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 1.15 1995/02/25 07:06:38 cgd 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; /* handy integer (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 #ifdef FLOATING_POINT 174 char *decimal_point = localeconv()->decimal_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 realsz; /* field size expanded by dprec */ 192 int size; /* size of converted field or string */ 193 char *xdigs; /* digits for [xX] conversion */ 194 #define NIOV 8 195 struct __suio uio; /* output information: summary */ 196 struct __siov iov[NIOV];/* ... and individual io vectors */ 197 char buf[BUF]; /* space for %c, %[diouxX], %[eEfgG] */ 198 char ox[2]; /* space for 0x hex-prefix */ 199 200 /* 201 * Choose PADSIZE to trade efficiency vs. size. If larger printf 202 * fields occur frequently, increase PADSIZE and make the initialisers 203 * below longer. 204 */ 205 #define PADSIZE 16 /* pad chunk size */ 206 static char blanks[PADSIZE] = 207 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '}; 208 static char zeroes[PADSIZE] = 209 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'}; 210 211 /* 212 * BEWARE, these `goto error' on error, and PAD uses `n'. 213 */ 214 #define PRINT(ptr, len) { \ 215 iovp->iov_base = (ptr); \ 216 iovp->iov_len = (len); \ 217 uio.uio_resid += (len); \ 218 iovp++; \ 219 if (++uio.uio_iovcnt >= NIOV) { \ 220 if (__sprint(fp, &uio)) \ 221 goto error; \ 222 iovp = iov; \ 223 } \ 224 } 225 #define PAD(howmany, with) { \ 226 if ((n = (howmany)) > 0) { \ 227 while (n > PADSIZE) { \ 228 PRINT(with, PADSIZE); \ 229 n -= PADSIZE; \ 230 } \ 231 PRINT(with, n); \ 232 } \ 233 } 234 #define FLUSH() { \ 235 if (uio.uio_resid && __sprint(fp, &uio)) \ 236 goto error; \ 237 uio.uio_iovcnt = 0; \ 238 iovp = iov; \ 239 } 240 241 /* 242 * To extend shorts properly, we need both signed and unsigned 243 * argument extraction methods. 244 */ 245 #define SARG() \ 246 (flags&QUADINT ? va_arg(ap, quad_t) : \ 247 flags&LONGINT ? va_arg(ap, long) : \ 248 flags&SHORTINT ? (long)(short)va_arg(ap, int) : \ 249 (long)va_arg(ap, int)) 250 #define UARG() \ 251 (flags&QUADINT ? va_arg(ap, u_quad_t) : \ 252 flags&LONGINT ? va_arg(ap, u_long) : \ 253 flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \ 254 (u_long)va_arg(ap, u_int)) 255 256 /* sorry, fprintf(read_only_file, "") returns EOF, not 0 */ 257 if (cantwrite(fp)) 258 return (EOF); 259 260 /* optimise fprintf(stderr) (and other unbuffered Unix files) */ 261 if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) && 262 fp->_file >= 0) 263 return (__sbprintf(fp, fmt0, ap)); 264 265 fmt = (char *)fmt0; 266 uio.uio_iov = iovp = iov; 267 uio.uio_resid = 0; 268 uio.uio_iovcnt = 0; 269 ret = 0; 270 271 /* 272 * Scan the format for conversions (`%' character). 273 */ 274 for (;;) { 275 for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++) 276 /* void */; 277 if ((n = fmt - cp) != 0) { 278 PRINT(cp, n); 279 ret += n; 280 } 281 if (ch == '\0') 282 goto done; 283 fmt++; /* skip over '%' */ 284 285 flags = 0; 286 dprec = 0; 287 width = 0; 288 prec = -1; 289 sign = '\0'; 290 291 rflag: ch = *fmt++; 292 reswitch: switch (ch) { 293 case ' ': 294 /* 295 * ``If the space and + flags both appear, the space 296 * flag will be ignored.'' 297 * -- ANSI X3J11 298 */ 299 if (!sign) 300 sign = ' '; 301 goto rflag; 302 case '#': 303 flags |= ALT; 304 goto rflag; 305 case '*': 306 /* 307 * ``A negative field width argument is taken as a 308 * - flag followed by a positive field width.'' 