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[] = "@(#)vfprintf.c 5.50 (Berkeley) 12/16/92"; 39 #endif /* LIBC_SCCS and not lint */ 40 41 /* 42 * Actual printf innards. 43 * 44 * This code is large and complicated... 45 */ 46 47 #include <sys/types.h> 48 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 53 #if __STDC__ 54 #include <stdarg.h> 55 #else 56 #include <varargs.h> 57 #endif 58 59 #include "local.h" 60 #include "fvwrite.h" 61 62 /* Define FLOATING_POINT to get floating point. */ 63 #define FLOATING_POINT 64 65 /* 66 * Flush out all the vectors defined by the given uio, 67 * then reset it so that it can be reused. 68 */ 69 static int 70 __sprint(fp, uio) 71 FILE *fp; 72 register struct __suio *uio; 73 { 74 register int err; 75 76 if (uio->uio_resid == 0) { 77 uio->uio_iovcnt = 0; 78 return (0); 79 } 80 err = __sfvwrite(fp, uio); 81 uio->uio_resid = 0; 82 uio->uio_iovcnt = 0; 83 return (err); 84 } 85 86 /* 87 * Helper function for `fprintf to unbuffered unix file': creates a 88 * temporary buffer. We only work on write-only files; this avoids 89 * worries about ungetc buffers and so forth. 90 */ 91 static int 92 __sbprintf(fp, fmt, ap) 93 register FILE *fp; 94 const char *fmt; 95 va_list ap; 96 { 97 int ret; 98 FILE fake; 99 unsigned char buf[BUFSIZ]; 100 101 /* copy the important variables */ 102 fake._flags = fp->_flags & ~__SNBF; 103 fake._file = fp->_file; 104 fake._cookie = fp->_cookie; 105 fake._write = fp->_write; 106 107 /* set up the buffer */ 108 fake._bf._base = fake._p = buf; 109 fake._bf._size = fake._w = sizeof(buf); 110 fake._lbfsize = 0; /* not actually used, but Just In Case */ 111 112 /* do the work, then copy any error status */ 113 ret = vfprintf(&fake, fmt, ap); 114 if (ret >= 0 && fflush(&fake)) 115 ret = EOF; 116 if (fake._flags & __SERR) 117 fp->_flags |= __SERR; 118 return (ret); 119 } 120 121 122 #ifdef FLOATING_POINT 123 #include <math.h> 124 #include "floatio.h" 125 126 #define BUF (MAXEXP+MAXFRACT+1) /* + decimal point */ 127 #define DEFPREC 6 128 129 static char *cvt __P((double, int, int, char *, int *, int, int *)); 130 static int exponent __P((char *, int, int)); 131 132 #else /* no FLOATING_POINT */ 133 134 #define BUF 40 135 136 #endif /* FLOATING_POINT */ 137 138 139 /* 140 * Macros for converting digits to letters and vice versa 141 */ 142 #define to_digit(c) ((c) - '0') 143 #define is_digit(c) ((unsigned)to_digit(c) <= 9) 144 #define to_char(n) ((n) + '0') 145 146 /* 147 * Flags used during conversion. 148 */ 149 #define ALT 0x001 /* alternate form */ 150 #define HEXPREFIX 0x002 /* add 0x or 0X prefix */ 151 #define LADJUST 0x004 /* left adjustment */ 152 #define LONGDBL 0x008 /* long double; unimplemented */ 153 #define LONGINT 0x010 /* long integer */ 154 #define QUADINT 0x020 /* quad integer */ 155 #define SHORTINT 0x040 /* short integer */ 156 #define ZEROPAD 0x080 /* zero (as opposed to blank) pad */ 157 #define FPT 0x100 /* Floating point number */ 158 int 159 vfprintf(fp, fmt0, ap) 160 FILE *fp; 161 const char *fmt0; 162 _VA_LIST_ ap; 163 { 