mpdm_r.c

   1 /*
   2
   3     MPDM - Minimum Profit Data Manager
   4     Copyright (C) 2003/2010 Angel Ortega <angel@triptico.com>
   5
   6     mpdm_r.c - Regular expressions
   7
   8     This program is free software; you can redistribute it and/or
   9     modify it under the terms of the GNU General Public License
  10     as published by the Free Software Foundation; either version 2
  11     of the License, or (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17
  18     You should have received a copy of the GNU General Public License
  19     along with this program; if not, write to the Free Software
  20     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21
  22     http://www.triptico.com
  23
  24 */
  25
  26 #include "config.h"
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <wchar.h>
  32
  33 #include "mpdm.h"
  34
  35 #ifdef CONFOPT_PCRE
  36 #include <pcreposix.h>
  37 #endif
  38
  39 #ifdef CONFOPT_SYSTEM_REGEX
  40 #include <regex.h>
  41 #endif
  42
  43 #ifdef CONFOPT_INCLUDED_REGEX
  44 #include "gnu_regex.h"
  45 #endif
  46
  47
  48 /** data **/
  49
  50 /* matching of the last regex */
  51
  52 int mpdm_regex_offset = -1;
  53 int mpdm_regex_size = 0;
  54
  55 /* number of substitutions in last sregex */
  56
  57 int mpdm_sregex_count = 0;
  58
  59
  60 /** code **/
  61
  62 static wchar_t *regex_flags(const mpdm_t r)
  63 {
  64     return wcsrchr((wchar_t *) r->data, *(wchar_t *) r->data);
  65 }
  66
  67
  68 static mpdm_t mpdm_regcomp(mpdm_t r)
  69 {
  70     mpdm_t c = NULL;
  71     mpdm_t regex_cache = NULL;
  72
  73     mpdm_ref(r);
  74
  75     /* if cache does not exist, create it */
  76     if ((regex_cache =
  77          mpdm_hget_s(mpdm_root(), L"__REGEX_CACHE__")) == NULL) {
  78         regex_cache = MPDM_H(0);
  79         mpdm_hset_s(mpdm_root(), L"__REGEX_CACHE__", regex_cache);
  80     }
  81
  82     /* search the regex in the cache */
  83     if ((c = mpdm_hget(regex_cache, r)) == NULL) {
  84         mpdm_t rmb;
  85         regex_t re;
  86         char *regex;
  87         char *flags;
  88         int f = REG_EXTENDED;
  89
  90         /* not found; regex must be compiled */
  91
  92         /* convert to mbs */
  93         rmb = mpdm_ref(MPDM_2MBS(r->data));
  94         regex = (char *) rmb->data;
  95
  96         if ((flags = strrchr(regex, *regex)) != NULL) {
  97
  98             if (strchr(flags, 'i') != NULL)
  99                 f |= REG_ICASE;
 100             if (strchr(flags, 'm') != NULL)
 101                 f |= REG_NEWLINE;
 102
 103             regex++;
 104             *flags = '\0';
 105
 106             if (!regcomp(&re, regex, f)) {
 107                 c = MPDM_C(MPDM_REGEX, &re, sizeof(regex_t));
 108                 mpdm_hset(regex_cache, r, c);
 109             }
 110         }
 111
 112         mpdm_unref(rmb);
 113     }
 114
 115     mpdm_unref(r);
 116
 117     return c;
 118 }
 119
 120
 121 static mpdm_t regex1(mpdm_t r, const mpdm_t v, int offset)
 122 /* test for one regex */
 123 {
 124     mpdm_t w = NULL;
 125     mpdm_t cr;
 126
 127     mpdm_ref(r);
 128     mpdm_ref(v);
 129
 130     /* no matching yet */
 131     mpdm_regex_offset = -1;
 132
 133     /* compile the regex */
 134     if ((cr = mpdm_regcomp(r)) != NULL) {
 135         regmatch_t rm;
 136         char *ptr;
 137         wchar_t *last;
 138         int o = 0;
 139         int f = 0;
 140
 141         /* takes pointer to 'last' flag */
 142         if ((last = regex_flags(r)) != NULL)
 143             last = wcschr(last, 'l');
 144
 145         /* convert to mbs */
 146         ptr = mpdm_wcstombs((wchar_t *) v->data + offset, NULL);
 147
 148         /* match? */
 149         while (regexec((regex_t *) cr->data, ptr + o, 1,
 150                        &rm, offset > 0 ? REG_NOTBOL : 0) == 0) {
