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 1.7 1993/08/26 00:47:33 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 /* Define FLOATING_POINT to get floating point. */ 64 #define FLOATING_POINT 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 <math.h> 125 #include "floatio.h" 126 127 #define BUF (MAXEXP+MAXFRACT+1) /* + decimal point */ 128 #define DEFPREC 6 129 130 static char *cvt __P((double, int, int, char *, int *, int, int *)); 131 static int exponent __P((char *, int, int)); 132 133 #else /* no FLOATING_POINT */ 134 135 #define BUF 40 136 137 #endif /* FLOATING_POINT */ 138 139 140 /* 141 * Macros for converting digits to letters and vice versa 142 */ 143 #define to_digit(c) ((c) - '0') 144 #define is_digit(c) ((unsigned)to_digit(c) <= 9) 145 #define to_char(n) ((n) + '0') 146 147 /* 148 * Flags used during conversion. 149 */ 150 #define ALT 0x001 /* alternate form */ 151 #define HEXPREFIX 0x002 /* add 0x or 0X prefix */ 152 #define LADJUST 0x004 /* left adjustment */ 153 #define LONGDBL 0x008 /* long double; unimplemented */ 154 #define LONGINT 0x010 /* long integer */ 155 #define QUADINT 0x020 /* quad integer */ 156 #define SHORTINT 0x040 /* short integer */ 157 #define ZEROPAD 0x080 /* zero (as opposed to blank) pad */ 158 #define FPT 0x100 /* Floating point number */ 159 int 160 vfprintf(fp, fmt0, ap) 161 FILE *fp; 162 const char *fmt0; 163 _VA_LIST_ ap; 164 { 165 register char *fmt; /* format string */ 166 register int ch; /* character from fmt */ 167 register int n; /* handy integer (short term usage) */ 168 register char *cp; /* handy char pointer (short term usage) */ 169 register struct __siov *iovp;/* for PRINT macro */ 170 register int flags; /* flags as above */ 171 int ret; /* return value accumulator */ 172 int width; /* width from format (%8d), or 0 */ 173 int prec; /* precision from format (%.3d), or -1 */ 174 char sign; /* sign prefix (' ', '+', '-', or \0) */ 175 #ifdef FLOATING_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 fieldsz; /* field size expanded by sign, etc */ 193 int realsz; /* field size expanded by dprec */ 194 int size; /* size of converted field or string */ 195 char *xdigs; /* digits for [xX] conversion */ 196 #define NIOV 8 197 struct __suio uio; /* output information: summary */ 198 struct __siov iov[NIOV];/* ... and individual io vectors */ 199 char buf[BUF]; /* space for %c, %[diouxX], %[eEfgG] */ 200 char ox[2]; /* space for 0x hex-prefix */ 201 202 /* 203 * Choose PADSIZE to trade efficiency vs. size. If larger printf 204 * fields occur frequently, increase PADSIZE and make the initialisers 205 * below longer. 206 */ 207 #define PADSIZE 16 /* pad chunk size */ 208 static char blanks[PADSIZE] = 209 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '}; 210 static char zeroes[PADSIZE] = 211 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'}; 212 213 /* 214 * BEWARE, these `goto error' on error, and PAD uses `n'. 215 */ 216 #define PRINT(ptr, len) { \ 217 iovp->iov_base = (ptr); \ 218 iovp->iov_len = (len); \ 219 uio.uio_resid += (len); \ 220 iovp++; \ 221 if (++uio.uio_iovcnt >= NIOV) { \ 222 if (__sprint(fp, &uio)) \ 223 goto error; \ 224 iovp = iov; \ 225 } \ 226 } 227 #define PAD(howmany, with) { \ 228 if ((n = (howmany)) > 0) { \ 229 while (n > PADSIZE) { \ 230 PRINT(with, PADSIZE); \ 231 n -= PADSIZE; \ 232 } \ 233 PRINT(with, n); \ 234 } \ 235 } 236 #define FLUSH() { \ 237 if (uio.uio_resid && __sprint(fp, &uio)) \ 238 goto error; \ 239 uio.uio_iovcnt = 0; \ 240 iovp = iov; \ 241 } 242 243 /* 244 * To extend shorts properly, we need both signed and unsigned 245 * argument extraction methods. 