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 "sbr/ambigsw.h"
  10 #include "sbr/error.h"
  11 #include "h/tws.h"
  12 #include "h/picksbr.h"
  13 #include "h/utils.h"
  14
  15 #ifdef HAVE_SYS_TIME_H
  16 # include <sys/time.h>
  17 #endif
  18 #include <time.h>
  19
  20 #define PARSE_SWITCHES \
  21     X("and", 0, PRAND) \
  22     X("or", 0, PROR) \
  23     X("not", 0, PRNOT) \
  24     X("lbrace", 0, PRLBR) \
  25     X("rbrace", 0, PRRBR) \
  26     X("cc  pattern", 0, PRCC) \
  27     X("date  pattern", 0, PRDATE) \
  28     X("from  pattern", 0, PRFROM) \
  29     X("search  pattern", 0, PRSRCH) \
  30     X("subject  pattern", 0, PRSUBJ) \
  31     X("to  pattern", 0, PRTO) \
  32     X("-othercomponent  pattern", 15, PROTHR) \
  33     X("after date", 0, PRAFTR) \
  34     X("before date", 0, PRBEFR) \
  35     X("datefield field", 5, PRDATF) \
  36
  37 #define X(sw, minchars, id) id,
  38 DEFINE_SWITCH_ENUM(PARSE);
  39 #undef X
  40
  41 #define X(sw, minchars, id) { sw, minchars, id },
  42 DEFINE_SWITCH_ARRAY(PARSE, parswit);
  43 #undef X
  44
  45 /* DEFINITIONS FOR PATTERN MATCHING */
  46
  47 /*
  48  * We really should be using re_comp() and re_exec() here.  Unfortunately,
  49  * pick advertises that lowercase characters matches characters of both
  50  * cases.  Since re_exec() doesn't exhibit this behavior, we are stuck
  51  * with this version.  Furthermore, we need to be able to save and restore
  52  * the state of the pattern matcher in order to do things "efficiently".
  53  *
  54  * The matching power of this algorithm isn't as powerful as the re_xxx()
  55  * routines (no \(xxx\) and \n constructs).  Such is life.
  56  */
  57
  58 #define CCHR    2
  59 #define CDOT    4
  60 #define CCL     6
  61 #define NCCL    8
  62 #define CDOL    10
  63 #define CEOF    11
  64
  65 #define STAR    01
  66
  67 #define LBSIZE  NMH_BUFSIZ
  68 #define ESIZE   1024
  69
  70
  71 static char linebuf[LBSIZE + 1];
  72 static char decoded_linebuf[LBSIZE + 1];
  73
  74 /* the magic array for case-independence */
  75 static unsigned char cc[] = {
  76         0000,0001,0002,0003,0004,0005,0006,0007,
  77         0010,0011,0012,0013,0014,0015,0016,0017,
  78         0020,0021,0022,0023,0024,0025,0026,0027,
  79         0030,0031,0032,0033,0034,0035,0036,0037,
  80         0040,0041,0042,0043,0044,0045,0046,0047,
  81         0050,0051,0052,0053,0054,0055,0056,0057,
  82         0060,0061,0062,0063,0064,0065,0066,0067,
  83         0070,0071,0072,0073,0074,0075,0076,0077,
  84         0100,0141,0142,0143,0144,0145,0146,0147,
  85         0150,0151,0152,0153,0154,0155,0156,0157,
  86         0160,0161,0162,0163,0164,0165,0166,0167,
  87         0170,0171,0172,0133,0134,0135,0136,0137,
  88         0140,0141,0142,0143,0144,0145,0146,0147,
  89         0150,0151,0152,0153,0154,0155,0156,0157,
  90         0160,0161,0162,0163,0164,0165,0166,0167,
  91         0170,0171,0172,0173,0174,0175,0176,0177,
  92
  93         0200,0201,0202,0203,0204,0205,0206,0207,
  94         0210,0211,0212,0213,0214,0215,0216,0217,
  95         0220,0221,0222,0223,0224,0225,0226,0227,
  96         0230,0231,0232,0233,0234,0235,0236,0237,
  97         0240,0241,0242,0243,0244,0245,0246,0247,
  98         0250,0251,0252,0253,0254,0255,0256,0257,
  99         0260,0261,0262,0263,0264,0265,0266,0267,
 100         0270,0271,0272,0273,0274,0275,0276,0277,
 101         0300,0301,0302,0303,0304,0305,0306,0307,
 102         0310,0311,0312,0313,0314,0315,0316,0317,
 103         0320,0321,0322,0323,0324,0325,0326,0327,
 104         0330,0331,0332,0333,0334,0335,0336,0337,
 105         0340,0341,0342,0343,0344,0345,0346,0347,
 106         0350,0351,0352,0353,0354,0355,0356,0357,
 107         0360,0361,0362,0363,0364,0365,0366,0367,
 108         0370,0371,0372,0373,0374,0375,0376,0377,
 109 };
 110
 111 /*
 112  * DEFINITIONS FOR NEXUS
 113  */
 114
 115 #define nxtarg()        (*argp ? *argp++ : NULL)
 116 #define prvarg()        argp--
 117
 118 #define pinform         if (!talked++) inform
 119
 120 struct nexus {
 121     int (*n_action)(struct nexus *n, FILE *fp, int msgnum, long start, long stop);
