doprnt.c

Algorithms for Image Processing and Computer Vision Source Code

/* This is file DOPRNT.C */
/* This file may have been modified by DJ Delorie (Jan 1991).  If so,
** these modifications are Coyright (C) 1993 DJ Delorie, 24 Kirsten Ave,
** Rochester NH, 03867-2954, USA.
*/

/*
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted provided
 * that: (1) source distributions retain this entire copyright notice and
 * comment, and (2) distributions including binaries display the following
 * acknowledgement:  ``This product includes software developed by the
 * University of California, Berkeley and its contributors'' in the
 * documentation or other materials provided with the distribution and in
 * all advertising materials mentioning features or use of this software.
 * Neither the name of the University nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)doprnt.c	5.39 (Berkeley) 6/28/90";
#endif /* LIBC_SCCS and not lint */

#define _doprnt ____doprnt
#include <sys/types.h>
#include <varargs.h>
#include <stdio.h>
#include <ctype.h>
#include <locale.h>
#include <stdlib.h>
#include <string.h>
#undef _doprnt

static char decimal = '.';

/* 11-bit exponent (VAX G floating point) is 308 decimal digits */
#define	MAXEXP		308
#define MAXEXPLD        4952 /* this includes subnormal numbers */
/* 128 bit fraction takes up 39 decimal digits; max reasonable precision */
#define	MAXFRACT	39

#define	DEFPREC		6
#define	DEFLPREC	14

#define	BUF		(MAXEXPLD+MAXFRACT+1)	/* + decimal point */

#define	PUTC(ch)	(void) putc(ch, fp)

#define ARG(basetype) \
	_ulong = flags&LONGINT ? va_arg(argp, long basetype) : \
	    flags&SHORTINT ? (short basetype)va_arg(argp, int) : \
	    va_arg(argp, int)

static int nan = 0;

#if 0
#define	todigit(c)	((c) - '0')
#define	tochar(n)	((n) + '0')
#else
static int todigit(char c)
{
  if (c<='0') return 0;
  if (c>='9') return 9;
  return c-'0';
}
static char tochar(int n)
{
  if (n>=9) return '9';
  if (n<=0) return '0';
  return n+'0';
}
#endif

/* have to deal with the negative buffer count kludge */

#define	LONGINT		0x01		/* long integer */
#define	LONGDBL		0x02		/* long double */
#define	SHORTINT	0x04		/* short integer */
#define	ALT		0x08		/* alternate form */
#define	LADJUST		0x10		/* left adjustment */
#define	ZEROPAD		0x20		/* zero (as opposed to blank) pad */
#define	HEXPREFIX	0x40		/* add 0x or 0X prefix */

static cvtl(long double number, int prec, int flags, char *signp,
	    u_char fmtch, char *startp, char *endp);
static char *roundl(long double fract, int *exp, char *start, char *end,
		    char ch, char *signp);
static char *exponentl(char *p, int exp, u_char fmtch);
#ifdef __GO32__
static int isspeciall(long double d, char *bufp);
#endif

/* don't want to include <math.h> */
long double modfl(long double, long double *);
long double scalbl(long double, int);

int
_doprnt(fmt0, argp, fp)
	const char *fmt0;
	va_list argp;
	FILE *fp;
{
	const char *fmt;	/* format string */
	int ch;			/* character from fmt */
	int cnt;		/* return value accumulator */
	int n;			/* random handy integer */
	char *t;		/* buffer pointer */
	long double _ldouble;	/* double and long double precision arguments
				   %L.[eEfgG] */
	u_long _ulong;		/* integer arguments %[diouxX] */
	int base;		/* base for [diouxX] conversion */
	int dprec;		/* decimal precision in [diouxX] */
	int fieldsz;		/* field size expanded by sign, etc */
	int flags;		/* flags as above */
	int fpprec;		/* `extra' floating precision in [eEfgG] */
	int prec;		/* precision from format (%.3d), or -1 */
	int realsz;		/* field size expanded by decimal precision */
	int size;		/* size of converted field or string */
	int width;		/* width from format (%8d), or 0 */
	char sign;		/* sign prefix (' ', '+', '-', or \0) */
	char softsign;		/* temporary negative sign for floats */
	char *digs;		/* digits for [diouxX] conversion */
	char buf[BUF];		/* space for %c, %[diouxX], %[eEfgG] */