246 */ 247 #define SARG() \ 248 (flags&QUADINT ? va_arg(ap, quad_t) : \ 249 flags&LONGINT ? va_arg(ap, long) : \ 250 flags&SHORTINT ? (long)(short)va_arg(ap, int) : \ 251 (long)va_arg(ap, int)) 252 #define UARG() \ 253 (flags&QUADINT ? va_arg(ap, u_quad_t) : \ 254 flags&LONGINT ? va_arg(ap, u_long) : \ 255 flags&SHORTINT ? (u_long)(u_short)va_arg(ap, int) : \ 256 (u_long)va_arg(ap, u_int)) 257 258 /* sorry, fprintf(read_only_file, "") returns EOF, not 0 */ 259 if (cantwrite(fp)) 260 return (EOF); 261 262 /* optimise fprintf(stderr) (and other unbuffered Unix files) */ 263 if ((fp->_flags & (__SNBF|__SWR|__SRW)) == (__SNBF|__SWR) && 264 fp->_file >= 0) 265 return (__sbprintf(fp, fmt0, ap)); 266 267 fmt = (char *)fmt0; 268 uio.uio_iov = iovp = iov; 269 uio.uio_resid = 0; 270 uio.uio_iovcnt = 0; 271 ret = 0; 272 273 /* 274 * Scan the format for conversions (`%' character). 275 */ 276 for (;;) { 277 for (cp = fmt; (ch = *fmt) != '\0' && ch != '%'; fmt++) 278 /* void */; 279 if ((n = fmt - cp) != 0) { 280 PRINT(cp, n); 281 ret += n; 282 } 283 if (ch == '\0') 284 goto done; 285 fmt++; /* skip over '%' */ 286 287 flags = 0; 288 dprec = 0; 289 width = 0; 290 prec = -1; 291 sign = '\0'; 292 293 rflag: ch = *fmt++; 294 reswitch: switch (ch) { 295 case ' ': 296 /* 297 * ``If the space and + flags both appear, the space 298 * flag will be ignored.'' 299 * -- ANSI X3J11 300 */ 301 if (!sign) 302 sign = ' '; 303 goto rflag; 304 case '#': 305 flags |= ALT; 306 goto rflag; 307 case '*': 308 /* 309 * ``A negative field width argument is taken as a 310 * - flag followed by a positive field width.'' 311 * -- ANSI X3J11 312 * They don't exclude field widths read from args. 313 */ 314 if ((width = va_arg(ap, int)) >= 0) 315 goto rflag; 316 width = -width; 317 /* FALLTHROUGH */ 318 case '-': 319 flags |= LADJUST; 320 goto rflag; 321 case '+': 322 sign = '+'; 323 goto rflag; 324 case '.': 325 if ((ch = *fmt++) == '*') { 326 n = va_arg(ap, int); 327 prec = n < 0 ? -1 : n; 328 goto rflag; 329 } 330 n = 0; 331 while (is_digit(ch)) { 332 n = 10 * n + to_digit(ch); 333 ch = *fmt++; 334 } 335 prec = n < 0 ? -1 : n; 336 goto reswitch; 337 case '0': 338 /* 339 * ``Note that 0 is taken as a flag, not as the 340 * beginning of a field width.'' 341 * -- ANSI X3J11 342 */ 343 flags |= ZEROPAD; 344 goto rflag; 345 case '1': case '2': case '3': case '4': 346 case '5': case '6': case '7': case '8': case '9': 347 n = 0; 348 do { 349 n = 10 * n + to_digit(ch); 350 ch = *fmt++; 351 } while (is_digit(ch)); 352 width = n; 353 goto reswitch; 354 #ifdef FLOATING_POINT 355 case 'L': 356 flags |= LONGDBL; 357 goto rflag; 358 #endif 359 case 'h': 360 flags |= SHORTINT; 361 goto rflag; 362 case 'l': 363 flags |= LONGINT; 364 goto rflag; 365 case 'q': 366 flags |= QUADINT; 367 goto rflag; 368 case 'c': 369 *(cp = buf) = va_arg(ap, int); 370 size = 1; 371 sign = '\0'; 372 break; 373 case 'D': 374 flags |= LONGINT; 375 /*FALLTHROUGH*/ 376 case 'd': 377 case 'i': 378 _uquad = SARG(); 379 if ((quad_t)_uquad < 0) { 380 _uquad = -_uquad; 381 sign = '-'; 382 } 383 base = DEC; 384 goto number; 385 #ifdef FLOATING_POINT 386 case 'e': /* anomalous precision */ 387 case 'E': 388 prec = (prec == -1) ? 