1 /* $NetBSD: vfprintf.c,v 1.19 1997/05/03 09:01:50 kleink Exp $ */ 2 3 /*- 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #if defined(LIBC_SCCS) && !defined(lint) 40 /*static char *sccsid = "from: @(#)vfprintf.c 5.50 (Berkeley) 12/16/92";*/ 41 static char *rcsid = "$NetBSD: vfprintf.c,v 1.19 1997/05/03 09:01:50 kleink Exp $"; 42 #endif /* LIBC_SCCS and not lint */ 43 44 /* 45 * Actual printf innards. 46 * 47 * This code is large and complicated... 48 */ 49 50 #include <sys/types.h> 51 52 #include <errno.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 57 #if __STDC__ 58 #include <stdarg.h> 59 #else 60 #include <varargs.h> 61 #endif 62 63 #include "local.h" 64 #include "fvwrite.h" 65 66 /* 67 * Flush out all the vectors defined by the given uio, 68 * then reset it so that it can be reused. 69 */ 70 static int 71 __sprint(fp, uio) 72 FILE *fp; 73 register struct __suio *uio; 74 { 75 register int err; 76 77 if (uio->uio_resid == 0) { 78 uio->uio_iovcnt = 0; 79 return (0); 80 } 81 err = __sfvwrite(fp, uio); 82 uio->uio_resid = 0; 83 uio->uio_iovcnt = 0; 84 return (err); 85 } 86 87 /* 88 * Helper function for `fprintf to unbuffered unix file': creates a 89 * temporary buffer. We only work on write-only files; this avoids 90 * worries about ungetc buffers and so forth. 91 */ 92 static int 93 __sbprintf(fp, fmt, ap) 94 register FILE *fp; 95 const char *fmt; 96 va_list ap; 97 { 98 int ret; 99 FILE fake; 100 unsigned char buf[BUFSIZ]; 101 102 /* copy the important variables */ 103 fake._flags = fp->_flags & ~__SNBF; 104 fake._file = fp->_file; 105 fake._cookie = fp->_cookie; 106 fake._write = fp->_write; 107 108 /* set up the buffer */ 109 fake._bf._base = fake._p = buf; 110 fake._bf._size = fake._w = sizeof(buf); 111 fake._lbfsize = 0; /* not actually used, but Just In Case */ 112 113 /* do the work, then copy any error status */ 114 ret = vfprintf(&fake, fmt, ap); 115 if (ret >= 0 && fflush(&fake)) 116 ret = EOF; 117 if (fake._flags & __SERR) 118 fp->_flags |= __SERR; 119 return (ret); 120 } 121 122 123 #ifdef FLOATING_POINT 124 #include <locale.h> 125 #include <math.h> 126 #include "floatio.h" 127 128 #define BUF (MAXEXP+MAXFRACT+1) /* + decimal point */ 129 #define DEFPREC 6 130 131 static char *cvt __P((double, int, int, char *, int *, int, int *)); 132 static int exponent __P((char *, int, int)); 133 134 #else /* no FLOATING_POINT */ 135 136 #define BUF 40 137 138 #endif /* FLOATING_POINT */ 139 140 141 /* 142 * Macros for converting digits to letters and vice versa 143 */ 144 #define to_digit(c) ((c) - '0') 145 #define is_digit(c) ((unsigned)to_digit(c) <= 9) 146 #define to_char(n) ((n) + '0') 147 148 /* 149 * Flags used during conversion. 