164 register char *fmt; /* format string */ 165 register int ch; /* character from fmt */ 166 register int n; /* handy integer (short term usage) */ 167 register char *cp; /* handy char pointer (short term usage) */ 168 register struct __siov *iovp;/* for PRINT macro */ 169 register int flags; /* flags as above */ 170 int ret; /* return value accumulator */ 171 int width; /* width from format (%8d), or 0 */ 172 int prec; /* precision from format (%.3d), or -1 */ 173 char sign; /* sign prefix (' ', '+', '-', or \0) */ 174 #ifdef FLOATING_POINT 175 char softsign; /* temporary negative sign for floats */ 176 double _double; /* double precision arguments %[eEfgG] */ 177 int expt; /* integer value of exponent */ 178 int expsize; /* character count for expstr */ 179 int ndig; /* actual number of digits returned by cvt */ 180 char expstr[7]; /* buffer for exponent string */ 181 #endif 182 183 #ifdef __GNUC__ /* gcc has builtin quad type (long long) SOS */ 184 #define quad_t long long 185 #define u_quad_t unsigned long long 186 #endif 187 188 u_quad_t _uquad; /* integer arguments %[diouxX] */ 189 enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */ 190 int dprec; /* a copy of prec if [diouxX], 0 otherwise */ 191 int fieldsz; /* field size expanded by sign, etc */ 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 for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++) 277 /* void */; 278 if ((n = fmt - cp) != 0) { 279 PRINT(cp, n); 280 ret += n; 281 } 282 if (ch == '\0') 283 goto done; 284 fmt++; /* skip over '%' */ 285 286 flags = 0; 287 dprec = 0; 288 width = 0; 289 prec = -1; 290 sign = '\0'; 291 292 rflag: ch = *fmt++; 293 reswitch: switch (ch) { 294 case ' ': 295 /* 296 * ``If the space and + flags both appear, the space 297 * flag will be ignored.'' 298 * -- ANSI X3J11 299 */ 300 if (!sign) 301 sign = ' '; 302 goto rflag; 303 case '#': 304 flags |= ALT; 305 goto rflag; 306 case '*': 307 /* 308 * ``A negative field width argument is taken as a 309 * - flag followed by a positive field width.'' 310 * -- ANSI X3J11 311 * They don't exclude field widths read from args. 312 */ 313 if ((width = va_arg(ap, int)) >= 0) 314 goto rflag; 315 width = -width; 316 /* FALLTHROUGH */ 317 case '-': 318 flags |= LADJUST; 319 goto rflag; 320 case '+': 321 sign = '+'; 322 goto rflag; 323 case '.': 324 if ((ch = *fmt++) == '*') { 325 n = va_arg(ap, int); 326 prec = n < 0 ? -1 : n; 327 goto rflag; 328 } 329 n = 0; 330 while (is_digit(ch)) { 331 n = 10 * n + to_digit(ch); 332 ch = *fmt++; 333 } 334 prec = n < 0 ? -1 : n; 335 goto reswitch; 336 case '0': 337 /* 338 * ``Note that 0 is taken as a flag, not as the 339 * beginning of a field width.'' 