openbsd-compat/bsd-snprintf.c

   1 /*
   2  * Copyright Patrick Powell 1995
   3  * This code is based on code written by Patrick Powell (papowell@astart.com)
   4  * It may be used for any purpose as long as this notice remains intact
   5  * on all source code distributions
   6  */
   7
   8 /**************************************************************
   9  * Original:
  10  * Patrick Powell Tue Apr 11 09:48:21 PDT 1995
  11  * A bombproof version of doprnt (dopr) included.
  12  * Sigh.  This sort of thing is always nasty do deal with.  Note that
  13  * the version here does not include floating point...
  14  *
  15  * snprintf() is used instead of sprintf() as it does limit checks
  16  * for string length.  This covers a nasty loophole.
  17  *
  18  * The other functions are there to prevent NULL pointers from
  19  * causing nast effects.
  20  *
  21  * More Recently:
  22  *  Brandon Long <blong@fiction.net> 9/15/96 for mutt 0.43
  23  *  This was ugly.  It is still ugly.  I opted out of floating point
  24  *  numbers, but the formatter understands just about everything
  25  *  from the normal C string format, at least as far as I can tell from
  26  *  the Solaris 2.5 printf(3S) man page.
  27  *
  28  *  Brandon Long <blong@fiction.net> 10/22/97 for mutt 0.87.1
  29  *    Ok, added some minimal floating point support, which means this
  30  *    probably requires libm on most operating systems.  Don't yet
  31  *    support the exponent (e,E) and sigfig (g,G).  Also, fmtint()
  32  *    was pretty badly broken, it just wasn't being exercised in ways
  33  *    which showed it, so that's been fixed.  Also, formated the code
  34  *    to mutt conventions, and removed dead code left over from the
  35  *    original.  Also, there is now a builtin-test, just compile with:
  36  *           gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
  37  *    and run snprintf for results.
  38  *
  39  *  Thomas Roessler <roessler@guug.de> 01/27/98 for mutt 0.89i
  40  *    The PGP code was using unsigned hexadecimal formats.
  41  *    Unfortunately, unsigned formats simply didn't work.
  42  *
  43  *  Michael Elkins <me@cs.hmc.edu> 03/05/98 for mutt 0.90.8
  44  *    The original code assumed that both snprintf() and vsnprintf() were
  45  *    missing.  Some systems only have snprintf() but not vsnprintf(), so
  46  *    the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
  47  *
  48  *  Ben Lindstrom <mouring@eviladmin.org> 09/27/00 for OpenSSH
  49  *    Welcome to the world of %lld and %qd support.  With other
  50  *    long long support.  This is needed for sftp-server to work
  51  *    right.
  52  *
  53  *  Ben Lindstrom <mouring@eviladmin.org> 02/12/01 for OpenSSH
  54  *    Removed all hint of VARARGS stuff and banished it to the void,
  55  *    and did a bit of KNF style work to make things a bit more
  56  *    acceptable.  Consider stealing from mutt or enlightenment.
