libc/vsprintf.c

   1 /*
   2  * String functions for logger.
   3  */
   4
   5 /*
   6  *  linux/lib/vsprintf.c
   7  *
   8  *  Copyright (C) 1991, 1992  Linus Torvalds
   9  */
  10
  11 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
  12 /*
  13  * Wirzenius wrote this portably, Torvalds fucked it up :-)
  14  */
  15
  16 /*
  17  * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
  18  * - changed to provide snprintf and vsnprintf functions
  19  */
  20
  21 #include "config.h"
  22 #include "libc/string.h"
  23 #include "libc/vsprintf.h"
  24
  25 static int skip_atoi(const char **s)
  26 {
  27         int i=0;
  28
  29         while (isdigit(**s))
  30                 i = i*10 + *((*s)++) - '0';
  31         return i;
  32 }
  33
  34 #define ZEROPAD 1               /* pad with zero */
  35 #define SIGN    2               /* unsigned/signed long */
  36 #define PLUS    4               /* show plus */
  37 #define SPACE   8               /* space if plus */
  38 #define LEFT    16              /* left justified */
  39 #define SPECIAL 32              /* 0x */
  40 #define LARGE   64              /* use 'ABCDEF' instead of 'abcdef' */
  41
  42 #define do_div(n,base) ({ \
  43 int __res; \
  44 __res = ((unsigned long long) n) % (unsigned) base; \
  45 n = ((unsigned long long) n) / (unsigned) base; \
  46 __res; })
  47
  48 static int mstrlen( const char *str );
  49
  50 #ifndef PAGE_SIZE
  51 #define PAGE_SIZE 4096
  52 #endif
  53
  54 static char * number(char * buf, char * end, long long num, int base, int size, int precision, int type)
  55 {
  56         char c,sign,tmp[66];
  57         const char *digits;
  58         static const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz";
  59         static const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  60         int i;
  61
  62         digits = (type & LARGE) ? large_digits : small_digits;
  63         if (type & LEFT)
  64                 type &= ~ZEROPAD;
  65         if (base < 2 || base > 36)
  66                 return NULL;
  67         c = (type & ZEROPAD) ? '0' : ' ';
  68         sign = 0;
  69         if (type & SIGN) {
  70                 if (num < 0) {
  71                         sign = '-';
  72                         num = -num;
  73                         size--;
  74                 } else if (type & PLUS) {
  75                         sign = '+';
  76                         size--;
  77                 } else if (type & SPACE) {
  78                         sign = ' ';
  79                         size--;
  80                 }
  81         }
  82         if (type & SPECIAL) {
  83                 if (base == 16)
  84                         size -= 2;
  85                 else if (base == 8)
  86                         size--;
  87         }
  88         i = 0;
  89         if (num == 0)
  90                 tmp[i++]='0';
  91         else while (num != 0)
  92                 tmp[i++] = digits[do_div(num,base)];
  93         if (i > precision)
  94                 precision = i;
  95         size -= precision;
  96         if (!(type&(ZEROPAD+LEFT))) {
  97                 while(size-->0) {
  98                         if (buf <= end)
  99                                 *buf = ' ';
 100                         ++buf;
 101                 }
 102         }
 103         if (sign) {
 104                 if (buf <= end)
 105                         *buf = sign;
 106                 ++buf;
 107         }
 108         if (type & SPECIAL) {
 109                 if (base==8) {
 110                         if (buf <= end)
 111                                 *buf = '0';
 112                         ++buf;
 113                 } else if (base==16) {
 114                         if (buf <= end)
 115                                 *buf = '0';
 116                         ++buf;
 117                         if (buf <= end)
 118                                 *buf = digits[33];
 119                         ++buf;
 120                 }
 121         }
 122         if (!(type & LEFT)) {
 123                 while (size-- > 0) {
 124                         if (buf <= end)
 125                                 *buf = c;
 126                         ++buf;
 127                 }
 128         }
 129         while (i < precision--) {
 130                 if (buf <= end)
 131                         *buf = '0';
 132                 ++buf;
 133         }
 134         while (i-- > 0) {
 135                 if (buf <= end)
 136                         *buf = tmp[i];
 137                 ++buf;
 138         }
 139         while (size-- > 0) {
 140                 if (buf <= end)
 141                         *buf = ' ';
 142                 ++buf;
 143         }
 144         return buf;
 145 }
 146
 147 /**
 148 * vsnprintf - Format a string and place it in a buffer
 149 * @buf: The buffer to place the result into
 150 * @size: The size of the buffer, including the trailing null space
 151 * @fmt: The format string to use
 152 * @args: Arguments for the format string
 153 *
 154 * Call this function if you are already dealing with a va_list.
