1 /* 2 * Copyright (c) 1988 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #if defined(LIBC_SCCS) && !defined(lint) 19 static char sccsid[] = "@(#)vfprintf.c 5.36 (Berkeley) 10/23/88"; 20 #endif /* LIBC_SCCS and not lint */ 21 22 #include <sys/types.h> 23 #include <varargs.h> 24 #include <stdio.h> 25 #include <ctype.h> 26 27 /* 11-bit exponent (VAX G floating point) is 308 decimal digits */ 28 #define MAXEXP 308 29 /* 128 bit fraction takes up 39 decimal digits; max reasonable precision */ 30 #define MAXFRACT 39 31 32 #define DEFPREC 6 33 34 #define BUF (MAXEXP+MAXFRACT+1) /* + decimal point */ 35 36 #define PUTC(ch) (void) putc(ch, fp) 37 38 #define ARG(basetype) \ 39 _ulong = flags&LONGINT ? va_arg(argp, long basetype) : \ 40 flags&SHORTINT ? (short basetype)va_arg(argp, int) : \ 41 va_arg(argp, int) 42 43 #define todigit(c) ((c) - '0') 44 #define tochar(n) ((n) + '0') 45 46 /* have to deal with the negative buffer count kludge */ 47 #define NEGATIVE_COUNT_KLUDGE 48 49 #define LONGINT 0x01 /* long integer */ 50 #define LONGDBL 0x02 /* long double; unimplemented */ 51 #define SHORTINT 0x04 /* short integer */ 52 #define ALT 0x08 /* alternate form */ 53 #define LADJUST 0x10 /* left adjustment */ 54 #define ZEROPAD 0x20 /* zero (as opposed to blank) pad */ 55 #define HEXPREFIX 0x40 /* add 0x or 0X prefix */ 56 57 _doprnt(fmt0, argp, fp) 58 u_char *fmt0; 59 va_list argp; 60 register FILE *fp; 61 { 62 register u_char *fmt; /* format string */ 63 register int ch; /* character from fmt */ 64 register int cnt; /* return value accumulator */ 65 register int n; /* random handy integer */ 66 register char *t; /* buffer pointer */ 67 double _double; /* double precision arguments %[eEfgG] */ 68 u_long _ulong; /* integer arguments %[diouxX] */ 69 int base; /* base for [diouxX] conversion */ 70 int dprec; /* decimal precision in [diouxX] */ 71 int fieldsz; /* field size expanded by sign, etc */ 72 int flags; /* flags as above */ 73 int fpprec; /* `extra' floating precision in [eEfgG] */ 74 int prec; /* precision from format (%.3d), or -1 */ 75 int realsz; /* field size expanded by decimal precision */ 76 int size; /* size of converted field or string */ 77 int width; /* width from format (%8d), or 0 */ 78 char sign; /* sign prefix (' ', '+', '-', or \0) */ 79 char softsign; /* temporary negative sign for floats */ 80 char *digs; /* digits for [diouxX] conversion */ 81 char buf[BUF]; /* space for %c, %[diouxX], %[eEfgG] */ 82 83 if (fp->_flag & _IORW) { 84 fp->_flag |= _IOWRT; 85 fp->_flag &= ~(_IOEOF|_IOREAD); 86 } 87 if ((fp->_flag & _IOWRT) == 0) 88 return (EOF); 89 90 fmt = fmt0; 91 digs = "0123456789abcdef"; 92 for (cnt = 0;; ++fmt) { 93 n = fp->_cnt; 94 for (t = (char *)fp->_ptr; (ch = *fmt) && ch != '%'; 95 ++cnt, ++fmt) 96 if (--n < 0 97 #ifdef NEGATIVE_COUNT_KLUDGE 98 && (!(fp->_flag & _IOLBF) || -n >= fp->_bufsiz) 99 #endif 100 || ch == '\n' && fp->_flag & _IOLBF) { 101 fp->_cnt = n; 102 fp->_ptr = t; 103 (void) _flsbuf((u_char)ch, fp); 104 n = fp->_cnt; 105 t = (char *)fp->_ptr; 106 } else 107 *t++ = ch; 108 fp->_cnt = n; 109 fp->_ptr = t; 110 if (!ch) 111 return (cnt); 112 113 flags = 0; dprec = 0; fpprec = 0; width = 0; 114 prec = -1; 115 sign = '\0'; 116 117 rflag: switch (*++fmt) { 118 case ' ': 119 /* 120 * ``If the space and + flags both appear, the space 121 * flag will be ignored.'' 