	decimal = localeconv()->decimal_point[0];

	if (fp->_flag & _IORW) {
		fp->_flag |= _IOWRT;
		fp->_flag &= ~(_IOEOF|_IOREAD);
	}
	if ((fp->_flag & _IOWRT) == 0)
		return (EOF);

	fmt = fmt0;
	digs = "0123456789abcdef";
	for (cnt = 0;; ++fmt) {
		n = fp->_cnt;
		for (t = (char *)fp->_ptr; (ch = *fmt) && ch != '%';
		     ++cnt, ++fmt)
			if ((--n < 0
			    && (!(fp->_flag & _IOLBF) || -n >= fp->_bufsiz))
			    || (ch == '\n' && fp->_flag & _IOLBF)) {
				fp->_cnt = n;
				fp->_ptr = t;
				(void) _flsbuf((u_char)ch, fp);
				n = fp->_cnt;
				t = (char *)fp->_ptr;
			} else
				*t++ = ch;
		fp->_cnt = n;
		fp->_ptr = t;
		if (!ch)
			return (cnt);
		flags = 0; dprec = 0; fpprec = 0; width = 0;
		prec = -1;
		sign = '\0';
rflag:		switch (*++fmt) {
		case ' ':
			/*
			 * ``If the space and + flags both appear, the space
			 * flag will be ignored.''
			 *	-- ANSI X3J11
			 */
			if (!sign)
				sign = ' ';
			goto rflag;
		case '#':
			flags |= ALT;
			goto rflag;
		case '*':
			/*
			 * ``A negative field width argument is taken as a
			 * - flag followed by a  positive field width.''
			 *	-- ANSI X3J11
			 * They don't exclude field widths read from args.
			 */
			if ((width = va_arg(argp, int)) >= 0)
				goto rflag;
			width = -width;
			/* FALLTHROUGH */
		case '-':
			flags |= LADJUST;
			goto rflag;
		case '+':
			sign = '+';
			goto rflag;
		case '.':
			if (*++fmt == '*')
				n = va_arg(argp, int);
			else {
				n = 0;
				while (isascii(*fmt) && isdigit(*fmt))
					n = 10 * n + todigit(*fmt++);
				--fmt;
			}
			prec = n < 0 ? -1 : n;
			goto rflag;
		case '0':
			/*
			 * ``Note that 0 is taken as a flag, not as the
			 * beginning of a field width.''
			 *	-- ANSI X3J11
			 */
			flags |= ZEROPAD;
			goto rflag;
		case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
			n = 0;
			do {
				n = 10 * n + todigit(*fmt);
			} while (isascii(*++fmt) && isdigit(*fmt));
			width = n;
			--fmt;
			goto rflag;
		case 'L':
			flags |= LONGDBL;
			goto rflag;
		case 'h':
			flags |= SHORTINT;
			goto rflag;
		case 'l':
			flags |= LONGINT;
			goto rflag;
		case 'c':
			*(t = buf) = va_arg(argp, int);
			size = 1;
			sign = '\0';
			goto pforw;
		case 'D':
			flags |= LONGINT;
			/*FALLTHROUGH*/
		case 'd':
		case 'i':
			ARG(int);
			if ((long)_ulong < 0) {
				_ulong = -_ulong;
				sign = '-';
			}
			base = 10;
			goto number;
		case 'e':
		case 'E':
		case 'f':
		case 'g':
		case 'G':
			if (flags & LONGDBL)
			    _ldouble = va_arg(argp, long double);
			else
			    _ldouble = (long double)va_arg(argp, double);
			/*
			 * don't do unrealistic precision; just pad it with
			 * zeroes later, so buffer size stays rational.
			 */
			if (prec > MAXFRACT) {
				if (*fmt != 'g' && (*fmt != 'G' || (flags&ALT)))
					fpprec = prec - MAXFRACT;
				prec = MAXFRACT;
			}
			else if (prec == -1)
			{
				if (flags&LONGINT)
					prec = DEFLPREC;
				else
					prec = DEFPREC;
			}
			/*
			 * softsign avoids negative 0 if _double is < 0 and
			 * no significant digits will be shown
			 */
			if (_ldouble < 0) {
				softsign = '-';
				_ldouble = -_ldouble;
			}
			else
				softsign = 0;
			/*
			 * cvt may have to round up past the "start" of the
			 * buffer, i.e. ``intf("%.2f", (double)9.999);'';
			 * if the first char isn't NULL, it did.
			 */
			*buf = NULL;
			size = cvtl(_ldouble, prec, flags, &softsign, *fmt, buf,
			    buf + sizeof(buf));
			if (softsign && !nan)
				sign = '-';
			nan = 0;
			t = *buf ? buf : buf + 1;
			goto pforw;
		case 'n':
			if (flags & LONGINT)
				*va_arg(argp, long *) = cnt;
			else if (flags & SHORTINT)
				*va_arg(argp, short *) = cnt;
			else
				*va_arg(argp, int *) = cnt;
			break;
		case 'O':
			flags |= LONGINT;
			/*FALLTHROUGH*/
		case 'o':
			ARG(unsigned);
			base = 8;
			goto nosign;
		case 'p':
			/*
			 * ``The argument shall be a pointer to void.  The
			 * value of the pointer is converted to a sequence
			 * of printable characters, in an implementation-
			 * defined manner.''
			 *	-- ANSI X3J11
			 */
			/* NOSTRICT */
			_ulong = (u_long)va_arg(argp, void *);
			base = 16;
			goto nosign;
		case 's':
			if (!(t = va_arg(argp, char *)))
				t = "(null)";
			if (prec >= 0) {
				/*
				 * can't use strlen; can only look for the
				 * NUL in the first `prec' characters, and
				 * strlen() will go further.
				 */
				char *p/*, *memchr() */;

