clients/lib/strlib.c

   1 /*
   2 ** strlib.c
   3 ** String library to LUA
   4 */
   5
   6 char *rcs_strlib="$Id: strlib.c,v 1.46 1997/06/19 18:49:40 roberto Exp $";
   7
   8 #include <string.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <ctype.h>
  12
  13 #include "lua.h"
  14 #include "auxlib.h"
  15 #include "lualib.h"
  16
  17
  18 struct lbuff {
  19   char *b;
  20   size_t max;
  21   size_t size;
  22 };
  23
  24 static struct lbuff lbuffer = {NULL, 0, 0};
  25
  26
  27 static char *strbuffer (unsigned long size)
  28 {
  29   if (size > lbuffer.max) {
  30     /* ANSI "realloc" doesn't need this test, but some machines (Sun!)
  31        don't follow ANSI */
  32     lbuffer.b = (lbuffer.b) ? realloc(lbuffer.b, lbuffer.max=size) :
  33                               malloc(lbuffer.max=size);
  34     if (lbuffer.b == NULL)
  35       lua_error("memory overflow");
  36   }
  37   return lbuffer.b;
  38 }
  39
  40 static char *openspace (unsigned long size)
  41 {
  42   char *buff = strbuffer(lbuffer.size+size);
  43   return buff+lbuffer.size;
  44 }
  45
  46 char *luaI_addchar (int c)
  47 {
  48   if (lbuffer.size >= lbuffer.max)
  49     strbuffer(lbuffer.max == 0 ? 100 : lbuffer.max*2);
  50   lbuffer.b[lbuffer.size++] = c;
  51   return lbuffer.b;
  52 }
  53
  54 void luaI_emptybuff (void)
  55 {
  56   lbuffer.size = 0;  /* prepare for next string */
  57 }
  58
  59
  60 static void addnchar (char *s, int n)
  61 {
  62   char *b = openspace(n);
  63   strncpy(b, s, n);
  64   lbuffer.size += n;
  65 }
  66
  67 static void addstr (char *s)
  68 {
  69   addnchar(s, strlen(s));
  70 }
  71
  72
  73 /*
  74 ** Return the string length
  75 */
  76 static void str_len (void)
  77 {
  78  lua_pushnumber(strlen(luaL_check_string(1)));
  79 }
  80
  81 /*
  82 ** Return the substring of a string
  83 */
  84 static void str_sub (void)
  85 {
  86   char *s = luaL_check_string(1);
  87   long l = strlen(s);
  88   long start = (long)luaL_check_number(2);
  89   long end = (long)luaL_opt_number(3, -1);
  90   if (start < 0) start = l+start+1;
  91   if (end < 0) end = l+end+1;
  92   if (1 <= start && start <= end && end <= l) {
  93     luaI_emptybuff();
  94     addnchar(s+start-1, end-start+1);
  95     lua_pushstring(luaI_addchar(0));
  96   }
  97   else lua_pushstring("");
  98 }
  99
 100 /*
 101 ** Convert a string to lower case.
 102 */
 103 static void str_lower (void)
 104 {
 105   char *s;
 106   luaI_emptybuff();
 107   for (s = luaL_check_string(1); *s; s++)
 108     luaI_addchar(tolower((unsigned char)*s));
 109   lua_pushstring(luaI_addchar(0));
 110 }
 111
 112 /*
 113 ** Convert a string to upper case.