122 * -- ANSI X3J11 123 */ 124 if (!sign) 125 sign = ' '; 126 goto rflag; 127 case '#': 128 flags |= ALT; 129 goto rflag; 130 case '*': 131 /* 132 * ``A negative field width argument is taken as a 133 * - flag followed by a positive field width.'' 134 * -- ANSI X3J11 135 * They don't exclude field widths read from args. 136 */ 137 if ((width = va_arg(argp, int)) >= 0) 138 goto rflag; 139 width = -width; 140 /* FALLTHROUGH */ 141 case '-': 142 flags |= LADJUST; 143 goto rflag; 144 case '+': 145 sign = '+'; 146 goto rflag; 147 case '.': 148 if (*++fmt == '*') 149 n = va_arg(argp, int); 150 else { 151 n = 0; 152 while (isascii(*fmt) && isdigit(*fmt)) 153 n = 10 * n + todigit(*fmt++); 154 --fmt; 155 } 156 prec = n < 0 ? -1 : n; 157 goto rflag; 158 case '0': 159 /* 160 * ``Note that 0 is taken as a flag, not as the 161 * beginning of a field width.'' 162 * -- ANSI X3J11 163 */ 164 flags |= ZEROPAD; 165 goto rflag; 166 case '1': case '2': case '3': case '4': 167 case '5': case '6': case '7': case '8': case '9': 168 n = 0; 169 do { 170 n = 10 * n + todigit(*fmt); 171 } while (isascii(*++fmt) && isdigit(*fmt)); 172 width = n; 173 --fmt; 174 goto rflag; 175 case 'L': 176 flags |= LONGDBL; 177 goto rflag; 178 case 'h': 179 flags |= SHORTINT; 180 goto rflag; 181 case 'l': 182 flags |= LONGINT; 183 goto rflag; 184 case 'c': 185 *(t = buf) = va_arg(argp, int); 186 size = 1; 187 sign = '\0'; 188 goto pforw; 189 case 'D': 190 flags |= LONGINT; 191 /*FALLTHROUGH*/ 192 case 'd': 193 case 'i': 194 ARG(int); 195 if ((long)_ulong < 0) { 196 _ulong = -_ulong; 197 sign = '-'; 198 } 199 base = 10; 200 goto number; 201 case 'e': 202 case 'E': 203 case 'f': 204 case 'g': 205 case 'G': 206 _double = va_arg(argp, double); 207 /* 208 * don't do unrealistic precision; just pad it with 209 * zeroes later, so buffer size stays rational. 210 */ 211 if (prec > MAXFRACT) { 212 if (*fmt != 'g' && *fmt != 'G' || (flags&ALT)) 213 fpprec = prec - MAXFRACT; 214 prec = MAXFRACT; 215 } 216 else if (prec == -1) 217 prec = DEFPREC; 218 /* 219 * softsign avoids negative 0 if _double is < 0 and 220 * no significant digits will be shown 221 */ 222 if (_double < 0) { 223 softsign = '-'; 224 _double = -_double; 225 } 226 else 227 softsign = 0; 228 /* 229 * cvt may have to round up past the "start" of the 230 * buffer, i.e. ``intf("%.2f", (double)9.999);''; 231 * if the first char isn't NULL, it did. 232 */ 233 *buf = NULL; 234 size = cvt(_double, prec, flags, &softsign, *fmt, buf, 235 buf + sizeof(buf)); 236 if (softsign) 237 sign = '-'; 238 t = *buf ? buf : buf + 1; 239 goto pforw; 240 case 'n': 241 if (flags & LONGINT) 242 *va_arg(argp, long *) = cnt; 243 else if (flags & SHORTINT) 244 *va_arg(argp, short *) = cnt; 245 else 246 *va_arg(argp, int *) = cnt; 247 break; 248 case 'O': 249 flags |= LONGINT; 250 /*FALLTHROUGH*/ 251 case 'o': 252 ARG(unsigned); 253 base = 8; 254 goto nosign; 255 case 'p': 256 /* 257 * ``The argument shall be a pointer to void. The 258 * value of the pointer is converted to a sequence 259 * of printable characters, in an implementation- 260 * defined manner.'' 