389 DEFPREC + 1 : prec + 1; 390 /* FALLTHROUGH */ 391 goto fp_begin; 392 case 'f': /* always print trailing zeroes */ 393 if (prec != 0) 394 flags |= ALT; 395 case 'g': 396 case 'G': 397 if (prec == -1) 398 prec = DEFPREC; 399 fp_begin: _double = va_arg(ap, double); 400 /* do this before tricky precision changes */ 401 if (isinf(_double)) { 402 if (_double < 0) 403 sign = '-'; 404 cp = "Inf"; 405 size = 3; 406 break; 407 } 408 if (isnan(_double)) { 409 cp = "NaN"; 410 size = 3; 411 break; 412 } 413 flags |= FPT; 414 cp = cvt(_double, prec, flags, &softsign, 415 &expt, ch, &ndig); 416 if (ch == 'g' || ch == 'G') { 417 if (expt <= -4 || expt > prec) 418 ch = (ch == 'g') ? 'e' : 'E'; 419 else 420 ch = 'g'; 421 } 422 if (ch <= 'e') { /* 'e' or 'E' fmt */ 423 --expt; 424 expsize = exponent(expstr, expt, ch); 425 size = expsize + ndig; 426 if (ndig > 1 || flags & ALT) 427 ++size; 428 } else if (ch == 'f') { /* f fmt */ 429 if (expt > 0) { 430 size = expt; 431 if (prec || flags & ALT) 432 size += prec + 1; 433 } else /* "0.X" */ 434 size = prec + 2; 435 } else if (expt >= ndig) { /* fixed g fmt */ 436 size = expt; 437 if (flags & ALT) 438 ++size; 439 } else 440 size = ndig + (expt > 0 ? 441 1 : 2 - expt); 442 443 if (softsign) 444 sign = '-'; 445 break; 446 #endif /* FLOATING_POINT */ 447 case 'n': 448 if (flags & QUADINT) 449 *va_arg(ap, quad_t *) = ret; 450 else if (flags & LONGINT) 451 *va_arg(ap, long *) = ret; 452 else if (flags & SHORTINT) 453 *va_arg(ap, short *) = ret; 454 else 455 *va_arg(ap, int *) = ret; 456 continue; /* no output */ 457 case 'O': 458 flags |= LONGINT; 459 /*FALLTHROUGH*/ 460 case 'o': 461 _uquad = UARG(); 462 base = OCT; 463 goto nosign; 464 case 'p': 465 /* 466 * ``The argument shall be a pointer to void. The 467 * value of the pointer is converted to a sequence 468 * of printable characters, in an implementation- 469 * defined manner.'' 470 * -- ANSI X3J11 471 */ 472 /* NOSTRICT */ 473 _uquad = (u_quad_t)va_arg(ap, void *); 474 base = HEX; 475 xdigs = "0123456789abcdef"; 476 flags |= HEXPREFIX; 477 ch = 'x'; 478 goto nosign; 479 case 's': 480 if ((cp = va_arg(ap, char *)) == NULL) 481 cp = "(null)"; 482 if (prec >= 0) { 483 /* 484 * can't use strlen; can only look for the 485 * NUL in the first `prec' characters, and 486 * strlen() will go further. 487 */ 488 char *p = memchr(cp, 0, prec); 489 490 if (p != NULL) { 491 size = p - cp; 492 if (size > prec) 493 size = prec; 494 } else 495 size = prec; 496 } else 497 size = strlen(cp); 498 sign = '\0'; 499 break; 500 case 'U': 501 flags |= LONGINT; 502 /*FALLTHROUGH*/ 503 case 'u': 504 _uquad = UARG(); 505 base = DEC; 506 goto nosign; 507 case 'X': 508 xdigs = "0123456789ABCDEF"; 509 goto hex; 510 case 'x': 511 xdigs = "0123456789abcdef"; 512 hex: _uquad = UARG(); 513 base = HEX; 514 /* leading 0x/X only if non-zero */ 515 if (flags & ALT && _uquad != 0) 516 flags |= HEXPREFIX; 517 518 /* unsigned conversions */ 519 nosign: sign = '\0'; 520 /* 521 * ``... diouXx conversions ... if a precision is 522 * specified, the 0 flag will be ignored.'' 523 * -- ANSI X3J11 524 */ 525 number: if ((dprec = prec) >= 0) 526 flags &= ~ZEROPAD; 527 528 /* 529 * ``The result of converting a zero value with an 530 * explicit precision of zero is no characters.'' 531 * -- ANSI X3J11 532 */ 533 cp = buf + BUF; 534 if (_uquad != 0 || prec != 0) { 535 /* 536 * Unsigned mod is hard, and unsigned mod 537 * by a constant is easier than that by 538 * a variable; hence this switch. 