 114 */
 115 static void str_upper (void)
 116 {
 117   char *s;
 118   luaI_emptybuff();
 119   for (s = luaL_check_string(1); *s; s++)
 120     luaI_addchar(toupper((unsigned char)*s));
 121   lua_pushstring(luaI_addchar(0));
 122 }
 123
 124 static void str_rep (void)
 125 {
 126   char *s = luaL_check_string(1);
 127   int n = (int)luaL_check_number(2);
 128   luaI_emptybuff();
 129   while (n-- > 0)
 130     addstr(s);
 131   lua_pushstring(luaI_addchar(0));
 132 }
 133
 134 /*
 135 ** get ascii value of a character in a string
 136 */
 137 static void str_ascii (void)
 138 {
 139   char *s = luaL_check_string(1);
 140   long pos = (long)luaL_opt_number(2, 1) - 1;
 141   luaL_arg_check(0<=pos && pos<strlen(s), 2,  "out of range");
 142   lua_pushnumber((unsigned char)s[pos]);
 143 }
 144
 145
 146 /* pattern matching */
 147
 148 #define ESC     '%'
 149 #define SPECIALS  "^$*?.([%-"
 150
 151 static char *bracket_end (char *p)
 152 {
 153   return (*p == 0) ? NULL : strchr((*p=='^') ? p+2 : p+1, ']');
 154 }
 155
 156 char *luaL_item_end (char *p)
 157 {
 158   switch (*p++) {
 159     case '\0': return p-1;
 160     case ESC:
 161       if (*p == 0) luaL_verror("incorrect pattern (ends with `%c')", ESC);
 162       return p+1;
 163     case '[': {
 164       char *end = bracket_end(p);
 165       if (end == NULL) lua_error("incorrect pattern (missing `]')");
 166       return end+1;
 167     }
 168     default:
 169       return p;
 170   }
 171 }
 172
 173 static int matchclass (int c, int cl)
 174 {
 175   int res;
 176   switch (tolower((unsigned char)cl)) {
 177     case 'a' : res = isalpha((unsigned char)c); break;
 178     case 'c' : res = iscntrl((unsigned char)c); break;
 179     case 'd' : res = isdigit((unsigned char)c); break;
 180     case 'l' : res = islower((unsigned char)c); break;
 181     case 'p' : res = ispunct((unsigned char)c); break;
 182     case 's' : res = isspace((unsigned char)c); break;
 183     case 'u' : res = isupper((unsigned char)c); break;
 184     case 'w' : res = isalnum((unsigned char)c); break;
 185     default: return (cl == c);
 186   }
 187   return (islower((unsigned char)cl) ? res : !res);
 188 }
 189
 190 int luaL_singlematch (int c, char *p)
 191 {
 192   if (c == 0) return 0;
 193   switch (*p) {
 194     case '.': return 1;
 195     case ESC: return matchclass(c, *(p+1));
 196     case '[': {
 197       char *end = bracket_end(p+1);
 198       int sig = *(p+1) == '^' ? (p++, 0) : 1;
 199       while (++p < end) {
 200         if (*p == ESC) {
 201           if (((p+1) < end) && matchclass(c, *++p)) return sig;
 202         }
 203         else if ((*(p+1) == '-') && (p+2 < end)) {
 204           p+=2;
 205           if (*(p-2) <= c && c <= *p) return sig;
 206         }
 207         else if (*p == c) return sig;
 208       }
 209       return !sig;
 210     }
 211     default: return (*p == c);
 212   }
 213 }
 214
 215 #define MAX_CAPT 9
 216
 217 static struct {
 218   char *init;
 219   int len;  /* -1 signals unfinished capture */
 220 } capture[MAX_CAPT];
 221
 222 static int num_captures;  /* only valid after a sucessful call to match */
 223
 224
 225 static void push_captures (void)
 226 {
 227   int i;
 228   for (i=0; i<num_captures; i++) {
 229     int l = capture[i].len;
 230     char *buff = openspace(l+1);
 231     if (l == -1) lua_error("unfinished capture");
 232     strncpy(buff, capture[i].init, l);
 233     buff[l] = 0;
 234     lua_pushstring(buff);
 235   }
 236 }
 237
 238 static int check_cap (int l, int level)
 239 {
 240   l -= '1';
 241   if (!(0 <= l && l < level && capture[l].len != -1))
 242     lua_error("invalid capture index");
 243   return l;
 244 }
 245
 246 static int capture_to_close (int level)
 247 {
 248   for (level--; level>=0; level--)
 249     if (capture[level].len == -1) return level;
 250   lua_error("invalid pattern capture");
 251   return 0;  /* to avoid warnings */
 252 }
 253
 254 static char *matchbalance (char *s, int b, int e)
 255 {
 256   if (*s != b) return NULL;
 257   else {
 258     int cont = 1;
 259     while (*(++s)) {
 260       if (*s == e) {
 261         if (--cont == 0) return s+1;
 262       }
 263       else if (*s == b) cont++;
 264     }
 265   }
 266   return NULL;  /* string ends out of balance */
 267 }
 268
 269 static char *match (char *s, char *p, int level)
 270 {
 271   init: /* using goto's to optimize tail recursion */
