1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 /*static char *sccsid = "from: @(#)vfprintf.c 5.50 (Berkeley) 12/16/92";*/ 39 static char *rcsid = "$Id: vfprintf.c,v 1.17 1995/05/02 19:52:41 jtc Exp $"; 40 #endif /* LIBC_SCCS and not lint */ 41 42 /* 43 * Actual printf innards. 44 * 45 * This code is large and complicated... 46 */ 47 48 #include <sys/types.h> 49 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 54 #if __STDC__ 55 #include <stdarg.h> 56 #else 57 #include <varargs.h> 58 #endif 59 60 #include "local.h" 61 #include "fvwrite.h" 62 63 /* 64 * Flush out all the vectors defined by the given uio, 65 * then reset it so that it can be reused. 66 */ 67 static int 68 __sprint(fp, uio) 69 FILE *fp; 70 register struct __suio *uio; 71 { 72 register int err; 73 74 if (uio->uio_resid == 0) { 75 uio->uio_iovcnt = 0; 76 return (0); 77 } 78 err = __sfvwrite(fp, uio); 79 uio->uio_resid = 0; 80 uio->uio_iovcnt = 0; 81 return (err); 82 } 83 84 /* 85 * Helper function for `fprintf to unbuffered unix file': creates a 86 * temporary buffer. We only work on write-only files; this avoids 87 * worries about ungetc buffers and so forth. 88 */ 89 static int 90 __sbprintf(fp, fmt, ap) 91 register FILE *fp; 92 const char *fmt; 93 va_list ap; 94 { 95 int ret; 96 FILE fake; 97 unsigned char buf[BUFSIZ]; 98 99 /* copy the important variables */ 100 fake._flags = fp->_flags & ~__SNBF; 101 fake._file = fp->_file; 102 fake._cookie = fp->_cookie; 103 fake._write = fp->_write; 104 105 /* set up the buffer */ 106 fake._bf._base = fake._p = buf; 107 fake._bf._size = fake._w = sizeof(buf); 108 fake._lbfsize = 0; /* not actually used, but Just In Case */ 109 110 /* do the work, then copy any error status */ 111 ret = vfprintf(&fake, fmt, ap); 112 if (ret >= 0 && fflush(&fake)) 113 ret = EOF; 114 if (fake._flags & __SERR) 115 fp->_flags |= __SERR; 116 return (ret); 117 } 118 119 120 #ifdef FLOATING_POINT 121 #include <locale.h> 122 #include <math.h> 123 #include "floatio.h" 124 125 #define BUF (MAXEXP+MAXFRACT+1) /* + decimal point */ 126 #define DEFPREC 6 127 128 static char *cvt __P((double, int, int, char *, int *, int, int *)); 129 static int exponent __P((char *, int, int)); 130 131 #else /* no FLOATING_POINT */ 132 133 #define BUF 40 134 135 #endif /* FLOATING_POINT */ 136 137 138 /* 139 * Macros for converting digits to letters and vice versa 140 */ 141 #define to_digit(c) ((c) - '0') 142 #define is_digit(c) ((unsigned)to_digit(c) <= 9) 143 #define to_char(n) ((n) + '0') 144 145 /* 146 * Flags used during conversion. 147 */ 148 #define ALT 0x001 /* alternate form */ 149 #define HEXPREFIX 0x002 /* add 0x or 0X prefix */ 150 #define LADJUST 0x004 /* left adjustment */ 151 #define LONGDBL 0x008 /* long double; unimplemented */ 152 #define LONGINT 0x010 /* long integer */ 153 #define QUADINT 0x020 /* quad integer */ 154 #define SHORTINT 0x040 /* short integer */ 155 #define ZEROPAD 0x080 /* zero (as opposed to blank) pad */ 156 #define FPT 0x100 /* Floating point number */ 157 int 158 