diplodocus.org Git - nmh/blob - uip/picksbr.c

   1 /* picksbr.c -- routines to help pick along...
   2  *
   3  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   4  * COPYRIGHT file in the root directory of the nmh distribution for
   5  * complete copyright information.
   6  */
   7
   8 #include <h/mh.h>
   9 #include <h/tws.h>
  10 #include <h/picksbr.h>
  11 #include <h/utils.h>
  12
  13 #ifdef HAVE_SYS_TIME_H
  14 # include <sys/time.h>
  15 #endif
  16 #include <time.h>
  17
  18 #define PARSE_SWITCHES \
  19     X("and", 0, PRAND) \
  20     X("or", 0, PROR) \
  21     X("not", 0, PRNOT) \
  22     X("lbrace", 0, PRLBR) \
  23     X("rbrace", 0, PRRBR) \
  24     X("cc  pattern", 0, PRCC) \
  25     X("date  pattern", 0, PRDATE) \
  26     X("from  pattern", 0, PRFROM) \
  27     X("search  pattern", 0, PRSRCH) \
  28     X("subject  pattern", 0, PRSUBJ) \
  29     X("to  pattern", 0, PRTO) \
  30     X("-othercomponent  pattern", 15, PROTHR) \
  31     X("after date", 0, PRAFTR) \
  32     X("before date", 0, PRBEFR) \
  33     X("datefield field", 5, PRDATF) \
  34
  35 #define X(sw, minchars, id) id,
  36 DEFINE_SWITCH_ENUM(PARSE);
  37 #undef X
  38
  39 #define X(sw, minchars, id) { sw, minchars, id },
  40 DEFINE_SWITCH_ARRAY(PARSE, parswit);
  41 #undef X
  42
  43 /* DEFINITIONS FOR PATTERN MATCHING */
  44
  45 /*
  46  * We really should be using re_comp() and re_exec() here.  Unfortunately,
  47  * pick advertises that lowercase characters matches characters of both
  48  * cases.  Since re_exec() doesn't exhibit this behavior, we are stuck
  49  * with this version.  Furthermore, we need to be able to save and restore
  50  * the state of the pattern matcher in order to do things "efficiently".
  51  *
  52  * The matching power of this algorithm isn't as powerful as the re_xxx()
  53  * routines (no \(xxx\) and \n constructs).  Such is life.
  54  */
  55
  56 #define CCHR    2
  57 #define CDOT    4
  58 #define CCL     6
  59 #define NCCL    8
  60 #define CDOL    10
  61 #define CEOF    11
  62
  63 #define STAR    01
  64
  65 #define LBSIZE  NMH_BUFSIZ
  66 #define ESIZE   1024
  67
  68
  69 static char linebuf[LBSIZE + 1];
  70 static char decoded_linebuf[LBSIZE + 1];
  71
  72 /* the magic array for case-independence */
  73 static unsigned char cc[] = {
  74         0000,0001,0002,0003,0004,0005,0006,0007,
  75         0010,0011,0012,0013,0014,0015,0016,0017,
  76         0020,0021,0022,0023,0024,0025,0026,0027,
  77         0030,0031,0032,0033,0034,0035,0036,0037,
  78         0040,0041,0042,0043,0044,0045,0046,0047,
  79         0050,0051,0052,0053,0054,0055,0056,0057,
  80         0060,0061,0062,0063,0064,0065,0066,0067,
  81         0070,0071,0072,0073,0074,0075,0076,0077,
  82         0100,0141,0142,0143,0144,0145,0146,0147,
  83         0150,0151,0152,0153,0154,0155,0156,0157,
  84         0160,0161,0162,0163,0164,0165,0166,0167,
  85         0170,0171,0172,0133,0134,0135,0136,0137,
  86         0140,0141,0142,0143,0144,0145,0146,0147,
  87         0150,0151,0152,0153,0154,0155,0156,0157,
  88         0160,0161,0162,0163,0164,0165,0166,0167,
  89         0170,0171,0172,0173,0174,0175,0176,0177,
  90
  91         0200,0201,0202,0203,0204,0205,0206,0207,
  92         0210,0211,0212,0213,0214,0215,0216,0217,
  93         0220,0221,0222,0223,0224,0225,0226,0227,
  94         0230,0231,0232,0233,0234,0235,0236,0237,
  95         0240,0241,0242,0243,0244,0245,0246,0247,
  96         0250,0251,0252,0253,0254,0255,0256,0257,
  97         0260,0261,0262,0263,0264,0265,0266,0267,
  98         0270,0271,0272,0273,0274,0275,0276,0277,
  99         0300,0301,0302,0303,0304,0305,0306,0307,
 100         0310,0311,0312,0313,0314,0315,0316,0317,
 101         0320,0321,0322,0323,0324,0325,0326,0327,
 102         0330,0331,0332,0333,0334,0335,0336,0337,
 103         0340,0341,0342,0343,0344,0345,0346,0347,
 104         0350,0351,0352,0353,0354,0355,0356,0357,
 105         0360,0361,0362,0363,0364,0365,0366,0367,
 106         0370,0371,0372,0373,0374,0375,0376,0377,
 107 };
 108
 109 /*
 110  * DEFINITIONS FOR NEXUS
 111  */
 112
 113 #define nxtarg()        (*argp ? *argp++ : NULL)
