Net2/usr/src/lib/libc/stdio/vfprintf.c
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)vfprintf.c 5.47 (Berkeley) 3/22/91";
#endif /* LIBC_SCCS and not lint */
/*
* Actual printf innards.
*
* This code is large and complicated...
*/
#include <sys/types.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#include "local.h"
#include "fvwrite.h"
/*
* Define FLOATING_POINT to get floating point.
* Define CSH to get a csh-specific version (grr).
*/
#ifndef CSH
#define FLOATING_POINT
#endif
/* end of configuration stuff */
#ifdef CSH
/*
* C shell hacks. Ick, gag.
*/
#undef BUFSIZ
#include "sh.h"
#if __STDC__
int
printf(const char *fmt, ...) {
FILE f;
va_list ap;
int ret;
va_start(ap, fmt);
f._flags = __SWR;
f._write = NULL;
ret = vfprintf(&f, fmt, ap);
va_end(ap);
return ret;
}
#else
int
printf(fmt, args)
char *fmt;
{
FILE f;
f._flags = __SWR;
f._write = NULL;
return (vfprintf(&f, fmt, &args));
}
#endif
int
__sprint(fp, uio)
FILE *fp;
register struct __suio *uio;
{
register char *p;
register int n, ch, iovcnt;
register struct __siov *iov;
/* must allow sprintf to work, might as well allow others too */
if (fp->_write || fp->_flags & __SSTR) {
if (uio->uio_resid == 0) {
uio->uio_iovcnt = 0;
return (0);
}
n = __sfvwrite(fp, uio);
uio->uio_resid = 0;
uio->uio_iovcnt = 0;
return (n);
}
iov = uio->uio_iov;
for (iovcnt = uio->uio_iovcnt; --iovcnt >= 0; iov++) {
for (p = iov->iov_base, n = iov->iov_len; --n >= 0;) {
#ifdef CSHPUTCHAR
ch = *p++;
CSHPUTCHAR; /* this horrid macro uses `ch' */
#else
#undef putchar
putchar(*p++);
#endif
}
}
uio->uio_resid = 0;
uio->uio_iovcnt = 0;
return (0);
}
#else /* CSH */
/*
* Flush out all the vectors defined by the given uio,
* then reset it so that it can be reused.
*/
static int
__sprint(fp, uio)
FILE *fp;
register struct __suio *uio;
{
register int err;
if (uio->uio_resid == 0) {
uio->uio_iovcnt = 0;
return (0);
}
err = __sfvwrite(fp, uio);
uio->uio_resid = 0;
uio->uio_iovcnt = 0;
return (err);
}
/*
* Helper function for `fprintf to unbuffered unix file': creates a
* temporary buffer. We only work on write-only files; this avoids
* worries about ungetc buffers and so forth.
*/
static int
__sbprintf(fp, fmt, ap)
register FILE *fp;
const char *fmt;
va_list ap;
{
int ret;
FILE fake;
unsigned char buf[BUFSIZ];
/* copy the important variables */
fake._flags = fp->_flags & ~__SNBF;
fake._file = fp->_file;
fake._cookie = fp->_cookie;
fake._write = fp->_write;
/* set up the buffer */
fake._bf._base = fake._p = buf;
fake._bf._size = fake._w = sizeof(buf);
fake._lbfsize = 0; /* not actually used, but Just In Case */
/* do the work, then copy any error status */
ret = vfprintf(&fake, fmt, ap);
if (ret >= 0 && fflush(&fake))
ret = EOF;
if (fake._flags & __SERR)
fp->_flags |= __SERR;
return (ret);
}
#endif /* CSH */
#ifdef FLOATING_POINT
#include "floatio.h"
#define BUF (MAXEXP+MAXFRACT+1) /* + decimal point */
#define DEFPREC 6
static int cvt();
#else /* no FLOATING_POINT */
#define BUF 40
#endif /* FLOATING_POINT */
/*
* Macros for converting digits to letters and vice versa
*/
#define to_digit(c) ((c) - '0')
#define is_digit(c) ((unsigned)to_digit(c) <= 9)
#define to_char(n) ((n) + '0')
/*
* Flags used during conversion.
