lib/roken/snprintf.c

   1 /*
   2  * Copyright (c) 1995-2002 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  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  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 RCSID("$Id$");
  37 #endif
  38 #include <stdio.h>
  39 #include <stdarg.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <ctype.h>
  43 #include <roken.h>
  44
  45 enum format_flags {
  46     minus_flag     =  1,
  47     plus_flag      =  2,
  48     space_flag     =  4,
  49     alternate_flag =  8,
  50     zero_flag      = 16
  51 };
  52
  53 /*
  54  * Common state
  55  */
  56
  57 struct snprintf_state {
  58   unsigned char *str;
  59   unsigned char *s;
  60   unsigned char *theend;
  61   size_t sz;
  62   size_t max_sz;
  63   void (*append_char)(struct snprintf_state *, unsigned char);
  64   /* XXX - methods */
  65 };
  66
  67 #if TEST_SNPRINTF
  68 #include "snprintf-test.h"
  69 #endif /* TEST_SNPRINTF */
  70
  71 #if !defined(HAVE_VSNPRINTF) || defined(TEST_SNPRINTF)
  72 static int
  73 sn_reserve (struct snprintf_state *state, size_t n)
  74 {
  75   return state->s + n > state->theend;
  76 }
  77
  78 static void
  79 sn_append_char (struct snprintf_state *state, unsigned char c)
  80 {
  81   if (!sn_reserve (state, 1))
  82     *state->s++ = c;
  83 }
  84 #endif
  85
  86 static int
  87 as_reserve (struct snprintf_state *state, size_t n)
  88 {
  89   if (state->s + n > state->theend) {
  90     int off = state->s - state->str;
  91     unsigned char *tmp;
  92
  93     if (state->max_sz && state->sz >= state->max_sz)
  94       return 1;
  95
  96     state->sz = max(state->sz * 2, state->sz + n);
  97     if (state->max_sz)
  98       state->sz = min(state->sz, state->max_sz);
  99     tmp = realloc (state->str, state->sz);
 100     if (tmp == NULL)
 101       return 1;
 102     state->str = tmp;
 103     state->s = state->str + off;
 104     state->theend = state->str + state->sz - 1;
 105   }
 106   return 0;
 107 }
 108
 109 static void
 110 as_append_char (struct snprintf_state *state, unsigned char c)
 111 {
 112   if(!as_reserve (state, 1))
 113     *state->s++ = c;
 114 }
 115
 116 /* longest integer types */
 117
 118 #ifdef HAVE_LONG_LONG
 119 typedef unsigned long long u_longest;
 120 typedef long long longest;
 121 #else
 122 typedef unsigned long u_longest;
 123 typedef long longest;
 124 #endif
 125
 126 /*
 127  * is # supposed to do anything?
 128  */
 129
 130 static int
 131 use_alternative (int flags, u_longest num, unsigned base)
 132 {
 133   return flags & alternate_flag && (base == 16 || base == 8) && num != 0;
 134 }
 135
 136 static int
 137 append_number(struct snprintf_state *state,
 138               u_longest num, unsigned base, const char *rep,
 139               int width, int prec, int flags, int minusp)
 140 {
 141   int len = 0;
 142   int i;
 143   u_longest n = num;
 144
 145   /* given precision, ignore zero flag */
 146   if(prec != -1)
 147     flags &= ~zero_flag;
 148   else
 149     prec = 1;
 150   /* zero value with zero precision -> "" */
 151   if(prec == 0 && n == 0)
 152     return 0;
 153   do{
 154     (*state->append_char)(state, rep[n % base]);
 155     ++len;
 156     n /= base;
 157   } while(n);
 158   prec -= len;
 159   /* pad with prec zeros */
 160   while(prec-- > 0){
 161     (*state->append_char)(state, '0');
 162     ++len;
 163   }
 164   /* add length of alternate prefix (added later) to len */
 165   if(use_alternative(flags, num, base))
 166     len += base / 8;
 167   /* pad with zeros */
 168   if(flags & zero_flag){
 169     width -= len;
 170     if(minusp || (flags & space_flag) || (flags & plus_flag))
 171       width--;
 172     while(width-- > 0){
 173       (*state->append_char)(state, '0');
 174       len++;
 175     }
 176   }
 177   /* add alternate prefix */
 178   if(use_alternative(flags, num, base)){
 179     if(base == 16)
 180       (*state->append_char)(state, rep[10] + 23); /* XXX */
 181     (*state->append_char)(state, '0');
 182   }
 183   /* add sign */
 184   if(minusp){
 185     (*state->append_char)(state, '-');
 186     ++len;
 187   } else if(flags & plus_flag) {
 188     (*state->append_char)(state, '+');