 114 #define prvarg()        argp--
 115
 116 #define pinform         if (!talked++) inform
 117
 118 struct nexus {
 119     int (*n_action)(struct nexus *n, FILE *fp, int msgnum, long start, long stop);
 120
 121     union {
 122         /* for {OR,AND,NOT}action */
 123         struct {
 124             struct nexus *un_L_child;
 125             struct nexus *un_R_child;
 126         } st1;
 127
 128         /* for GREPaction */
 129         struct {
 130             int   un_header;
 131             int   un_circf;
 132             char  un_expbuf[ESIZE];
 133             char *un_patbuf;
 134         } st2;
 135
 136         /* for TWSaction */
 137         struct {
 138             char *un_datef;
 139             int   un_after;
 140             struct tws un_tws;
 141         } st3;
 142     } un;
 143 };
 144
 145 #define n_L_child un.st1.un_L_child
 146 #define n_R_child un.st1.un_R_child
 147
 148 #define n_header un.st2.un_header
 149 #define n_circf  un.st2.un_circf
 150 #define n_expbuf un.st2.un_expbuf
 151 #define n_patbuf un.st2.un_patbuf
 152
 153 #define n_datef  un.st3.un_datef
 154 #define n_after  un.st3.un_after
 155 #define n_tws    un.st3.un_tws
 156
 157 static int talked;
 158
 159 static char *datesw;
 160 static char **argp;
 161
 162 static struct nexus *head;
 163
 164 /*
 165  * prototypes for date routines
 166  */
 167 static struct tws *tws_parse(char *, int);
 168 static struct tws *tws_special(char *);
 169
 170 /*
 171  * static prototypes
 172  */
 173 static void PRaction(struct nexus *, int);
 174 static int gcompile(struct nexus *, char *);
 175 static int advance(char *, char *);
 176 static int cclass(unsigned char *, int, int);
 177 static int tcompile(char *, struct tws *, int);
 178
 179 static struct nexus *parse(void);
 180 static struct nexus *nexp1(void);
 181 static struct nexus *nexp2(void);
 182 static struct nexus *nexp3(void);
 183 static struct nexus *newnexus(int (*action)(struct nexus *n,
 184     FILE *fp, int msgnum, long start, long stop));
 185
 186 static int ORaction(struct nexus *n, FILE *fp, int msgnum,
 187     long start, long stop);
 188 static int ANDaction(struct nexus *n, FILE *fp, int msgnum,
 189     long start, long stop);
 190 static int NOTaction(struct nexus *n, FILE *fp, int msgnum,
 191     long start, long stop);
 192 static int GREPaction(struct nexus *n, FILE *fp, int msgnum,
 193     long start, long stop);
 194 static int TWSaction(struct nexus *n, FILE *fp, int msgnum,
 195     long start, long stop);
 196
 197
 198 int
 199 pcompile (char **vec, char *date)
 200 {
 201     argp = vec;
 202     if ((datesw = date) == NULL)
 203         datesw = "date";
 204     talked = 0;
 205
 206     if ((head = parse ()) == NULL)
 207         return !talked;
 208
 209     if (*argp) {
 210         inform("%s unexpected", *argp);
 211         return 0;
 212     }
 213
 214     return 1;
 215 }
 216
 217
 218 static struct nexus *
 219 parse (void)
 220 {
 221     char  *cp;
 222     struct nexus *n, *o;
 223
 224     if ((n = nexp1 ()) == NULL || (cp = nxtarg ()) == NULL)
 225         return n;
 226
 227     if (*cp != '-') {
 228         pinform("%s unexpected", cp);
 229         return NULL;
 230     }
 231
 232     if (*++cp == '-')
 233         goto header;
 234     switch (smatch (cp, parswit)) {
 235         case AMBIGSW:
 236             ambigsw (cp, parswit);
 237             talked++;
 238             return NULL;
 239         case UNKWNSW:
 240             fprintf (stderr, "-%s unknown\n", cp);
 241             talked++;
 242             return NULL;
 243
 244         case PROR:
 245             o = newnexus (ORaction);
 246             o->n_L_child = n;
 247             if ((o->n_R_child = parse ()))
 248                 return o;
 249             pinform("missing disjunctive");
 250             free (o);
 251             return NULL;
 252
 253 header: ;
 254         default:
 255             prvarg ();
 256             return n;
 257     }
 258 }
 259
 260 static struct nexus *
 261 nexp1 (void)
 262 {
 263     char *cp;
 264     struct nexus *n, *o;
 265
 266     if ((n = nexp2 ()) == NULL || (cp = nxtarg ()) == NULL)