vfprintf(fp, fmt0, ap) 159 FILE *fp; 160 const char *fmt0; 161 _BSD_VA_LIST_ ap; 162 { 163 register char *fmt; /* format string */ 164 register int ch; /* character from fmt */ 165 register int n, m; /* handy integers (short term usage) */ 166 register char *cp; /* handy char pointer (short term usage) */ 167 register struct __siov *iovp;/* for PRINT macro */ 168 register int flags; /* flags as above */ 169 int ret; /* return value accumulator */ 170 int width; /* width from format (%8d), or 0 */ 171 int prec; /* precision from format (%.3d), or -1 */ 172 char sign; /* sign prefix (' ', '+', '-', or \0) */ 173 wchar_t wc; 174 #ifdef FLOATING_POINT 175 char *decimal_point = localeconv()->decimal_point; 176 char softsign; /* temporary negative sign for floats */ 177 double _double; /* double precision arguments %[eEfgG] */ 178 int expt; /* integer value of exponent */ 179 int expsize; /* character count for expstr */ 180 int ndig; /* actual number of digits returned by cvt */ 181 char expstr[7]; /* buffer for exponent string */ 182 #endif 183 184 #ifdef __GNUC__ /* gcc has builtin quad type (long long) SOS */ 185 #define quad_t long long 186 #define u_quad_t unsigned long long 187 #endif 188 189 u_quad_t _uquad; /* integer arguments %[diouxX] */ 190 enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */ 191 int dprec; /* a copy of prec if [diouxX], 0 otherwise */ 192 int realsz; /* field size expanded by dprec */ 193 int size; /* size of converted field or string */ 194 char *xdigs; /* digits for [xX] conversion */ 195 #define NIOV 8 196 struct __suio uio; /* output information: summary */ 197 struct __siov iov[NIOV];/* ... and individual io vectors */ 198 char buf[BUF]; /* space for %c, %[diouxX], %[eEfgG] */ 199 char ox[2]; /* space for 0x hex-prefix */ 200 201 /* 202 * Choose PADSIZE to trade efficiency vs. size. If larger printf 203 * fields occur frequently, increase PADSIZE and make the initialisers 204 * below longer. 205 */ 206 #define PADSIZE 16 /* pad chunk size */ 207 static char blanks[PADSIZE] = 208 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '}; 209 static char zeroes[PADSIZE] = 210 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'}; 211 212 /* 213 * BEWARE, these `goto error' on error, and PAD uses `n'. 214 */ 215 #define PRINT(ptr, len) { \ 216 iovp->iov_base = (ptr); \ 217 iovp->iov_len = (len); \ 218 uio.uio_resid += (len); \ 219 iovp++; \ 220 if (++uio.uio_iovcnt >= NIOV) { \ 221 if (__sprint(fp, &uio)) \ 222 goto error; \ 223 iovp = iov; \ 224 } \ 225 } 226 #define PAD(howmany, with) { \ 227 if ((n = (howmany)) > 0) { \ 228 while (n > PADSIZE) { \ 229 PRINT(with, PADSIZE); \ 230 n -= PADSIZE; \ 231 } \ 232 PRINT(with, n); \ 233 } \ 234 } 235 #define FLUSH() { \ 236 if (uio.uio_resid && __sprint(fp, &uio)) \ 237 goto error; \ 238 uio.uio_iovcnt = 0; \ 239 iovp = iov; \ 240 } 241 242 /* 243 * To extend shorts properly, we need both signed and unsigned 244 * argument extraction methods. 