150 */ 151 #define ALT 0x001 /* alternate form */ 152 #define HEXPREFIX 0x002 /* add 0x or 0X prefix */ 153 #define LADJUST 0x004 /* left adjustment */ 154 #define LONGDBL 0x008 /* long double; unimplemented */ 155 #define LONGINT 0x010 /* long integer */ 156 #define QUADINT 0x020 /* quad integer */ 157 #define SHORTINT 0x040 /* short integer */ 158 #define ZEROPAD 0x080 /* zero (as opposed to blank) pad */ 159 #define FPT 0x100 /* Floating point number */ 160 int 161 vfprintf(fp, fmt0, ap) 162 FILE *fp; 163 const char *fmt0; 164 _BSD_VA_LIST_ ap; 165 { 166 register char *fmt; /* format string */ 167 register int ch; /* character from fmt */ 168 register int n, m; /* handy integers (short term usage) */ 169 register char *cp; /* handy char pointer (short term usage) */ 170 register struct __siov *iovp;/* for PRINT macro */ 171 register int flags; /* flags as above */ 172 int ret; /* return value accumulator */ 173 int width; /* width from format (%8d), or 0 */ 174 int prec; /* precision from format (%.3d), or -1 */ 175 char sign; /* sign prefix (' ', '+', '-', or \0) */ 176 wchar_t wc; 177 #ifdef FLOATING_POINT 178 char *decimal_point = localeconv()->decimal_point; 179 char softsign; /* temporary negative sign for floats */ 180 double _double; /* double precision arguments %[eEfgG] */ 181 int expt; /* integer value of exponent */ 182 int expsize; /* character count for expstr */ 183 int ndig; /* actual number of digits returned by cvt */ 184 char expstr[7]; /* buffer for exponent string */ 185 #endif 186 187 #ifdef __GNUC__ /* gcc has builtin quad type (long long) SOS */ 188 #define quad_t long long 189 #define u_quad_t unsigned long long 190 #endif 191 192 u_quad_t _uquad; /* integer arguments %[diouxX] */ 193 enum { OCT, DEC, HEX } base;/* base for [diouxX] conversion */ 194 int dprec; /* a copy of prec if [diouxX], 0 otherwise */ 195 int realsz; /* field size expanded by dprec */ 196 int size; /* size of converted field or string */ 197 char *xdigs; /* digits for [xX] conversion */ 198 #define NIOV 8 199 struct __suio uio; /* output information: summary */ 200 struct __siov iov[NIOV];/* ... and individual io vectors */ 201 char buf[BUF]; /* space for %c, %[diouxX], %[eEfgG] */ 202 char ox[2]; /* space for 0x hex-prefix */ 203 204 /* 205 * Choose PADSIZE to trade efficiency vs. size. If larger printf 206 * fields occur frequently, increase PADSIZE and make the initialisers 207 * below longer. 208 */ 209 #define PADSIZE 16 /* pad chunk size */ 210 static char blanks[PADSIZE] = 211 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '}; 212 static char zeroes[PADSIZE] = 213 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'}; 214 215 /* 216 * BEWARE, these `goto error' on error, and PAD uses `n'. 217 */ 218 #define PRINT(ptr, len) { \ 219 iovp->iov_base = (ptr); \ 220 iovp->iov_len = (len); \ 221 uio.uio_resid += (len); \ 222 iovp++; \ 223 if (++uio.uio_iovcnt >= NIOV) { \ 224 if (__sprint(fp, &uio)) \ 225 goto error; \ 226 iovp = iov; \ 227 } \ 228 } 229 #define PAD(howmany, with) { \ 230 if ((n = (howmany)) > 0) { \ 231 while (n > PADSIZE) { \ 232 PRINT(with, PADSIZE); \ 233 n -= PADSIZE; \ 234 } \ 235 PRINT(with, n); \ 236 } \ 237 } 238 #define FLUSH() { \ 239 if (uio.uio_resid && __sprint(fp, &uio)) \ 240 goto error; \ 241 uio.uio_iovcnt = 0; \ 242 iovp = iov; \ 243 } 244 245 /* 246 * To extend shorts properly, we need both signed and unsigned 247 * argument extraction methods. 