 267         return n;
 268
 269     if (*cp != '-') {
 270         pinform("%s unexpected", cp);
 271         free (n);
 272         return NULL;
 273     }
 274
 275     if (*++cp == '-')
 276         goto header;
 277     switch (smatch (cp, parswit)) {
 278         case AMBIGSW:
 279             ambigsw (cp, parswit);
 280             talked++;
 281             free (n);
 282             return NULL;
 283         case UNKWNSW:
 284             fprintf (stderr, "-%s unknown\n", cp);
 285             talked++;
 286             free (n);
 287             return NULL;
 288
 289         case PRAND:
 290             o = newnexus (ANDaction);
 291             o->n_L_child = n;
 292             if ((o->n_R_child = nexp1 ()))
 293                 return o;
 294             pinform("missing conjunctive");
 295             free (o);
 296             return NULL;
 297
 298 header: ;
 299         default:
 300             prvarg ();
 301             return n;
 302     }
 303 }
 304
 305
 306 static struct nexus *
 307 nexp2 (void)
 308 {
 309     char *cp;
 310     struct nexus *n;
 311
 312     if ((cp = nxtarg ()) == NULL)
 313         return NULL;
 314
 315     if (*cp != '-') {
 316         prvarg ();
 317         return nexp3 ();
 318     }
 319
 320     if (*++cp == '-')
 321         goto header;
 322     switch (smatch (cp, parswit)) {
 323         case AMBIGSW:
 324             ambigsw (cp, parswit);
 325             talked++;
 326             return NULL;
 327         case UNKWNSW:
 328             fprintf (stderr, "-%s unknown\n", cp);
 329             talked++;
 330             return NULL;
 331
 332         case PRNOT:
 333             n = newnexus (NOTaction);
 334             if ((n->n_L_child = nexp3 ()))
 335                 return n;
 336             pinform("missing negation");
 337             free (n);
 338             return NULL;
 339
 340 header: ;
 341         default:
 342             prvarg ();
 343             return nexp3 ();
 344     }
 345 }
 346
 347 static struct nexus *
 348 nexp3 (void)
 349 {
 350     int i;
 351     char *cp, *dp;
 352     char buffer[BUFSIZ], temp[64];
 353     struct nexus *n;
 354
 355     if ((cp = nxtarg ()) == NULL)
 356         return NULL;
 357
 358     if (*cp != '-') {
 359         pinform("%s unexpected", cp);
 360         return NULL;
 361     }
 362
 363     if (*++cp == '-') {
 364         dp = ++cp;
 365         goto header;
 366     }
 367     switch (i = smatch (cp, parswit)) {
 368         case AMBIGSW:
 369             ambigsw (cp, parswit);
 370             talked++;
 371             return NULL;
 372         case UNKWNSW:
 373             fprintf (stderr, "-%s unknown\n", cp);
 374             talked++;
 375             return NULL;
 376
 377         case PRLBR:
 378             if ((n = parse ()) == NULL) {
 379                 pinform("missing group");
 380                 return NULL;
 381             }
 382             if ((cp = nxtarg ()) == NULL) {
 383                 pinform("missing -rbrace");
 384                 return NULL;
 385             }
 386             if (*cp++ == '-' && smatch (cp, parswit) == PRRBR)
 387                 return n;
 388             pinform("%s unexpected", --cp);
 389             return NULL;
 390
 391         default:
 392             prvarg ();
 393             return NULL;
 394
 395         case PRCC:
 396         case PRDATE:
 397         case PRFROM:
 398         case PRTO:
 399         case PRSUBJ:
 400             strncpy(temp, parswit[i].sw, sizeof(temp));
 401             temp[sizeof(temp) - 1] = '\0';
 402             dp = *brkstring (temp, " ", NULL);
 403     header: ;
 404             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 405                 pinform("missing argument to %s", argp[-2]);
 406                 return NULL;
 407             }
 408             n = newnexus (GREPaction);
 409             n->n_header = 1;
 410             snprintf (buffer, sizeof(buffer), "^%s[ \t]*:.*%s", dp, cp);
 411             dp = buffer;
 412             goto pattern;
 413
 414         case PRSRCH:
 415             n = newnexus (GREPaction);
 416             n->n_header = 0;