 189     ++len;
 190   } else if(flags & space_flag) {
 191     (*state->append_char)(state, ' ');
 192     ++len;
 193   }
 194   if(flags & minus_flag)
 195     /* swap before padding with spaces */
 196     for(i = 0; i < len / 2; i++){
 197       char c = state->s[-i-1];
 198       state->s[-i-1] = state->s[-len+i];
 199       state->s[-len+i] = c;
 200     }
 201   width -= len;
 202   while(width-- > 0){
 203     (*state->append_char)(state,  ' ');
 204     ++len;
 205   }
 206   if(!(flags & minus_flag))
 207     /* swap after padding with spaces */
 208     for(i = 0; i < len / 2; i++){
 209       char c = state->s[-i-1];
 210       state->s[-i-1] = state->s[-len+i];
 211       state->s[-len+i] = c;
 212     }
 213   return len;
 214 }
 215
 216 /*
 217  * return length
 218  */
 219
 220 static int
 221 append_string (struct snprintf_state *state,
 222                const unsigned char *arg,
 223                int width,
 224                int prec,
 225                int flags)
 226 {
 227     int len = 0;
 228
 229     if(arg == NULL)
 230         arg = (const unsigned char*)"(null)";
 231
 232     if(prec != -1)
 233         width -= prec;
 234     else
 235         width -= strlen((const char *)arg);
 236     if(!(flags & minus_flag))
 237         while(width-- > 0) {
 238             (*state->append_char) (state, ' ');
 239             ++len;
 240         }
 241     if (prec != -1) {
 242         while (*arg && prec--) {
 243             (*state->append_char) (state, *arg++);
 244             ++len;
 245         }
 246     } else {
 247         while (*arg) {
 248             (*state->append_char) (state, *arg++);
 249             ++len;
 250         }
 251     }
 252     if(flags & minus_flag)
 253         while(width-- > 0) {
 254             (*state->append_char) (state, ' ');
 255             ++len;
 256         }
 257     return len;
 258 }
 259
 260 static int
 261 append_char(struct snprintf_state *state,
 262             unsigned char arg,
 263             int width,
 264             int flags)
 265 {
 266   int len = 0;
 267
 268   while(!(flags & minus_flag) && --width > 0) {
 269     (*state->append_char) (state, ' ')    ;
 270     ++len;
 271   }
 272   (*state->append_char) (state, arg);
 273   ++len;
 274   while((flags & minus_flag) && --width > 0) {
 275     (*state->append_char) (state, ' ');
 276     ++len;
 277   }
 278   return 0;
 279 }
 280
 281 /*
 282  * This can't be made into a function...
 283  */
 284
 285 #ifdef HAVE_LONG_LONG
 286
 287 #define PARSE_INT_FORMAT(res, arg, unsig) \
 288 if (long_long_flag) \
 289      res = (unsig long long)va_arg(arg, unsig long long); \
 290 else if (long_flag) \
 291      res = (unsig long)va_arg(arg, unsig long); \
 292 else if (short_flag) \
 293      res = (unsig short)va_arg(arg, unsig int); \
 294 else \
 295      res = (unsig int)va_arg(arg, unsig int)
 296
 297 #else
 298
 299 #define PARSE_INT_FORMAT(res, arg, unsig) \
 300 if (long_flag) \
 301      res = (unsig long)va_arg(arg, unsig long); \
 302 else if (short_flag) \
 303      res = (unsig short)va_arg(arg, unsig int); \
 304 else \
 305      res = (unsig int)va_arg(arg, unsig int)
 306
 307 #endif
 308
 309 /*
 310  * zyxprintf - return length, as snprintf
 311  */
 312
 313 static int
 314 xyzprintf (struct snprintf_state *state, const char *char_format, va_list ap)
 315 {
 316   const unsigned char *format = (const unsigned char *)char_format;
 317   unsigned char c;
 318   int len = 0;
 319
 320   while((c = *format++)) {
 321     if (c == '%') {
 322       int flags          = 0;
 323       int width          = 0;
 324       int prec           = -1;
 325       int long_long_flag = 0;
 326       int long_flag      = 0;
 327       int short_flag     = 0;
 328
 329       /* flags */
 330       while((c = *format++)){
 331         if(c == '-')
 332           flags |= minus_flag;
 333         else if(c == '+')
 334           flags |= plus_flag;
 335         else if(c == ' ')
 336           flags |= space_flag;
 337         else if(c == '#')
 338           flags |= alternate_flag;
 339         else if(c == '0')
 340           flags |= zero_flag;
 341         else
 342           break;
 343       }
 344