340 * -- ANSI X3J11 341 */ 342 flags |= ZEROPAD; 343 goto rflag; 344 case '1': case '2': case '3': case '4': 345 case '5': case '6': case '7': case '8': case '9': 346 n = 0; 347 do { 348 n = 10 * n + to_digit(ch); 349 ch = *fmt++; 350 } while (is_digit(ch)); 351 width = n; 352 goto reswitch; 353 #ifdef FLOATING_POINT 354 case 'L': 355 flags |= LONGDBL; 356 goto rflag; 357 #endif 358 case 'h': 359 flags |= SHORTINT; 360 goto rflag; 361 case 'l': 362 flags |= LONGINT; 363 goto rflag; 364 case 'q': 365 flags |= QUADINT; 366 goto rflag; 367 case 'c': 368 *(cp = buf) = va_arg(ap, int); 369 size = 1; 370 sign = '\0'; 371 break; 372 case 'D': 373 flags |= LONGINT; 374 /*FALLTHROUGH*/ 375 case 'd': 376 case 'i': 377 _uquad = SARG(); 378 if ((quad_t)_uquad < 0) { 379 _uquad = -_uquad; 380 sign = '-'; 381 } 382 base = DEC; 383 goto number; 384 #ifdef FLOATING_POINT 385 case 'e': /* anomalous precision */ 386 case 'E': 387 prec = (prec == -1) ? 388 DEFPREC + 1 : prec + 1; 389 /* FALLTHROUGH */ 390 goto fp_begin; 391 case 'f': /* always print trailing zeroes */ 392 if (prec != 0) 393 flags |= ALT; 394 case 'g': 395 case 'G': 396 if (prec == -1) 397 prec = DEFPREC; 398 fp_begin: _double = va_arg(ap, double); 399 /* do this before tricky precision changes */ 400 if (isinf(_double)) { 401 if (_double < 0) 402 sign = '-'; 403 cp = "Inf"; 404 size = 3; 405 break; 406 } 407 if (isnan(_double)) { 408 cp = "NaN"; 409 size = 3; 410 break; 411 } 412 flags |= FPT; 413 cp = cvt(_double, prec, flags, &softsign, 414 &expt, ch, &ndig); 415 if (ch == 'g' || ch == 'G') { 416 if (expt <= -4 || expt > prec) 417 ch = (ch == 'g') ? 'e' : 'E'; 418 else 419 ch = 'g'; 420 } 421 if (ch <= 'e') { /* 'e' or 'E' fmt */ 422 --expt; 423 expsize = exponent(expstr, expt, ch); 424 size = expsize + ndig; 425 if (ndig > 1 || flags & ALT) 426 ++size; 427 } else if (ch == 'f') { /* f fmt */ 428 if (expt > 0) { 429 size = expt; 430 if (prec || flags & ALT) 431 size += prec + 1; 432 } else /* "0.X" */ 433 size = prec + 2; 434 } else if (expt >= ndig) { /* fixed g fmt */ 435 size = expt; 436 if (flags & ALT) 437 ++size; 438 } else 439 size = ndig + (expt > 0 ? 440 1 : 2 - expt); 441 442 if (softsign) 443 sign = '-'; 444 break; 445 #endif /* FLOATING_POINT */ 446 case 'n': 447 if (flags & QUADINT) 448 *va_arg(ap, quad_t *) = ret; 449 else if (flags & LONGINT) 450 *va_arg(ap, long *) = ret; 451 else if (flags & SHORTINT) 452 *va_arg(ap, short *) = ret; 453 else 454 *va_arg(ap, int *) = ret; 455 continue; /* no output */ 456 case 'O': 457 flags |= LONGINT; 458 /*FALLTHROUGH*/ 459 case 'o': 460 _uquad = UARG(); 461 base = OCT; 462 goto nosign; 463 case 'p': 464 /* 465 * ``The argument shall be a pointer to void. The 466 * value of the pointer is converted to a sequence 467 * of printable characters, in an implementation- 468 * defined manner.'' 469 * -- ANSI X3J11 470 */ 471 /* NOSTRICT */ 472 _uquad = (u_quad_t)va_arg(ap, void *); 473 base = HEX; 474 xdigs = "0123456789abcdef"; 475 flags |= HEXPREFIX; 476 ch = 'x'; 477 goto nosign; 478 case 's': 479 if ((cp = va_arg(ap, char *)) == NULL) 480 cp = "(null)"; 481 if (prec >= 0) { 482 /* 483 * can't use strlen; can only look for the 484 * NUL in the first `prec' characters, and 485 * strlen() will go further. 