 417             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 418                 pinform("missing argument to %s", argp[-2]);
 419                 free (n);
 420                 return NULL;
 421             }
 422             dp = cp;
 423     pattern: ;
 424             if (!gcompile (n, dp)) {
 425                 pinform("pattern error in %s %s", argp[-2], cp);
 426                 free (n);
 427                 return NULL;
 428             }
 429             n->n_patbuf = mh_xstrdup(dp);
 430             return n;
 431
 432         case PROTHR:
 433             pinform("internal error!");
 434             return NULL;
 435
 436         case PRDATF:
 437             if (!(datesw = nxtarg ()) || *datesw == '-') {
 438                 pinform("missing argument to %s", argp[-2]);
 439                 return NULL;
 440             }
 441             return nexp3 ();
 442
 443         case PRAFTR:
 444         case PRBEFR:
 445             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 446                 pinform("missing argument to %s", argp[-2]);
 447                 return NULL;
 448             }
 449             n = newnexus (TWSaction);
 450             n->n_datef = datesw;
 451             if (!tcompile (cp, &n->n_tws, n->n_after = i == PRAFTR)) {
 452                 pinform("unable to parse %s %s", argp[-2], cp);
 453                 free (n);
 454                 return NULL;
 455             }
 456             return n;
 457     }
 458 }
 459
 460
 461 static struct nexus *
 462 newnexus(int (*action)(struct nexus *n, FILE *fp, int msgnum,
 463     long start, long stop))
 464 {
 465     struct nexus *p;
 466
 467     NEW0(p);
 468     p->n_action = action;
 469     return p;
 470 }
 471
 472
 473 int
 474 pmatches (FILE *fp, int msgnum, long start, long stop, int debug)
 475 {
 476     if (!head)
 477         return 1;
 478
 479     if (!talked++ && debug)
 480         PRaction (head, 0);
 481
 482     return (*head->n_action)(head, fp, msgnum, start, stop);
 483 }
 484
 485
 486 static void
 487 PRaction (struct nexus *n, int level)
 488 {
 489     int i;
 490
 491     for (i = 0; i < level; i++)
 492         fprintf (stderr, "| ");
 493
 494     if (n->n_action == ORaction) {
 495         fprintf (stderr, "OR\n");
 496         PRaction (n->n_L_child, level + 1);
 497         PRaction (n->n_R_child, level + 1);
 498         return;
 499     }
 500     if (n->n_action == ANDaction) {
 501         fprintf (stderr, "AND\n");
 502         PRaction (n->n_L_child, level + 1);
 503         PRaction (n->n_R_child, level + 1);
 504         return;
 505     }
 506     if (n->n_action == NOTaction) {
 507         fprintf (stderr, "NOT\n");
 508         PRaction (n->n_L_child, level + 1);
 509         return;
 510     }
 511     if (n->n_action == GREPaction) {
 512         fprintf (stderr, "PATTERN(%s) %s\n",
 513                 n->n_header ? "header" : "body", n->n_patbuf);
 514         return;
 515     }
 516     if (n->n_action == TWSaction) {
 517         fprintf (stderr, "TEMPORAL(%s) %s: %s\n",
 518                 n->n_after ? "after" : "before", n->n_datef,
 519                 dasctime (&n->n_tws, TW_NULL));
 520         return;
 521     }
 522     fprintf(stderr, "UNKNOWN(%#llx)\n", (unsigned long long)n->n_action);
 523 }
 524
 525
 526 static int
 527 ORaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 528 {
 529     if ((*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop))
 530         return 1;
 531     return (*n->n_R_child->n_action)(n->n_R_child, fp, msgnum, start, stop);
 532 }
 533
 534
 535 static int
 536 ANDaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 537 {
 538     if (!(*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop))
 539         return 0;
 540     return (*n->n_R_child->n_action)(n->n_R_child, fp, msgnum, start, stop);
 541 }
 542
 543
 544 static int
 545 NOTaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 546 {
 547     return (!(*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop));
 548 }
 549
 550
 551 static int
 552 gcompile (struct nexus *n, char *astr)
 553 {
 554     int c;
 555     int cclcnt;