261 * -- ANSI X3J11 262 */ 263 /* NOSTRICT */ 264 _ulong = (u_long)va_arg(argp, void *); 265 base = 16; 266 goto nosign; 267 case 's': 268 if (!(t = va_arg(argp, char *))) 269 t = "(null)"; 270 if (prec >= 0) { 271 /* 272 * can't use strlen; can only look for the 273 * NUL in the first `prec' characters, and 274 * strlen() will go further. 275 */ 276 char *p, *memchr(); 277 278 if (p = memchr(t, 0, prec)) { 279 size = p - t; 280 if (size > prec) 281 size = prec; 282 } else 283 size = prec; 284 } else 285 size = strlen(t); 286 sign = '\0'; 287 goto pforw; 288 case 'U': 289 flags |= LONGINT; 290 /*FALLTHROUGH*/ 291 case 'u': 292 ARG(unsigned); 293 base = 10; 294 goto nosign; 295 case 'X': 296 digs = "0123456789ABCDEF"; 297 /* FALLTHROUGH */ 298 case 'x': 299 ARG(unsigned); 300 base = 16; 301 /* leading 0x/X only if non-zero */ 302 if (flags & ALT && _ulong != 0) 303 flags |= HEXPREFIX; 304 305 /* unsigned conversions */ 306 nosign: sign = '\0'; 307 /* 308 * ``... diouXx conversions ... if a precision is 309 * specified, the 0 flag will be ignored.'' 310 * -- ANSI X3J11 311 */ 312 number: if ((dprec = prec) >= 0) 313 flags &= ~ZEROPAD; 314 315 /* 316 * ``The result of converting a zero value with an 317 * explicit precision of zero is no characters.'' 318 * -- ANSI X3J11 319 */ 320 t = buf + BUF; 321 if (_ulong != 0 || prec != 0) { 322 do { 323 *--t = digs[_ulong % base]; 324 _ulong /= base; 325 } while (_ulong); 326 digs = "0123456789abcdef"; 327 if (flags & ALT && base == 8 && *t != '0') 328 *--t = '0'; /* octal leading 0 */ 329 } 330 size = buf + BUF - t; 331 332 pforw: 333 /* 334 * All reasonable formats wind up here. At this point, 335 * `t' points to a string which (if not flags&LADJUST) 336 * should be padded out to `width' places. If 337 * flags&ZEROPAD, it should first be prefixed by any 338 * sign or other prefix; otherwise, it should be blank 339 * padded before the prefix is emitted. After any 340 * left-hand padding and prefixing, emit zeroes 341 * required by a decimal [diouxX] precision, then print 342 * the string proper, then emit zeroes required by any 343 * leftover floating precision; finally, if LADJUST, 344 * pad with blanks. 345 */ 346 347 /* 348 * compute actual size, so we know how much to pad 349 * fieldsz excludes decimal prec; realsz includes it 350 */ 351 fieldsz = size + fpprec; 352 if (sign) 353 fieldsz++; 354 if (flags & HEXPREFIX) 355 fieldsz += 2; 356 realsz = dprec > fieldsz ? dprec : fieldsz; 357 358 /* right-adjusting blank padding */ 359 if ((flags & (LADJUST|ZEROPAD)) == 0 && width) 360 for (n = realsz; n < width; n++) 361 PUTC(' '); 362 /* prefix */ 363 if (sign) 364 PUTC(sign); 365 if (flags & HEXPREFIX) { 366 PUTC('0'); 367 PUTC((char)*fmt); 368 } 369 /* right-adjusting zero padding */ 370 if ((flags & (LADJUST|ZEROPAD)) == ZEROPAD) 371 for (n = realsz; n < width; n++) 372 PUTC('0'); 373 /* leading zeroes from decimal precision */ 374 for (n = fieldsz; n < dprec; n++) 375 PUTC('0'); 376 377 /* the string or number proper */ 378 if (fp->_cnt - (n = size) >= 0 && 379 (fp->_flag & _IOLBF) == 0) { 380 fp->_cnt -= n; 381 bcopy(t, (char *)fp->_ptr, n); 382 fp->_ptr += n; 383 } else 384 while (--n >= 0) 385 PUTC(*t++); 386 /* trailing f.p. zeroes */ 387 while (--fpprec >= 0) 388 