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 #include <stdarg.h>
  13 #include <linux/types.h>
  14 #include <linux/string.h>
  15 #include <linux/ctype.h>
  16
  17 #include <asm/div64.h>
  18
  19 unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
  20 {
  21         unsigned long result = 0,value;
  22
  23         if (!base) {
  24                 base = 10;
  25                 if (*cp == '0') {
  26                         base = 8;
  27                         cp++;
  28                         if ((*cp == 'x') && isxdigit(cp[1])) {
  29                                 cp++;
  30                                 base = 16;
  31                         }
  32                 }
  33         }
  34         while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
  35             ? toupper(*cp) : *cp)-'A'+10) < base) {
  36                 result = result*base + value;
  37                 cp++;
  38         }
  39         if (endp)
  40                 *endp = (char *)cp;
  41         return result;
  42 }
  43
  44 long simple_strtol(const char *cp,char **endp,unsigned int base)
  45 {
  46         if(*cp=='-')
  47                 return -simple_strtoul(cp+1,endp,base);
  48         return simple_strtoul(cp,endp,base);
  49 }
  50
  51 /* we use this so that we can do without the ctype library */
  52 #define is_digit(c)     ((c) >= '0' && (c) <= '9')
  53
  54 static int skip_atoi(const char **s)
  55 {
  56         int i=0;
  57
  58         while (is_digit(**s))
  59                 i = i*10 + *((*s)++) - '0';
  60         return i;
  61 }
  62
  63 #define ZEROPAD 1               /* pad with zero */
  64 #define SIGN    2               /* unsigned/signed long */
  65 #define PLUS    4               /* show plus */
  66 #define SPACE   8               /* space if plus */
  67 #define LEFT    16              /* left justified */
  68 #define SPECIAL 32              /* 0x */
  69 #define LARGE   64              /* use 'ABCDEF' instead of 'abcdef' */
  70
  71 static char * number(char * str, long long num, int base, int size, int precision, int type)
  72 {
  73         char c,sign,tmp[66];
  74         const char *digits="0123456789abcdefghijklmnopqrstuvwxyz";
  75         int i;
  76
  77         if (type & LARGE)
  78                 digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
  79         if (type & LEFT)
  80                 type &= ~ZEROPAD;
  81         if (base < 2 || base > 36)
  82                 return 0;
  83         c = (type & ZEROPAD) ? '0' : ' ';
  84         sign = 0;
  85         if (type & SIGN) {
  86                 if (num < 0) {
  87                         sign = '-';
  88                         num = -num;
  89                         size--;
  90                 } else if (type & PLUS) {
  91                         sign = '+';
  92                         size--;
  93                 } else if (type & SPACE) {
  94                         sign = ' ';
  95                         size--;
  96                 }
  97         }
  98         if (type & SPECIAL) {
  99                 if (base == 16)
 100                         size -= 2;
 101                 else if (base == 8)
 102                         size--;
 103         }
 104         i = 0;
 105         if (num == 0)
 106                 tmp[i++]='0';
 107         else while (num != 0)
 108                 tmp[i++] = digits[do_div(num,base)];
 109         if (i > precision)
 110                 precision = i;
 111         size -= precision;
 112         if (!(type&(ZEROPAD+LEFT)))
 113                 while(size-->0)
 114                         *str++ = ' ';
 115         if (sign)
 116                 *str++ = sign;
 117         if (type & SPECIAL) {
 118                 if (base==8)
 119                         *str++ = '0';
 120                 else if (base==16) {
 121                         *str++ = '0';
 122                         *str++ = digits[33];
 123                 }
 124         }
 125         if (!(type & LEFT))
 126                 while (size-- > 0)
 127                         *str++ = c;
 128         while (i < precision--)
 129                 *str++ = '0';
 130         while (i-- > 0)
 131                 *str++ = tmp[i];
 132         while (size-- > 0)
 133                 *str++ = ' ';
 134         return str;
 135 }
 136
 137 /* Forward decl. needed for IP address printing stuff... */
 138 int sprintf(char * buf, const char *fmt, ...);
 139
 140 int vsprintf(char *buf, const char *fmt, va_list args)
 141 {
 142         int len;
 143         unsigned long long num;
 144         int i, base;
 145         char * str;
 146         const char *s;
 147
 148         int flags;              /* flags to number() */
 149
 150         int field_width;        /* width of output field */
 151         int precision;          /* min. # of digits for integers; max
 152                                    number of chars for from string */
 153         int qualifier;          /* 'h', 'l', or 'L' for integer fields */
 154                                 /* 'z' support added 23/7/1999 S.H.    */
 155                                 /* 'z' changed to 'Z' --davidm 1/25/99 */
 156
 157
 158         for (str=buf ; *fmt ; ++fmt) {
 159                 if (*fmt != '%') {
 160                         *str++ = *fmt;
 161                         continue;
 162                 }
 163
 164                 /* process flags */
 165                 flags = 0;
 166                 repeat:
 167                         ++fmt;          /* this also skips first '%' */
 168                         switch (*fmt) {
 169                                 case '-': flags |= LEFT; goto repeat;
 170                                 case '+': flags |= PLUS; goto repeat;
 171                                 case ' ': flags |= SPACE; goto repeat;
 172                                 case '#': flags |= SPECIAL; goto repeat;
 173                                 case '0': flags |= ZEROPAD; goto repeat;
 174                                 }
 175
 176                 /* get field width */
 177                 field_width = -1;