*/
#define LONGINT 0x01 /* long integer */
#define LONGDBL 0x02 /* long double; unimplemented */
#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 */
int
vfprintf(fp, fmt0, ap)
FILE *fp;
const char *fmt0;
#if tahoe
register /* technically illegal, since we do not know what type va_list is */
#endif
va_list ap;
{
register char *fmt; /* format string */
register int ch; /* character from fmt */
register int n; /* handy integer (short term usage) */
register char *cp; /* handy char pointer (short term usage) */
register struct __siov *iovp;/* for PRINT macro */
register int flags; /* flags as above */
int ret; /* return value accumulator */
int width; /* width from format (%8d), or 0 */
int prec; /* precision from format (%.3d), or -1 */
char sign; /* sign prefix (' ', '+', '-', or \0) */
#ifdef FLOATING_POINT
char softsign; /* temporary negative sign for floats */
double _double; /* double precision arguments %[eEfgG] */
int fpprec; /* `extra' floating precision in [eEfgG] */
#endif
u_long _ulong; /* integer arguments %[diouxX] */
enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */
int dprec; /* a copy of prec if [diouxX], 0 otherwise */
int fieldsz; /* field size expanded by sign, etc */
int realsz; /* field size expanded by dprec */
int size; /* size of converted field or string */
char *xdigs; /* digits for [xX] conversion */
#define NIOV 8
struct __suio uio; /* output information: summary */
struct __siov iov[NIOV];/* ... and individual io vectors */
char buf[BUF]; /* space for %c, %[diouxX], %[eEfgG] */
char ox[2]; /* space for 0x hex-prefix */
/*
* Choose PADSIZE to trade efficiency vs size. If larger
* printf fields occur frequently, increase PADSIZE (and make
* the initialisers below longer).
*/
#define PADSIZE 16 /* pad chunk size */
static char blanks[PADSIZE] =
{' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
static char zeroes[PADSIZE] =
{'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
/*
* BEWARE, these `goto error' on error, and PAD uses `n'.
*/
#define PRINT(ptr, len) { \
iovp->iov_base = (ptr); \
iovp->iov_len = (len); \
uio.uio_resid += (len); \
iovp++; \
if (++uio.uio_iovcnt >= NIOV) { \
if (__sprint(fp, &uio)) \
goto error; \
iovp = iov; \
} \
}
#define PAD(howmany, with) { \
if ((n = (howmany)) > 0) { \
while (n > PADSIZE) { \
PRINT(with, PADSIZE); \
n -= PADSIZE; \
} \
PRINT(with, n); \
} \
}
#define FLUSH() { \
if (uio.uio_resid && __sprint(fp, &uio)) \
goto error; \
uio.uio_iovcnt = 0; \
iovp = iov; \
}
/*
* To extend shorts properly, we need both signed and unsigned
* argument extraction methods.
*/
#define SARG() \
(flags&LONGINT ? va_arg(ap, long) : \
flags&SHORTINT ? (long)(short)va_arg(ap, int) : \
(long)va_arg(ap, int))
#define UARG() \
(flags&LONGINT ? va_arg(ap, u_long) : \
flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \
(u_long)va_arg(ap, u_int))
#ifndef CSH
/* sorry, fprintf(read_only_file, "") returns EOF, not 0 */
if (cantwrite(fp))
return (EOF);
/* optimise fprintf(stderr) (and other unbuffered Unix files) */
if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) &&
fp->_file >= 0)
return (__sbprintf(fp, fmt0, ap));
#endif /* CSH */
fmt = (char *)fmt0;
uio.uio_iov = iovp = iov;
uio.uio_resid = 0;
uio.uio_iovcnt = 0;
ret = 0;
/*
* Scan the format for conversions (`%' character).
