lib/vsprintf.c

   1 /*
   2  *  linux/lib/vsprintf.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
   8 /*
   9  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  10  */
  11
  12 /*
  13  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  14  * - changed to provide snprintf and vsnprintf functions
  15  */
  16
  17 #include <stdarg.h>
  18 #include <linux/types.h>
  19 #include <linux/string.h>
  20 #include <linux/ctype.h>
  21 #include <linux/kernel.h>
  22
  23 #include <asm/div64.h>
  24
  25 /**
  26  * simple_strtoul - convert a string to an unsigned long
  27  * @cp: The start of the string
  28  * @endp: A pointer to the end of the parsed string will be placed here
  29  * @base: The number base to use
  30  */
  31 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
  32 {
  33         unsigned long result = 0,value;
  34
  35         if (!base) {
  36                 base = 10;
  37                 if (*cp == '0') {
  38                         base = 8;
  39                         cp++;
  40                         if ((*cp == 'x') && isxdigit(cp[1])) {
  41                                 cp++;
  42                                 base = 16;
  43                         }
  44                 }
  45         }
  46         while (isxdigit(*cp) &&
  47                (value = isdigit(*cp) ? *cp-'0' : toupper(*cp)-'A'+10) < base) {
  48                 result = result*base + value;
  49                 cp++;
  50         }
  51         if (endp)
  52                 *endp = (char *)cp;
  53         return result;
  54 }
  55
  56 /**
  57  * simple_strtol - convert a string to a signed long
  58  * @cp: The start of the string
  59  * @endp: A pointer to the end of the parsed string will be placed here
  60  * @base: The number base to use
  61  */
  62 long simple_strtol(const char *cp,char **endp,unsigned int base)
  63 {
  64         if(*cp=='-')
  65                 return -simple_strtoul(cp+1,endp,base);
  66         return simple_strtoul(cp,endp,base);
  67 }
  68
  69 /**
  70  * simple_strtoull - convert a string to an unsigned long long
  71  * @cp: The start of the string
  72  * @endp: A pointer to the end of the parsed string will be placed here
  73  * @base: The number base to use
  74  */
  75 unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
  76 {
  77         unsigned long long result = 0,value;
  78
  79         if (!base) {
  80                 base = 10;
  81                 if (*cp == '0') {
  82                         base = 8;
  83                         cp++;
  84                         if ((*cp == 'x') && isxdigit(cp[1])) {
  85                                 cp++;
  86                                 base = 16;
  87                         }
  88                 }
  89         }
  90         while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
  91             ? toupper(*cp) : *cp)-'A'+10) < base) {
  92                 result = result*base + value;
  93                 cp++;
  94         }
  95         if (endp)
  96                 *endp = (char *)cp;
  97         return result;
  98 }
  99
 100 /**
 101  * simple_strtoll - convert a string to a signed long long
 102  * @cp: The start of the string
 103  * @endp: A pointer to the end of the parsed string will be placed here
 104  * @base: The number base to use
 105  */
 106 long long simple_strtoll(const char *cp,char **endp,unsigned int base)
 107 {
 108         if(*cp=='-')
 109                 return -simple_strtoull(cp+1,endp,base);
 110         return simple_strtoull(cp,endp,base);
 111 }
 112
 113 static int skip_atoi(const char **s)
 114 {
 115         int i=0;
 116
 117         while (isdigit(**s))
 118                 i = i*10 + *((*s)++) - '0';
 119         return i;
 120 }
 121
 122 #define ZEROPAD 1               /* pad with zero */
 123 #define SIGN    2               /* unsigned/signed long */
 124 #define PLUS    4               /* show plus */
 125 #define SPACE   8               /* space if plus */
 126 #define LEFT    16              /* left justified */
 127 #define SPECIAL 32              /* 0x */
 128 #define LARGE   64              /* use 'ABCDEF' instead of 'abcdef' */
 129
 130 static char * number(char * buf, char * end, long long num, int base, int size, int precision, int type)
 131 {
 132         char c,sign,tmp[66];
 133         const char *digits;
 134         static const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
 135         static const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 136         int i;
 137
 138         digits = (type & LARGE) ? large_digits : small_digits;
 139         if (type & LEFT)
 140                 type &= ~ZEROPAD;
 141         if (base < 2 || base > 36)
 142                 return 0;
 143         c = (type & ZEROPAD) ? '0' : ' ';
 144         sign = 0;
 145         if (type & SIGN) {
 146                 if (num < 0) {
 147                         sign = '-';
 148                         num = -num;
 149                         size--;
 150                 } else if (type & PLUS) {
 151                         sign = '+';
 152                         size--;
 153                 } else if (type & SPACE) {
 154                         sign = ' ';
 155                         size--;
 156                 }
 157         }
 158         if (type & SPECIAL) {
 159                 if (base == 16)
 160                         size -= 2;
 161                 else if (base == 8)
 162                         size--;
 163         }
 164         i = 0;
 165         if (num == 0)
 166                 tmp[i++]='0';
 167         else while (num != 0)
 168                 tmp[i++] = digits[do_div(num,base)];
 169         if (i > precision)
 170                 precision = i;
 171         size -= precision;
 172         if (!(type&(ZEROPAD+LEFT))) {
 173                 while(size-->0) {
 174                         if (buf <= end)
 175                                 *buf = ' ';
 176                         ++buf;
 177                 }
 178         }
 179         if (sign) {
 180                 if (buf <= end)
 181                         *buf = sign;
 182                 ++buf;
 183         }
 184         if (type & SPECIAL) {
 185                 if (base==8) {