 155 * You probably want snprintf instead.
 156  */
 157 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 158 {
 159         int len;
 160         unsigned long long num;
 161         int i, base;
 162         char *str, *end, c;
 163         const char *s;
 164
 165         int flags;              /* flags to number() */
 166
 167         int field_width;        /* width of output field */
 168         int precision;          /* min. # of digits for integers; max
 169                                    number of chars for from string */
 170         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 171                                 /* 'z' support added 23/7/1999 S.H.    */
 172                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 173
 174         str = buf;
 175         end = buf + size - 1;
 176
 177         if (end < buf - 1) {
 178                 end = ((void *) -1);
 179                 size = end - buf + 1;
 180         }
 181
 182         for (; *fmt ; ++fmt) {
 183                 if (*fmt != '%') {
 184                         if (str <= end)
 185                                 *str = *fmt;
 186                         ++str;
 187                         continue;
 188                 }
 189
 190                 /* process flags */
 191                 flags = 0;
 192                 repeat:
 193                         ++fmt;          /* this also skips first '%' */
 194                         switch (*fmt) {
 195                                 case '-': flags |= LEFT; goto repeat;
 196                                 case '+': flags |= PLUS; goto repeat;
 197                                 case ' ': flags |= SPACE; goto repeat;
 198                                 case '#': flags |= SPECIAL; goto repeat;
 199                                 case '0': flags |= ZEROPAD; goto repeat;
 200                         }
 201
 202                 /* get field width */
 203                 field_width = -1;
 204                 if (isdigit(*fmt))
 205                         field_width = skip_atoi(&fmt);
 206                 else if (*fmt == '*') {
 207                         ++fmt;
 208                         /* it's the next argument */
 209                         field_width = va_arg(args, int);
 210                         if (field_width < 0) {
 211                                 field_width = -field_width;
 212                                 flags |= LEFT;
 213                         }
 214                 }
 215
 216                 /* get the precision */
 217                 precision = -1;
 218                 if (*fmt == '.') {
 219                         ++fmt;
 220                         if (isdigit(*fmt))
 221                                 precision = skip_atoi(&fmt);
 222                         else if (*fmt == '*') {
 223                                 ++fmt;
 224                                 /* it's the next argument */
 225                                 precision = va_arg(args, int);
 226                         }
 227                         if (precision < 0)
 228                                 precision = 0;
 229                 }
 230
 231                 /* get the conversion qualifier */
 232                 qualifier = -1;
 233                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
 234                     *fmt =='Z' || *fmt == 'z') {
 235                         qualifier = *fmt;
 236                         ++fmt;
 237                         if (qualifier == 'l' && *fmt == 'l') {
 238                                 qualifier = 'L';
 239                                 ++fmt;
 240                         }
 241                 }
 242
 243                 /* default base */
 244                 base = 10;
 245
 246                 switch (*fmt) {
 247                         case 'c':
 248                                 if (!(flags & LEFT)) {
 249                                         while (--field_width > 0) {
 250                                                 if (str <= end)
 251                                                         *str = ' ';
 252                                                 ++str;
 253                                         }
 254                                 }
 255                                 c = (unsigned char) va_arg(args, int);
 256                                 if (str <= end)
 257                                         *str = c;
 258                                 ++str;
 259                                 while (--field_width > 0) {
 260                                         if (str <= end)
 261                                                 *str = ' ';
 262                                         ++str;
 263                                 }
 264                                 continue;
 265
 266                         case 's':
 267                                 s = va_arg(args, char *);
 268                                 if ((unsigned long)s < PAGE_SIZE)
 269                                         s = "<NULL>";
 270
 271 #if 0
 272                                 len = strnlen(s, precision);
 273 #else
 274                                 len = mstrlen(s);
 275                                 if( precision > len )
 276                                     len = precision;
 277 #endif
 278                                 if (!(flags & LEFT)) {
 279                                         while (len < field_width--) {
 280                                                 if (str <= end)
 281                                                         *str = ' ';
 282                                                 ++str;
 283                                         }
 284                                 }
 285                                 for (i = 0; i < len; ++i) {
 286                                         if (str <= end)
 287                                                 *str = *s;
 288                                         ++str; ++s;
 289                                 }
 290                                 while (len < field_width--) {
 291                                         if (str <= end)
 292                                                 *str = ' ';