*/
for (;;) {
for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++)
/* void */;
if ((n = fmt - cp) != 0) {
PRINT(cp, n);
ret += n;
}
if (ch == '\0')
goto done;
fmt++; /* skip over '%' */
flags = 0;
dprec = 0;
#ifdef FLOATING_POINT
fpprec = 0;
#endif
width = 0;
prec = -1;
sign = '\0';
rflag: ch = *fmt++;
reswitch: switch (ch) {
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(ap, int)) >= 0)
goto rflag;
width = -width;
/* FALLTHROUGH */
case '-':
flags |= LADJUST;
goto rflag;
case '+':
sign = '+';
goto rflag;
case '.':
if ((ch = *fmt++) == '*') {
n = va_arg(ap, int);
prec = n < 0 ? -1 : n;
goto rflag;
}
n = 0;
while (is_digit(ch)) {
n = 10 * n + to_digit(ch);
ch = *fmt++;
}
prec = n < 0 ? -1 : n;
goto reswitch;
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 + to_digit(ch);
ch = *fmt++;
} while (is_digit(ch));
width = n;
goto reswitch;
#ifdef FLOATING_POINT
case 'L':
flags |= LONGDBL;
goto rflag;
#endif
case 'h':
flags |= SHORTINT;
goto rflag;
case 'l':
flags |= LONGINT;
goto rflag;
case 'c':
*(cp = buf) = va_arg(ap, int);
size = 1;
sign = '\0';
break;
case 'D':
flags |= LONGINT;
/*FALLTHROUGH*/
case 'd':
case 'i':
_ulong = SARG();
if ((long)_ulong < 0) {
_ulong = -_ulong;
sign = '-';
}
base = DEC;
goto number;
#ifdef FLOATING_POINT
case 'e':
case 'E':
case 'f':
case 'g':
case 'G':
_double = va_arg(ap, double);
/* do this before tricky precision changes */
if (isinf(_double)) {
if (_double < 0)
sign = '-';
cp = "Inf";
size = 3;
break;
}
if (isnan(_double)) {
cp = "NaN";
size = 3;
break;
}
/*
* don't do unrealistic precision; just pad it with
* zeroes later, so buffer size stays rational.
*/
if (prec > MAXFRACT) {
if (ch != 'g' && ch != 'G' || (flags&ALT))
fpprec = prec - MAXFRACT;
prec = MAXFRACT;
} else if (prec == -1)
prec = DEFPREC;
/*
* cvt may have to round up before the "start" of
* its buffer, i.e. ``intf("%.2f", (double)9.999);'';
* if the first character is still NUL, it did.
* softsign avoids negative 0 if _double < 0 but
* no significant digits will be shown.
*/
cp = buf;
*cp = '\0';
size = cvt(_double, prec, flags, &softsign, ch,
cp, buf + sizeof(buf));
if (softsign)
sign = '-';
if (*cp == '\0')
cp++;
break;
#endif /* FLOATING_POINT */
case 'n':
if (flags & LONGINT)
*va_arg(ap, long *) = ret;
else if (flags & SHORTINT)
*va_arg(ap, short *) = ret;
else
*va_arg(ap, int *) = ret;
continue; /* no output */
case 'O':
flags |= LONGINT;
/*FALLTHROUGH*/
case 'o':
_ulong = UARG();
base = OCT;
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(ap, void *);
base = HEX;
xdigs = "0123456789abcdef";
flags |= HEXPREFIX;
ch = 'x';
goto nosign;
case 's':
if ((cp = va_arg(ap, char *)) == NULL)
cp = "(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(cp, 0, prec);
if (p != NULL) {
size = p - cp;
if (size > prec)
size = prec;
} else
size = prec;
} else
size = strlen(cp);
sign = '\0';
break;
case 'U':
flags |= LONGINT;
/*FALLTHROUGH*/
case 'u':
_ulong = UARG();
base = DEC;
goto nosign;
case 'X':
xdigs = "0123456789ABCDEF";
goto hex;
case 'x':
xdigs = "0123456789abcdef";
hex: _ulong = UARG();
base = HEX;
/* 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
*/
cp = buf + BUF;
if (_ulong != 0 || prec != 0) {
/*
* unsigned mod is hard, and unsigned mod
* by a constant is easier than that by
* a variable; hence this switch.