 151             f++;
 152
 153             /* if 'last' is not set, it's done */
 154             if (last == NULL)
 155                 break;
 156
 157             rm.rm_so += o;
 158             rm.rm_eo += o;
 159             o = rm.rm_eo;
 160         }
 161
 162         if (f) {
 163             /* converts to mbs the string from the beginning
 164                to the start of the match, just to know
 165                the size (and immediately frees it) */
 166             free(mpdm_mbstowcs(ptr, &mpdm_regex_offset, rm.rm_so));
 167
 168             /* add the offset */
 169             mpdm_regex_offset += offset;
 170
 171             /* create now the matching string */
 172             w = MPDM_NMBS(ptr + rm.rm_so, rm.rm_eo - rm.rm_so);
 173
 174             /* and store the size */
 175             mpdm_regex_size = mpdm_size(w);
 176         }
 177
 178         free(ptr);
 179     }
 180
 181     mpdm_unref(v);
 182     mpdm_unref(r);
 183
 184     return w;
 185 }
 186
 187
 188 /**
 189  * mpdm_regex - Matches a regular expression.
 190  * @r: the regular expression
 191  * @v: the value to be matched
 192  * @offset: offset from the start of v->data
 193  *
 194  * Matches a regular expression against a value. Valid flags are 'i',
 195  * for case-insensitive matching, 'm', to treat the string as a
 196  * multiline string (i.e., one containing newline characters), so
 197  * that ^ and $ match the boundaries of each line instead of the
 198  * whole string, 'l', to return the last matching instead of the
 199  * first one, or 'g', to match globally; in that last case, an array
 200  * containing all matches is returned instead of a string scalar.
 201  *
 202  * If @r is a string, an ordinary regular expression matching is tried
 203  * over the @v string. If the matching is possible, the match result
 204  * is returned, or NULL otherwise.
 205  *
 206  * If @r is an array (of strings), each element is tried sequentially
 207  * as an individual regular expression over the @v string, each one using
 208  * the offset returned by the previous match. All regular expressions
 209  * must match to be successful. If this is the case, an array (with
 210  * the same number of arguments) is returned containing the matched
 211  * strings, or NULL otherwise.
 212  *
 213  * If @r is NULL, the result of the previous regex matching
 214  * is returned as a two element array. The first element will contain
 215  * the character offset of the matching and the second the number of
 216  * characters matched. If the previous regex was unsuccessful, NULL
 217  * is returned.
 218  * [Regular Expressions]
 219  */
 220 mpdm_t mpdm_regex(mpdm_t r, const mpdm_t v, int offset)
 221 {
 222     mpdm_t w = NULL;
 223
 224     mpdm_ref(r);
 225     mpdm_ref(v);
 226
 227     /* special case: if r is NULL, return previous match */
 228     if (r == NULL) {
 229         /* if previous regex was successful... */
 230         if (mpdm_regex_offset != -1) {
 231             w = MPDM_A(2);
 232
 233             mpdm_ref(w);
 234             mpdm_aset(w, MPDM_I(mpdm_regex_offset), 0);
 235             mpdm_aset(w, MPDM_I(mpdm_regex_size), 1);
 236             mpdm_unrefnd(w);
 237         }
 238     }
 239     else
 240     if (v != NULL) {
 241         if (r->flags & MPDM_MULTIPLE) {
 242             int n;
 243             mpdm_t t;
 244
 245             /* multiple value; try sequentially all regexes,
 246                moving the offset forward */
 247
 248             w = MPDM_A(0);
 249             mpdm_ref(w);
 250
 251             for (n = 0; n < mpdm_size(r); n++) {
 252                 t = mpdm_regex(mpdm_aget(r, n), v, offset);
 253
 254                 if (t == NULL)
 255                     break;
 256
 257                 /* found; store and move forward */