245 */ 246 #define SARG() \ 247 (flags&QUADINT ? va_arg(ap, quad_t) : \ 248 flags&LONGINT ? va_arg(ap, long) : \ 249 flags&SHORTINT ? (long)(short)va_arg(ap, int) : \ 250 (long)va_arg(ap, int)) 251 #define UARG() \ 252 (flags&QUADINT ? va_arg(ap, u_quad_t) : \ 253 flags&LONGINT ? va_arg(ap, u_long) : \ 254 flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \ 255 (u_long)va_arg(ap, u_int)) 256 257 /* sorry, fprintf(read_only_file, "") returns EOF, not 0 */ 258 if (cantwrite(fp)) 259 return (EOF); 260 261 /* optimise fprintf(stderr) (and other unbuffered Unix files) */ 262 if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) && 263 fp->_file >= 0) 264 return (__sbprintf(fp, fmt0, ap)); 265 266 fmt = (char *)fmt0; 267 uio.uio_iov = iovp = iov; 268 uio.uio_resid = 0; 269 uio.uio_iovcnt = 0; 270 ret = 0; 271 272 /* 273 * Scan the format for conversions (`%' character). 274 */ 275 for (;;) { 276 cp = fmt; 277 while ((n = mbtowc(&wc, fmt, MB_CUR_MAX)) > 0) { 278 fmt += n; 279 if (wc == '%') { 280 fmt--; 281 break; 282 } 283 } 284 if ((m = fmt - cp) != 0) { 285 PRINT(cp, m); 286 ret += m; 287 } 288 if (n <= 0) 289 goto done; 290 fmt++; /* skip over '%' */ 291 292 flags = 0; 293 dprec = 0; 294 width = 0; 295 prec = -1; 296 sign = '\0'; 297 298 rflag: ch = *fmt++; 299 reswitch: switch (ch) { 300 case ' ': 301 /* 302 * ``If the space and + flags both appear, the space 303 * flag will be ignored.'' 304 * -- ANSI X3J11 305 */ 306 if (!sign) 307 sign = ' '; 308 goto rflag; 309 case '#': 310 flags |= ALT; 311 goto rflag; 312 case '*': 313 /* 314 * ``A negative field width argument is taken as a 315 * - flag followed by a positive field width.'' 316 * -- ANSI X3J11 317 * They don't exclude field widths read from args. 318 */ 319 if ((width = va_arg(ap, int)) >= 0) 320 goto rflag; 321 width = -width; 322 /* FALLTHROUGH */ 323 case '-': 324 flags |= LADJUST; 325 goto rflag; 326 case '+': 327 sign = '+'; 328 goto rflag; 329 case '.': 330 if ((ch = *fmt++) == '*') { 331 n = va_arg(ap, int); 332 prec = n < 0 ? -1 : n; 333 goto rflag; 334 } 335 n = 0; 336 while (is_digit(ch)) { 337 n = 10 * n + to_digit(ch); 338 ch = *fmt++; 339 } 340 prec = n < 0 ? -1 : n; 341 goto reswitch; 342 case '0': 343 /* 344 * ``Note that 0 is taken as a flag, not as the 345 * beginning of a field width.'' 346 * -- ANSI X3J11 347 */ 348 flags |= ZEROPAD; 349 goto rflag; 350 case '1': case '2': case '3': case '4': 351 case '5': case '6': case '7': case '8': case '9': 352 n = 0; 353 do { 354 n = 10 * n + to_digit(ch); 355 ch = *fmt++; 356 } while (is_digit(ch)); 357 width = n; 358 goto reswitch; 359 #ifdef FLOATING_POINT 360 case 'L': 361 flags |= LONGDBL; 362 goto rflag; 363 #endif 364 case 'h': 365 flags |= SHORTINT; 366 goto rflag; 367 case 'l': 368 if (*fmt == 'l') { 369 fmt++; 370 flags |= QUADINT; 371 } else { 372 flags |= LONGINT; 373 } 374 goto rflag; 375 case 'q': 376 flags |= QUADINT; 377 goto rflag; 378 case 'c': 379 *(cp = buf) = va_arg(ap, int); 380 size = 1; 381 sign = '\0'; 382 break; 383 case 'D': 384 flags |= LONGINT; 385 /*FALLTHROUGH*/ 386 case 'd': 387 case 'i': 388 _uquad = SARG(); 389 if ((quad_t)_uquad < 0) { 390 _uquad = -_uquad; 391 sign = '-'; 392 } 393 base = DEC; 394 goto number; 395 #ifdef FLOATING_POINT 396 case 'e': 397 case 'E': 398 case 'f': 399 case 'g': 400 case 'G': 401 if (prec == -1) { 402 prec = DEFPREC; 403 } else if ((ch == 'g' || ch == 'G') && prec == 0) { 404 prec = 1; 405 } 406 407 if (flags & LONGDBL) { 408 _double = (double) va_arg(ap, long double); 409 } else { 410 _double = va_arg(ap, double); 411 } 412 413 /* do this before tricky precision changes */ 414 if (isinf(_double)) { 415 if (_double < 0) 416 sign = '-'; 417 cp = "Inf"; 418 size = 3; 419 break; 420 } 421 if (isnan(_double)) { 422 cp = "NaN"; 423 size = 3; 424 break; 425 } 426 427 flags |= FPT; 428 cp = cvt(_double, prec, flags, &softsign, 429 &expt, ch, &ndig); 430 if (ch == 'g' || ch == 'G') { 431 if (expt <= -4 || expt > prec) 432 ch = (ch == 'g') ? 'e' : 'E'; 433 else 434 ch = 'g'; 435 } 436 if (ch <= 'e') { /* 'e' or 'E' fmt */ 437 --expt; 438 expsize = exponent(expstr, expt, ch); 439 size = expsize + ndig; 440 if (ndig > 1 || flags & ALT) 441 ++size; 442 } else if (ch == 'f') { /* f fmt */ 443 if (expt > 0) { 444 size = expt; 445 if (prec || flags & ALT) 446 size += prec + 1; 447 } else /* "0.X" */ 448 size = prec + 2; 449 } else if (expt >= ndig) { /* fixed g fmt */ 450 size = expt; 451 if (flags & ALT) 452 ++size; 453 } else 454 size = ndig + (expt > 0 ? 455 1 : 2 - expt); 456 457 if (softsign) 458 sign = '-'; 459 break; 460 #endif /* FLOATING_POINT */ 461 case 'n': 462 if (flags & QUADINT) 463 *va_arg(ap, quad_t *) = ret; 464 else if (flags & LONGINT) 465 *va_arg(ap, long *) = ret; 466 else if (flags & SHORTINT) 467 *va_arg(ap, short *) = ret; 468 else 469 *va_arg(ap, int *) = ret; 470 continue; /* no output */ 471 case 'O': 472 flags |= LONGINT; 473 /*FALLTHROUGH*/ 474 case 'o': 475 _uquad = UARG(); 476 base = OCT; 477 goto nosign; 478 case 'p': 479 /* 480 * ``The argument shall be a pointer to void. The 481 * value of the pointer is converted to a sequence 482 * of printable characters, in an implementation- 483 * defined manner.'' 484 * -- ANSI X3J11 485 */ 486 /* NOSTRICT */ 487 _uquad = (u_long)va_arg(ap, void *); 488 base = HEX; 489 xdigs = "0123456789abcdef"; 490 flags |= HEXPREFIX; 491 ch = 'x'; 492 goto nosign; 493 case 's': 494 if ((cp = va_arg(ap, char *)) == NULL) 495 cp = "(null)"; 496 if (prec >= 0) { 497 /* 498 * can't use strlen; can only look for the 499 * NUL in the first `prec' characters, and 500 * strlen() will go further. 501 */ 502 char *p = memchr(cp, 0, prec); 503 504 if (p != NULL) { 505 size = p - cp; 506 if (size > prec) 507 size = prec; 508 } else 509 size = prec; 510 } else 511 size = strlen(cp); 512 sign = '\0'; 513 break; 514 case 'U': 515 flags |= LONGINT; 516 /*FALLTHROUGH*/ 517 case 'u': 518 _uquad = UARG(); 519 base = DEC; 520 goto nosign; 521 case 'X': 522 xdigs = "0123456789ABCDEF"; 523 goto hex; 524 case 'x': 525 xdigs = "0123456789abcdef"; 526 hex: _uquad = UARG(); 527 base = HEX; 528 /* leading 0x/X only if non-zero */ 529 if (flags & ALT && _uquad != 0) 530 flags |= HEXPREFIX; 531 532 /* unsigned conversions */ 533 nosign: sign = '\0'; 534 /* 535 * ``... diouXx conversions ... if a precision is 536 * specified, the 0 flag will be ignored.'' 