PUTC('0'); 389 /* left-adjusting padding (always blank) */ 390 if (flags & LADJUST) 391 for (n = realsz; n < width; n++) 392 PUTC(' '); 393 /* finally, adjust cnt */ 394 cnt += width > realsz ? width : realsz; 395 break; 396 case '\0': /* "%?" prints ?, unless ? is NULL */ 397 return (cnt); 398 default: 399 PUTC((char)*fmt); 400 cnt++; 401 } 402 } 403 /* NOTREACHED */ 404 } 405 406 static 407 cvt(number, prec, flags, signp, fmtch, startp, endp) 408 double number; 409 register int prec; 410 int flags; 411 u_char fmtch; 412 char *signp, *startp, *endp; 413 { 414 register char *p, *t; 415 register double fract; 416 int dotrim, expcnt, gformat; 417 double integer, tmp, modf(); 418 char *exponent(), *round(); 419 420 dotrim = expcnt = gformat = 0; 421 fract = modf(number, &integer); 422 423 /* get an extra slot for rounding. */ 424 t = ++startp; 425 426 /* 427 * get integer portion of number; put into the end of the buffer; the 428 * .01 is added for modf(356.0 / 10, &integer) returning .59999999... 429 */ 430 for (p = endp - 1; integer; ++expcnt) { 431 tmp = modf(integer / 10, &integer); 432 *p-- = tochar((int)((tmp + .01) * 10)); 433 } 434 switch(fmtch) { 435 case 'f': 436 /* reverse integer into beginning of buffer */ 437 if (expcnt) 438 for (; ++p < endp; *t++ = *p); 439 else 440 *t++ = '0'; 441 /* 442 * if precision required or alternate flag set, add in a 443 * decimal point. 444 */ 445 if (prec || flags&ALT) 446 *t++ = '.'; 447 /* if requires more precision and some fraction left */ 448 if (fract) { 449 if (prec) 450 do { 451 fract = modf(fract * 10, &tmp); 452 *t++ = tochar((int)tmp); 453 } while (--prec && fract); 454 if (fract) 455 startp = round(fract, (int *)NULL, startp, 456 t - 1, (char)0, signp); 457 } 458 for (; prec--; *t++ = '0'); 459 break; 460 case 'e': 461 case 'E': 462 eformat: if (expcnt) { 463 *t++ = *++p; 464 if (prec || flags&ALT) 465 *t++ = '.'; 466 /* if requires more precision and some integer left */ 467 for (; prec && ++p < endp; --prec) 468 *t++ = *p; 469 /* 470 * if done precision and more of the integer component, 471 * round using it; adjust fract so we don't re-round 472 * later. 473 */ 474 if (!prec && ++p < endp) { 475 fract = 0; 476 startp = round((double)0, &expcnt, startp, 477 t - 1, *p, signp); 478 } 479 /* adjust expcnt for digit in front of decimal */ 480 --expcnt; 481 } 482 /* until first fractional digit, decrement exponent */ 483 else if (fract) { 484 /* adjust expcnt for digit in front of decimal */ 485 for (expcnt = -1;; --expcnt) { 486 fract = modf(fract * 10, &tmp); 487 if (tmp) 488 break; 489 } 490 *t++ = tochar((int)tmp); 491 if (prec || flags&ALT) 492 *t++ = '.'; 493 } 494 else { 495 *t++ = '0'; 496 if (prec || flags&ALT) 497 *t++ = '.'; 498 } 499 /* if requires more precision and some fraction left */ 500 if (fract) { 501 if (prec) 502 do { 503 fract = modf(fract * 10, &tmp); 504 *t++ = tochar((int)tmp); 505 } while (--prec && fract); 506 if (fract) 507 startp = round(fract, &expcnt, startp, 508 t - 1, (char)0, signp); 509 } 510 /* if requires more precision */ 511 for (; prec--; *t++ = '0'); 512 513 /* unless alternate flag, trim any g/G format trailing 0's */ 514 if (gformat && !(flags&ALT)) { 515 while (t > startp && *--t == '0'); 516 if (*t == '.') 