 272   switch (*p) {
 273     case '(':  /* start capture */
 274       if (level >= MAX_CAPT) lua_error("too many captures");
 275       capture[level].init = s;
 276       capture[level].len = -1;
 277       level++; p++; goto init;  /* return match(s, p+1, level); */
 278     case ')': {  /* end capture */
 279       int l = capture_to_close(level);
 280       char *res;
 281       capture[l].len = s - capture[l].init;  /* close capture */
 282       if ((res = match(s, p+1, level)) == NULL) /* match failed? */
 283         capture[l].len = -1;  /* undo capture */
 284       return res;
 285     }
 286     case ESC:
 287       if (isdigit((unsigned char)(*(p+1)))) {  /* capture */
 288         int l = check_cap(*(p+1), level);
 289         if (strncmp(capture[l].init, s, capture[l].len) == 0) {
 290           /* return match(p+2, s+capture[l].len, level); */
 291           p+=2; s+=capture[l].len; goto init;
 292         }
 293         else return NULL;
 294       }
 295       else if (*(p+1) == 'b') {  /* balanced string */
 296         if (*(p+2) == 0 || *(p+3) == 0)
 297           lua_error("bad balanced pattern specification");
 298         s = matchbalance(s, *(p+2), *(p+3));
 299         if (s == NULL) return NULL;
 300         else {  /* return match(p+4, s, level); */
 301           p+=4; goto init;
 302         }
 303       }
 304       else goto dflt;
 305     case '\0': case '$':  /* (possibly) end of pattern */
 306       if (*p == 0 || (*(p+1) == 0 && *s == 0)) {
 307         num_captures = level;
 308         return s;
 309       }
 310       else goto dflt;
 311     default: dflt: {  /* it is a pattern item */
 312       int m = luaL_singlematch(*s, p);
 313       char *ep = luaL_item_end(p);  /* get what is next */
 314       switch (*ep) {
 315         case '*': {  /* repetition */
 316           char *res;
 317           if (m && (res = match(s+1, p, level)))
 318             return res;
 319           p=ep+1; goto init;  /* else return match(s, ep+1, level); */
 320         }
 321         case '-': {  /* repetition */
 322           char *res;
 323           if ((res = match(s, ep+1, level)) != 0)
 324             return res;
 325           else if (m) {
 326             s++;
 327             goto init;  /* return match(s+1, p, level); */
 328           }
 329           else
 330             return NULL;
 331         }
 332         case '?': {  /* optional */
 333           char *res;
 334           if (m && (res = match(s+1, ep+1, level)))
 335             return res;
 336           p=ep+1; goto init;  /* else return match(s, ep+1, level); */
 337         }
 338         default:
 339           if (m) { s++; p=ep; goto init; }  /* return match(s+1, ep, level); */
 340           else return NULL;
 341       }
 342     }
 343   }
 344 }
 345
 346 static void str_find (void)
 347 {
 348   char *s = luaL_check_string(1);
 349   char *p = luaL_check_string(2);
 350   long init = (long)luaL_opt_number(3, 1) - 1;
 351   luaL_arg_check(0 <= init && init <= strlen(s), 3, "out of range");
 352   if (lua_getparam(4) != LUA_NOOBJECT ||
 353       strpbrk(p, SPECIALS) == NULL) {  /* no special caracters? */
 354     char *s2 = strstr(s+init, p);
 355     if (s2) {
 356       lua_pushnumber(s2-s+1);
 357       lua_pushnumber(s2-s+strlen(p));
 358     }
 359   }
 360   else {
 361     int anchor = (*p == '^') ? (p++, 1) : 0;
 362     char *s1=s+init;
 363     do {
 364       char *res;
 365       if ((res=match(s1, p, 0)) != NULL) {
 366         lua_pushnumber(s1-s+1);  /* start */
 367         lua_pushnumber(res-s);   /* end */
 368         push_captures();
 369         return;
 370       }
 371     } while (*s1++ && !anchor);
 372   }
 373 }
 374
 375 static void add_s (lua_Object newp, lua_Object table, int n)
 376 {
 377   if (lua_isstring(newp)) {
 378     char *news = lua_getstring(newp);
 379     while (*news) {
 380       if (*news != ESC || !isdigit((unsigned char)*++news))
 381         luaI_addchar(*news++);
 382       else {
 383         int l = check_cap(*news++, num_captures);
 384         addnchar(capture[l].init, capture[l].len);
 385       }
 386     }
 387   }
 388   else if (lua_isfunction(newp)) {
 389     lua_Object res;
 390     struct lbuff oldbuff;
 391     int status;
 392     lua_beginblock();
 393     if (lua_istable(table)) {
 394       lua_pushobject(table);