537 * -- ANSI X3J11 538 */ 539 number: if ((dprec = prec) >= 0) 540 flags &= ~ZEROPAD; 541 542 /* 543 * ``The result of converting a zero value with an 544 * explicit precision of zero is no characters.'' 545 * -- ANSI X3J11 546 */ 547 cp = buf + BUF; 548 if (_uquad != 0 || prec != 0) { 549 /* 550 * Unsigned mod is hard, and unsigned mod 551 * by a constant is easier than that by 552 * a variable; hence this switch. 553 */ 554 switch (base) { 555 case OCT: 556 do { 557 *--cp = to_char(_uquad & 7); 558 _uquad >>= 3; 559 } while (_uquad); 560 /* handle octal leading 0 */ 561 if (flags & ALT && *cp != '0') 562 *--cp = '0'; 563 break; 564 565 case DEC: 566 /* many numbers are 1 digit */ 567 while (_uquad >= 10) { 568 *--cp = to_char(_uquad % 10); 569 _uquad /= 10; 570 } 571 *--cp = to_char(_uquad); 572 break; 573 574 case HEX: 575 do { 576 *--cp = xdigs[_uquad & 15]; 577 _uquad >>= 4; 578 } while (_uquad); 579 break; 580 581 default: 582 cp = "bug in vfprintf: bad base"; 583 size = strlen(cp); 584 goto skipsize; 585 } 586 } 587 size = buf + BUF - cp; 588 skipsize: 589 break; 590 default: /* "%?" prints ?, unless ? is NUL */ 591 if (ch == '\0') 592 goto done; 593 /* pretend it was %c with argument ch */ 594 cp = buf; 595 *cp = ch; 596 size = 1; 597 sign = '\0'; 598 break; 599 } 600 601 /* 602 * All reasonable formats wind up here. At this point, `cp' 603 * points to a string which (if not flags&LADJUST) should be 604 * padded out to `width' places. If flags&ZEROPAD, it should 605 * first be prefixed by any sign or other prefix; otherwise, 606 * it should be blank padded before the prefix is emitted. 607 * After any left-hand padding and prefixing, emit zeroes 608 * required by a decimal [diouxX] precision, then print the 609 * string proper, then emit zeroes required by any leftover 610 * floating precision; finally, if LADJUST, pad with blanks. 611 * 612 * Compute actual size, so we know how much to pad. 613 * size excludes decimal prec; realsz includes it. 614 */ 615 realsz = dprec > size ? dprec : size; 616 if (sign) 617 realsz++; 618 else if (flags & HEXPREFIX) 619 realsz+= 2; 620 621 /* right-adjusting blank padding */ 622 if ((flags & (LADJUST|ZEROPAD)) == 0) 623 PAD(width - realsz, blanks); 624 625 /* prefix */ 626 if (sign) { 627 PRINT(&sign, 1); 628 } else if (flags & HEXPREFIX) { 629 ox[0] = '0'; 630 ox[1] = ch; 631 PRINT(ox, 2); 632 } 633 634 /* right-adjusting zero padding */ 635 if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) 636 PAD(width - realsz, zeroes); 637 638 /* leading zeroes from decimal precision */ 639 PAD(dprec - size, zeroes); 640 641 /* the string or number proper */ 642 #ifdef FLOATING_POINT 643 if ((flags & FPT) == 0) { 644 PRINT(cp, size); 645 } else { /* glue together f_p fragments */ 646 if (ch >= 'f') { /* 