 556     unsigned char *ep, *dp, *sp, *lastep = 0;
 557
 558     dp = (ep = (unsigned char *) n->n_expbuf) + sizeof n->n_expbuf;
 559     sp = (unsigned char *) astr;
 560     if (*sp == '^') {
 561         n->n_circf = 1;
 562         sp++;
 563     }
 564     else
 565         n->n_circf = 0;
 566     for (;;) {
 567         if (ep >= dp)
 568             goto cerror;
 569         if ((c = *sp++) != '*')
 570             lastep = ep;
 571         switch (c) {
 572             case '\0':
 573                 *ep++ = CEOF;
 574                 return 1;
 575
 576             case '.':
 577                 *ep++ = CDOT;
 578                 continue;
 579
 580             case '*':
 581                 if (lastep == 0)
 582                     goto defchar;
 583                 *lastep |= STAR;
 584                 continue;
 585
 586             case '$':
 587                 if (*sp != '\0')
 588                     goto defchar;
 589                 *ep++ = CDOL;
 590                 continue;
 591
 592             case '[':
 593                 *ep++ = CCL;
 594                 *ep++ = 0;
 595                 cclcnt = 0;
 596                 if ((c = *sp++) == '^') {
 597                     c = *sp++;
 598                     ep[-2] = NCCL;
 599                 }
 600                 if (c == '-') {
 601                     *ep++ = c;
 602                     cclcnt++;
 603                     c = *sp++;
 604                 }
 605                 do {
 606                     if (c == '-' && *sp != '\0' && *sp != ']') {
 607                         for (c = ep[-1]+1; c < *sp; c++) {
 608                             *ep++ = c;
 609                             cclcnt++;
 610                             if (c == '\0' || ep >= dp)
 611                                 goto cerror;
 612                         }
 613                     } else {
 614                         *ep++ = c;
 615                         cclcnt++;
 616                         if (c == '\0' || ep >= dp)
 617                             goto cerror;
 618                     }
 619                 } while ((c = *sp++) != ']');
 620                 if (cclcnt > 255)
 621                     goto cerror;
 622                 lastep[1] = cclcnt;
 623                 continue;
 624
 625             case '\\':
 626                 if ((c = *sp++) == '\0')
 627                     goto cerror;
 628                 /* FALLTHRU */
 629         defchar:
 630             default:
 631                 *ep++ = CCHR;
 632                 *ep++ = c;
 633         }
 634     }
 635
 636 cerror: ;
 637     return 0;
 638 }
 639
 640
 641 static int
 642 GREPaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 643 {
 644     int c, body, lf;
 645     long pos = start;
 646     char *p1, *p2, *ebp, *cbp;
 647     char ibuf[BUFSIZ];
 648     NMH_UNUSED (msgnum);
 649
 650     fseek (fp, start, SEEK_SET);
 651     body = 0;
 652     ebp = cbp = ibuf;
 653     for (;;) {
 654         if (body && n->n_header)
 655             return 0;
 656         p1 = linebuf;
 657         p2 = cbp;
 658         lf = 0;
 659         for (;;) {
 660             if (p2 >= ebp) {
 661                 if (fgets (ibuf, sizeof ibuf, fp) == NULL
 662                         || (stop && pos >= stop)) {
 663                     if (lf)
 664                         break;
 665                     return 0;
 666                 }
 667                 pos += (long) strlen (ibuf);
 668                 p2 = ibuf;
 669                 ebp = ibuf + strlen (ibuf);
 670             }
 671             c = *p2++;
 672             if (lf && c != '\n') {
 673                 if (c != ' ' && c != '\t') {
 674                     --p2;
 675                     break;
 676                 }
 677                 lf = 0;
 678             }
 679             if (c == '\n') {
 680                 if (body)
 681                     break;
 682                 if (lf) {
 683                     body++;
 684                     break;
 685                 }
 686                 lf++;
 687                 /* Unfold by skipping the newline. */
 688                 c = 0;
 689             }
