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/brkstring.h"
  10 #include "sbr/ambigsw.h"
  11 #include "sbr/error.h"
  12 #include "h/tws.h"
  13 #include "h/picksbr.h"
  14 #include "h/utils.h"
  15
  16 #ifdef HAVE_SYS_TIME_H
  17 # include <sys/time.h>
  18 #endif
  19 #include <time.h>
  20
  21 #define PARSE_SWITCHES \
  22     X("and", 0, PRAND) \
  23     X("or", 0, PROR) \
  24     X("not", 0, PRNOT) \
  25     X("lbrace", 0, PRLBR) \
  26     X("rbrace", 0, PRRBR) \
  27     X("cc  pattern", 0, PRCC) \
  28     X("date  pattern", 0, PRDATE) \
  29     X("from  pattern", 0, PRFROM) \
  30     X("search  pattern", 0, PRSRCH) \
  31     X("subject  pattern", 0, PRSUBJ) \
  32     X("to  pattern", 0, PRTO) \
  33     X("-othercomponent  pattern", 15, PROTHR) \
  34     X("after date", 0, PRAFTR) \
  35     X("before date", 0, PRBEFR) \
  36     X("datefield field", 5, PRDATF) \
  37
  38 #define X(sw, minchars, id) id,
  39 DEFINE_SWITCH_ENUM(PARSE);
  40 #undef X
  41
  42 #define X(sw, minchars, id) { sw, minchars, id },
  43 DEFINE_SWITCH_ARRAY(PARSE, parswit);
  44 #undef X
  45
  46 /* DEFINITIONS FOR PATTERN MATCHING */
  47
  48 /*
  49  * We really should be using re_comp() and re_exec() here.  Unfortunately,
  50  * pick advertises that lowercase characters matches characters of both
  51  * cases.  Since re_exec() doesn't exhibit this behavior, we are stuck
  52  * with this version.  Furthermore, we need to be able to save and restore
  53  * the state of the pattern matcher in order to do things "efficiently".
  54  *
  55  * The matching power of this algorithm isn't as powerful as the re_xxx()
  56  * routines (no \(xxx\) and \n constructs).  Such is life.
  57  */
  58
  59 #define CCHR    2
  60 #define CDOT    4
  61 #define CCL     6
  62 #define NCCL    8
  63 #define CDOL    10
  64 #define CEOF    11
  65
  66 #define STAR    01
  67
  68 #define LBSIZE  NMH_BUFSIZ
  69 #define ESIZE   1024
  70
  71
  72 static char linebuf[LBSIZE + 1];
  73 static char decoded_linebuf[LBSIZE + 1];
  74
  75 /* the magic array for case-independence */
  76 static unsigned char cc[] = {
  77         0000,0001,0002,0003,0004,0005,0006,0007,
  78         0010,0011,0012,0013,0014,0015,0016,0017,
  79         0020,0021,0022,0023,0024,0025,0026,0027,
  80         0030,0031,0032,0033,0034,0035,0036,0037,
  81         0040,0041,0042,0043,0044,0045,0046,0047,
  82         0050,0051,0052,0053,0054,0055,0056,0057,
  83         0060,0061,0062,0063,0064,0065,0066,0067,
  84         0070,0071,0072,0073,0074,0075,0076,0077,
  85         0100,0141,0142,0143,0144,0145,0146,0147,
  86         0150,0151,0152,0153,0154,0155,0156,0157,
  87         0160,0161,0162,0163,0164,0165,0166,0167,
  88         0170,0171,0172,0133,0134,0135,0136,0137,
  89         0140,0141,0142,0143,0144,0145,0146,0147,
  90         0150,0151,0152,0153,0154,0155,0156,0157,
  91         0160,0161,0162,0163,0164,0165,0166,0167,
  92         0170,0171,0172,0173,0174,0175,0176,0177,
  93
  94         0200,0201,0202,0203,0204,0205,0206,0207,
  95         0210,0211,0212,0213,0214,0215,0216,0217,
  96         0220,0221,0222,0223,0224,0225,0226,0227,
  97         0230,0231,0232,0233,0234,0235,0236,0237,
  98         0240,0241,0242,0243,0244,0245,0246,0247,
  99         0250,0251,0252,0253,0254,0255,0256,0257,
 100         0260,0261,0262,0263,0264,0265,0266,0267,
 101         0270,0271,0272,0273,0274,0275,0276,0277,
 102         0300,0301,0302,0303,0304,0305,0306,0307,
 103         0310,0311,0312,0313,0314,0315,0316,0317,
 104         0320,0321,0322,0323,0324,0325,0326,0327,
 105         0330,0331,0332,0333,0334,0335,0336,0337,
 106         0340,0341,0342,0343,0344,0345,0346,0347,
 107         0350,0351,0352,0353,0354,0355,0356,0357,