 178                 if (is_digit(*fmt))
 179                         field_width = skip_atoi(&fmt);
 180                 else if (*fmt == '*') {
 181                         ++fmt;
 182                         /* it's the next argument */
 183                         field_width = va_arg(args, int);
 184                         if (field_width < 0) {
 185                                 field_width = -field_width;
 186                                 flags |= LEFT;
 187                         }
 188                 }
 189
 190                 /* get the precision */
 191                 precision = -1;
 192                 if (*fmt == '.') {
 193                         ++fmt;
 194                         if (is_digit(*fmt))
 195                                 precision = skip_atoi(&fmt);
 196                         else if (*fmt == '*') {
 197                                 ++fmt;
 198                                 /* it's the next argument */
 199                                 precision = va_arg(args, int);
 200                         }
 201                         if (precision < 0)
 202                                 precision = 0;
 203                 }
 204
 205                 /* get the conversion qualifier */
 206                 qualifier = -1;
 207                 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || *fmt =='Z') {
 208                         qualifier = *fmt;
 209                         ++fmt;
 210                 }
 211
 212                 /* default base */
 213                 base = 10;
 214
 215                 switch (*fmt) {
 216                 case 'c':
 217                         if (!(flags & LEFT))
 218                                 while (--field_width > 0)
 219                                         *str++ = ' ';
 220                         *str++ = (unsigned char) va_arg(args, int);
 221                         while (--field_width > 0)
 222                                 *str++ = ' ';
 223                         continue;
 224
 225                 case 's':
 226                         s = va_arg(args, char *);
 227                         if (!s)
 228                                 s = "<NULL>";
 229
 230                         len = strnlen(s, precision);
 231
 232                         if (!(flags & LEFT))
 233                                 while (len < field_width--)
 234                                         *str++ = ' ';
 235                         for (i = 0; i < len; ++i)
 236                                 *str++ = *s++;
 237                         while (len < field_width--)
 238                                 *str++ = ' ';
 239                         continue;
 240
 241                 case 'p':
 242                         if (field_width == -1) {
 243                                 field_width = 2*sizeof(void *);
 244                                 flags |= ZEROPAD;
 245                         }
 246                         str = number(str,
 247                                 (unsigned long) va_arg(args, void *), 16,
 248                                 field_width, precision, flags);
 249                         continue;
 250
 251
 252                 case 'n':
 253                         if (qualifier == 'l') {
 254                                 long * ip = va_arg(args, long *);
 255                                 *ip = (str - buf);
 256                         } else if (qualifier == 'Z') {
 257                                 size_t * ip = va_arg(args, size_t *);
 258                                 *ip = (str - buf);
 259                         } else {
 260                                 int * ip = va_arg(args, int *);
 261                                 *ip = (str - buf);
 262                         }
 263                         continue;
 264
 265                 case '%':
 266                         *str++ = '%';
 267                         continue;
 268
 269                 /* integer number formats - set up the flags and "break" */
 270                 case 'o':
 271                         base = 8;
 272                         break;
 273
 274                 case 'X':
 275                         flags |= LARGE;
 276                 case 'x':
 277                         base = 16;
 278                         break;
 279
 280                 case 'd':
 281                 case 'i':
 282                         flags |= SIGN;
 283                 case 'u':
 284                         break;
 285
 286                 default:
 287                         *str++ = '%';
 288                         if (*fmt)
 289                                 *str++ = *fmt;
 290                         else
 291                                 --fmt;
 292                         continue;
 293                 }
 294                 if (qualifier == 'L')
 295                         num = va_arg(args, long long);
 296                 else if (qualifier == 'l') {
 297                         num = va_arg(args, unsigned long);
 298                         if (flags & SIGN)
 299                                 num = (signed long) num;
 300                 } else if (qualifier == 'Z') {
 301                         num = va_arg(args, size_t);
 302                 } else if (qualifier == 'h') {
 303                         num = (unsigned short) va_arg(args, int);
 304                         if (flags & SIGN)
 305                                 num = (signed short) num;
 306                 } else {
 307                         num = va_arg(args, unsigned int);
 308                         if (flags & SIGN)
 309                                 num = (signed int) num;
 310                 }
 311                 str = number(str, num, base, field_width, precision, flags);
 312         }
 313         *str = '\0';
 314         return str-buf;
 315 }
 316
 317 int sprintf(char * buf, const char *fmt, ...)
 318 {
 319         va_list args;
 320         int i;
 321
 322         va_start(args, fmt);
 323         i=vsprintf(buf,fmt,args);
 324         va_end(args);
 325         return i;
 326 }