 186                         if (buf <= end)
 187                                 *buf = '0';
 188                         ++buf;
 189                 } else if (base==16) {
 190                         if (buf <= end)
 191                                 *buf = '0';
 192                         ++buf;
 193                         if (buf <= end)
 194                                 *buf = digits[33];
 195                         ++buf;
 196                 }
 197         }
 198         if (!(type & LEFT)) {
 199                 while (size-- > 0) {
 200                         if (buf <= end)
 201                                 *buf = c;
 202                         ++buf;
 203                 }
 204         }
 205         while (i < precision--) {
 206                 if (buf <= end)
 207                         *buf = '0';
 208                 ++buf;
 209         }
 210         while (i-- > 0) {
 211                 if (buf <= end)
 212                         *buf = tmp[i];
 213                 ++buf;
 214         }
 215         while (size-- > 0) {
 216                 if (buf <= end)
 217                         *buf = ' ';
 218                 ++buf;
 219         }
 220         return buf;
 221 }
 222
 223 /**
 224 * vsnprintf - Format a string and place it in a buffer
 225 * @buf: The buffer to place the result into
 226 * @size: The size of the buffer, including the trailing null space
 227 * @fmt: The format string to use
 228 * @args: Arguments for the format string
 229 *
 230 * Call this function if you are already dealing with a va_list.
 231 * You probably want snprintf instead.
 232  */
 233 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 234 {
 235         int len;
 236         unsigned long long num;
 237         int i, base;
 238         char *str, *end, c;
 239         const char *s;
 240
 241         int flags;              /* flags to number() */
 242
 243         int field_width;        /* width of output field */
 244         int precision;          /* min. # of digits for integers; max
 245                                    number of chars for from string */
 246         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 247                                 /* 'z' support added 23/7/1999 S.H.    */
 248                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 249
 250         str = buf;
 251         end = buf + size - 1;
 252
 253         if (end < buf - 1) {
 254                 end = ((void *) -1);
 255                 size = end - buf + 1;
 256         }
 257
 258         for (; *fmt ; ++fmt) {
 259                 if (*fmt != '%') {
 260                         if (str <= end)
 261                                 *str = *fmt;
 262                         ++str;
 263                         continue;
 264                 }
 265
 266                 /* process flags */
 267                 flags = 0;
 268                 repeat:
 269                         ++fmt;          /* this also skips first '%' */
 270                         switch (*fmt) {
 271                                 case '-': flags |= LEFT; goto repeat;
 272                                 case '+': flags |= PLUS; goto repeat;
 273                                 case ' ': flags |= SPACE; goto repeat;
 274                                 case '#': flags |= SPECIAL; goto repeat;
 275                                 case '0': flags |= ZEROPAD; goto repeat;
 276                         }
 277
 278                 /* get field width */
 279                 field_width = -1;
 280                 if (isdigit(*fmt))
 281                         field_width = skip_atoi(&fmt);
 282                 else if (*fmt == '*') {
 283                         ++fmt;
 284                         /* it's the next argument */
 285                         field_width = va_arg(args, int);
 286                         if (field_width < 0) {
 287                                 field_width = -field_width;
 288                                 flags |= LEFT;
 289                         }
 290                 }
 291
 292                 /* get the precision */
 293                 precision = -1;
 294                 if (*fmt == '.') {
 295                         ++fmt;
 296                         if (isdigit(*fmt))
 297                                 precision = skip_atoi(&fmt);
 298                         else if (*fmt == '*') {
 299                                 ++fmt;
 300                                 /* it's the next argument */
 301                                 precision = va_arg(args, int);
 302                         }
 303                         if (precision < 0)
 304                                 precision = 0;
 305                 }
 306
 307                 /* get the conversion qualifier */
 308                 qualifier = -1;
 309                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 310                     *fmt =='Z' || *fmt == 'z') {
 311                         qualifier = *fmt;
 312                         ++fmt;
 313                         if (qualifier == 'l' && *fmt == 'l') {
 314                                 qualifier = 'L';
 315                                 ++fmt;
 316                         }
 317                 }
 318
 319                 /* default base */
 320                 base = 10;
 321
 322                 switch (*fmt) {
 323                         case 'c':
 324                                 if (!(flags & LEFT)) {
 325                                         while (--field_width > 0) {
 326                                                 if (str <= end)
 327                                                         *str = ' ';
 328                                                 ++str;
 329                                         }
 330                                 }
 331                                 c = (unsigned char) va_arg(args, int);
 332                                 if (str <= end)
 333                                         *str = c;
 334                                 ++str;
 335                                 while (--field_width > 0) {
 336                                         if (str <= end)
 337                                                 *str = ' ';