 395       lua_pushnumber(n);
 396     }
 397     push_captures();
 398     /* function may use lbuffer, so save it and create a new one */
 399     oldbuff = lbuffer;
 400     lbuffer.b = NULL; lbuffer.max = lbuffer.size = 0;
 401     status = lua_callfunction(newp);
 402     /* restore old buffer */
 403     free(lbuffer.b);
 404     lbuffer = oldbuff;
 405     if (status != 0)
 406       lua_error(NULL);
 407     res = lua_getresult(1);
 408     addstr(lua_isstring(res) ? lua_getstring(res) : "");
 409     lua_endblock();
 410   }
 411   else luaL_arg_check(0, 3, NULL);
 412 }
 413
 414 static void str_gsub (void)
 415 {
 416   char *src = luaL_check_string(1);
 417   char *p = luaL_check_string(2);
 418   lua_Object newp = lua_getparam(3);
 419   lua_Object table = lua_getparam(4);
 420   int max_s = (int)luaL_opt_number(lua_istable(table)?5:4, strlen(src)+1);
 421   int anchor = (*p == '^') ? (p++, 1) : 0;
 422   int n = 0;
 423   luaI_emptybuff();
 424   while (n < max_s) {
 425     char *e = match(src, p, 0);
 426     if (e) {
 427       n++;
 428       add_s(newp, table, n);
 429     }
 430     if (e && e>src) /* non empty match? */
 431       src = e;  /* skip it */
 432     else if (*src)
 433       luaI_addchar(*src++);
 434     else break;
 435     if (anchor) break;
 436   }
 437   addstr(src);
 438   lua_pushstring(luaI_addchar(0));
 439   lua_pushnumber(n);  /* number of substitutions */
 440 }
 441
 442 static void str_set (void)
 443 {
 444   char *item = luaL_check_string(1);
 445   int i;
 446   luaL_arg_check(*luaL_item_end(item) == 0, 1, "wrong format");
 447   luaI_emptybuff();
 448   for (i=1; i<256; i++)  /* 0 cannot be part of a set */
 449     if (luaL_singlematch(i, item))
 450       luaI_addchar(i);
 451   lua_pushstring(luaI_addchar(0));
 452 }
 453
 454
 455 void luaI_addquoted (char *s)
 456 {
 457   luaI_addchar('"');
 458   for (; *s; s++) {
 459     if (strchr("\"\\\n", *s))
 460       luaI_addchar('\\');
 461     luaI_addchar(*s);
 462   }
 463   luaI_addchar('"');
 464 }
 465
 466 #define MAX_FORMAT 200
 467
 468 static void str_format (void)
 469 {
 470   int arg = 1;
 471   char *strfrmt = luaL_check_string(arg++);
 472   luaI_emptybuff();  /* initialize */
 473   while (*strfrmt) {
 474     if (*strfrmt != '%')
 475       luaI_addchar(*strfrmt++);
 476     else if (*++strfrmt == '%')
 477       luaI_addchar(*strfrmt++);  /* %% */
 478     else { /* format item */
 479       char form[MAX_FORMAT];      /* store the format ('%...') */
 480       char *buff;
 481       char *initf = strfrmt-1;  /* -1 to include % */
 482       strfrmt = match(strfrmt, "[-+ #]*(%d*)%.?(%d*)", 0);
 483       if (capture[0].len > 3 || capture[1].len > 3)  /* < 1000? */
 484         lua_error("invalid format (width or precision too long)");
 485       strncpy(form, initf, strfrmt-initf+1); /* +1 to include convertion */
 486       form[strfrmt-initf+1] = 0;
 487       buff = openspace(1000);  /* to store the formated value */
 488       switch (*strfrmt++) {
 489         case 'q':
 490           luaI_addquoted(luaL_check_string(arg++));
 491           continue;
 492         case 's': {
 493           char *s = luaL_check_string(arg++);
 494           buff = openspace(strlen(s));
 495           sprintf(buff, form, s);
 496           break;
 497         }
 498         case 'c':  case 'd':  case 'i': case 'o':
 499         case 'u':  case 'x':  case 'X':
 500           sprintf(buff, form, (int)luaL_check_number(arg++));
 501           break;
 502         case 'e':  case 'E': case 'f': case 'g':
 503           sprintf(buff, form, luaL_check_number(arg++));
 504           break;
 505         default:  /* also treat cases 'pnLlh' */
 506           lua_error("invalid format option in function `format'");
 507       }
 508       lbuffer.size += strlen(buff);
 509     }
 510   }
 511   lua_pushstring(luaI_addchar(0));  /* push the result */
 512 }
 513
 514
 515 static struct luaL_reg strlib[] = {
 516 {"strlen", str_len},
 517 {"strsub", str_sub},
 518 {"strset", str_set},
 519 {"strlower", str_lower},
 520 {"strupper", str_upper},
 521 {"strrep", str_rep},
 522 {"ascii", str_ascii},
 523 {"format", str_format},
 524 {"strfind", str_find},
 525 {"gsub", str_gsub}
 526 };
 527
 528
 529 /*
 530 ** Open string library
 531 */
 532 void strlib_open (void)
 533 {
 534   luaL_openlib(strlib, (sizeof(strlib)/sizeof(strlib[0])));
 535 }