 690             if (c && p1 < &linebuf[LBSIZE - 1])
 691                 *p1++ = c;
 692         }
 693
 694         *p1++ = 0;
 695         cbp = p2;
 696         p1 = linebuf;
 697         p2 = n->n_expbuf;
 698
 699         /* Attempt to decode as a MIME header.  If it's the last header,
 700            body will be 1 and lf will be at least 1. */
 701         if ((body == 0 || lf > 0)  &&
 702             decode_rfc2047 (linebuf, decoded_linebuf, sizeof decoded_linebuf)) {
 703             p1 = decoded_linebuf;
 704         }
 705
 706         if (n->n_circf) {
 707             if (advance (p1, p2))
 708                 return 1;
 709             continue;
 710         }
 711
 712         if (*p2 == CCHR) {
 713             c = p2[1];
 714             do {
 715                 if (*p1 == c || cc[(unsigned char)*p1] == c)
 716                     if (advance (p1, p2))
 717                         return 1;
 718             } while (*p1++);
 719             continue;
 720         }
 721
 722         do {
 723             if (advance (p1, p2))
 724                 return 1;
 725         } while (*p1++);
 726     }
 727 }
 728
 729
 730 static int
 731 advance (char *alp, char *aep)
 732 {
 733     unsigned char *lp, *ep, *curlp;
 734
 735     lp = (unsigned char *)alp;
 736     ep = (unsigned char *)aep;
 737     for (;;)
 738         switch (*ep++) {
 739             case CCHR:
 740                 if (*ep++ == *lp++ || ep[-1] == cc[lp[-1]])
 741                     continue;
 742                 return 0;
 743
 744             case CDOT:
 745                 if (*lp++)
 746                     continue;
 747                 return 0;
 748
 749             case CDOL:
 750                 if (*lp == 0)
 751                     continue;
 752                 return 0;
 753
 754             case CEOF:
 755                 return 1;
 756
 757             case CCL:
 758                 if (cclass (ep, *lp++, 1)) {
 759                     ep += *ep + 1;
 760                     continue;
 761                 }
 762                 return 0;
 763
 764             case NCCL:
 765                 if (cclass (ep, *lp++, 0)) {
 766                     ep += *ep + 1;
 767                     continue;
 768                 }
 769                 return 0;
 770
 771             case CDOT | STAR:
 772                 curlp = lp;
 773                 while (*lp++)
 774                     continue;
 775                 goto star;
 776
 777             case CCHR | STAR:
 778                 curlp = lp;
 779                 while (*lp++ == *ep || cc[lp[-1]] == *ep)
 780                     continue;
 781                 ep++;
 782                 goto star;
 783
 784             case CCL | STAR:
 785             case NCCL | STAR:
 786                 curlp = lp;
 787                 while (cclass (ep, *lp++, ep[-1] == (CCL | STAR)))
 788                     continue;
 789                 ep += *ep + 1;
 790                 goto star;
 791
 792         star:
 793                 do {
 794                     lp--;
 795                     if (advance ((char *) lp, (char *) ep))
 796                         return (1);
 797                 } while (lp > curlp);
 798                 return 0;
 799
 800             default:
 801                 inform("advance() botch -- you lose big, continuing...");
 802                 return 0;
 803         }
 804 }
 805
 806
 807 static int
 808 cclass (unsigned char *aset, int ac, int af)
 809 {
 810     unsigned int    n;
 811     unsigned char   c, *set;
 812
 813     set = aset;
 814     if ((c = ac) == 0)
 815         return (0);
 816
 817     n = *set++;
 818     while (n--)
 819         if (*set++ == c || set[-1] == cc[c])
 820             return (af);
 821
 822     return (!af);
 823 }
 824
 825
 826 static int
 827 tcompile (char *ap, struct tws *tb, int isafter)
 828 {
 829     struct tws *tw;
 830
 831     if ((tw = tws_parse (ap, isafter)) == NULL)
 832         return 0;
 833
 834     *tb = *tw;
 835     return 1;
 836 }
 837
 838
 839 static struct tws *
 840 tws_parse (char *ap, int isafter)
 841 {
 842     char buffer[BUFSIZ];
 843     struct tws *tw, *ts;