248 */ 249 #define SARG() \ 250 (flags&QUADINT ? va_arg(ap, quad_t) : \ 251 flags&LONGINT ? va_arg(ap, long) : \ 252 flags&SHORTINT ? (long)(short)va_arg(ap, int) : \ 253 (long)va_arg(ap, int)) 254 #define UARG() \ 255 (flags&QUADINT ? va_arg(ap, u_quad_t) : \ 256 flags&LONGINT ? va_arg(ap, u_long) : \ 257 flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \ 258 (u_long)va_arg(ap, u_int)) 259 260 /* sorry, fprintf(read_only_file, "") returns EOF, not 0 */ 261 if (cantwrite(fp)) { 262 errno = EBADF; 263 return (EOF); 264 } 265 266 /* optimise fprintf(stderr) (and other unbuffered Unix files) */ 267 if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) && 268 fp->_file >= 0) 269 return (__sbprintf(fp, fmt0, ap)); 270 271 fmt = (char *)fmt0; 272 uio.uio_iov = iovp = iov; 273 uio.uio_resid = 0; 274 uio.uio_iovcnt = 0; 275 ret = 0; 276 277 /* 278 * Scan the format for conversions (`%' character). 279 */ 280 for (;;) { 281 cp = fmt; 282 while ((n = mbtowc(&wc, fmt, MB_CUR_MAX)) > 0) { 283 fmt += n; 284 if (wc == '%') { 285 fmt--; 286 break; 287 } 288 } 289 if ((m = fmt - cp) != 0) { 290 PRINT(cp, m); 291 ret += m; 292 } 293 if (n <= 0) 294 goto done; 295 fmt++; /* skip over '%' */ 296 297 flags = 0; 298 dprec = 0; 299 width = 0; 300 prec = -1; 301 sign = '\0'; 302 303 rflag: ch = *fmt++; 304 reswitch: switch (ch) { 305 case ' ': 306 /* 307 * ``If the space and + flags both appear, the space 308 * flag will be ignored.'' 309 * -- ANSI X3J11 310 */ 311 if (!sign) 312 sign = ' '; 313 goto rflag; 314 case '#': 315 flags |= ALT; 316 goto rflag; 317 case '*': 318 /* 319 * ``A negative field width argument is taken as a 320 * - flag followed by a positive field width.'' 321 * -- ANSI X3J11 322 * They don't exclude field widths read from args. 323 */ 324 if ((width = va_arg(ap, int)) >= 0) 325 goto rflag; 326 width = -width; 327 /* FALLTHROUGH */ 328 case '-': 329 flags |= LADJUST; 330 goto rflag; 331 case '+': 332 sign = '+'; 333 goto rflag; 334 case '.': 335 if ((ch = *fmt++) == '*') { 336 n = va_arg(ap, int); 337 prec = n < 0 ? -1 : n; 338 goto rflag; 339 } 340 n = 0; 341 while (is_digit(ch)) { 342 n = 10 * n + to_digit(ch); 343 ch = *fmt++; 344 } 345 prec = n < 0 ? -1 : n; 346 goto reswitch; 347 case '0': 348 /* 349 * ``Note that 0 is taken as a flag, not as the 350 * beginning of a field width.'' 351 * -- ANSI X3J11 352 */ 353 flags |= ZEROPAD; 354 goto rflag; 355 case '1': case '2': case '3': case '4': 356 case '5': case '6': case '7': case '8': case '9': 357 n = 0; 358 do { 359 n = 10 * n + to_digit(ch); 360 ch = *fmt++; 361 } while (is_digit(ch)); 362 width = n; 363 goto reswitch; 364 #ifdef FLOATING_POINT 365 case 'L': 366 flags |= LONGDBL; 367 goto rflag; 368 #endif 369 case 'h': 370 flags |= SHORTINT; 371 goto rflag; 372 case 'l': 373 if (*fmt == 'l') { 374 fmt++; 375 flags |= QUADINT; 376 } else { 377 flags |= LONGINT; 378 } 379 goto rflag; 380 case 'q': 381 flags |= QUADINT; 382 goto rflag; 383 case 'c': 384 *(cp = buf) = va_arg(ap, int); 385 size = 1; 386 sign = '\0'; 387 break; 