				if ((p = memchr(t, 0, prec))) {
					size = p - t;
					if (size > prec)
						size = prec;
				} else
					size = prec;
			} else
				size = strlen(t);
			sign = '\0';
			goto pforw;
		case 'U':
			flags |= LONGINT;
			/*FALLTHROUGH*/
		case 'u':
			ARG(unsigned);
			base = 10;
			goto nosign;
		case 'X':
			digs = "0123456789ABCDEF";
			/* FALLTHROUGH */
		case 'x':
			ARG(unsigned);
			base = 16;
			/* leading 0x/X only if non-zero */
			if (flags & ALT && _ulong != 0)
				flags |= HEXPREFIX;

			/* unsigned conversions */
nosign:			sign = '\0';
			/*
			 * ``... diouXx conversions ... if a precision is
			 * specified, the 0 flag will be ignored.''
			 *	-- ANSI X3J11
			 */
number:			if ((dprec = prec) >= 0)
				flags &= ~ZEROPAD;

			/*
			 * ``The result of converting a zero value with an
			 * explicit precision of zero is no characters.''
			 *	-- ANSI X3J11
			 */
			t = buf + BUF;
			if (_ulong != 0 || prec != 0) {
				do {
					*--t = digs[_ulong % base];
					_ulong /= base;
				} while (_ulong);
				digs = "0123456789abcdef";
				if (flags & ALT && base == 8 && *t != '0')
					*--t = '0'; /* octal leading 0 */
			}
			size = buf + BUF - t;

pforw:
			/*
			 * All reasonable formats wind up here.  At this point,
			 * `t' points to a string which (if not flags&LADJUST)
			 * should be padded out to `width' places.  If
			 * flags&ZEROPAD, it should first be prefixed by any
			 * sign or other prefix; otherwise, it should be blank
			 * padded before the prefix is emitted.  After any
			 * left-hand padding and prefixing, emit zeroes
			 * required by a decimal [diouxX] precision, then print
			 * the string proper, then emit zeroes required by any
			 * leftover floating precision; finally, if LADJUST,
			 * pad with blanks.
			 */

			/*
			 * compute actual size, so we know how much to pad
			 * fieldsz excludes decimal prec; realsz includes it
			 */
			fieldsz = size + fpprec;
			realsz = dprec > fieldsz ? dprec : fieldsz;
			if (sign)
				realsz++;
			if (flags & HEXPREFIX)
				realsz += 2;

			/* right-adjusting blank padding */
			if ((flags & (LADJUST|ZEROPAD)) == 0 && width)
				for (n = realsz; n < width; n++)
					PUTC(' ');
			/* prefix */
			if (sign)
				PUTC(sign);
			if (flags & HEXPREFIX) {
				PUTC('0');
				PUTC((char)*fmt);
			}
			/* right-adjusting zero padding */
			if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD)
				for (n = realsz; n < width; n++)
					PUTC('0');
			/* leading zeroes from decimal precision */