'f' or 'g' */ 647 if (_double == 0) { 648 /* kludge for __dtoa irregularity */ 649 PRINT("0", 1); 650 if (expt < ndig || (flags & ALT) != 0) { 651 PRINT(decimal_point, 1); 652 PAD(ndig - 1, zeroes); 653 } 654 } else if (expt <= 0) { 655 PRINT("0", 1); 656 PRINT(decimal_point, 1); 657 PAD(-expt, zeroes); 658 PRINT(cp, ndig); 659 } else if (expt >= ndig) { 660 PRINT(cp, ndig); 661 PAD(expt - ndig, zeroes); 662 if (flags & ALT) 663 PRINT(".", 1); 664 } else { 665 PRINT(cp, expt); 666 cp += expt; 667 PRINT(".", 1); 668 PRINT(cp, ndig-expt); 669 } 670 } else { /* 'e' or 'E' */ 671 if (ndig > 1 || flags & ALT) { 672 ox[0] = *cp++; 673 ox[1] = '.'; 674 PRINT(ox, 2); 675 if (_double || flags & ALT == 0) { 676 PRINT(cp, ndig-1); 677 } else /* 0.[0..] */ 678 /* __dtoa irregularity */ 679 PAD(ndig - 1, zeroes); 680 } else /* XeYYY */ 681 PRINT(cp, 1); 682 PRINT(expstr, expsize); 683 } 684 } 685 #else 686 PRINT(cp, size); 687 #endif 688 /* left-adjusting padding (always blank) */ 689 if (flags & LADJUST) 690 PAD(width - realsz, blanks); 691 692 /* finally, adjust ret */ 693 ret += width > realsz ? width : realsz; 694 695 FLUSH(); /* copy out the I/O vectors */ 696 } 697 done: 698 FLUSH(); 699 error: 700 return (__sferror(fp) ? EOF : ret); 701 /* NOTREACHED */ 702 } 703 704 #ifdef FLOATING_POINT 705 706 extern char *__dtoa __P((double, int, int, int *, int *, char **)); 707 708 static char * 709 cvt(value, ndigits, flags, sign, decpt, ch, length) 710 double value; 711 int ndigits, flags, *decpt, ch, *length; 712 char *sign; 713 { 714 int mode, dsgn; 715 char *digits, *bp, *rve; 716 717 if (ch == 'f') { 718 mode = 3; /* ndigits after the decimal point */ 719 } else { 720 /* To obtain ndigits after the decimal point for the 'e' 721 * and 'E' formats, round to ndigits + 1 significant 722 * figures. 723 */ 724 if (ch == 'e' || ch == 'E') { 725 ndigits++; 726 } 727 mode = 2; /* ndigits significant digits */ 728 } 729 730 if (value < 0) { 731 value = -value; 732 *sign = '-'; 733 } else 734 *sign = '\000'; 735 digits = __dtoa(value, mode, ndigits, decpt, &dsgn, &rve); 736 if ((ch != 'g' && ch != 'G') || flags & ALT) { /* Print trailing zeros */ 737 bp = digits + ndigits; 738 if (ch == 'f') { 739 if (*digits == '0' && value) 740 *decpt = -ndigits + 1; 741 bp += *decpt; 742 } 743 if (value == 0) /* kludge for __dtoa irregularity */ 744 rve = bp; 745 while (rve < bp) 746 *rve++ = '0'; 747 } 748 *length = rve - digits; 749 return (digits); 750 } 751 752 static int 753 exponent(p0, exp, fmtch) 754 char *p0; 755 int exp, fmtch; 756 { 757 register char *p, *t; 758 char expbuf[MAXEXP]; 759 760 p = p0; 761 *p++ = fmtch; 762 if (exp < 0) { 763 exp = -exp; 764 *p++ = '-'; 765 } 766 else 767 *p++ = '+'; 768 t = expbuf + MAXEXP; 769 if (exp > 9) { 770 do { 771 *--t = to_char(exp % 10); 772 } while ((exp /= 10) > 9); 773 *--t = to_char(exp); 774 for (; t < expbuf + MAXEXP; *p++ = *t++); 775 } 776 else { 777 *p++ = '0'; 778 *p++ = to_char(exp); 779 } 780 return (p - p0); 781 } 782 #endif /* FLOATING_POINT */ 783