 122
 123     union {
 124         /* for {OR,AND,NOT}action */
 125         struct {
 126             struct nexus *un_L_child;
 127             struct nexus *un_R_child;
 128         } st1;
 129
 130         /* for GREPaction */
 131         struct {
 132             int   un_header;
 133             int   un_circf;
 134             char  un_expbuf[ESIZE];
 135             char *un_patbuf;
 136         } st2;
 137
 138         /* for TWSaction */
 139         struct {
 140             char *un_datef;
 141             int   un_after;
 142             struct tws un_tws;
 143         } st3;
 144     } un;
 145 };
 146
 147 #define n_L_child un.st1.un_L_child
 148 #define n_R_child un.st1.un_R_child
 149
 150 #define n_header un.st2.un_header
 151 #define n_circf  un.st2.un_circf
 152 #define n_expbuf un.st2.un_expbuf
 153 #define n_patbuf un.st2.un_patbuf
 154
 155 #define n_datef  un.st3.un_datef
 156 #define n_after  un.st3.un_after
 157 #define n_tws    un.st3.un_tws
 158
 159 static int talked;
 160
 161 static char *datesw;
 162 static char **argp;
 163
 164 static struct nexus *head;
 165
 166 /*
 167  * prototypes for date routines
 168  */
 169 static struct tws *tws_parse(char *, int);
 170 static struct tws *tws_special(char *);
 171
 172 /*
 173  * static prototypes
 174  */
 175 static void PRaction(struct nexus *, int);
 176 static int gcompile(struct nexus *, char *);
 177 static int advance(char *, char *);
 178 static int cclass(unsigned char *, int, int);
 179 static int tcompile(char *, struct tws *, int);
 180
 181 static struct nexus *parse(void);
 182 static struct nexus *nexp1(void);
 183 static struct nexus *nexp2(void);
 184 static struct nexus *nexp3(void);
 185 static struct nexus *newnexus(int (*action)(struct nexus *n,
 186     FILE *fp, int msgnum, long start, long stop));
 187
 188 static int ORaction(struct nexus *n, FILE *fp, int msgnum,
 189     long start, long stop);
 190 static int ANDaction(struct nexus *n, FILE *fp, int msgnum,
 191     long start, long stop);
 192 static int NOTaction(struct nexus *n, FILE *fp, int msgnum,
 193     long start, long stop);
 194 static int GREPaction(struct nexus *n, FILE *fp, int msgnum,
 195     long start, long stop);
 196 static int TWSaction(struct nexus *n, FILE *fp, int msgnum,
 197     long start, long stop);
 198
 199
 200 int
 201 pcompile (char **vec, char *date)
 202 {
 203     argp = vec;
 204     if ((datesw = date) == NULL)
 205         datesw = "date";
 206     talked = 0;
 207
 208     if ((head = parse ()) == NULL)
 209         return !talked;
 210
 211     if (*argp) {
 212         inform("%s unexpected", *argp);
 213         return 0;
 214     }
 215
 216     return 1;
 217 }
 218
 219
 220 static struct nexus *
 221 parse (void)
 222 {
 223     char  *cp;
 224     struct nexus *n, *o;
 225
 226     if ((n = nexp1 ()) == NULL || (cp = nxtarg ()) == NULL)
 227         return n;
 228
 229     if (*cp != '-') {
 230         pinform("%s unexpected", cp);
 231         return NULL;
 232     }
 233
 234     if (*++cp == '-')
 235         goto header;
 236     switch (smatch (cp, parswit)) {
 237         case AMBIGSW:
 238             ambigsw (cp, parswit);
 239             talked++;
 240             return NULL;
 241         case UNKWNSW:
 242             fprintf (stderr, "-%s unknown\n", cp);
 243             talked++;
 244             return NULL;
 245
 246         case PROR:
 247             o = newnexus (ORaction);
 248             o->n_L_child = n;
 249             if ((o->n_R_child = parse ()))
 250                 return o;
 251             pinform("missing disjunctive");
 252             free (o);
 253             return NULL;
 254
 255 header: ;
 256         default:
 257             prvarg ();
 258             return n;
 259     }
 260 }
 261
 262 static struct nexus *
 263 nexp1 (void)
 264 {
 265     char *cp;
 266     struct nexus *n, *o;
 267
 268     if ((n = nexp2 ()) == NULL || (cp = nxtarg ()) == NULL)
 269         return n;
 270
 271     if (*cp != '-') {
 272         pinform("%s unexpected", cp);
 273         free (n);
 274         return NULL;
 275     }