539 */ 540 switch (base) { 541 case OCT: 542 do { 543 *--cp = to_char(_uquad & 7); 544 _uquad >>= 3; 545 } while (_uquad); 546 /* handle octal leading 0 */ 547 if (flags & ALT && *cp != '0') 548 *--cp = '0'; 549 break; 550 551 case DEC: 552 /* many numbers are 1 digit */ 553 while (_uquad >= 10) { 554 *--cp = to_char(_uquad % 10); 555 _uquad /= 10; 556 } 557 *--cp = to_char(_uquad); 558 break; 559 560 case HEX: 561 do { 562 *--cp = xdigs[_uquad & 15]; 563 _uquad >>= 4; 564 } while (_uquad); 565 break; 566 567 default: 568 cp = "bug in vfprintf: bad base"; 569 size = strlen(cp); 570 goto skipsize; 571 } 572 } 573 size = buf + BUF - cp; 574 skipsize: 575 break; 576 default: /* "%?" prints ?, unless ? is NUL */ 577 if (ch == '\0') 578 goto done; 579 /* pretend it was %c with argument ch */ 580 cp = buf; 581 *cp = ch; 582 size = 1; 583 sign = '\0'; 584 break; 585 } 586 587 /* 588 * All reasonable formats wind up here. At this point, `cp' 589 * points to a string which (if not flags&LADJUST) should be 590 * padded out to `width' places. If flags&ZEROPAD, it should 591 * first be prefixed by any sign or other prefix; otherwise, 592 * it should be blank padded before the prefix is emitted. 593 * After any left-hand padding and prefixing, emit zeroes 594 * required by a decimal [diouxX] precision, then print the 595 * string proper, then emit zeroes required by any leftover 596 * floating precision; finally, if LADJUST, pad with blanks. 597 * 598 * Compute actual size, so we know how much to pad. 599 * fieldsz excludes decimal prec; realsz includes it. 600 */ 601 fieldsz = size; 602 if (sign) 603 fieldsz++; 604 else if (flags & HEXPREFIX) 605 fieldsz += 2; 606 realsz = dprec > fieldsz ? dprec : fieldsz; 607 608 /* right-adjusting blank padding */ 609 if ((flags & (LADJUST|ZEROPAD)) == 0) 610 PAD(width - realsz, blanks); 611 612 /* prefix */ 613 if (sign) { 614 PRINT(&sign, 1); 615 } else if (flags & HEXPREFIX) { 616 ox[0] = '0'; 617 ox[1] = ch; 618 PRINT(ox, 2); 619 } 620 621 /* right-adjusting zero padding */ 622 if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) 623 PAD(width - realsz, zeroes); 624 625 /* leading zeroes from decimal precision */ 626 PAD(dprec - fieldsz, zeroes); 627 628 /* the string or number proper */ 629 #ifdef FLOATING_POINT 630 if ((flags & FPT) == 0) { 631 PRINT(cp, size); 632 } else { /* glue together f_p fragments */ 633 if (ch >= 'f') { /* 'f' or 'g' */ 634 if (_double == 0) { 635 /* kludge for __dtoa irregularity */ 636 if (prec == 0 || 637 (flags & ALT) == 0) { 638 PRINT("0", 1); 639 } else { 640 PRINT("0.", 2); 641 PAD(ndig - 1, zeroes); 642 } 643 } else if (expt <= 0) { 644 PRINT("0.", 2); 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; 707 else { 708 mode = 2; 709 } 710 if (value < 0) { 711 value = -value; 712 *sign = '-'; 713 } else 714 *sign = '\000'; 715 digits = __dtoa(value, mode, ndigits, decpt, &dsgn, &rve); 716 if (flags & ALT) { /* Print trailing zeros */ 717 bp = digits + ndigits; 718 if (ch == 'f') { 719 if (*digits == '0' && value) 720 *decpt = -ndigits + 1; 721 bp += *decpt; 722 } 723 if (value == 0) /* kludge for __dtoa irregularity */ 724 rve = bp; 725 while (rve < bp) 726 *rve++ = '0'; 727 } 728 *length = rve - digits; 729 return (digits); 730 } 731 732 static int 733 exponent(p0, exp, fmtch) 734 char *p0; 735 int exp, fmtch; 736 { 737 register char *p, *t; 738 char expbuf[MAXEXP]; 739 740 p = p0; 741 *p++ = fmtch; 742 if (exp < 0) { 743 exp = -exp; 744 *p++ = '-'; 745 } 746 else 747 *p++ = '+'; 748 t = expbuf + MAXEXP; 749 if (exp > 9) { 750 do { 751 *--t = to_char(exp % 10); 752 } while ((exp /= 10) > 9); 753 *--t = to_char(exp); 754 for (; t < expbuf + MAXEXP; *p++ = *t++); 755 } 756 else { 757 *p++ = '0'; 758 *p++ = to_char(exp); 759 } 760 return (p - p0); 761 } 762 #endif /* FLOATING_POINT */ 763