 108         0360,0361,0362,0363,0364,0365,0366,0367,
 109         0370,0371,0372,0373,0374,0375,0376,0377,
 110 };
 111
 112 /*
 113  * DEFINITIONS FOR NEXUS
 114  */
 115
 116 #define nxtarg()        (*argp ? *argp++ : NULL)
 117 #define prvarg()        argp--
 118
 119 #define pinform         if (!talked++) inform
 120
 121 struct nexus {
 122     int (*n_action)(struct nexus *n, FILE *fp, int msgnum, long start, long stop);
 123
 124     union {
 125         /* for {OR,AND,NOT}action */
 126         struct {
 127             struct nexus *un_L_child;
 128             struct nexus *un_R_child;
 129         } st1;
 130
 131         /* for GREPaction */
 132         struct {
 133             int   un_header;
 134             int   un_circf;
 135             char  un_expbuf[ESIZE];
 136             char *un_patbuf;
 137         } st2;
 138
 139         /* for TWSaction */
 140         struct {
 141             char *un_datef;
 142             int   un_after;
 143             struct tws un_tws;
 144         } st3;
 145     } un;
 146 };
 147
 148 #define n_L_child un.st1.un_L_child
 149 #define n_R_child un.st1.un_R_child
 150
 151 #define n_header un.st2.un_header
 152 #define n_circf  un.st2.un_circf
 153 #define n_expbuf un.st2.un_expbuf
 154 #define n_patbuf un.st2.un_patbuf
 155
 156 #define n_datef  un.st3.un_datef
 157 #define n_after  un.st3.un_after
 158 #define n_tws    un.st3.un_tws
 159
 160 static int talked;
 161
 162 static char *datesw;
 163 static char **argp;
 164
 165 static struct nexus *head;
 166
 167 /*
 168  * prototypes for date routines
 169  */
 170 static struct tws *tws_parse(char *, int);
 171 static struct tws *tws_special(char *);
 172
 173 /*
 174  * static prototypes
 175  */
 176 static void PRaction(struct nexus *, int);
 177 static int gcompile(struct nexus *, char *);
 178 static int advance(char *, char *);
 179 static int cclass(unsigned char *, int, int);
 180 static int tcompile(char *, struct tws *, int);
 181
 182 static struct nexus *parse(void);
 183 static struct nexus *nexp1(void);
 184 static struct nexus *nexp2(void);
 185 static struct nexus *nexp3(void);
 186 static struct nexus *newnexus(int (*action)(struct nexus *n,
 187     FILE *fp, int msgnum, long start, long stop));
 188
 189 static int ORaction(struct nexus *n, FILE *fp, int msgnum,
 190     long start, long stop);
 191 static int ANDaction(struct nexus *n, FILE *fp, int msgnum,
 192     long start, long stop);
 193 static int NOTaction(struct nexus *n, FILE *fp, int msgnum,
 194     long start, long stop);
 195 static int GREPaction(struct nexus *n, FILE *fp, int msgnum,
 196     long start, long stop);
 197 static int TWSaction(struct nexus *n, FILE *fp, int msgnum,
 198     long start, long stop);
 199
 200
 201 int
 202 pcompile (char **vec, char *date)
 203 {
 204     argp = vec;
 205     if ((datesw = date) == NULL)
 206         datesw = "date";
 207     talked = 0;
 208
 209     if ((head = parse ()) == NULL)
 210         return !talked;
 211
 212     if (*argp) {
 213         inform("%s unexpected", *argp);
 214         return 0;
 215     }
 216
 217     return 1;
 218 }
 219
 220
 221 static struct nexus *
 222 parse (void)
 223 {
 224     char  *cp;
 225     struct nexus *n, *o;
 226
 227     if ((n = nexp1 ()) == NULL || (cp = nxtarg ()) == NULL)
 228         return n;
 229
 230     if (*cp != '-') {
 231         pinform("%s unexpected", cp);
 232         return NULL;
 233     }
 234
 235     if (*++cp == '-')
 236         goto header;
 237     switch (smatch (cp, parswit)) {
 238         case AMBIGSW:
 239             ambigsw (cp, parswit);
 240             talked++;
 241             return NULL;
 242         case UNKWNSW:
 243             fprintf (stderr, "-%s unknown\n", cp);
 244             talked++;
 245             return NULL;
