1 /* 2 * Oh, it's a waste of space, but oh-so-yummy for debugging. It's just 3 * initialization code anyway, so it doesn't take up space when we're 4 * actually running. This version of printf() does not include 64-bit 5 * support. "Live with it." 6 * 7 * Most of this code was shamelessly snarfed from the Linux kernel, then 8 * modified. It's therefore GPL. 9 * 10 * printf() isn't actually needed to build syslinux.com, but during 11 * debugging it's handy. 12 */ 13 14 #include <stdarg.h> 15 #include <stdio.h> 16 #include "mystuff.h" 17 18 static int strnlen(const char *s, int maxlen) 19 { 20 const char *es = s; 21 while (*es && maxlen) { 22 es++; 23 maxlen--; 24 } 25 26 return (es - s); 27 } 28 29 #define ZEROPAD 1 /* pad with zero */ 30 #define SIGN 2 /* unsigned/signed long */ 31 #define PLUS 4 /* show plus */ 32 #define SPACE 8 /* space if plus */ 33 #define LEFT 16 /* left justified */ 34 #define SPECIAL 32 /* 0x */ 35 #define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */ 36 37 #define do_div(n,base) ({ \ 38 int __res; \ 39 __res = ((unsigned long) n) % (unsigned) base; \ 40 n = ((unsigned long) n) / (unsigned) base; \ 41 __res; }) 42 43 static char *number(char *str, long num, int base, int size, int precision, 44 int type) 45 { 46 char c, sign, tmp[66]; 47 const char *digits = "0123456789abcdefghijklmnopqrstuvwxyz"; 48 int i; 49 50 if (type & LARGE) 51 digits = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; 52 if (type & LEFT) 53 type &= ~ZEROPAD; 54 if (base < 2 || base > 36) 55 return 0; 56 c = (type & ZEROPAD) ? '0' : ' '; 57 sign = 0; 58 if (type & SIGN) { 59 if (num < 0) { 60 sign = '-'; 61 num = -num; 62 size--; 63 } else if (type & PLUS) { 64 sign = '+'; 65 size--; 66 } else if (type & SPACE) { 67 sign = ' '; 68 size--; 69 } 70 } 71 if (type & SPECIAL) { 72 if (base == 16) 73 size -= 2; 74 else if (base == 8) 75 size--; 76 } 77 i = 0; 78 if (num == 0) 79 tmp[i++] = '0'; 80 else 81 while (num != 0) 82 tmp[i++] = digits[do_div(num, base)]; 83 if (i > precision) 84 precision = i; 85 size -= precision; 86 if (!(type & (ZEROPAD + LEFT))) 87 while (size-- > 0) 88 *str++ = ' '; 89 if (sign) 90 *str++ = sign; 91 if (type & SPECIAL) { 92 if (base == 8) 93 *str++ = '0'; 94 else if (base == 16) { 95 *str++ = '0'; 96 *str++ = digits[33]; 97 } 98 } 99 if (!(type & LEFT)) 100 while (size-- > 0) 101 *str++ = c; 102 while (i < precision--) 103 *str++ = '0'; 104 while (i-- > 0) 105 *str++ = tmp[i]; 106 while (size-- > 0) 107 *str++ = ' '; 108 return str; 109 } 110 111 /* Forward decl. needed for IP address printing stuff... */ 112 int sprintf(char *buf, const char *fmt, ...); 113 114 int vsprintf(char *buf, const char *fmt, va_list args) 115 { 116 int len; 117 unsigned long num; 118 int i, base; 119 char *str; 120 const char *s; 121 122 int flags; /* flags to number() */ 123 124 int field_width; /* width of output field */ 125 int precision; /* min. # of digits for integers; max 126 number of chars for from string */ 127 int qualifier; /* 'h', 'l', or 'L' for integer fields */ 128 129 for (str = buf; *fmt; ++fmt) { 130 if (*fmt != '%') { 131 *str++ = *fmt; 132 continue; 133 } 134 135 /* process flags */ 136 flags = 0; 137 repeat: 138 ++fmt; /* this also skips first '%' */ 139 switch (*fmt) { 140 case '-': 141 flags |= LEFT; 142 goto repeat; 143 case '+': 144 flags |= PLUS; 145 goto repeat; 146 case ' ': 147 flags |= SPACE; 148 goto repeat; 149 case '#': 150 flags |= SPECIAL; 151 goto repeat; 152 case '0': 153 flags |= ZEROPAD; 154 goto repeat; 155 } 156 157 /* get field width */ 158 field_width = -1; 159 if (isdigit(*fmt)) 160 field_width = skip_atou(&fmt); 161 else if (*fmt == '*') { 162 ++fmt; 163 /* it's the next argument */ 164 field_width = va_arg(args, int); 165 if (field_width < 0) { 166 field_width = -field_width; 167 flags |= LEFT; 168 } 169 } 170 171 /* get the precision */ 172 precision = -1; 173 if (*fmt == '.') { 174 ++fmt; 175 if (isdigit(*fmt)) 176 precision = skip_atou(&fmt); 177 else if (*fmt == '*') { 178 ++fmt; 179 /* it's the next argument */ 180 precision = va_arg(args, int); 181 } 182 if (precision < 0) 183 precision = 0; 184 } 185 186 /* get the conversion qualifier */ 187 qualifier = -1; 188 if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') { 189 qualifier = *fmt; 190 ++fmt; 191 } 192 193 /* default base */ 194 base = 10; 195 196 switch (*fmt) { 197 case 'c': 198 if (!(flags & LEFT)) 199 while (--field_width > 0) 200 *str++ = ' '; 201 *str++ = (unsigned char)va_arg(args, int); 202 while (--field_width > 0) 203 *str++ = ' '; 204 continue; 205 206 case 's': 207 s = va_arg(args, char *); 208 len = strnlen(s, precision); 209 210 if (!(flags & LEFT)) 211 while (len < field_width--) 212 *str++ = ' '; 213 for (i = 0; i < len; ++i) 214 *str++ = *s++; 215 while (len < field_width--) 216 *str++ = ' '; 217 continue; 218 219 case 'p': 220 if (field_width == -1) { 221 field_width = 2 * sizeof(void *); 222 flags |= ZEROPAD; 223 } 224 str = number(str, 225 (unsigned long)va_arg(args, void *), 16, 226 field_width, precision, flags); 227 continue; 228 229 case 'n': 230 if (qualifier == 'l') { 231 long *ip = va_arg(args, long *); 232 *ip = (str - buf); 233 } else { 234 int *ip = va_arg(args, int *); 235 *ip = (str - buf); 236 } 237 continue; 238 239 case '%': 240 *str++ = '%'; 241 continue; 242 243 /* integer number formats - set up the flags and "break" */ 244 case 'o': 245 base = 8; 246 break; 247 248 case 'X': 249 flags |= LARGE; 250 case 'x': 251 base = 16; 252 break; 253 254 case 'd': 255 case 'i': 256 flags |= SIGN; 257 case 'u': 258 break; 259 260 default: 261 *str++ = '%'; 262 if (*fmt) 263 *str++ = *fmt; 264 else 265 --fmt; 266 continue; 267 } 268 if (qualifier == 'l') 269 num = va_arg(args, unsigned long); 270 else if (qualifier == 'h') { 271 num = (unsigned short)va_arg(args, int); 272 if (flags & SIGN) 273 num = (short)num; 274 } else if (flags & SIGN) 275 num = va_arg(args, int); 276 else 277 num = va_arg(args, unsigned int); 278 str = number(str, num, base, field_width, precision, flags); 279 } 280 *str = '\0'; 281 return str - buf; 282 } 283 284 int sprintf(char *buf, const char *fmt, ...) 285 { 286 va_list args; 287 int i; 288 289 va_start(args, fmt); 290 i = vsprintf(buf, fmt, args); 291 va_end(args); 292 return i; 293 } 294 295 int printf(const char *fmt, ...) 296 { 297 char printf_buf[1024]; 298 va_list args; 299 int printed; 300 301 va_start(args, fmt); 302 printed = vsprintf(printf_buf, fmt, args); 303 va_end(args); 304 305 puts(printf_buf); 306 307 return printed; 308 } 309