 345       if((flags & space_flag) && (flags & plus_flag))
 346         flags ^= space_flag;
 347
 348       if((flags & minus_flag) && (flags & zero_flag))
 349         flags ^= zero_flag;
 350
 351       /* width */
 352       if (isdigit(c))
 353         do {
 354           width = width * 10 + c - '0';
 355           c = *format++;
 356         } while(isdigit(c));
 357       else if(c == '*') {
 358         width = va_arg(ap, int);
 359         c = *format++;
 360       }
 361
 362       /* precision */
 363       if (c == '.') {
 364         prec = 0;
 365         c = *format++;
 366         if (isdigit(c))
 367           do {
 368             prec = prec * 10 + c - '0';
 369             c = *format++;
 370           } while(isdigit(c));
 371         else if (c == '*') {
 372           prec = va_arg(ap, int);
 373           c = *format++;
 374         }
 375       }
 376
 377       /* size */
 378
 379       if (c == 'h') {
 380         short_flag = 1;
 381         c = *format++;
 382       } else if (c == 'l') {
 383         long_flag = 1;
 384         c = *format++;
 385         if (c == 'l') {
 386             long_long_flag = 1;
 387             c = *format++;
 388         }
 389       }
 390
 391       switch (c) {
 392       case 'c' :
 393         append_char(state, va_arg(ap, int), width, flags);
 394         ++len;
 395         break;
 396       case 's' :
 397         len += append_string(state,
 398                              va_arg(ap, unsigned char*),
 399                              width,
 400                              prec,
 401                              flags);
 402         break;
 403       case 'd' :
 404       case 'i' : {
 405         longest arg;
 406         u_longest num;
 407         int minusp = 0;
 408
 409         PARSE_INT_FORMAT(arg, ap, signed);
 410
 411         if (arg < 0) {
 412           minusp = 1;
 413           num = -arg;
 414         } else
 415           num = arg;
 416
 417         len += append_number (state, num, 10, "0123456789",
 418                               width, prec, flags, minusp);
 419         break;
 420       }
 421       case 'u' : {
 422         u_longest arg;
 423
 424         PARSE_INT_FORMAT(arg, ap, unsigned);
 425
 426         len += append_number (state, arg, 10, "0123456789",
 427                               width, prec, flags, 0);
 428         break;
 429       }
 430       case 'o' : {
 431         u_longest arg;
 432
 433         PARSE_INT_FORMAT(arg, ap, unsigned);
 434
 435         len += append_number (state, arg, 010, "01234567",
 436                               width, prec, flags, 0);
 437         break;
 438       }
 439       case 'x' : {
 440         u_longest arg;
 441
 442         PARSE_INT_FORMAT(arg, ap, unsigned);
 443
 444         len += append_number (state, arg, 0x10, "0123456789abcdef",
 445                               width, prec, flags, 0);
 446         break;
 447       }
 448       case 'X' :{
 449         u_longest arg;
 450
 451         PARSE_INT_FORMAT(arg, ap, unsigned);
 452
 453         len += append_number (state, arg, 0x10, "0123456789ABCDEF",
 454                               width, prec, flags, 0);
 455         break;
 456       }
 457       case 'p' : {
 458         unsigned long arg = (unsigned long)va_arg(ap, void*);
 459
 460         len += append_number (state, arg, 0x10, "0123456789ABCDEF",
 461                               width, prec, flags, 0);
 462         break;
 463       }
 464       case 'n' : {
 465         int *arg = va_arg(ap, int*);
 466         *arg = state->s - state->str;
 467         break;
 468       }
 469       case '\0' :
 470           --format;
 471           /* FALLTHROUGH */
 472       case '%' :
 473         (*state->append_char)(state, c);
 474         ++len;
 475         break;
 476       default :
 477         (*state->append_char)(state, '%');
 478         (*state->append_char)(state, c);
 479         len += 2;
 480         break;
 481       }
 482     } else {
 483       (*state->append_char) (state, c);
 484       ++len;
 485     }
 486   }
 487   return len;
 488 }
 489
 490 #if !defined(HAVE_SNPRINTF) || defined(TEST_SNPRINTF)
 491 int
 492 snprintf (char *str, size_t sz, const char *format, ...)