  57  **************************************************************/
  58
  59 #include "includes.h"
  60
  61 RCSID("$Id: bsd-snprintf.c,v 1.9 2004/09/23 11:35:09 dtucker Exp $");
  62
  63 #if defined(BROKEN_SNPRINTF)            /* For those with broken snprintf() */
  64 # undef HAVE_SNPRINTF
  65 # undef HAVE_VSNPRINTF
  66 #endif
  67
  68 #if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF)
  69
  70 static void
  71 dopr(char *buffer, size_t maxlen, const char *format, va_list args);
  72
  73 static void
  74 fmtstr(char *buffer, size_t *currlen, size_t maxlen, char *value, int flags,
  75     int min, int max);
  76
  77 static void
  78 fmtint(char *buffer, size_t *currlen, size_t maxlen, long value, int base,
  79     int min, int max, int flags);
  80
  81 static void
  82 fmtfp(char *buffer, size_t *currlen, size_t maxlen, long double fvalue,
  83     int min, int max, int flags);
  84
  85 static void
  86 dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c);
  87
  88 /*
  89  * dopr(): poor man's version of doprintf
  90  */
  91
  92 /* format read states */
  93 #define DP_S_DEFAULT 0
  94 #define DP_S_FLAGS   1
  95 #define DP_S_MIN     2
  96 #define DP_S_DOT     3
  97 #define DP_S_MAX     4
  98 #define DP_S_MOD     5
  99 #define DP_S_CONV    6
 100 #define DP_S_DONE    7
 101
 102 /* format flags - Bits */
 103 #define DP_F_MINUS      (1 << 0)
 104 #define DP_F_PLUS       (1 << 1)
 105 #define DP_F_SPACE      (1 << 2)
 106 #define DP_F_NUM        (1 << 3)
 107 #define DP_F_ZERO       (1 << 4)
 108 #define DP_F_UP         (1 << 5)
 109 #define DP_F_UNSIGNED   (1 << 6)
 110
 111 /* Conversion Flags */
 112 #define DP_C_SHORT     1
 113 #define DP_C_LONG      2
 114 #define DP_C_LDOUBLE   3
 115 #define DP_C_LONG_LONG 4
 116
 117 #define char_to_int(p) (p - '0')
 118 #define abs_val(p) (p < 0 ? -p : p)
 119
 120
 121 static void
 122 dopr(char *buffer, size_t maxlen, const char *format, va_list args)
 123 {
 124         char *strvalue, ch;
 125         long value;
 126         long double fvalue;
 127         int min = 0, max = -1, state = DP_S_DEFAULT, flags = 0, cflags = 0;
 128         size_t currlen = 0;
 129
 130         ch = *format++;
 131
 132         while (state != DP_S_DONE) {
 133                 if ((ch == '\0') || (currlen >= maxlen))
 134                         state = DP_S_DONE;
 135
 136                 switch(state) {
 137                 case DP_S_DEFAULT:
 138                         if (ch == '%')
 139                                 state = DP_S_FLAGS;
 140                         else
 141                                 dopr_outch(buffer, &currlen, maxlen, ch);
 142                         ch = *format++;
 143                         break;
 144                 case DP_S_FLAGS:
 145                         switch (ch) {
 146                         case '-':
 147                                 flags |= DP_F_MINUS;
 148                                 ch = *format++;
 149                                 break;
 150                         case '+':
 151                                 flags |= DP_F_PLUS;
 152                                 ch = *format++;
 153                                 break;
 154                         case ' ':
 155                                 flags |= DP_F_SPACE;
 156                                 ch = *format++;
 157                                 break;
 158                         case '#':
 159                                 flags |= DP_F_NUM;
 160                                 ch = *format++;
 161                                 break;
 162                         case '0':
 163                                 flags |= DP_F_ZERO;
 164                                 ch = *format++;
 165                                 break;
 166                         default:
 167                                 state = DP_S_MIN;
 168                                 break;
 169                         }
 170                         break;
 171                 case DP_S_MIN:
 172                         if (isdigit((unsigned char)ch)) {
 173                                 min = 10 * min + char_to_int (ch);
 174                                 ch = *format++;
 175                         } else if (ch == '*') {
 176                                 min = va_arg (args, int);
 177                                 ch = *format++;
 178                                 state = DP_S_DOT;
 179                         } else
 180                                 state = DP_S_DOT;
 181                         break;
 182                 case DP_S_DOT:
 183                         if (ch == '.') {
 184                                 state = DP_S_MAX;
 185                                 ch = *format++;
 186                         } else
 187                                 state = DP_S_MOD;