 276
 277     if (*++cp == '-')
 278         goto header;
 279     switch (smatch (cp, parswit)) {
 280         case AMBIGSW:
 281             ambigsw (cp, parswit);
 282             talked++;
 283             free (n);
 284             return NULL;
 285         case UNKWNSW:
 286             fprintf (stderr, "-%s unknown\n", cp);
 287             talked++;
 288             free (n);
 289             return NULL;
 290
 291         case PRAND:
 292             o = newnexus (ANDaction);
 293             o->n_L_child = n;
 294             if ((o->n_R_child = nexp1 ()))
 295                 return o;
 296             pinform("missing conjunctive");
 297             free (o);
 298             return NULL;
 299
 300 header: ;
 301         default:
 302             prvarg ();
 303             return n;
 304     }
 305 }
 306
 307
 308 static struct nexus *
 309 nexp2 (void)
 310 {
 311     char *cp;
 312     struct nexus *n;
 313
 314     if ((cp = nxtarg ()) == NULL)
 315         return NULL;
 316
 317     if (*cp != '-') {
 318         prvarg ();
 319         return nexp3 ();
 320     }
 321
 322     if (*++cp == '-')
 323         goto header;
 324     switch (smatch (cp, parswit)) {
 325         case AMBIGSW:
 326             ambigsw (cp, parswit);
 327             talked++;
 328             return NULL;
 329         case UNKWNSW:
 330             fprintf (stderr, "-%s unknown\n", cp);
 331             talked++;
 332             return NULL;
 333
 334         case PRNOT:
 335             n = newnexus (NOTaction);
 336             if ((n->n_L_child = nexp3 ()))
 337                 return n;
 338             pinform("missing negation");
 339             free (n);
 340             return NULL;
 341
 342 header: ;
 343         default:
 344             prvarg ();
 345             return nexp3 ();
 346     }
 347 }
 348
 349 static struct nexus *
 350 nexp3 (void)
 351 {
 352     int i;
 353     char *cp, *dp;
 354     char buffer[BUFSIZ], temp[64];
 355     struct nexus *n;
 356
 357     if ((cp = nxtarg ()) == NULL)
 358         return NULL;
 359
 360     if (*cp != '-') {
 361         pinform("%s unexpected", cp);
 362         return NULL;
 363     }
 364
 365     if (*++cp == '-') {
 366         dp = ++cp;
 367         goto header;
 368     }
 369     switch (i = smatch (cp, parswit)) {
 370         case AMBIGSW:
 371             ambigsw (cp, parswit);
 372             talked++;
 373             return NULL;
 374         case UNKWNSW:
 375             fprintf (stderr, "-%s unknown\n", cp);
 376             talked++;
 377             return NULL;
 378
 379         case PRLBR:
 380             if ((n = parse ()) == NULL) {
 381                 pinform("missing group");
 382                 return NULL;
 383             }
 384             if ((cp = nxtarg ()) == NULL) {
 385                 pinform("missing -rbrace");
 386                 return NULL;
 387             }
 388             if (*cp++ == '-' && smatch (cp, parswit) == PRRBR)
 389                 return n;
 390             pinform("%s unexpected", --cp);
 391             return NULL;
 392
 393         default:
 394             prvarg ();
 395             return NULL;
 396
 397         case PRCC:
 398         case PRDATE:
 399         case PRFROM:
 400         case PRTO:
 401         case PRSUBJ:
 402             strncpy(temp, parswit[i].sw, sizeof(temp));
 403             temp[sizeof(temp) - 1] = '\0';
 404             dp = *brkstring (temp, " ", NULL);
 405     header: ;
 406             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 407                 pinform("missing argument to %s", argp[-2]);
 408                 return NULL;
 409             }
 410             n = newnexus (GREPaction);
 411             n->n_header = 1;
 412             snprintf (buffer, sizeof(buffer), "^%s[ \t]*:.*%s", dp, cp);
 413             dp = buffer;
 414             goto pattern;
 415
 416         case PRSRCH:
 417             n = newnexus (GREPaction);
 418             n->n_header = 0;
 419             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 420                 pinform("missing argument to %s", argp[-2]);