 338                                         ++str;
 339                                 }
 340                                 continue;
 341
 342                         case 's':
 343                                 s = va_arg(args, char *);
 344                                 if (!s)
 345                                         s = "<NULL>";
 346
 347                                 len = strnlen(s, precision);
 348
 349                                 if (!(flags & LEFT)) {
 350                                         while (len < field_width--) {
 351                                                 if (str <= end)
 352                                                         *str = ' ';
 353                                                 ++str;
 354                                         }
 355                                 }
 356                                 for (i = 0; i < len; ++i) {
 357                                         if (str <= end)
 358                                                 *str = *s;
 359                                         ++str; ++s;
 360                                 }
 361                                 while (len < field_width--) {
 362                                         if (str <= end)
 363                                                 *str = ' ';
 364                                         ++str;
 365                                 }
 366                                 continue;
 367
 368                         case 'p':
 369                                 if (field_width == -1) {
 370                                         field_width = 2*sizeof(void *);
 371                                         flags |= ZEROPAD;
 372                                 }
 373                                 str = number(str, end,
 374                                                 (unsigned long) va_arg(args, void *),
 375                                                 16, field_width, precision, flags);
 376                                 continue;
 377
 378
 379                         case 'n':
 380                                 /* FIXME:
 381                                 * What does C99 say about the overflow case here? */
 382                                 if (qualifier == 'l') {
 383                                         long * ip = va_arg(args, long *);
 384                                         *ip = (str - buf);
 385                                 } else if (qualifier == 'Z' || qualifier == 'z') {
 386                                         size_t * ip = va_arg(args, size_t *);
 387                                         *ip = (str - buf);
 388                                 } else {
 389                                         int * ip = va_arg(args, int *);
 390                                         *ip = (str - buf);
 391                                 }
 392                                 continue;
 393
 394                         case '%':
 395                                 if (str <= end)
 396                                         *str = '%';
 397                                 ++str;
 398                                 continue;
 399
 400                                 /* integer number formats - set up the flags and "break" */
 401                         case 'o':
 402                                 base = 8;
 403                                 break;
 404
 405                         case 'X':
 406                                 flags |= LARGE;
 407                         case 'x':
 408                                 base = 16;
 409                                 break;
 410
 411                         case 'd':
 412                         case 'i':
 413                                 flags |= SIGN;
 414                         case 'u':
 415                                 break;
 416
 417                         default:
 418                                 if (str <= end)
 419                                         *str = '%';
 420                                 ++str;
 421                                 if (*fmt) {
 422                                         if (str <= end)
 423                                                 *str = *fmt;
 424                                         ++str;
 425                                 } else {
 426                                         --fmt;
 427                                 }
 428                                 continue;
 429                 }
 430                 if (qualifier == 'L')
 431                         num = va_arg(args, long long);
 432                 else if (qualifier == 'l') {
 433                         num = va_arg(args, unsigned long);
 434                         if (flags & SIGN)
 435                                 num = (signed long) num;
 436                 } else if (qualifier == 'Z' || qualifier == 'z') {
 437                         num = va_arg(args, size_t);
 438                 } else if (qualifier == 'h') {
 439                         num = (unsigned short) va_arg(args, int);
 440                         if (flags & SIGN)
 441                                 num = (signed short) num;
 442                 } else {
 443                         num = va_arg(args, unsigned int);
 444                         if (flags & SIGN)
 445                                 num = (signed int) num;
 446                 }
 447                 str = number(str, end, num, base,
 448                                 field_width, precision, flags);
 449         }
 450         if (str <= end)
 451                 *str = '\0';
 452         else if (size > 0)
 453                 /* don't write out a null byte if the buf size is zero */
 454                 *end = '\0';
 455         /* the trailing null byte doesn't count towards the total
 456         * ++str;
 457         */
 458         return str-buf;
 459 }
 460
 461 /**
 462  * snprintf - Format a string and place it in a buffer
 463  * @buf: The buffer to place the result into
 464  * @size: The size of the buffer, including the trailing null space
 465  * @fmt: The format string to use
 466  * @...: Arguments for the format string
 467  */
 468 int snprintf(char * buf, size_t size, const char *fmt, ...)