 258                 mpdm_push(w, t);
 259                 offset = mpdm_regex_offset + mpdm_regex_size;
 260             }
 261
 262             mpdm_unrefnd(w);
 263         }
 264         else {
 265             wchar_t *global;
 266
 267             /* takes pointer to 'global' flag */
 268             if ((global = regex_flags(r)) !=NULL)
 269                 global = wcschr(global, 'g');
 270
 271             if (global !=NULL) {
 272                 mpdm_t t;
 273
 274                 /* match sequentially until done */
 275                 w = MPDM_A(0);
 276                 mpdm_ref(w);
 277
 278                 while ((t = regex1(r, v, offset)) != NULL) {
 279                     mpdm_push(w, t);
 280
 281                     offset = mpdm_regex_offset + mpdm_regex_size;
 282                 }
 283
 284                 mpdm_unrefnd(w);
 285             }
 286             else
 287                 w = regex1(r, v, offset);
 288         }
 289     }
 290
 291     mpdm_unref(v);
 292     mpdm_unref(r);
 293
 294     return w;
 295 }
 296
 297
 298 static mpdm_t expand_ampersands(const mpdm_t s, const mpdm_t t)
 299 /* substitutes all unescaped ampersands in s with t */
 300 {
 301     const wchar_t *sptr = mpdm_string(s);
 302     wchar_t *wptr;
 303     wchar_t *optr = NULL;
 304     int osize = 0;
 305     mpdm_t r = NULL;
 306
 307     mpdm_ref(s);
 308     mpdm_ref(t);
 309
 310     if (s != NULL) {
 311         while ((wptr = wcschr(sptr, L'\\')) != NULL ||
 312                (wptr = wcschr(sptr, L'&')) != NULL) {
 313             int n = wptr - sptr;
 314
 315             /* add the leading part */
 316             optr = mpdm_pokewsn(optr, &osize, sptr, n);
 317
 318             if (*wptr == L'\\') {
 319                 if (*(wptr + 1) == L'&' || *(wptr + 1) == L'\\')
 320                     wptr++;
 321
 322                 optr = mpdm_pokewsn(optr, &osize, wptr, 1);
 323             }
 324             else
 325             if (*wptr == '&')
 326                 optr = mpdm_pokev(optr, &osize, t);
 327
 328             sptr = wptr + 1;
 329         }
 330
 331         /* add the rest of the string */
 332         optr = mpdm_pokews(optr, &osize, sptr);
 333         optr = mpdm_pokewsn(optr, &osize, L"", 1);
 334         r = MPDM_ENS(optr, osize - 1);
 335     }
 336
 337     mpdm_unref(t);
 338     mpdm_unref(s);
 339
 340     return r;
 341 }
 342
 343
 344 /**
 345  * mpdm_sregex - Matches and substitutes a regular expression.
 346  * @r: the regular expression
 347  * @v: the value to be matched
 348  * @s: the substitution string, hash or code
 349  * @offset: offset from the start of v->data
 350  *
 351  * Matches a regular expression against a value, and substitutes the
 352  * found substring with @s. Valid flags are 'i', for case-insensitive
 353  * matching, and 'g', for global replacements (all ocurrences in @v
 354  * will be replaced, instead of just the first found one).
 355  *
 356  * If @s is executable, it's executed with the matched part as
 357  * the only argument and its return value is used as the
 358  * substitution string.
 359  *
 360  * If @s is a hash, the matched string is used as a key to it and
 361  * its value used as the substitution. If this value itself is
 362  * executable, it's executed with the matched string as its only
 363  * argument and its return value used as the substitution.
 364  *
 365  * If @r is NULL, returns the number of substitutions made in the
 366  * previous call to mpdm_sregex() (can be zero if none was done).
 367  *
 368  * The global variables @mpdm_regex_offset and @mpdm_regex_size are
 369  * set to the offset of the matched string and the size of the
 370  * replaced string, respectively.
 371  *
 372  * Always returns a new string (either modified or an exact copy).