 421                 free (n);
 422                 return NULL;
 423             }
 424             dp = cp;
 425     pattern: ;
 426             if (!gcompile (n, dp)) {
 427                 pinform("pattern error in %s %s", argp[-2], cp);
 428                 free (n);
 429                 return NULL;
 430             }
 431             n->n_patbuf = mh_xstrdup(dp);
 432             return n;
 433
 434         case PROTHR:
 435             pinform("internal error!");
 436             return NULL;
 437
 438         case PRDATF:
 439             if (!(datesw = nxtarg ()) || *datesw == '-') {
 440                 pinform("missing argument to %s", argp[-2]);
 441                 return NULL;
 442             }
 443             return nexp3 ();
 444
 445         case PRAFTR:
 446         case PRBEFR:
 447             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 448                 pinform("missing argument to %s", argp[-2]);
 449                 return NULL;
 450             }
 451             n = newnexus (TWSaction);
 452             n->n_datef = datesw;
 453             if (!tcompile (cp, &n->n_tws, n->n_after = i == PRAFTR)) {
 454                 pinform("unable to parse %s %s", argp[-2], cp);
 455                 free (n);
 456                 return NULL;
 457             }
 458             return n;
 459     }
 460 }
 461
 462
 463 static struct nexus *
 464 newnexus(int (*action)(struct nexus *n, FILE *fp, int msgnum,
 465     long start, long stop))
 466 {
 467     struct nexus *p;
 468
 469     NEW0(p);
 470     p->n_action = action;
 471     return p;
 472 }
 473
 474
 475 int
 476 pmatches (FILE *fp, int msgnum, long start, long stop, int debug)
 477 {
 478     if (!head)
 479         return 1;
 480
 481     if (!talked++ && debug)
 482         PRaction (head, 0);
 483
 484     return (*head->n_action)(head, fp, msgnum, start, stop);
 485 }
 486
 487
 488 static void
 489 PRaction (struct nexus *n, int level)
 490 {
 491     int i;
 492
 493     for (i = 0; i < level; i++)
 494         fprintf (stderr, "| ");
 495
 496     if (n->n_action == ORaction) {
 497         fprintf (stderr, "OR\n");
 498         PRaction (n->n_L_child, level + 1);
 499         PRaction (n->n_R_child, level + 1);
 500         return;
 501     }
 502     if (n->n_action == ANDaction) {
 503         fprintf (stderr, "AND\n");
 504         PRaction (n->n_L_child, level + 1);
 505         PRaction (n->n_R_child, level + 1);
 506         return;
 507     }
 508     if (n->n_action == NOTaction) {
 509         fprintf (stderr, "NOT\n");
 510         PRaction (n->n_L_child, level + 1);
 511         return;
 512     }
 513     if (n->n_action == GREPaction) {
 514         fprintf (stderr, "PATTERN(%s) %s\n",
 515                 n->n_header ? "header" : "body", n->n_patbuf);
 516         return;
 517     }
 518     if (n->n_action == TWSaction) {
 519         fprintf (stderr, "TEMPORAL(%s) %s: %s\n",
 520                 n->n_after ? "after" : "before", n->n_datef,
 521                 dasctime (&n->n_tws, TW_NULL));
 522         return;
 523     }
 524
 525     generic_pointer gp;
 526     gp.f = (void (*)(void))n->n_action;
 527     fprintf(stderr, "UNKNOWN(%p)\n", gp.v);
 528 }
 529
 530
 531 static int
 532 ORaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 533 {
 534     if ((*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop))
 535         return 1;
 536     return (*n->n_R_child->n_action)(n->n_R_child, fp, msgnum, start, stop);
 537 }
 538
 539
 540 static int
 541 ANDaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 542 {
 543     if (!(*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop))
 544         return 0;
 545     return (*n->n_R_child->n_action)(n->n_R_child, fp, msgnum, start, stop);
 546 }
 547
 548
 549 static int
 550 NOTaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 551 {
 552     return (!(*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop));
 553 }
 554
 555
 556 static int
 557 gcompile (struct nexus *n, char *astr)
 558 {
 559     int c;
 560     int cclcnt;
 561     unsigned char *ep, *dp, *sp, *lastep = 0;
 562