 469 {
 470         va_list args;
 471         int i;
 472
 473         va_start(args, fmt);
 474         i=vsnprintf(buf,size,fmt,args);
 475         va_end(args);
 476         return i;
 477 }
 478
 479 /**
 480  * vsprintf - Format a string and place it in a buffer
 481  * @buf: The buffer to place the result into
 482  * @fmt: The format string to use
 483  * @args: Arguments for the format string
 484  *
 485  * Call this function if you are already dealing with a va_list.
 486  * You probably want sprintf instead.
 487  */
 488 int vsprintf(char *buf, const char *fmt, va_list args)
 489 {
 490         return vsnprintf(buf, 0xFFFFFFFFUL, fmt, args);
 491 }
 492
 493
 494 /**
 495  * sprintf - Format a string and place it in a buffer
 496  * @buf: The buffer to place the result into
 497  * @fmt: The format string to use
 498  * @...: Arguments for the format string
 499  */
 500 int sprintf(char * buf, const char *fmt, ...)
 501 {
 502         va_list args;
 503         int i;
 504
 505         va_start(args, fmt);
 506         i=vsprintf(buf,fmt,args);
 507         va_end(args);
 508         return i;
 509 }
 510
 511 /**
 512  * vsscanf - Unformat a buffer into a list of arguments
 513  * @buf:        input buffer
 514  * @fmt:        format of buffer
 515  * @args:       arguments
 516  */
 517 int vsscanf(const char * buf, const char * fmt, va_list args)
 518 {
 519         const char *str = buf;
 520         char *next;
 521         char digit;
 522         int num = 0;
 523         int qualifier;
 524         int base;
 525         int field_width;
 526         int is_sign = 0;
 527
 528         while(*fmt && *str) {
 529                 /* skip any white space in format */
 530                 /* white space in format matchs any amount of
 531                  * white space, including none, in the input.
 532                  */
 533                 if (isspace(*fmt)) {
 534                         while (isspace(*fmt))
 535                                 ++fmt;
 536                         while (isspace(*str))
 537                                 ++str;
 538                 }
 539
 540                 /* anything that is not a conversion must match exactly */
 541                 if (*fmt != '%' && *fmt) {
 542                         if (*fmt++ != *str++)
 543                                 break;
 544                         continue;
 545                 }
 546
 547                 if (!*fmt)
 548                         break;
 549                 ++fmt;
 550
 551                 /* skip this conversion.