 493 {
 494   va_list args;
 495   int ret;
 496
 497   va_start(args, format);
 498   ret = vsnprintf (str, sz, format, args);
 499   va_end(args);
 500
 501 #ifdef PARANOIA
 502   {
 503     int ret2;
 504     char *tmp;
 505
 506     tmp = malloc (sz);
 507     if (tmp == NULL)
 508       abort ();
 509
 510     va_start(args, format);
 511     ret2 = vsprintf (tmp, format, args);
 512     va_end(args);
 513     if (ret != ret2 || strcmp(str, tmp))
 514       abort ();
 515     free (tmp);
 516   }
 517 #endif
 518
 519   return ret;
 520 }
 521 #endif
 522
 523 #if !defined(HAVE_ASPRINTF) || defined(TEST_SNPRINTF)
 524 int
 525 asprintf (char **ret, const char *format, ...)
 526 {
 527   va_list args;
 528   int val;
 529
 530   va_start(args, format);
 531   val = vasprintf (ret, format, args);
 532   va_end(args);
 533
 534 #ifdef PARANOIA
 535   {
 536     int ret2;
 537     char *tmp;
 538     tmp = malloc (val + 1);
 539     if (tmp == NULL)
 540       abort ();
 541
 542     va_start(args, format);
 543     ret2 = vsprintf (tmp, format, args);
 544     va_end(args);
 545     if (val != ret2 || strcmp(*ret, tmp))
 546       abort ();
 547     free (tmp);
 548   }
 549 #endif
 550
 551   return val;
 552 }
 553 #endif
 554
 555 #if !defined(HAVE_ASNPRINTF) || defined(TEST_SNPRINTF)
 556 int
 557 asnprintf (char **ret, size_t max_sz, const char *format, ...)
 558 {
 559   va_list args;
 560   int val;
 561
 562   va_start(args, format);
 563   val = vasnprintf (ret, max_sz, format, args);
 564
 565 #ifdef PARANOIA
 566   {
 567     int ret2;
 568     char *tmp;
 569     tmp = malloc (val + 1);
 570     if (tmp == NULL)
 571       abort ();
 572
 573     ret2 = vsprintf (tmp, format, args);
 574     if (val != ret2 || strcmp(*ret, tmp))
 575       abort ();
 576     free (tmp);
 577   }
 578 #endif
 579
 580   va_end(args);
 581   return val;
 582 }
 583 #endif
 584
 585 #if !defined(HAVE_VASPRINTF) || defined(TEST_SNPRINTF)
 586 int
 587 vasprintf (char **ret, const char *format, va_list args)
 588 {
 589   return vasnprintf (ret, 0, format, args);
 590 }
 591 #endif
 592
 593
 594 #if !defined(HAVE_VASNPRINTF) || defined(TEST_SNPRINTF)
 595 int
 596 vasnprintf (char **ret, size_t max_sz, const char *format, va_list args)
 597 {
 598   int st;
 599   struct snprintf_state state;
 600
 601   state.max_sz = max_sz;
 602   state.sz     = 1;
 603   state.str    = malloc(state.sz);
 604   if (state.str == NULL) {
 605     *ret = NULL;
 606     return -1;
 607   }
 608   state.s = state.str;
 609   state.theend = state.s + state.sz - 1;
 610   state.append_char = as_append_char;
 611
 612   st = xyzprintf (&state, format, args);
 613   if (st > state.sz) {
 614     free (state.str);
 615     *ret = NULL;
 616     return -1;
 617   } else {
 618     char *tmp;
 619
 620     *state.s = '\0';
 621     tmp = realloc (state.str, st+1);
 622     if (tmp == NULL) {
 623       free (state.str);
 624       *ret = NULL;
 625       return -1;
 626     }
 627     *ret = tmp;
 628     return st;
 629   }
 630 }
 631 #endif
 632
 633 #if !defined(HAVE_VSNPRINTF) || defined(TEST_SNPRINTF)
 634 int
 635 vsnprintf (char *str, size_t sz, const char *format, va_list args)
 636 {
 637   struct snprintf_state state;
 638   int ret;
 639   unsigned char *ustr = (unsigned char *)str;
 640
 641   state.max_sz = 0;
 642   state.sz     = sz;
 643   state.str    = ustr;
 644   state.s      = ustr;
 645   state.theend = ustr + sz - (sz > 0);
 646   state.append_char = sn_append_char;
 647
 648   ret = xyzprintf (&state, format, args);
 649   if (state.s != NULL)
 650     *state.s = '\0';
 651   return ret;
 652 }
 653 #endif