 563     dp = (ep = (unsigned char *) n->n_expbuf) + sizeof n->n_expbuf;
 564     sp = (unsigned char *) astr;
 565     if (*sp == '^') {
 566         n->n_circf = 1;
 567         sp++;
 568     }
 569     else
 570         n->n_circf = 0;
 571     for (;;) {
 572         if (ep >= dp)
 573             goto cerror;
 574         if ((c = *sp++) != '*')
 575             lastep = ep;
 576         switch (c) {
 577             case '\0':
 578                 *ep++ = CEOF;
 579                 return 1;
 580
 581             case '.':
 582                 *ep++ = CDOT;
 583                 continue;
 584
 585             case '*':
 586                 if (lastep == 0)
 587                     goto defchar;
 588                 *lastep |= STAR;
 589                 continue;
 590
 591             case '$':
 592                 if (*sp != '\0')
 593                     goto defchar;
 594                 *ep++ = CDOL;
 595                 continue;
 596
 597             case '[':
 598                 *ep++ = CCL;
 599                 *ep++ = 0;
 600                 cclcnt = 0;
 601                 if ((c = *sp++) == '^') {
 602                     c = *sp++;
 603                     ep[-2] = NCCL;
 604                 }
 605                 if (c == '-') {
 606                     *ep++ = c;
 607                     cclcnt++;
 608                     c = *sp++;
 609                 }
 610                 do {
 611                     if (c == '-' && *sp != '\0' && *sp != ']') {
 612                         for (c = ep[-1]+1; c < *sp; c++) {
 613                             *ep++ = c;
 614                             cclcnt++;
 615                             if (c == '\0' || ep >= dp)
 616                                 goto cerror;
 617                         }
 618                     } else {
 619                         *ep++ = c;
 620                         cclcnt++;
 621                         if (c == '\0' || ep >= dp)
 622                             goto cerror;
 623                     }
 624                 } while ((c = *sp++) != ']');
 625                 if (cclcnt > 255)
 626                     goto cerror;
 627                 lastep[1] = cclcnt;
 628                 continue;
 629
 630             case '\\':
 631                 if ((c = *sp++) == '\0')
 632                     goto cerror;
 633                 /* FALLTHRU */
 634         defchar:
 635             default:
 636                 *ep++ = CCHR;
 637                 *ep++ = c;
 638         }
 639     }
 640
 641 cerror: ;
 642     return 0;
 643 }
 644
 645
 646 static int
 647 GREPaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 648 {
 649     int c;
 650     bool body;
 651     bool lf;
 652     long pos = start;
 653     char *p1, *p2, *ebp, *cbp;
 654     char ibuf[BUFSIZ];
 655     NMH_UNUSED (msgnum);
 656
 657     fseek (fp, start, SEEK_SET);
 658     body = false;
 659     ebp = cbp = ibuf;
 660     for (;;) {
 661         if (body && n->n_header)
 662             return 0;
 663         p1 = linebuf;
 664         p2 = cbp;
 665         lf = false;
 666         for (;;) {
 667             if (p2 >= ebp) {
 668                 if (fgets (ibuf, sizeof ibuf, fp) == NULL
 669                         || (stop && pos >= stop)) {
 670                     if (lf)
 671                         break;
 672                     return 0;
 673                 }
 674                 pos += (long) strlen (ibuf);
 675                 p2 = ibuf;
 676                 ebp = ibuf + strlen (ibuf);
 677             }
 678             c = *p2++;
 679             if (lf && c != '\n') {
 680                 if (c != ' ' && c != '\t') {
 681                     --p2;
 682                     break;
 683                 }
 684                 lf = false;
 685             }
 686             if (c == '\n') {
 687                 if (body)
 688                     break;
 689                 if (lf) {
 690                     body = true;
 691                     break;
 692                 }
 693                 lf = true;
 694                 /* Unfold by skipping the newline. */
 695                 c = 0;
 696             }
