php addslashes函數最終對應的c函數為： 3244 PHPAPI char *php_addslashes_ex(char *str, int length, int *new_length, int should_free, int ignore_sybase TS RMLS_DC) 3245 { 3246 /* maximum string length, worst case situation */ 3247 char *new_str; 3248 char *source, *target; 3249 char *end; 3250 int local_new_length; 3251 3252 if (!new_length) { 3253 new_length = &local_new_length; 3254 } 3255 if (!str) { 3256 *new_length = 0; 3257 return str; 3258 } 3259 new_str = (char *) safe_emalloc(2, (length ? length : (length = strlen(str))), 1); 3260 source = str; 3261 end = source + length; 3262 target = new_str; 3263 3264 if (!ignore_sybase && PG(magic_quotes_sybase)) { 3265 while (source < end) { 3266 switch (*source) { 3267 case '\0': 3268 *target++ = '\\'; 3269 *target++ = '0'; 3270 break; 3271 case '\'': 3272 *target++ = '\''; 3273 *target++ = '\''; 3274 break; 3275 default: 3276 *target++ = *source; 3277 break; 3278 } 3279 source++; 3280 } 3281 } else { 3282 while (source < end) { 3283 switch (*source) { 3284 case '\0': 3285 *target++ = '\\'; 3286 *target++ = '0'; 3287 break; 3288 case '\'': 3289 case '\"': 3290 case '\\': 3291 *target++ = '\\'; 3292 /* break is missing *intentionally* */ 3293 default: 3294 *target++ = *source; 3295 break; 3296 } 3297 3298 source++; 3299 } 3300 } 3301 3302 *target = 0; 3303 *new_length = target - new_str; 3304 if (should_free) { 3305 STR_FREE(str); 3306 } 3307 new_str = (char *) erealloc(new_str, *new_length + 1); 3308 return new_str; 3309 } 從上面看addslashes函數處理的是單字節的字節。 但是gbk編碼是雙字節的。而且5c又可以做雙字節的低位。