 188                         break;
 189                 case DP_S_MAX:
 190                         if (isdigit((unsigned char)ch)) {
 191                                 if (max < 0)
 192                                         max = 0;
 193                                 max = 10 * max + char_to_int(ch);
 194                                 ch = *format++;
 195                         } else if (ch == '*') {
 196                                 max = va_arg (args, int);
 197                                 ch = *format++;
 198                                 state = DP_S_MOD;
 199                         } else
 200                                 state = DP_S_MOD;
 201                         break;
 202                 case DP_S_MOD:
 203                         switch (ch) {
 204                         case 'h':
 205                                 cflags = DP_C_SHORT;
 206                                 ch = *format++;
 207                                 break;
 208                         case 'l':
 209                                 cflags = DP_C_LONG;
 210                                 ch = *format++;
 211                                 if (ch == 'l') {
 212                                         cflags = DP_C_LONG_LONG;
 213                                         ch = *format++;
 214                                 }
 215                                 break;
 216                         case 'q':
 217                                 cflags = DP_C_LONG_LONG;
 218                                 ch = *format++;
 219                                 break;
 220                         case 'L':
 221                                 cflags = DP_C_LDOUBLE;
 222                                 ch = *format++;
 223                                 break;
 224                         default:
 225                                 break;
 226                         }
 227                         state = DP_S_CONV;
 228                         break;
 229                 case DP_S_CONV:
 230                         switch (ch) {
 231                         case 'd':
 232                         case 'i':
 233                                 if (cflags == DP_C_SHORT)
 234                                         value = va_arg(args, int);
 235                                 else if (cflags == DP_C_LONG)
 236                                         value = va_arg(args, long int);
 237                                 else if (cflags == DP_C_LONG_LONG)
 238                                         value = va_arg (args, long long);
 239                                 else
 240                                         value = va_arg (args, int);
 241                                 fmtint(buffer, &currlen, maxlen, value, 10, min, max, flags);
 242                                 break;
 243                         case 'o':
 244                                 flags |= DP_F_UNSIGNED;
 245                                 if (cflags == DP_C_SHORT)
 246                                         value = va_arg(args, unsigned int);
 247                                 else if (cflags == DP_C_LONG)
 248                                         value = va_arg(args, unsigned long int);
 249                                 else if (cflags == DP_C_LONG_LONG)
 250                                         value = va_arg(args, unsigned long long);
 251                                 else
 252                                         value = va_arg(args, unsigned int);
 253                                 fmtint(buffer, &currlen, maxlen, value, 8, min, max, flags);
 254                                 break;
 255                         case 'u':
 256                                 flags |= DP_F_UNSIGNED;
 257                                 if (cflags == DP_C_SHORT)
 258                                         value = va_arg(args, unsigned int);
 259                                 else if (cflags == DP_C_LONG)
 260                                         value = va_arg(args, unsigned long int);
 261                                 else if (cflags == DP_C_LONG_LONG)
 262                                         value = va_arg(args, unsigned long long);
 263                                 else
 264                                         value = va_arg(args, unsigned int);
 265                                 fmtint (buffer, &currlen, maxlen, value, 10, min, max, flags);
 266                                 break;
 267                         case 'X':
 268                                 flags |= DP_F_UP;
 269                         case 'x':
 270                                 flags |= DP_F_UNSIGNED;
 271                                 if (cflags == DP_C_SHORT)
 272                                         value = va_arg(args, unsigned int);