 552                  * advance both strings to next white space
 553                  */
 554                 if (*fmt == '*') {
 555                         while (!isspace(*fmt) && *fmt)
 556                                 fmt++;
 557                         while (!isspace(*str) && *str)
 558                                 str++;
 559                         continue;
 560                 }
 561
 562                 /* get field width */
 563                 field_width = -1;
 564                 if (isdigit(*fmt))
 565                         field_width = skip_atoi(&fmt);
 566
 567                 /* get conversion qualifier */
 568                 qualifier = -1;
 569                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 570                     *fmt == 'Z' || *fmt == 'z') {
 571                         qualifier = *fmt;
 572                         fmt++;
 573                 }
 574                 base = 10;
 575                 is_sign = 0;
 576
 577                 if (!*fmt || !*str)
 578                         break;
 579
 580                 switch(*fmt++) {
 581                 case 'c':
 582                 {
 583                         char *s = (char *) va_arg(args,char*);
 584                         if (field_width == -1)
 585                                 field_width = 1;
 586                         do {
 587                                 *s++ = *str++;
 588                         } while(field_width-- > 0 && *str);
 589                         num++;
 590                 }
 591                 continue;
 592                 case 's':
 593                 {
 594                         char *s = (char *) va_arg(args, char *);
 595                         if(field_width == -1)
 596                                 field_width = INT_MAX;
 597                         /* first, skip leading white space in buffer */
 598                         while (isspace(*str))
 599                                 str++;
 600
 601                         /* now copy until next white space */
 602                         while (*str && !isspace(*str) && field_width--) {
 603                                 *s++ = *str++;
 604                         }
 605                         *s = '\0';
 606                         num++;
 607                 }
 608                 continue;
 609                 case 'n':
 610                         /* return number of characters read so far */
 611                 {
 612                         int *i = (int *)va_arg(args,int*);
 613                         *i = str - buf;
 614                 }
 615                 continue;
 616                 case 'o':
 617                         base = 8;
 618                         break;
 619                 case 'x':
 620                 case 'X':
 621                         base = 16;
 622                         break;
 623                 case 'i':
 624                         base = 0;
 625                 case 'd':
 626                         is_sign = 1;
 627                 case 'u':
 628                         break;
 629                 case '%':
 630                         /* looking for '%' in str */
 631                         if (*str++ != '%')
 632                                 return num;
 633                         continue;
 634                 default:
 635                         /* invalid format; stop here */
 636                         return num;
 637                 }
 638
 639                 /* have some sort of integer conversion.
 640                  * first, skip white space in buffer.
 641                  */
 642                 while (isspace(*str))
 643                         str++;
 644
 645                 digit = *str;
 646                 if (is_sign && digit == '-')
 647                         digit = *(str + 1);
 648
 649                 if (!digit
 650                     || (base == 16 && !isxdigit(digit))
 651                     || (base == 10 && !isdigit(digit))
 652                     || (base == 8 && (!isdigit(digit) || digit > '7'))
 653                     || (base == 0 && !isdigit(digit)))
 654                                 break;
 655
 656                 switch(qualifier) {
 657                 case 'h':
 658                         if (is_sign) {
 659                                 short *s = (short *) va_arg(args,short *);
 660                                 *s = (short) simple_strtol(str,&next,base);
 661                         } else {
 662                                 unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
 663                                 *s = (unsigned short) simple_strtoul(str, &next, base);
 664                         }
 665                         break;
 666                 case 'l':
 667                         if (is_sign) {
 668                                 long *l = (long *) va_arg(args,long *);
 669                                 *l = simple_strtol(str,&next,base);
 670                         } else {
 671                                 unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
 672                                 *l = simple_strtoul(str,&next,base);
 673                         }
 674                         break;
 675                 case 'L':
 676                         if (is_sign) {
 677                                 long long *l = (long long*) va_arg(args,long long *);
 678                                 *l = simple_strtoll(str,&next,base);
 679                         } else {
 680                                 unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
 681                                 *l = simple_strtoull(str,&next,base);
 682                         }
 683                         break;
 684                 case 'Z':
 685                 case 'z':
 686                 {
 687                         size_t *s = (size_t*) va_arg(args,size_t*);
 688                         *s = (size_t) simple_strtoul(str,&next,base);
 689                 }
 690                 break;
 691                 default:
 692                         if (is_sign) {
 693                                 int *i = (int *) va_arg(args, int*);
 694                                 *i = (int) simple_strtol(str,&next,base);
 695                         } else {
 696                                 unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
 697                                 *i = (unsigned int) simple_strtoul(str,&next,base);
 698                         }
 699                         break;
 700                 }
 701                 num++;
 702
 703                 if (!next)
 704                         break;
 705                 str = next;
 706         }
 707         return num;
 708 }
 709
 710 /**
 711  * sscanf - Unformat a buffer into a list of arguments
 712  * @buf:        input buffer
 713  * @fmt:        formatting of buffer
 714  * @...:        resulting arguments
 715  */
 716 int sscanf(const char * buf, const char * fmt, ...)
 717 {
 718         va_list args;
 719         int i;
 720
 721         va_start(args,fmt);
 722         i = vsscanf(buf,fmt,args);
 723         va_end(args);
 724         return i;
 725 }