 373  * [Regular Expressions]
 374  */
 375 mpdm_t mpdm_sregex(mpdm_t r, const mpdm_t v, const mpdm_t s, int offset)
 376 {
 377     mpdm_t cr;
 378     wchar_t *optr = NULL;
 379     int osize = 0;
 380     mpdm_t o = NULL;
 381
 382     mpdm_ref(r);
 383     mpdm_ref(v);
 384     mpdm_ref(s);
 385
 386     if (r == NULL) {
 387         /* return last count */
 388         o = MPDM_I(mpdm_sregex_count);
 389     }
 390     else
 391     if (v != NULL) {
 392         /* compile the regex */
 393         if ((cr = mpdm_regcomp(r)) != NULL) {
 394             char *ptr;
 395             int f, i = 0;
 396             wchar_t *global;
 397             mpdm_t t;
 398
 399             /* takes pointer to global flag */
 400             if ((global = regex_flags(r)) !=NULL)
 401                 global = wcschr(global, 'g');
 402
 403             /* store the first part */
 404             optr = mpdm_pokewsn(optr, &osize, v->data, offset);
 405
 406             /* convert to mbs */
 407             ptr = mpdm_wcstombs((wchar_t *) v->data + offset, NULL);
 408
 409             /* reset count */
 410             mpdm_sregex_count = 0;
 411             mpdm_regex_offset = -1;
 412
 413             do {
 414                 regmatch_t rm;
 415
 416                 /* try match */
 417                 f = !regexec((regex_t *) cr->data, ptr + i,
 418                              1, &rm, offset > 0 ? REG_NOTBOL : 0);
 419
 420                 if (f) {
 421                     /* creates a string from the beginning
 422                        to the start of the match */
 423                     t = mpdm_ref(MPDM_NMBS(ptr + i, rm.rm_so));
 424                     optr = mpdm_pokev(optr, &osize, t);
 425
 426                     /* store offset of substitution */
 427                     mpdm_regex_offset = mpdm_size(t) + offset;
 428
 429                     mpdm_unref(t);
 430
 431                     /* get the matched part */
 432                     t = MPDM_NMBS(ptr + i + rm.rm_so, rm.rm_eo - rm.rm_so);
 433
 434                     /* is s an executable value? */
 435                     if (MPDM_IS_EXEC(s)) {
 436                         /* execute s, with t as argument */
 437                         t = mpdm_exec_1(s, t, NULL);
 438                     }
 439                     else
 440                         /* is s a hash? use match as key */
 441                     if (MPDM_IS_HASH(s)) {
 442                         mpdm_t v;
 443
 444                         mpdm_ref(t);
 445                         v = mpdm_hget(s, t);
 446
 447                         /* is the value executable? */
 448                         if (MPDM_IS_EXEC(v)) {
 449                             mpdm_t w = mpdm_ref(v);
 450
 451                             v = mpdm_exec_1(w, t, NULL);
 452
 453                             mpdm_unref(w);
 454                         }
 455
 456                         mpdm_unref(t);
 457
 458                         t = v;
 459                     }
 460                     else
 461                         t = expand_ampersands(s, t);
 462
 463                     /* appends the substitution string */
 464                     mpdm_ref(t);
 465
 466                     optr = mpdm_pokev(optr, &osize, t);
 467
 468                     /* store size of substitution */
 469                     mpdm_regex_size = mpdm_size(t);
 470
 471                     mpdm_unref(t);
 472
 473                     i += rm.rm_eo;
 474
 475                     /* one more substitution */
 476                     mpdm_sregex_count++;
 477                 }
 478             } while (f && global);
 479
 480             /* no (more) matches; convert and append the rest */
 481             t = MPDM_MBS(ptr + i);
 482             optr = mpdm_pokev(optr, &osize, t);
 483
 484             free(ptr);
 485         }
 486
 487         /* NULL-terminate */
 488         optr = mpdm_pokewsn(optr, &osize, L"", 1);
 489
 490         o = MPDM_ENS(optr, osize - 1);
 491     }
 492
 493     mpdm_unref(s);
 494     mpdm_unref(v);
 495     mpdm_unref(r);
 496
 497     return o;
 498 }