 273                                 else if (cflags == DP_C_LONG)
 274                                         value = va_arg(args, unsigned long int);
 275                                 else if (cflags == DP_C_LONG_LONG)
 276                                         value = va_arg(args, unsigned long long);
 277                                 else
 278                                         value = va_arg(args, unsigned int);
 279                                 fmtint(buffer, &currlen, maxlen, value, 16, min, max, flags);
 280                                 break;
 281                         case 'f':
 282                                 if (cflags == DP_C_LDOUBLE)
 283                                         fvalue = va_arg(args, long double);
 284                                 else
 285                                         fvalue = va_arg(args, double);
 286                                 /* um, floating point? */
 287                                 fmtfp(buffer, &currlen, maxlen, fvalue, min, max, flags);
 288                                 break;
 289                         case 'E':
 290                                 flags |= DP_F_UP;
 291                         case 'e':
 292                                 if (cflags == DP_C_LDOUBLE)
 293                                         fvalue = va_arg(args, long double);
 294                                 else
 295                                         fvalue = va_arg(args, double);
 296                                 break;
 297                         case 'G':
 298                                 flags |= DP_F_UP;
 299                         case 'g':
 300                                 if (cflags == DP_C_LDOUBLE)
 301                                         fvalue = va_arg(args, long double);
 302                                 else
 303                                         fvalue = va_arg(args, double);
 304                                 break;
 305                         case 'c':
 306                                 dopr_outch(buffer, &currlen, maxlen, va_arg(args, int));
 307                                 break;
 308                         case 's':
 309                                 strvalue = va_arg(args, char *);
 310                                 if (max < 0)
 311                                         max = maxlen; /* ie, no max */
 312                                 fmtstr(buffer, &currlen, maxlen, strvalue, flags, min, max);
 313                                 break;
 314                         case 'p':
 315                                 strvalue = va_arg(args, void *);
 316                                 fmtint(buffer, &currlen, maxlen, (long) strvalue, 16, min, max, flags);
 317                                 break;
 318                         case 'n':
 319                                 if (cflags == DP_C_SHORT) {
 320                                         short int *num;
 321                                         num = va_arg(args, short int *);
 322                                         *num = currlen;
 323                                 } else if (cflags == DP_C_LONG) {
 324                                         long int *num;
 325                                         num = va_arg(args, long int *);
 326                                         *num = currlen;
 327                                 } else if (cflags == DP_C_LONG_LONG) {
 328                                         long long *num;
 329                                         num = va_arg(args, long long *);
 330                                         *num = currlen;
 331                                 } else {
 332                                         int *num;
 333                                         num = va_arg(args, int *);
 334                                         *num = currlen;
 335                                 }
 336                                 break;
 337                         case '%':
 338                                 dopr_outch(buffer, &currlen, maxlen, ch);
 339                                 break;
 340                         case 'w': /* not supported yet, treat as next char */
 341                                 ch = *format++;
 342                                 break;
 343                         default: /* Unknown, skip */
 344                         break;
 345                         }
 346                         ch = *format++;
 347                         state = DP_S_DEFAULT;
 348                         flags = cflags = min = 0;
 349                         max = -1;
 350                         break;
 351                 case DP_S_DONE:
 352                         break;
 353                 default: /* hmm? */
 354                         break; /* some picky compilers need this */
 355                 }
