencep) \	while (*sequencep) \		sequencep++;	/* general reader of the next character */#define	NEXT_CHAR(read, filep, format, sequencep) \	read = fscanf(filep, "%c", sequencep); \	RETURN_ON_EOF(read); \	*++sequencep = '\0';	/* e.g. use %[0123456789] for {digit}, and check read */#define	SOME(read, filep, format, sequencep) \	read = fscanf(filep, format, sequencep); \	RETURN_ON_EOF(read); \	PUSH_TO_NULL(sequencep);	/* e.g. use %[0123456789] for digit {digit} */#define	AT_LEAST_ONE(read, filep, format, sequencep) \	read = fscanf(filep, format, sequencep); \	RETURN_ON_EOF(read); \	if (strlen(sequencep) < 1) \		return (0); \	PUSH_TO_NULL(sequencep);#define	ANY_ONE_OF(read, filep, format, sequencep) \	read = fscanf(filep, format, sequencep); \	RETURN_ON_EOF(read); \	if (strlen(sequencep) != 1) \		return (0); \	PUSH_TO_NULL(sequencep);#define	AT_MOST_ONE(read, filep, format, sequencep) \	read = fscanf(filep, format, sequencep); \	RETURN_ON_EOF(read); \	if (strlen(sequencep) > 1) \		return (0); \	PUSH_TO_NULL(sequencep);			sequencep = &sequence[0];	*sequencep = '\0';	/*	 *	skip leading whitespace	 */	SOME(read, filep, "%*[ \t\n]", sequencep);	/*	 *	this much is required:	 *	[ "+" | "-" ] digit {digits}	 */	AT_MOST_ONE(read, filep, "%[+-]", sequencep);	AT_LEAST_ONE(read, filep, "%[0123456789]", sequencep);	/*	 *	any of this is optional:	 *	[ `.' digit {digit} ] [ `e' [ `+' | `-' ] digit {digits} ]	 */	NEXT_CHAR(read, filep, "%c", sequencep);	switch (sequencep[-1]) {	default:		PUSHBACK(curfile, sequencep);		goto convert;	case '.':		SOME(read, filep, "%[0123456789]", sequencep);		if (!read) {			PUSHBACK(curfile, sequencep);			goto convert;		}		NEXT_CHAR(read, filep, "%c", sequencep);		if (sequencep[-1] != 'e') {			PUSHBACK(curfile, sequencep);			goto convert;		}		/* fall through */	case 'e':		NEXT_CHAR(read, filep, "%c", sequencep);		if (sequencep[-1] != '+' && sequencep[-1] != '-') {			PUSHBACK(curfile, sequencep);			SOME(read, filep, "%[0123456789]", sequencep);			if (!read)				PUSHBACK(curfile, sequencep);			goto convert;		}		SOME(read, filep, "%[0123456789]", sequencep);		if (!read) {			PUSHBACK(curfile, sequencep);			PUSHBACK(curfile, sequencep);		}	}convert:	/*	 * convert sequence to double	 */	*doublep = atof(&sequence[0]);	return (1);}