 697             if (c && p1 < &linebuf[LBSIZE - 1])
 698                 *p1++ = c;
 699         }
 700
 701         *p1++ = 0;
 702         cbp = p2;
 703         p1 = linebuf;
 704         p2 = n->n_expbuf;
 705
 706         /* Attempt to decode as a MIME header.  If it's the last header,
 707            body will be 1 and lf will be at least 1. */
 708         if ((!body || lf)  &&
 709             decode_rfc2047 (linebuf, decoded_linebuf, sizeof decoded_linebuf)) {
 710             p1 = decoded_linebuf;
 711         }
 712
 713         if (n->n_circf) {
 714             if (advance (p1, p2))
 715                 return 1;
 716             continue;
 717         }
 718
 719         if (*p2 == CCHR) {
 720             c = p2[1];
 721             do {
 722                 if (*p1 == c || cc[(unsigned char)*p1] == c)
 723                     if (advance (p1, p2))
 724                         return 1;
 725             } while (*p1++);
 726             continue;
 727         }
 728
 729         do {
 730             if (advance (p1, p2))
 731                 return 1;
 732         } while (*p1++);
 733     }
 734 }
 735
 736
 737 static int
 738 advance (char *alp, char *aep)
 739 {
 740     unsigned char *lp, *ep, *curlp;
 741
 742     lp = (unsigned char *)alp;
 743     ep = (unsigned char *)aep;
 744     for (;;)
 745         switch (*ep++) {
 746             case CCHR:
 747                 if (*ep++ == *lp++ || ep[-1] == cc[lp[-1]])
 748                     continue;
 749                 return 0;
 750
 751             case CDOT:
 752                 if (*lp++)
 753                     continue;
 754                 return 0;
 755
 756             case CDOL:
 757                 if (*lp == 0)
 758                     continue;
 759                 return 0;
 760
 761             case CEOF:
 762                 return 1;
 763
 764             case CCL:
 765                 if (cclass (ep, *lp++, 1)) {
 766                     ep += *ep + 1;
 767                     continue;
 768                 }
 769                 return 0;
 770
 771             case NCCL:
 772                 if (cclass (ep, *lp++, 0)) {
 773                     ep += *ep + 1;
 774                     continue;
 775                 }
 776                 return 0;
 777
 778             case CDOT | STAR:
 779                 curlp = lp;
 780                 while (*lp++)
 781                     continue;
 782                 goto star;
 783
 784             case CCHR | STAR:
 785                 curlp = lp;
 786                 while (*lp++ == *ep || cc[lp[-1]] == *ep)
 787                     continue;
 788                 ep++;
 789                 goto star;
 790
 791             case CCL | STAR:
 792             case NCCL | STAR:
 793                 curlp = lp;
 794                 while (cclass (ep, *lp++, ep[-1] == (CCL | STAR)))
 795                     continue;
 796                 ep += *ep + 1;
 797                 goto star;
 798
 799         star:
 800                 do {
 801                     lp--;
 802                     if (advance ((char *) lp, (char *) ep))
 803                         return 1;
 804                 } while (lp > curlp);
 805                 return 0;
 806
 807             default:
 808                 inform("advance() botch -- you lose big, continuing...");
 809                 return 0;
 810         }
 811 }
 812
 813
 814 static int
 815 cclass (unsigned char *aset, int ac, int af)
 816 {
 817     unsigned int    n;
 818     unsigned char   c, *set;
 819
 820     set = aset;
 821     if ((c = ac) == 0)
 822         return 0;
 823
 824     n = *set++;
 825     while (n--)
 826         if (*set++ == c || set[-1] == cc[c])
 827             return af;
 828
 829     return !af;
 830 }
 831
 832
 833 static int
 834 tcompile (char *ap, struct tws *tb, int isafter)
 835 {
 836     struct tws *tw;
 837
 838     if ((tw = tws_parse (ap, isafter)) == NULL)
 839         return 0;
 840
 841     *tb = *tw;
 842     return 1;
 843 }
 844
 845
 846 static struct tws *
 847 tws_parse (char *ap, int isafter)
 848 {
 849     char buffer[BUFSIZ];
 850     struct tws *tw, *ts;
 851