 356         }
 357         if (currlen < maxlen - 1)
 358                 buffer[currlen] = '\0';
 359         else
 360                 buffer[maxlen - 1] = '\0';
 361 }
 362
 363 static void
 364 fmtstr(char *buffer, size_t *currlen, size_t maxlen,
 365     char *value, int flags, int min, int max)
 366 {
 367         int cnt = 0, padlen, strln;     /* amount to pad */
 368
 369         if (value == 0)
 370                 value = "<NULL>";
 371
 372         for (strln = 0; strln < max && value[strln]; ++strln); /* strlen */
 373         padlen = min - strln;
 374         if (padlen < 0)
 375                 padlen = 0;
 376         if (flags & DP_F_MINUS)
 377                 padlen = -padlen; /* Left Justify */
 378
 379         while ((padlen > 0) && (cnt < max)) {
 380                 dopr_outch(buffer, currlen, maxlen, ' ');
 381                 --padlen;
 382                 ++cnt;
 383         }
 384         while (*value && (cnt < max)) {
 385                 dopr_outch(buffer, currlen, maxlen, *value++);
 386                 ++cnt;
 387         }
 388         while ((padlen < 0) && (cnt < max)) {
 389                 dopr_outch(buffer, currlen, maxlen, ' ');
 390                 ++padlen;
 391                 ++cnt;
 392         }
 393 }
 394
 395 /* Have to handle DP_F_NUM (ie 0x and 0 alternates) */
 396
 397 static void
 398 fmtint(char *buffer, size_t *currlen, size_t maxlen,
 399     long value, int base, int min, int max, int flags)
 400 {
 401         unsigned long uvalue;
 402         char convert[20];
 403         int signvalue = 0, place = 0, caps = 0;
 404         int spadlen = 0; /* amount to space pad */
 405         int zpadlen = 0; /* amount to zero pad */
 406
 407         if (max < 0)
 408                 max = 0;
 409
 410         uvalue = value;
 411
 412         if (!(flags & DP_F_UNSIGNED)) {
 413                 if (value < 0) {
 414                         signvalue = '-';
 415                         uvalue = -value;
 416                 } else if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
 417                         signvalue = '+';
 418                 else if (flags & DP_F_SPACE)
 419                         signvalue = ' ';
 420         }
 421
 422         if (flags & DP_F_UP)
 423                 caps = 1; /* Should characters be upper case? */
 424         do {
 425                 convert[place++] =
 426                     (caps ? "0123456789ABCDEF" : "0123456789abcdef")
 427                     [uvalue % (unsigned)base];
 428                 uvalue = (uvalue / (unsigned)base );
 429         } while (uvalue && (place < 20));
 430         if (place == 20)
 431                 place--;
 432         convert[place] = 0;
 433
 434         zpadlen = max - place;
 435         spadlen = min - MAX (max, place) - (signvalue ? 1 : 0);
 436         if (zpadlen < 0)
 437                 zpadlen = 0;
 438         if (spadlen < 0)
 439                 spadlen = 0;
 440         if (flags & DP_F_ZERO) {
 441                 zpadlen = MAX(zpadlen, spadlen);
 442                 spadlen = 0;
 443         }
 444         if (flags & DP_F_MINUS)
 445                 spadlen = -spadlen; /* Left Justifty */
 446
 447         /* Spaces */
 448         while (spadlen > 0) {
 449                 dopr_outch(buffer, currlen, maxlen, ' ');
 450                 --spadlen;
 451         }
 452
 453         /* Sign */
 454         if (signvalue)
 455                 dopr_outch(buffer, currlen, maxlen, signvalue);
 456
 457         /* Zeros */
 458         if (zpadlen > 0) {
 459                 while (zpadlen > 0) {
 460                         dopr_outch(buffer, currlen, maxlen, '0');
 461                         --zpadlen;
 462                 }
 463         }
 464
 465         /* Digits */
 466         while (place > 0)
 467                 dopr_outch(buffer, currlen, maxlen, convert[--place]);
 468
 469         /* Left Justified spaces */
 470         while (spadlen < 0) {
 471                 dopr_outch (buffer, currlen, maxlen, ' ');
 472                 ++spadlen;
 473         }
 474 }
 475
 476 static long double
 477 pow10(int exp)
 478 {
 479         long double result = 1;
 480
 481         while (exp) {
 482                 result *= 10;
 483                 exp--;
 484         }
 485
 486         return result;
 487 }
 488
 489 static long
 490 round(long double value)
 491 {
 492         long intpart = value;
 493
 494         value -= intpart;
 495         if (value >= 0.5)
 496                 intpart++;
 497
 498         return intpart;
 499 }
 500
 501 static void
 502 fmtfp(char *buffer, size_t *currlen, size_t maxlen, long double fvalue,
 503       int min, int max, int flags)
 504 {
 505         char iconvert[20], fconvert[20];
 506         int signvalue = 0, iplace = 0, fplace = 0;