309 * -- ANSI X3J11 310 * They don't exclude field widths read from args. 311 */ 312 if ((width = va_arg(ap, int)) >= 0) 313 goto rflag; 314 width = -width; 315 /* FALLTHROUGH */ 316 case '-': 317 flags |= LADJUST; 318 goto rflag; 319 case '+': 320 sign = '+'; 321 goto rflag; 322 case '.': 323 if ((ch = *fmt++) == '*') { 324 n = va_arg(ap, int); 325 prec = n < 0 ? -1 : n; 326 goto rflag; 327 } 328 n = 0; 329 while (is_digit(ch)) { 330 n = 10 * n + to_digit(ch); 331 ch = *fmt++; 332 } 333 prec = n < 0 ? -1 : n; 334 goto reswitch; 335 case '0': 336 /* 337 * ``Note that 0 is taken as a flag, not as the 338 * beginning of a field width.'' 339 * -- ANSI X3J11 340 */ 341 flags |= ZEROPAD; 342 goto rflag; 343 case '1': case '2': case '3': case '4': 344 case '5': case '6': case '7': case '8': case '9': 345 n = 0; 346 do { 347 n = 10 * n + to_digit(ch); 348 ch = *fmt++; 349 } while (is_digit(ch)); 350 width = n; 351 goto reswitch; 352 #ifdef FLOATING_POINT 353 case 'L': 354 flags |= LONGDBL; 355 goto rflag; 356 #endif 357 case 'h': 358 flags |= SHORTINT; 359 goto rflag; 360 case 'l': 361 flags |= LONGINT; 362 goto rflag; 363 case 'q': 364 flags |= QUADINT; 365 goto rflag; 366 case 'c': 367 *(cp = buf) = va_arg(ap, int); 368 size = 1; 369 sign = '\0'; 370 break; 371 case 'D': 372 flags |= LONGINT; 373 /*FALLTHROUGH*/ 374 case 'd': 375 case 'i': 376 _uquad = SARG(); 377 if ((quad_t)_uquad < 0) { 378 _uquad = -_uquad; 379 sign = '-'; 380 } 381 base = DEC; 382 goto number; 383 #ifdef FLOATING_POINT 384 case 'e': 385 case 'E': 386 case 'f': 387 case 'g': 388 case 'G': 389 if (prec == -1) { 390 prec = DEFPREC; 391 } else if ((ch == 'g' || ch == 'G') && prec == 0) { 392 prec = 1; 393 } 394 395 if (flags & LONGDBL) { 396 _double = (double) va_arg(ap, long double); 397 } else { 398 _double = va_arg(ap, double); 399 } 400 401 /* do this before tricky precision changes */ 402 if (isinf(_double)) { 403 if (_double < 0) 404 sign = '-'; 405 cp = "Inf"; 406 size = 3; 407 break; 408 } 409 if (isnan(_double)) { 410 cp = "NaN"; 411 size = 3; 412 break; 413 } 414 415 flags |= FPT; 416 cp = cvt(_double, prec, flags, &softsign, 417 &expt, ch, &ndig); 418 if (ch == 'g' || ch == 'G') { 419 if (expt <= -4 || expt > prec) 420 ch = (ch == 'g') ? 'e' : 'E'; 421 else 422 ch = 'g'; 423 } 424 if (ch <= 'e') { /* 'e' or 'E' fmt */ 425 --expt; 426 expsize = exponent(expstr, expt, ch); 427 size = expsize + ndig; 428 if (ndig > 1 || flags & ALT) 429 ++size; 430 } else if (ch == 'f') { /* f fmt */ 431 if (expt > 0) { 432 size = expt; 433 if (prec || flags & ALT) 434 size += prec + 1; 435 } else /* "0.X" */ 436 size = prec + 2; 437 } else if (expt >= ndig) { /* fixed g fmt */ 438 size = expt; 439 if (flags & ALT) 440 ++size; 441 } else 442 size = ndig + (expt > 0 ? 443 1 : 2 - expt); 444 445 if (softsign) 446 sign = '-'; 447 break; 448 #endif /* FLOATING_POINT */ 449 case 'n': 450 if (flags & QUADINT) 451 *va_arg(ap, quad_t *) = ret; 452 else if (flags & LONGINT) 453 *va_arg(ap, long *) = ret; 454 else if (flags & SHORTINT) 455 *va_arg(ap, short *) = ret; 456 else 457 *va_arg(ap, int *) = ret; 458 continue; /* no output */ 459 case 'O': 460 flags |= LONGINT; 461 /*FALLTHROUGH*/ 462 case 'o': 463 _uquad = UARG(); 464 base = OCT; 465 goto nosign; 466 case 'p': 467 /* 468 * ``The argument shall be a pointer to void. The 469 * value of the pointer is converted to a sequence 470 * of printable characters, in an implementation- 471 * defined manner.'' 