 293                                         ++str;
 294                                 }
 295                                 continue;
 296
 297                         case 'p':
 298                                 if (field_width == -1) {
 299                                         field_width = 2*sizeof(void *);
 300                                         flags |= ZEROPAD;
 301                                 }
 302                                 str = number(str, end,
 303                                                 (unsigned long) va_arg(args, void *),
 304                                                 16, field_width, precision, flags);
 305                                 continue;
 306
 307
 308                         case 'n':
 309                                 /* FIXME:
 310                                 * What does C99 say about the overflow case here? */
 311                                 if (qualifier == 'l') {
 312                                         long * ip = va_arg(args, long *);
 313                                         *ip = (str - buf);
 314                                 } else if (qualifier == 'Z' || qualifier == 'z') {
 315                                         size_t * ip = va_arg(args, size_t *);
 316                                         *ip = (str - buf);
 317                                 } else {
 318                                         int * ip = va_arg(args, int *);
 319                                         *ip = (str - buf);
 320                                 }
 321                                 continue;
 322
 323                         case '%':
 324                                 if (str <= end)
 325                                         *str = '%';
 326                                 ++str;
 327                                 continue;
 328
 329                                 /* integer number formats - set up the flags and "break" */
 330                         case 'o':
 331                                 base = 8;
 332                                 break;
 333
 334                         case 'X':
 335                                 flags |= LARGE;
 336                         case 'x':
 337                                 base = 16;
 338                                 break;
 339
 340                         case 'd':
 341                         case 'i':
 342                                 flags |= SIGN;
 343                         case 'u':
 344                                 break;
 345
 346                         default:
 347                                 if (str <= end)
 348                                         *str = '%';
 349                                 ++str;
 350                                 if (*fmt) {
 351                                         if (str <= end)
 352                                                 *str = *fmt;
 353                                         ++str;
 354                                 } else {
 355                                         --fmt;
 356                                 }
 357                                 continue;
 358                 }
 359                 if (qualifier == 'L')
 360                         num = va_arg(args, long long);
 361                 else if (qualifier == 'l') {
 362                         num = va_arg(args, unsigned long);
 363                         if (flags & SIGN)
 364                                 num = (signed long) num;
 365                 } else if (qualifier == 'Z' || qualifier == 'z') {
 366                         num = va_arg(args, size_t);
 367                 } else if (qualifier == 'h') {
 368                         num = (unsigned short) va_arg(args, int);
 369                         if (flags & SIGN)
 370                                 num = (signed short) num;
 371                 } else {
 372                         num = va_arg(args, unsigned int);
 373                         if (flags & SIGN)
 374                                 num = (signed int) num;
 375                 }
 376                 str = number(str, end, num, base,
 377                                 field_width, precision, flags);
 378         }
 379         if (str <= end)
 380                 *str = '\0';
 381         else if (size > 0)
 382                 /* don't write out a null byte if the buf size is zero */
 383                 *end = '\0';
 384         /* the trailing null byte doesn't count towards the total
 385         * ++str;
 386         */
 387         return str-buf;
 388 }
 389
 390 /**
 391  * snprintf - Format a string and place it in a buffer
 392  * @buf: The buffer to place the result into
 393  * @size: The size of the buffer, including the trailing null space
 394  * @fmt: The format string to use
 395  * @...: Arguments for the format string
 396  */
 397 int snprintf(char * buf, size_t size, const char *fmt, ...)
 398 {
 399         va_list args;
 400         int i;
 401
 402         va_start(args, fmt);
 403         i=vsnprintf(buf,size,fmt,args);
 404         va_end(args);
 405         return i;
 406 }
 407
 408 /**
 409  * vsprintf - Format a string and place it in a buffer
 410  * @buf: The buffer to place the result into
 411  * @fmt: The format string to use
 412  * @args: Arguments for the format string
 413  *
 414  * Call this function if you are already dealing with a va_list.
 415  * You probably want sprintf instead.
 416  */
 417 int vsprintf(char *buf, const char *fmt, va_list args)
 418 {
 419         return vsnprintf(buf, (~0U)>>1, fmt, args);
 420 }
 421
 422
 423 /**
 424  * sprintf - Format a string and place it in a buffer
 425  * @buf: The buffer to place the result into
 426  * @fmt: The format string to use
 427  * @...: Arguments for the format string
 428  */
 429 int sprintf(char * buf, const char *fmt, ...)
 430 {
 431         va_list args;
 432         int i;
 433
 434         va_start(args, fmt);
 435         i=vsprintf(buf,fmt,args);
 436         va_end(args);
 437         return i;
 438 }
 439
 440 static int mstrlen( const char *str )
 441 {
 442         int i=0;
 443         if( str == NULL )
 444                 return 0;
 445         while( *str++ )
 446                 i++;
 447         return i;
 448 }