388 case 'D': 389 flags |= LONGINT; 390 /*FALLTHROUGH*/ 391 case 'd': 392 case 'i': 393 _uquad = SARG(); 394 if ((quad_t)_uquad < 0) { 395 _uquad = -_uquad; 396 sign = '-'; 397 } 398 base = DEC; 399 goto number; 400 #ifdef FLOATING_POINT 401 case 'e': 402 case 'E': 403 case 'f': 404 case 'g': 405 case 'G': 406 if (prec == -1) { 407 prec = DEFPREC; 408 } else if ((ch == 'g' || ch == 'G') && prec == 0) { 409 prec = 1; 410 } 411 412 if (flags & LONGDBL) { 413 _double = (double) va_arg(ap, long double); 414 } else { 415 _double = va_arg(ap, double); 416 } 417 418 /* do this before tricky precision changes */ 419 if (isinf(_double)) { 420 if (_double < 0) 421 sign = '-'; 422 cp = "Inf"; 423 size = 3; 424 break; 425 } 426 if (isnan(_double)) { 427 cp = "NaN"; 428 size = 3; 429 break; 430 } 431 432 flags |= FPT; 433 cp = cvt(_double, prec, flags, &softsign, 434 &expt, ch, &ndig); 435 if (ch == 'g' || ch == 'G') { 436 if (expt <= -4 || expt > prec) 437 ch = (ch == 'g') ? 'e' : 'E'; 438 else 439 ch = 'g'; 440 } 441 if (ch <= 'e') { /* 'e' or 'E' fmt */ 442 --expt; 443 expsize = exponent(expstr, expt, ch); 444 size = expsize + ndig; 445 if (ndig > 1 || flags & ALT) 446 ++size; 447 } else if (ch == 'f') { /* f fmt */ 448 if (expt > 0) { 449 size = expt; 450 if (prec || flags & ALT) 451 size += prec + 1; 452 } else /* "0.X" */ 453 size = prec + 2; 454 } else if (expt >= ndig) { /* fixed g fmt */ 455 size = expt; 456 if (flags & ALT) 457 ++size; 458 } else 459 size = ndig + (expt > 0 ? 460 1 : 2 - expt); 461 462 if (softsign) 463 sign = '-'; 464 break; 465 #endif /* FLOATING_POINT */ 466 case 'n': 467 if (flags & QUADINT) 468 *va_arg(ap, quad_t *) = ret; 469 else if (flags & LONGINT) 470 *va_arg(ap, long *) = ret; 471 else if (flags & SHORTINT) 472 *va_arg(ap, short *) = ret; 473 else 474 *va_arg(ap, int *) = ret; 475 continue; /* no output */ 476 case 'O': 477 flags |= LONGINT; 478 /*FALLTHROUGH*/ 479 case 'o': 480 _uquad = UARG(); 481 base = OCT; 482 goto nosign; 483 case 'p': 484 /* 485 * ``The argument shall be a pointer to void. The 486 * value of the pointer is converted to a sequence 487 * of printable characters, in an implementation- 488 * defined manner.'' 489 * -- ANSI X3J11 490 */ 491 /* NOSTRICT */ 492 _uquad = (u_long)va_arg(ap, void *); 493 base = HEX; 494 xdigs = "0123456789abcdef"; 495 flags |= HEXPREFIX; 496 ch = 'x'; 497 goto nosign; 498 case 's': 499 if ((cp = va_arg(ap, char *)) == NULL) 500 cp = "(null)"; 501 if (prec >= 0) { 502 /* 503 * can't use strlen; can only look for the 504 * NUL in the first `prec' characters, and 505 * strlen() will go further. 506 */ 507 char *p = memchr(cp, 0, prec); 508 509 if (p != NULL) { 510 size = p - cp; 511 if (size > prec) 512 size = prec; 513 } else 514 size = prec; 515 } else 516 size = strlen(cp); 517 sign = '\0'; 518 break; 519 case 'U': 520 flags |= LONGINT; 521 /*FALLTHROUGH*/ 522 case 'u': 523 _uquad = UARG(); 524 base = DEC; 525 goto nosign; 526 case 'X': 527 xdigs = "0123456789ABCDEF"; 528 goto hex; 529 case 'x': 530 xdigs = "0123456789abcdef"; 531 hex: _uquad = UARG(); 532 base = HEX; 533 /* leading 0x/X only if non-zero */ 534 if (flags & ALT && _uquad != 0) 535 flags |= HEXPREFIX; 536 537 /* unsigned conversions */ 538 nosign: sign = '\0'; 539 /* 540 * ``... diouXx conversions ... if a precision is 541 * specified, the 0 flag will be ignored.'' 