472 * -- ANSI X3J11 473 */ 474 /* NOSTRICT */ 475 _uquad = (u_long)va_arg(ap, void *); 476 base = HEX; 477 xdigs = "0123456789abcdef"; 478 flags |= HEXPREFIX; 479 ch = 'x'; 480 goto nosign; 481 case 's': 482 if ((cp = va_arg(ap, char *)) == NULL) 483 cp = "(null)"; 484 if (prec >= 0) { 485 /* 486 * can't use strlen; can only look for the 487 * NUL in the first `prec' characters, and 488 * strlen() will go further. 489 */ 490 char *p = memchr(cp, 0, prec); 491 492 if (p != NULL) { 493 size = p - cp; 494 if (size > prec) 495 size = prec; 496 } else 497 size = prec; 498 } else 499 size = strlen(cp); 500 sign = '\0'; 501 break; 502 case 'U': 503 flags |= LONGINT; 504 /*FALLTHROUGH*/ 505 case 'u': 506 _uquad = UARG(); 507 base = DEC; 508 goto nosign; 509 case 'X': 510 xdigs = "0123456789ABCDEF"; 511 goto hex; 512 case 'x': 513 xdigs = "0123456789abcdef"; 514 hex: _uquad = UARG(); 515 base = HEX; 516 /* leading 0x/X only if non-zero */ 517 if (flags & ALT && _uquad != 0) 518 flags |= HEXPREFIX; 519 520 /* unsigned conversions */ 521 nosign: sign = '\0'; 522 /* 523 * ``... diouXx conversions ... if a precision is 524 * specified, the 0 flag will be ignored.'' 525 * -- ANSI X3J11 526 */ 527 number: if ((dprec = prec) >= 0) 528 flags &= ~ZEROPAD; 529 530 /* 531 * ``The result of converting a zero value with an 532 * explicit precision of zero is no characters.'' 533 * -- ANSI X3J11 534 */ 535 cp = buf + BUF; 536 if (_uquad != 0 || prec != 0) { 537 /* 538 * Unsigned mod is hard, and unsigned mod 539 * by a constant is easier than that by 540 * a variable; hence this switch. 541 */ 542 switch (base) { 543 case OCT: 544 do { 545 *--cp = to_char(_uquad & 7); 546 _uquad >>= 3; 547 } while (_uquad); 548 /* handle octal leading 0 */ 549 if (flags & ALT && *cp != '0') 550 *--cp = '0'; 551 break; 552 553 case DEC: 554 /* many numbers are 1 digit */ 555 while (_uquad >= 10) { 556 *--cp = to_char(_uquad % 10); 557 _uquad /= 10; 558 } 559 *--cp = to_char(_uquad); 560 break; 561 562 case HEX: 563 do { 564 *--cp = xdigs[_uquad & 15]; 565 _uquad >>= 4; 566 } while (_uquad); 567 break; 568 569 default: 570 cp = "bug in vfprintf: bad base"; 571 size = strlen(cp); 572 goto skipsize; 573 } 574 } 575 size = buf + BUF - cp; 576 skipsize: 577 break; 578 default: /* "%?" prints ?, unless ? is NUL */ 579 if (ch == '\0') 580 goto done; 581 /* pretend it was %c with argument ch */ 582 cp = buf; 583 *cp = ch; 584 size = 1; 585 sign = '\0'; 586 break; 587 } 588 589 /* 590 * All reasonable formats wind up here. At this point, `cp' 591 * points to a string which (if not flags&LADJUST) should be 592 * padded out to `width' places. If flags&ZEROPAD, it should 593 * first be prefixed by any sign or other prefix; otherwise, 594 * it should be blank padded before the prefix is emitted. 595 * After any left-hand padding and prefixing, emit zeroes 596 * required by a decimal [diouxX] precision, then print the 597 * string proper, then emit zeroes required by any leftover 598 * floating precision; finally, if LADJUST, pad with blanks. 