517 --t; 518 ++t; 519 } 520 t = exponent(t, expcnt, fmtch); 521 break; 522 case 'g': 523 case 'G': 524 /* a precision of 0 is treated as a precision of 1. */ 525 if (!prec) 526 ++prec; 527 /* 528 * ``The style used depends on the value converted; style e 529 * will be used only if the exponent resulting from the 530 * conversion is less than -4 or greater than the precision.'' 531 * -- ANSI X3J11 532 */ 533 if (expcnt > prec || !expcnt && fract && fract < .0001) { 534 /* 535 * g/G format counts "significant digits, not digits of 536 * precision; for the e/E format, this just causes an 537 * off-by-one problem, i.e. g/G considers the digit 538 * before the decimal point significant and e/E doesn't 539 * count it as precision. 540 */ 541 --prec; 542 fmtch -= 2; /* G->E, g->e */ 543 gformat = 1; 544 goto eformat; 545 } 546 /* 547 * reverse integer into beginning of buffer, 548 * note, decrement precision 549 */ 550 if (expcnt) 551 for (; ++p < endp; *t++ = *p, --prec); 552 else 553 *t++ = '0'; 554 /* 555 * if precision required or alternate flag set, add in a 556 * decimal point. If no digits yet, add in leading 0. 557 */ 558 if (prec || flags&ALT) { 559 dotrim = 1; 560 *t++ = '.'; 561 } 562 else 563 dotrim = 0; 564 /* if requires more precision and some fraction left */ 565 if (fract) { 566 if (prec) { 567 do { 568 fract = modf(fract * 10, &tmp); 569 *t++ = tochar((int)tmp); 570 } while(!tmp); 571 while (--prec && fract) { 572 fract = modf(fract * 10, &tmp); 573 *t++ = tochar((int)tmp); 574 } 575 } 576 if (fract) 577 startp = round(fract, (int *)NULL, startp, 578 t - 1, (char)0, signp); 579 } 580 /* alternate format, adds 0's for precision, else trim 0's */ 581 if (flags&ALT) 582 for (; prec--; *t++ = '0'); 583 else if (dotrim) { 584 while (t > startp && *--t == '0'); 585 if (*t != '.') 586 ++t; 587 } 588 } 589 return(t - startp); 590 } 591 592 static char * 593 round(fract, exp, start, end, ch, signp) 594 double fract; 595 int *exp; 596 register char *start, *end; 597 char ch, *signp; 598 { 599 double tmp; 600 601 if (fract) 602 (void)modf(fract * 10, &tmp); 603 else 604 tmp = todigit(ch); 605 if (tmp > 4) 606 for (;; --end) { 607 if (*end == '.') 608 --end; 609 if (++*end <= '9') 610 break; 611 *end = '0'; 612 if (end == start) { 613 if (exp) { /* e/E; increment exponent */ 614 *end = '1'; 615 ++*exp; 616 } 617 else { /* f; add extra digit */ 618 *--end = '1'; 619 --start; 620 } 621 break; 622 } 623 } 624 /* ``"%.3f", (double)-0.0004'' gives you a negative 0. */ 625 else if (*signp == '-') 626 for (;; --end) { 627 if (*end == '.') 628 --end; 629 if (*end != '0') 630 break; 631 if (end == start) 632 *signp = 0; 633 } 634 return(start); 635 } 636 637 static char * 638 exponent(p, exp, fmtch) 639 register char *p; 640 register int exp; 641 u_char fmtch; 642 { 643 register char *t; 644 char expbuf[MAXEXP]; 645 646 *p++ = fmtch; 647 if (exp < 0) { 648 exp = -exp; 649 *p++ = '-'; 650 } 651 else 652 *p++ = '+'; 653 t = expbuf + MAXEXP; 654 if (exp > 9) { 655 do { 656 *--t = tochar(exp % 10); 657 } while ((exp /= 10) > 9); 658 *--t = tochar(exp); 659 for (; t < expbuf + MAXEXP; *p++ = *t++); 660 } 661 else { 662 *p++ = '0'; 663 *p++ = tochar(exp); 664 } 665 return(p); 666 } 667