542 * -- ANSI X3J11 543 */ 544 number: if ((dprec = prec) >= 0) 545 flags &= ~ZEROPAD; 546 547 /* 548 * ``The result of converting a zero value with an 549 * explicit precision of zero is no characters.'' 550 * -- ANSI X3J11 551 */ 552 cp = buf + BUF; 553 if (_uquad != 0 || prec != 0) { 554 /* 555 * Unsigned mod is hard, and unsigned mod 556 * by a constant is easier than that by 557 * a variable; hence this switch. 558 */ 559 switch (base) { 560 case OCT: 561 do { 562 *--cp = to_char(_uquad & 7); 563 _uquad >>= 3; 564 } while (_uquad); 565 /* handle octal leading 0 */ 566 if (flags & ALT && *cp != '0') 567 *--cp = '0'; 568 break; 569 570 case DEC: 571 /* many numbers are 1 digit */ 572 while (_uquad >= 10) { 573 *--cp = to_char(_uquad % 10); 574 _uquad /= 10; 575 } 576 *--cp = to_char(_uquad); 577 break; 578 579 case HEX: 580 do { 581 *--cp = xdigs[_uquad & 15]; 582 _uquad >>= 4; 583 } while (_uquad); 584 break; 585 586 default: 587 cp = "bug in vfprintf: bad base"; 588 size = strlen(cp); 589 goto skipsize; 590 } 591 } 592 size = buf + BUF - cp; 593 skipsize: 594 break; 595 default: /* "%?" prints ?, unless ? is NUL */ 596 if (ch == '\0') 597 goto done; 598 /* pretend it was %c with argument ch */ 599 cp = buf; 600 *cp = ch; 601 size = 1; 602 sign = '\0'; 603 break; 604 } 605 606 /* 607 * All reasonable formats wind up here. At this point, `cp' 608 * points to a string which (if not flags&LADJUST) should be 609 * padded out to `width' places. If flags&ZEROPAD, it should 610 * first be prefixed by any sign or other prefix; otherwise, 611 * it should be blank padded before the prefix is emitted. 612 * After any left-hand padding and prefixing, emit zeroes 613 * required by a decimal [diouxX] precision, then print the 614 * string proper, then emit zeroes required by any leftover 615 * floating precision; finally, if LADJUST, pad with blanks. 616 * 617 * Compute actual size, so we know how much to pad. 618 * size excludes decimal prec; realsz includes it. 619 */ 620 realsz = dprec > size ? dprec : size; 621 if (sign) 622 realsz++; 623 else if (flags & HEXPREFIX) 624 realsz+= 2; 625 626 /* right-adjusting blank padding */ 627 if ((flags & (LADJUST|ZEROPAD)) == 0) 628 PAD(width - realsz, blanks); 629 630 /* prefix */ 631 if (sign) { 632 PRINT(&sign, 1); 633 } else if (flags & HEXPREFIX) { 634 ox[0] = '0'; 635 ox[1] = ch; 636 PRINT(ox, 2); 637 } 638 639 /* right-adjusting zero padding */ 640 if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) 641 PAD(width - realsz, zeroes); 642 643 /* leading zeroes from decimal precision */ 644 PAD(dprec - size, zeroes); 645 646 /* the string or number proper */ 647 #ifdef FLOATING_POINT 648 if ((flags & FPT) == 0) { 649 PRINT(cp, size); 650 } else { /* glue together f_p fragments */ 651 if (ch >= 'f') { /* 'f' or 'g' */ 652 if (_double == 0) { 653 /* kludge for __dtoa irregularity */ 654 PRINT("0", 1); 655 if (expt < ndig || (flags & ALT) != 0) { 656 PRINT(decimal_point, 1); 657 PAD(ndig - 1, zeroes); 658 } 659 } else if (expt <= 0) { 660 PRINT("0", 1); 661 PRINT(decimal_point, 1); 662 PAD(-expt, zeroes); 663 PRINT(cp, ndig); 664 } else if (expt >= ndig) { 665 PRINT(cp, ndig); 666 PAD(expt - ndig, zeroes); 667 if (flags & ALT) 668 PRINT(".", 1); 669 } else { 670 PRINT(cp, expt); 671 cp += expt; 672 PRINT(".", 1); 673 PRINT(cp, ndig-expt); 674 } 675 } else { /* 'e' or 'E' */ 676 if (ndig > 1 || flags & ALT) { 677 ox[0] = *cp++; 678 ox[1] = '.'; 679 PRINT(ox, 2); 680 if (_double || flags & ALT == 0) { 681 PRINT(cp, ndig-1); 682 } else /* 0.[0..] */ 683 /* __dtoa irregularity */ 684 PAD(ndig - 1, zeroes); 685 } else /* XeYYY */ 686 PRINT(cp, 1); 687 PRINT(expstr, expsize); 688 } 689 } 690 #else 691 PRINT(cp, size); 692 #endif 693 /* left-adjusting padding (always blank) */ 694 if (flags & LADJUST) 695 PAD(width - realsz, blanks); 696 697 /* finally, adjust ret */ 698 ret += width > realsz ? width : realsz; 699 700 FLUSH(); /* copy out the I/O vectors */ 701 } 702 done: 703 FLUSH(); 704 error: 705 return (__sferror(fp) ? EOF : ret); 706 /* NOTREACHED */ 707 } 708 709 #ifdef FLOATING_POINT 710 711 extern char *__dtoa __P((double, int, int, int *, int *, char **)); 712 713 static char * 714 cvt(value, ndigits, flags, sign, decpt, ch, length) 715 double value; 716 int ndigits, flags, *decpt, ch, *length; 717 char *sign; 718 { 719 int mode, dsgn; 720 char *digits, *bp, *rve; 721 722 if (ch == 'f') { 723 mode = 3; /* ndigits after the decimal point */ 724 } else { 725 /* To obtain ndigits after the decimal point for the 'e' 726 * and 'E' formats, round to ndigits + 1 significant 727 * figures. 728 */ 729 if (ch == 'e' || ch == 'E') { 730 ndigits++; 731 } 732 mode = 2; /* ndigits significant digits */ 733 } 734 735 if (value < 0) { 736 value = -value; 737 *sign = '-'; 738 } else 739 *sign = '\000'; 740 digits = __dtoa(value, mode, ndigits, decpt, &dsgn, &rve); 741 if ((ch != 'g' && ch != 'G') || flags & ALT) { /* Print trailing zeros */ 742 bp = digits + ndigits; 743 if (ch == 'f') { 744 if (*digits == '0' && value) 745 *decpt = -ndigits + 1; 746 bp += *decpt; 747 } 748 if (value == 0) /* kludge for __dtoa irregularity */ 749 rve = bp; 750 while (rve < bp) 751 *rve++ = '0'; 752 } 753 *length = rve - digits; 754 return (digits); 755 } 756 757 static int 758 exponent(p0, exp, fmtch) 759 char *p0; 760 int exp, fmtch; 761 { 762 register char *p, *t; 763 char expbuf[MAXEXP]; 764 765 p = p0; 766 *p++ = fmtch; 767 if (exp < 0) { 768 exp = -exp; 769 *p++ = '-'; 770 } 771 else 772 *p++ = '+'; 773 t = expbuf + MAXEXP; 774 if (exp > 9) { 775 do { 776 *--t = to_char(exp % 10); 777 } while ((exp /= 10) > 9); 778 *--t = to_char(exp); 779 for (; t < expbuf + MAXEXP; *p++ = *t++); 780 } 781 else { 782 *p++ = '0'; 783 *p++ = to_char(exp); 784 } 785 return (p - p0); 786 } 787 #endif /* FLOATING_POINT */ 788