 507         int padlen = 0; /* amount to pad */
 508         int zpadlen = 0, caps = 0;
 509         long intpart, fracpart;
 510         long double ufvalue;
 511
 512         /*
 513          * AIX manpage says the default is 0, but Solaris says the default
 514          * is 6, and sprintf on AIX defaults to 6
 515          */
 516         if (max < 0)
 517                 max = 6;
 518
 519         ufvalue = abs_val(fvalue);
 520
 521         if (fvalue < 0)
 522                 signvalue = '-';
 523         else if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
 524                 signvalue = '+';
 525         else if (flags & DP_F_SPACE)
 526                 signvalue = ' ';
 527
 528         intpart = ufvalue;
 529
 530         /*
 531          * Sorry, we only support 9 digits past the decimal because of our
 532          * conversion method
 533          */
 534         if (max > 9)
 535                 max = 9;
 536
 537         /* We "cheat" by converting the fractional part to integer by
 538          * multiplying by a factor of 10
 539          */
 540         fracpart = round((pow10 (max)) * (ufvalue - intpart));
 541
 542         if (fracpart >= pow10 (max)) {
 543                 intpart++;
 544                 fracpart -= pow10 (max);
 545         }
 546
 547         /* Convert integer part */
 548         do {
 549                 iconvert[iplace++] =
 550                     (caps ? "0123456789ABCDEF" : "0123456789abcdef")
 551                     [intpart % 10];
 552                 intpart = (intpart / 10);
 553         } while(intpart && (iplace < 20));
 554         if (iplace == 20)
 555                 iplace--;
 556         iconvert[iplace] = 0;
 557
 558         /* Convert fractional part */
 559         do {
 560                 fconvert[fplace++] =
 561                     (caps ? "0123456789ABCDEF" : "0123456789abcdef")
 562                     [fracpart % 10];
 563                 fracpart = (fracpart / 10);
 564         } while(fracpart && (fplace < 20));
 565         if (fplace == 20)
 566                 fplace--;
 567         fconvert[fplace] = 0;
 568
 569         /* -1 for decimal point, another -1 if we are printing a sign */
 570         padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0);
 571         zpadlen = max - fplace;
 572         if (zpadlen < 0)
 573                 zpadlen = 0;
 574         if (padlen < 0)
 575                 padlen = 0;
 576         if (flags & DP_F_MINUS)
 577                 padlen = -padlen; /* Left Justifty */
 578
 579         if ((flags & DP_F_ZERO) && (padlen > 0)) {
 580                 if (signvalue) {
 581                         dopr_outch(buffer, currlen, maxlen, signvalue);
 582                         --padlen;
 583                         signvalue = 0;
 584                 }
 585                 while (padlen > 0) {
 586                         dopr_outch(buffer, currlen, maxlen, '0');
 587                         --padlen;
 588                 }
 589         }
 590         while (padlen > 0) {
 591                 dopr_outch(buffer, currlen, maxlen, ' ');
 592                 --padlen;
 593         }
 594         if (signvalue)
 595                 dopr_outch(buffer, currlen, maxlen, signvalue);
 596
 597         while (iplace > 0)
 598                 dopr_outch(buffer, currlen, maxlen, iconvert[--iplace]);
 599
 600         /*
 601          * Decimal point.  This should probably use locale to find the
 602          * correct char to print out.
 603          */
 604         dopr_outch(buffer, currlen, maxlen, '.');
 605
 606         while (fplace > 0)
 607                 dopr_outch(buffer, currlen, maxlen, fconvert[--fplace]);
 608
 609         while (zpadlen > 0) {
 610                 dopr_outch(buffer, currlen, maxlen, '0');
 611                 --zpadlen;
 612         }
 613
 614         while (padlen < 0) {
 615                 dopr_outch(buffer, currlen, maxlen, ' ');
 616                 ++padlen;
 617         }
 618 }
 619
 620 static void
 621 dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c)
 622 {
 623         if (*currlen < maxlen)
 624                 buffer[(*currlen)++] = c;
 625 }
 626 #endif /* !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF) */
 627
 628 #ifndef HAVE_VSNPRINTF
 629 int
 630 vsnprintf(char *str, size_t count, const char *fmt, va_list args)
 631 {
 632         str[0] = 0;
 633         dopr(str, count, fmt, args);
 634
 635         return(strlen(str));
 636 }
 637 #endif /* !HAVE_VSNPRINTF */
 638
 639 #ifndef HAVE_SNPRINTF
 640 int
 641 snprintf(char *str,size_t count,const char *fmt,...)
 642 {
 643         va_list ap;
 644
 645         va_start(ap, fmt);
 646         (void) vsnprintf(str, count, fmt, ap);
 647         va_end(ap);
 648
 649         return(strlen(str));
 650 }
 651
 652 #endif /* !HAVE_SNPRINTF */