 246
 247         case PROR:
 248             o = newnexus (ORaction);
 249             o->n_L_child = n;
 250             if ((o->n_R_child = parse ()))
 251                 return o;
 252             pinform("missing disjunctive");
 253             free (o);
 254             return NULL;
 255
 256 header: ;
 257         default:
 258             prvarg ();
 259             return n;
 260     }
 261 }
 262
 263 static struct nexus *
 264 nexp1 (void)
 265 {
 266     char *cp;
 267     struct nexus *n, *o;
 268
 269     if ((n = nexp2 ()) == NULL || (cp = nxtarg ()) == NULL)
 270         return n;
 271
 272     if (*cp != '-') {
 273         pinform("%s unexpected", cp);
 274         free (n);
 275         return NULL;
 276     }
 277
 278     if (*++cp == '-')
 279         goto header;
 280     switch (smatch (cp, parswit)) {
 281         case AMBIGSW:
 282             ambigsw (cp, parswit);
 283             talked++;
 284             free (n);
 285             return NULL;
 286         case UNKWNSW:
 287             fprintf (stderr, "-%s unknown\n", cp);
 288             talked++;
 289             free (n);
 290             return NULL;
 291
 292         case PRAND:
 293             o = newnexus (ANDaction);
 294             o->n_L_child = n;
 295             if ((o->n_R_child = nexp1 ()))
 296                 return o;
 297             pinform("missing conjunctive");
 298             free (o);
 299             return NULL;
 300
 301 header: ;
 302         default:
 303             prvarg ();
 304             return n;
 305     }
 306 }
 307
 308
 309 static struct nexus *
 310 nexp2 (void)
 311 {
 312     char *cp;
 313     struct nexus *n;
 314
 315     if ((cp = nxtarg ()) == NULL)
 316         return NULL;
 317
 318     if (*cp != '-') {
 319         prvarg ();
 320         return nexp3 ();
 321     }
 322
 323     if (*++cp == '-')
 324         goto header;
 325     switch (smatch (cp, parswit)) {
 326         case AMBIGSW:
 327             ambigsw (cp, parswit);
 328             talked++;
 329             return NULL;
 330         case UNKWNSW:
 331             fprintf (stderr, "-%s unknown\n", cp);
 332             talked++;
 333             return NULL;
 334
 335         case PRNOT:
 336             n = newnexus (NOTaction);
 337             if ((n->n_L_child = nexp3 ()))
 338                 return n;
 339             pinform("missing negation");
 340             free (n);
 341             return NULL;
 342
 343 header: ;
 344         default:
 345             prvarg ();
 346             return nexp3 ();
 347     }
 348 }
 349
 350 static struct nexus *
 351 nexp3 (void)
 352 {
 353     int i;
 354     char *cp, *dp;
 355     char buffer[BUFSIZ], temp[64];
 356     struct nexus *n;
 357
 358     if ((cp = nxtarg ()) == NULL)
 359         return NULL;
 360
 361     if (*cp != '-') {
 362         pinform("%s unexpected", cp);
 363         return NULL;
 364     }
 365
 366     if (*++cp == '-') {
 367         dp = ++cp;
 368         goto header;
 369     }
 370     switch (i = smatch (cp, parswit)) {
 371         case AMBIGSW:
 372             ambigsw (cp, parswit);
 373             talked++;
 374             return NULL;
 375         case UNKWNSW:
 376             fprintf (stderr, "-%s unknown\n", cp);
 377             talked++;
 378             return NULL;
 379
 380         case PRLBR:
 381             if ((n = parse ()) == NULL) {
 382                 pinform("missing group");
 383                 return NULL;
 384             }
 385             if ((cp = nxtarg ()) == NULL) {
 386                 pinform("missing -rbrace");
 387                 return NULL;
 388             }
 389             if (*cp++ == '-' && smatch (cp, parswit) == PRRBR)
 390                 return n;
 391             pinform("%s unexpected", --cp);