 844
 845     if ((tw = tws_special (ap)) != NULL) {
 846         tw->tw_sec = tw->tw_min = isafter ? 59 : 0;
 847         tw->tw_hour = isafter ? 23 : 0;
 848         return tw;
 849     }
 850     if ((tw = dparsetime (ap)) != NULL)
 851         return tw;
 852
 853     if ((ts = dlocaltimenow ()) == NULL)
 854         return NULL;
 855
 856     snprintf (buffer, sizeof(buffer), "%s %s", ap, dtwszone (ts));
 857     if ((tw = dparsetime (buffer)) != NULL)
 858         return tw;
 859
 860     snprintf (buffer, sizeof(buffer), "%s %02d:%02d:%02d %s", ap,
 861             ts->tw_hour, ts->tw_min, ts->tw_sec, dtwszone (ts));
 862     if ((tw = dparsetime (buffer)) != NULL)
 863         return tw;
 864
 865     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s",
 866             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year, ap);
 867     if ((tw = dparsetime (buffer)) != NULL)
 868         return tw;
 869
 870     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s %s",
 871             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year,
 872             ap, dtwszone (ts));
 873     if ((tw = dparsetime (buffer)) != NULL)
 874         return tw;
 875
 876     return NULL;
 877 }
 878
 879
 880 static struct tws *
 881 tws_special (char *ap)
 882 {
 883     int i;
 884     time_t clock;
 885     struct tws *tw;
 886
 887     time (&clock);
 888     if (!strcasecmp (ap, "today"))
 889         return dlocaltime (&clock);
 890     if (!strcasecmp (ap, "yesterday")) {
 891         clock -= (long) (60 * 60 * 24);
 892         return dlocaltime (&clock);
 893     }
 894     if (!strcasecmp (ap, "tomorrow")) {
 895         clock += (long) (60 * 60 * 24);
 896         return dlocaltime (&clock);
 897     }
 898
 899     for (i = 0; tw_ldotw[i]; i++)
 900         if (!strcasecmp (ap, tw_ldotw[i]))
 901             break;
 902     if (tw_ldotw[i]) {
 903         if ((tw = dlocaltime (&clock)) == NULL)
 904             return NULL;
 905         if ((i -= tw->tw_wday) > 0)
 906             i -= 7;
 907     }
 908     else {
 909         if (*ap != '-')
 910             return NULL;
 911         /* -ddd days ago */
 912         i = atoi (ap);  /* we should error check this */
 913     }
 914
 915     clock += (long) ((60 * 60 * 24) * i);
 916     return dlocaltime (&clock);
 917 }
 918
 919
 920 static int
 921 TWSaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 922 {
 923     int state;
 924     char *bp;
 925     char buf[NMH_BUFSIZ], name[NAMESZ];
 926     struct tws *tw;
 927     m_getfld_state_t gstate;
 928     NMH_UNUSED (stop);
 929
 930     fseek (fp, start, SEEK_SET);
 931     gstate = m_getfld_state_init(fp);
 932     for (bp = NULL;;) {
 933         int bufsz = sizeof buf;
 934         switch (state = m_getfld2(&gstate, name, buf, &bufsz)) {
 935             case FLD:
 936             case FLDPLUS:
 937                 free(bp);
 938                 bp = mh_xstrdup(buf);
 939                 while (state == FLDPLUS) {
 940                     bufsz = sizeof buf;
 941                     state = m_getfld2(&gstate, name, buf, &bufsz);
 942                     bp = add (buf, bp);
 943                 }
 944                 if (!strcasecmp (name, n->n_datef))
 945                     break;
 946                 continue;
 947
 948             case BODY:
 949             case FILEEOF:
 950             case LENERR:
 951             case FMTERR:
 952                 if (state == LENERR || state == FMTERR)
 953                     inform("format error in message %d", msgnum);
 954                 free(bp);
 955                 return 0;
 956
 957             default:
 958                 adios (NULL, "internal error -- you lose");
 959         }
 960         break;
 961     }
 962     m_getfld_state_destroy (&gstate);
 963
 964     if ((tw = dparsetime (bp)) == NULL)
 965         inform("unable to parse %s field in message %d, matching...",
 966                 n->n_datef, msgnum), state = 1;
 967     else
 968         state = n->n_after ? (twsort (tw, &n->n_tws) > 0)
 969             : (twsort (tw, &n->n_tws) < 0);
 970
 971     free(bp);
 972     return state;
 973 }