 852     if ((tw = tws_special (ap)) != NULL) {
 853         tw->tw_sec = tw->tw_min = isafter ? 59 : 0;
 854         tw->tw_hour = isafter ? 23 : 0;
 855         return tw;
 856     }
 857     if ((tw = dparsetime (ap)) != NULL)
 858         return tw;
 859
 860     if ((ts = dlocaltimenow ()) == NULL)
 861         return NULL;
 862
 863     snprintf (buffer, sizeof(buffer), "%s %s", ap, dtwszone (ts));
 864     if ((tw = dparsetime (buffer)) != NULL)
 865         return tw;
 866
 867     snprintf (buffer, sizeof(buffer), "%s %02d:%02d:%02d %s", ap,
 868             ts->tw_hour, ts->tw_min, ts->tw_sec, dtwszone (ts));
 869     if ((tw = dparsetime (buffer)) != NULL)
 870         return tw;
 871
 872     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s",
 873             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year, ap);
 874     if ((tw = dparsetime (buffer)) != NULL)
 875         return tw;
 876
 877     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s %s",
 878             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year,
 879             ap, dtwszone (ts));
 880     if ((tw = dparsetime (buffer)) != NULL)
 881         return tw;
 882
 883     return NULL;
 884 }
 885
 886
 887 static struct tws *
 888 tws_special (char *ap)
 889 {
 890     int i;
 891     time_t clock;
 892     struct tws *tw;
 893
 894     time (&clock);
 895     if (!strcasecmp (ap, "today"))
 896         return dlocaltime (&clock);
 897     if (!strcasecmp (ap, "yesterday")) {
 898         clock -= (long) (60 * 60 * 24);
 899         return dlocaltime (&clock);
 900     }
 901     if (!strcasecmp (ap, "tomorrow")) {
 902         clock += (long) (60 * 60 * 24);
 903         return dlocaltime (&clock);
 904     }
 905
 906     for (i = 0; tw_ldotw[i]; i++)
 907         if (!strcasecmp (ap, tw_ldotw[i]))
 908             break;
 909     if (tw_ldotw[i]) {
 910         if ((tw = dlocaltime (&clock)) == NULL)
 911             return NULL;
 912         if ((i -= tw->tw_wday) > 0)
 913             i -= 7;
 914     }
 915     else {
 916         if (*ap != '-')
 917             return NULL;
 918         /* -ddd days ago */
 919         i = atoi (ap);  /* we should error check this */
 920     }
 921
 922     clock += (long) ((60 * 60 * 24) * i);
 923     return dlocaltime (&clock);
 924 }
 925
 926
 927 static int
 928 TWSaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 929 {
 930     int state;
 931     char *bp;
 932     char buf[NMH_BUFSIZ], name[NAMESZ];
 933     struct tws *tw;
 934     m_getfld_state_t gstate;
 935     NMH_UNUSED (stop);
 936
 937     fseek (fp, start, SEEK_SET);
 938     gstate = m_getfld_state_init(fp);
 939     for (bp = NULL;;) {
 940         int bufsz = sizeof buf;
 941         switch (state = m_getfld2(&gstate, name, buf, &bufsz)) {
 942             case FLD:
 943             case FLDPLUS:
 944                 free(bp);
 945                 bp = mh_xstrdup(buf);
 946                 while (state == FLDPLUS) {
 947                     bufsz = sizeof buf;
 948                     state = m_getfld2(&gstate, name, buf, &bufsz);
 949                     bp = add (buf, bp);
 950                 }
 951                 if (!strcasecmp (name, n->n_datef))
 952                     break;
 953                 continue;
 954
 955             case BODY:
 956             case FILEEOF:
 957             case LENERR:
 958             case FMTERR:
 959                 if (state == LENERR || state == FMTERR)
 960                     inform("format error in message %d", msgnum);
 961                 free(bp);
 962                 return 0;
 963
 964             default:
 965                 die("internal error -- you lose");
 966         }
 967         break;
 968     }
 969     m_getfld_state_destroy (&gstate);
 970
 971     if ((tw = dparsetime (bp)) == NULL)
 972         inform("unable to parse %s field in message %d, matching...",
 973                 n->n_datef, msgnum), state = 1;
 974     else
 975         state = n->n_after ? (twsort (tw, &n->n_tws) > 0)
 976             : (twsort (tw, &n->n_tws) < 0);
 977
 978     free(bp);
 979     return state;
 980 }