486 */ 487 char *p = memchr(cp, 0, prec); 488 489 if (p != NULL) { 490 size = p - cp; 491 if (size > prec) 492 size = prec; 493 } else 494 size = prec; 495 } else 496 size = strlen(cp); 497 sign = '\0'; 498 break; 499 case 'U': 500 flags |= LONGINT; 501 /*FALLTHROUGH*/ 502 case 'u': 503 _uquad = UARG(); 504 base = DEC; 505 goto nosign; 506 case 'X': 507 xdigs = "0123456789ABCDEF"; 508 goto hex; 509 case 'x': 510 xdigs = "0123456789abcdef"; 511 hex: _uquad = UARG(); 512 base = HEX; 513 /* leading 0x/X only if non-zero */ 514 if (flags & ALT && _uquad != 0) 515 flags |= HEXPREFIX; 516 517 /* unsigned conversions */ 518 nosign: sign = '\0'; 519 /* 520 * ``... diouXx conversions ... if a precision is 521 * specified, the 0 flag will be ignored.'' 522 * -- ANSI X3J11 523 */ 524 number: if ((dprec = prec) >= 0) 525 flags &= ~ZEROPAD; 526 527 /* 528 * ``The result of converting a zero value with an 529 * explicit precision of zero is no characters.'' 530 * -- ANSI X3J11 531 */ 532 cp = buf + BUF; 533 if (_uquad != 0 || prec != 0) { 534 /* 535 * Unsigned mod is hard, and unsigned mod 536 * by a constant is easier than that by 537 * a variable; hence this switch. 538 */ 539 switch (base) { 540 case OCT: 541 do { 542 *--cp = to_char(_uquad & 7); 543 _uquad >>= 3; 544 } while (_uquad); 545 /* handle octal leading 0 */ 546 if (flags & ALT && *cp != '0') 547 *--cp = '0'; 548 break; 549 550 case DEC: 551 /* many numbers are 1 digit */ 552 while (_uquad >= 10) { 553 *--cp = to_char(_uquad % 10); 554 _uquad /= 10; 555 } 556 *--cp = to_char(_uquad); 557 break; 558 559 case HEX: 560 do { 561 *--cp = xdigs[_uquad & 15]; 562 _uquad >>= 4; 563 } while (_uquad); 564 break; 565 566 default: 567 cp = "bug in vfprintf: bad base"; 568 size = strlen(cp); 569 goto skipsize; 570 } 571 } 572 size = buf + BUF - cp; 573 skipsize: 574 break; 575 default: /* "%?" prints ?, unless ? is NUL */ 576 if (ch == '\0') 577 goto done; 578 /* pretend it was %c with argument ch */ 579 cp = buf; 580 *cp = ch; 581 size = 1; 582 sign = '\0'; 583 break; 584 } 585 586 /* 587 * All reasonable formats wind up here. At this point, `cp' 588 * points to a string which (if not flags&LADJUST) should be 589 * padded out to `width' places. If flags&ZEROPAD, it should 590 * first be prefixed by any sign or other prefix; otherwise, 591 * it should be blank padded before the prefix is emitted. 592 * After any left-hand padding and prefixing, emit zeroes 593 * required by a decimal [diouxX] precision, then print the 594 * string proper, then emit zeroes required by any leftover 595 * floating precision; finally, if LADJUST, pad with blanks. 596 * 597 * Compute actual size, so we know how much to pad. 598 * fieldsz excludes decimal prec; realsz includes it. 599 */ 600 fieldsz = size; 601 if (sign) 602 fieldsz++; 603 else if (flags & HEXPREFIX) 604 fieldsz += 2; 605 realsz = dprec > fieldsz ? dprec : fieldsz; 606 607 /* right-adjusting blank padding */ 608 if ((flags & (LADJUST|ZEROPAD)) == 0) 609 PAD(width - realsz, blanks); 610 611 /* prefix */ 612 if (sign) { 613 PRINT(&sign, 1); 614 } else if (flags & HEXPREFIX) { 615 ox[0] = '0'; 616 ox[1] = ch; 617 PRINT(ox, 2); 618 } 619 620 /* right-adjusting zero padding */ 621 