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