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