*/
switch (base) {
case OCT:
do {
*--cp = to_char(_ulong & 7);
_ulong >>= 3;
} while (_ulong);
/* handle octal leading 0 */
if (flags & ALT && *cp != '0')
*--cp = '0';
break;
case DEC:
/* many numbers are 1 digit */
while (_ulong >= 10) {
*--cp = to_char(_ulong % 10);
_ulong /= 10;
}
*--cp = to_char(_ulong);
break;
case HEX:
do {
*--cp = xdigs[_ulong & 15];
_ulong >>= 4;
} while (_ulong);
break;
default:
cp = "bug in vfprintf: bad base";
size = strlen(cp);
goto skipsize;
}
}
size = buf + BUF - cp;
skipsize:
break;
default: /* "%?" prints ?, unless ? is NUL */
if (ch == '\0')
goto done;
/* pretend it was %c with argument ch */
cp = buf;
*cp = ch;
size = 1;
sign = '\0';
break;
}
/*
* All reasonable formats wind up here. At this point,
* `cp' 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
*/
#ifdef FLOATING_POINT
fieldsz = size + fpprec;
#else
fieldsz = size;
#endif
if (sign)
fieldsz++;
else if (flags & HEXPREFIX)
fieldsz += 2;
realsz = dprec > fieldsz ? dprec : fieldsz;
/* right-adjusting blank padding */
if ((flags & (LADJUST|ZEROPAD)) == 0)
PAD(width - realsz, blanks);
/* prefix */
if (sign) {
PRINT(&sign, 1);
} else if (flags & HEXPREFIX) {
ox[0] = '0';
ox[1] = ch;
PRINT(ox, 2);
}
/* right-adjusting zero padding */
if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD)
PAD(width - realsz, zeroes);
/* leading zeroes from decimal precision */
PAD(dprec - fieldsz, zeroes);
/* the string or number proper */
PRINT(cp, size);
#ifdef FLOATING_POINT
/* trailing f.p. zeroes */
PAD(fpprec, zeroes);
#endif
/* left-adjusting padding (always blank) */
if (flags & LADJUST)
PAD(width - realsz, blanks);
/* finally, adjust ret */
ret += width > realsz ? width : realsz;
FLUSH(); /* copy out the I/O vectors */
}
done:
FLUSH();
error:
return (__sferror(fp) ? EOF : ret);
/* NOTREACHED */
}
#ifdef FLOATING_POINT
#include <math.h>
static char *exponent();
static char *round();
static int
cvt(number, prec, flags, signp, fmtch, startp, endp)
double number;
register int prec;
int flags;
char *signp;
int fmtch;
char *startp, *endp;
{
register char *p, *t;
register double fract;
int dotrim, expcnt, gformat;
double integer, tmp;
dotrim = expcnt = gformat = 0;
if (number < 0) {
number = -number;
*signp = '-';
} else
*signp = 0;
fract = modf(number, &integer);
/* get an extra slot for rounding. */
t = ++startp;
/*
* get integer portion of number; put into the end of the buffer; the
* .01 is added for modf(356.0 / 10, &integer) returning .59999999...
*/
for (p = endp - 1; integer; ++expcnt) {
tmp = modf(integer / 10, &integer);
*p-- = to_char((int)((tmp + .01) * 10));
}
switch (fmtch) {
case 'f':
/* reverse integer into beginning of buffer */
if (expcnt)
for (; ++p < endp; *t++ = *p);
else
*t++ = '0';
/*
* if precision required or alternate flag set, add in a
* decimal point.
*/
if (prec || flags&ALT)
*t++ = '.';
/* if requires more precision and some fraction left */
if (fract) {
if (prec)
do {
fract = modf(fract * 10, &tmp);
*t++ = to_char((int)tmp);
} while (--prec && fract);
if (fract)
startp = round(fract, (int *)NULL, startp,
t - 1, (char)0, signp);
}
for (; prec--; *t++ = '0');
break;
case 'e':
case 'E':
eformat: if (expcnt) {
*t++ = *++p;
if (prec || flags&ALT)
*t++ = '.';
/* if requires more precision and some integer left */
for (; prec && ++p < endp; --prec)
*t++ = *p;
/*
* if done precision and more of the integer component,
* round using it; adjust fract so we don't re-round
* later.