599 * 600 * Compute actual size, so we know how much to pad. 601 * size excludes decimal prec; realsz includes it. 602 */ 603 realsz = dprec > size ? dprec : size; 604 if (sign) 605 realsz++; 606 else if (flags & HEXPREFIX) 607 realsz+= 2; 608 609 /* right-adjusting blank padding */ 610 if ((flags & (LADJUST|ZEROPAD)) == 0) 611 PAD(width - realsz, blanks); 612 613 /* prefix */ 614 if (sign) { 615 PRINT(&sign, 1); 616 } else if (flags & HEXPREFIX) { 617 ox[0] = '0'; 618 ox[1] = ch; 619 PRINT(ox, 2); 620 } 621 622 /* right-adjusting zero padding */ 623 if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) 624 PAD(width - realsz, zeroes); 625 626 /* leading zeroes from decimal precision */ 627 PAD(dprec - size, zeroes); 628 629 /* the string or number proper */ 630 #ifdef FLOATING_POINT 631 if ((flags & FPT) == 0) { 632 PRINT(cp, size); 633 } else { /* glue together f_p fragments */ 634 if (ch >= 'f') { /* 'f' or 'g' */ 635 if (_double == 0) { 636 /* kludge for __dtoa irregularity */ 637 PRINT("0", 1); 638 if (expt < ndig || (flags & ALT) != 0) { 639 PRINT(decimal_point, 1); 640 PAD(ndig - 1, zeroes); 641 } 642 } else if (expt <= 0) { 643 PRINT("0", 1); 644 PRINT(decimal_point, 1); 645 PAD(-expt, zeroes); 646 PRINT(cp, ndig); 647 } else if (expt >= ndig) { 648 PRINT(cp, ndig); 649 PAD(expt - ndig, zeroes); 650 if (flags & ALT) 651 PRINT(".", 1); 652 } else { 653 PRINT(cp, expt); 654 cp += expt; 655 PRINT(".", 1); 656 PRINT(cp, ndig-expt); 657 } 658 } else { /* 'e' or 'E' */ 659 if (ndig > 1 || flags & ALT) { 660 ox[0] = *cp++; 661 ox[1] = '.'; 662 PRINT(ox, 2); 663 if (_double || flags & ALT == 0) { 664 PRINT(cp, ndig-1); 665 } else /* 0.[0..] */ 666 /* __dtoa irregularity */ 667 PAD(ndig - 1, zeroes); 668 } else /* XeYYY */ 669 PRINT(cp, 1); 670 PRINT(expstr, expsize); 671 } 672 } 673 #else 674 PRINT(cp, size); 675 #endif 676 /* left-adjusting padding (always blank) */ 677 if (flags & LADJUST) 678 PAD(width - realsz, blanks); 679 680 /* finally, adjust ret */ 681 ret += width > realsz ? width : realsz; 682 683 FLUSH(); /* copy out the I/O vectors */ 684 } 685 done: 686 FLUSH(); 687 error: 688 return (__sferror(fp) ? EOF : ret); 689 /* NOTREACHED */ 690 } 691 692 #ifdef FLOATING_POINT 693 694 extern char *__dtoa __P((double, int, int, int *, int *, char **)); 695 696 static char * 697 cvt(value, ndigits, flags, sign, decpt, ch, length) 698 double value; 699 int ndigits, flags, *decpt, ch, *length; 700 char *sign; 701 { 702 int mode, dsgn; 703 char *digits, *bp, *rve; 704 705 if (ch == 'f') { 706 mode = 3; /* ndigits after the decimal point */ 707 } else { 708 /* To obtain ndigits after the decimal point for the 'e' 709 * and 'E' formats, round to ndigits + 1 significant 710 * figures. 711 */ 712 if (ch == 'e' || ch == 'E') { 713 ndigits++; 714 } 715 mode = 2; /* ndigits significant digits */ 716 } 717 718 if (value < 0) { 719 value = -value; 720 *sign = '-'; 721 } else 722 *sign = '\000'; 723 digits = __dtoa(value, mode, ndigits, decpt, &dsgn, &rve); 724 if ((ch != 'g' && ch != 'G') || flags & ALT) { /* Print trailing zeros */ 725 bp = digits + ndigits; 726 if (ch == 'f') { 727 if (*digits == '0' && value) 728 *decpt = -ndigits + 1; 729 bp += *decpt; 730 } 731 if (value == 0) /* kludge for __dtoa irregularity */ 732 rve = bp; 733 while (rve < bp) 734 *rve++ = '0'; 735 } 736 *length = rve - digits; 737 return (digits); 738 } 739 740 static int 741 exponent(p0, exp, fmtch) 742 char *p0; 743 int exp, fmtch; 744 { 745 register char *p, *t; 746 char expbuf[MAXEXP]; 747 748 p = p0; 749 *p++ = fmtch; 750 if (exp < 0) { 751 exp = -exp; 752 *p++ = '-'; 753 } 754 else 755 *p++ = '+'; 756 t = expbuf + MAXEXP; 757 if (exp > 9) { 758 do { 759 *--t = to_char(exp % 10); 760 } while ((exp /= 10) > 9); 761 *--t = to_char(exp); 762 for (; t < expbuf + MAXEXP; *p++ = *t++); 763 } 764 else { 765 *p++ = '0'; 766 *p++ = to_char(exp); 767 } 768 return (p - p0); 769 } 770 #endif /* FLOATING_POINT */ 771