if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) 622 PAD(width - realsz, zeroes); 623 624 /* leading zeroes from decimal precision */ 625 PAD(dprec - fieldsz, zeroes); 626 627 /* the string or number proper */ 628 #ifdef FLOATING_POINT 629 if ((flags & FPT) == 0) { 630 PRINT(cp, size); 631 } else { /* glue together f_p fragments */ 632 if (ch >= 'f') { /* 'f' or 'g' */ 633 if (_double == 0) { 634 /* kludge for __dtoa irregularity */ 635 if (prec == 0 || 636 (flags & ALT) == 0) { 637 PRINT("0", 1); 638 } else { 639 PRINT("0.", 2); 640 PAD(ndig - 1, zeroes); 641 } 642 } else if (expt <= 0) { 643 PRINT("0.", 2); 644 PAD(-expt, zeroes); 645 PRINT(cp, ndig); 646 } else if (expt >= ndig) { 647 PRINT(cp, ndig); 648 PAD(expt - ndig, zeroes); 649 if (flags & ALT) 650 PRINT(".", 1); 651 } else { 652 PRINT(cp, expt); 653 cp += expt; 654 PRINT(".", 1); 655 PRINT(cp, ndig-expt); 656 } 657 } else { /* 'e' or 'E' */ 658 if (ndig > 1 || flags & ALT) { 659 ox[0] = *cp++; 660 ox[1] = '.'; 661 PRINT(ox, 2); 662 if (_double || flags & ALT == 0) { 663 PRINT(cp, ndig-1); 664 } else /* 0.[0..] */ 665 /* __dtoa irregularity */ 666 PAD(ndig - 1, zeroes); 667 } else /* XeYYY */ 668 PRINT(cp, 1); 669 PRINT(expstr, expsize); 670 } 671 } 672 #else 673 PRINT(cp, size); 674 #endif 675 /* left-adjusting padding (always blank) */ 676 if (flags & LADJUST) 677 PAD(width - realsz, blanks); 678 679 /* finally, adjust ret */ 680 ret += width > realsz ? width : realsz; 681 682 FLUSH(); /* copy out the I/O vectors */ 683 } 684 done: 685 FLUSH(); 686 error: 687 return (__sferror(fp) ? EOF : ret); 688 /* NOTREACHED */ 689 } 690 691 #ifdef FLOATING_POINT 692 693 extern char *__dtoa __P((double, int, int, int *, int *, char **)); 694 695 static char * 696 cvt(value, ndigits, flags, sign, decpt, ch, length) 697 double value; 698 int ndigits, flags, *decpt, ch, *length; 699 char *sign; 700 { 701 int mode, dsgn; 702 char *digits, *bp, *rve; 703 704 if (ch == 'f') 705 mode = 3; 706 else { 707 mode = 2; 708 } 709 if (value < 0) { 710 value = -value; 711 *sign = '-'; 712 } else 713 *sign = '\000'; 714 digits = __dtoa(value, mode, ndigits, decpt, &dsgn, &rve); 715 if (flags & ALT) { /* Print trailing zeros */ 716 bp = digits + ndigits; 717 if (ch == 'f') { 718 if (*digits == '0' && value) 719 *decpt = -ndigits + 1; 720 bp += *decpt; 721 } 722 if (value == 0) /* kludge for __dtoa irregularity */ 723 rve = bp; 724 while (rve < bp) 725 *rve++ = '0'; 726 } 727 *length = rve - digits; 728 return (digits); 729 } 730 731 static int 732 exponent(p0, exp, fmtch) 733 char *p0; 734 int exp, fmtch; 735 { 736 register char *p, *t; 737 char expbuf[MAXEXP]; 738 739 p = p0; 740 *p++ = fmtch; 741 if (exp < 0) { 742 exp = -exp; 743 *p++ = '-'; 744 } 745 else 746 *p++ = '+'; 747 t = expbuf + MAXEXP; 748 if (exp > 9) { 749 do { 750 *--t = to_char(exp % 10); 751 } while ((exp /= 10) > 9); 752 *--t = to_char(exp); 753 for (; t < expbuf + MAXEXP; *p++ = *t++); 754 } 755 else { 756 *p++ = '0'; 757 *p++ = to_char(exp); 758 } 759 return (p - p0); 760 } 761 #endif /* FLOATING_POINT */ 762