*/
if (!prec && ++p < endp) {
fract = 0;
startp = round((double)0, &expcnt, startp,
t - 1, *p, signp);
}
/* adjust expcnt for digit in front of decimal */
--expcnt;
}
/* until first fractional digit, decrement exponent */
else if (fract) {
/* adjust expcnt for digit in front of decimal */
for (expcnt = -1;; --expcnt) {
fract = modf(fract * 10, &tmp);
if (tmp)
break;
}
*t++ = to_char((int)tmp);
if (prec || flags&ALT)
*t++ = '.';
}
else {
*t++ = '0';
if (prec || flags&ALT)
*t++ = '.';
}
/* if requires more precision and some fraction left */
if (fract) {
if (prec)
do {
fract = modf(fract * 10, &tmp);
*t++ = to_char((int)tmp);
} while (--prec && fract);
if (fract)
startp = round(fract, &expcnt, startp,
t - 1, (char)0, signp);
}
/* if requires more precision */
for (; prec--; *t++ = '0');
/* unless alternate flag, trim any g/G format trailing 0's */
if (gformat && !(flags&ALT)) {
while (t > startp && *--t == '0');
if (*t == '.')
--t;
++t;
}
t = exponent(t, expcnt, fmtch);
break;
case 'g':
case 'G':
/* a precision of 0 is treated as a precision of 1. */
if (!prec)
++prec;
/*
* ``The style used depends on the value converted; style e
* will be used only if the exponent resulting from the
* conversion is less than -4 or greater than the precision.''
* -- ANSI X3J11
*/
if (expcnt > prec || !expcnt && fract && fract < .0001) {
/*
* g/G format counts "significant digits, not digits of
* precision; for the e/E format, this just causes an
* off-by-one problem, i.e. g/G considers the digit
* before the decimal point significant and e/E doesn't
* count it as precision.
*/
--prec;
fmtch -= 2; /* G->E, g->e */
gformat = 1;
goto eformat;
}
/*
* reverse integer into beginning of buffer,
* note, decrement precision
*/
if (expcnt)
for (; ++p < endp; *t++ = *p, --prec);
else
*t++ = '0';
/*
* if precision required or alternate flag set, add in a
* decimal point. If no digits yet, add in leading 0.
*/
if (prec || flags&ALT) {
dotrim = 1;
*t++ = '.';
}
else
dotrim = 0;
/* if requires more precision and some fraction left */
if (fract) {
if (prec) {
do {
fract = modf(fract * 10, &tmp);
*t++ = to_char((int)tmp);
} while(!tmp);
while (--prec && fract) {
fract = modf(fract * 10, &tmp);
*t++ = to_char((int)tmp);
}
}
if (fract)
startp = round(fract, (int *)NULL, startp,
t - 1, (char)0, signp);
}
/* alternate format, adds 0's for precision, else trim 0's */
if (flags&ALT)
for (; prec--; *t++ = '0');
else if (dotrim) {
while (t > startp && *--t == '0');
if (*t != '.')
++t;
}
}
return (t - startp);
}
static char *
round(fract, exp, start, end, ch, signp)
double fract;
int *exp;
register char *start, *end;
char ch, *signp;
{
double tmp;
if (fract)
(void)modf(fract * 10, &tmp);
else
tmp = to_digit(ch);
if (tmp > 4)
for (;; --end) {
if (*end == '.')
--end;
if (++*end <= '9')
break;
*end = '0';
if (end == start) {
if (exp) { /* e/E; increment exponent */
*end = '1';
++*exp;
}
else { /* f; add extra digit */
*--end = '1';
--start;
}
break;
}
}
/* ``"%.3f", (double)-0.0004'' gives you a negative 0. */
else if (*signp == '-')
for (;; --end) {
if (*end == '.')
--end;
if (*end != '0')
break;
if (end == start)
*signp = 0;
}
return (start);
}
static char *
exponent(p, exp, fmtch)
register char *p;
register int exp;
int fmtch;
{
register char *t;
char expbuf[MAXEXP];
*p++ = fmtch;
if (exp < 0) {
exp = -exp;
*p++ = '-';
}
else
*p++ = '+';
t = expbuf + MAXEXP;
if (exp > 9) {
do {
*--t = to_char(exp % 10);
} while ((exp /= 10) > 9);
*--t = to_char(exp);
for (; t < expbuf + MAXEXP; *p++ = *t++);
}
else {
*p++ = '0';
*p++ = to_char(exp);
}
return (p);
}
#endif /* FLOATING_POINT */