 392             return NULL;
 393
 394         default:
 395             prvarg ();
 396             return NULL;
 397
 398         case PRCC:
 399         case PRDATE:
 400         case PRFROM:
 401         case PRTO:
 402         case PRSUBJ:
 403             strncpy(temp, parswit[i].sw, sizeof(temp));
 404             temp[sizeof(temp) - 1] = '\0';
 405             dp = *brkstring (temp, " ", NULL);
 406     header: ;
 407             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 408                 pinform("missing argument to %s", argp[-2]);
 409                 return NULL;
 410             }
 411             n = newnexus (GREPaction);
 412             n->n_header = 1;
 413             snprintf (buffer, sizeof(buffer), "^%s[ \t]*:.*%s", dp, cp);
 414             dp = buffer;
 415             goto pattern;
 416
 417         case PRSRCH:
 418             n = newnexus (GREPaction);
 419             n->n_header = 0;
 420             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 421                 pinform("missing argument to %s", argp[-2]);
 422                 free (n);
 423                 return NULL;
 424             }
 425             dp = cp;
 426     pattern: ;
 427             if (!gcompile (n, dp)) {
 428                 pinform("pattern error in %s %s", argp[-2], cp);
 429                 free (n);
 430                 return NULL;
 431             }
 432             n->n_patbuf = mh_xstrdup(dp);
 433             return n;
 434
 435         case PROTHR:
 436             pinform("internal error!");
 437             return NULL;
 438
 439         case PRDATF:
 440             if (!(datesw = nxtarg ()) || *datesw == '-') {
 441                 pinform("missing argument to %s", argp[-2]);
 442                 return NULL;
 443             }
 444             return nexp3 ();
 445
 446         case PRAFTR:
 447         case PRBEFR:
 448             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 449                 pinform("missing argument to %s", argp[-2]);
 450                 return NULL;
 451             }
 452             n = newnexus (TWSaction);
 453             n->n_datef = datesw;
 454             if (!tcompile (cp, &n->n_tws, n->n_after = i == PRAFTR)) {
 455                 pinform("unable to parse %s %s", argp[-2], cp);
 456                 free (n);
 457                 return NULL;
 458             }
 459             return n;
 460     }
 461 }
 462
 463
 464 static struct nexus *
 465 newnexus(int (*action)(struct nexus *n, FILE *fp, int msgnum,
 466     long start, long stop))
 467 {
 468     struct nexus *p;
 469
 470     NEW0(p);
 471     p->n_action = action;
 472     return p;
 473 }
 474
 475
 476 int
 477 pmatches (FILE *fp, int msgnum, long start, long stop, int debug)
 478 {
 479     if (!head)
 480         return 1;
 481
 482     if (!talked++ && debug)
 483         PRaction (head, 0);
 484
 485     return (*head->n_action)(head, fp, msgnum, start, stop);
 486 }
 487
 488
 489 static void
 490 PRaction (struct nexus *n, int level)
 491 {
 492     int i;
 493
 494     for (i = 0; i < level; i++)
 495         fprintf (stderr, "| ");
 496
 497     if (n->n_action == ORaction) {
 498         fprintf (stderr, "OR\n");
 499         PRaction (n->n_L_child, level + 1);
 500         PRaction (n->n_R_child, level + 1);
 501         return;
 502     }
 503     if (n->n_action == ANDaction) {
 504         fprintf (stderr, "AND\n");
 505         PRaction (n->n_L_child, level + 1);
 506         PRaction (n->n_R_child, level + 1);
 507         return;
 508     }
 509     if (n->n_action == NOTaction) {
 510         fprintf (stderr, "NOT\n");
 511         PRaction (n->n_L_child, level + 1);
 512         return;
 513     }
 514     if (n->n_action == GREPaction) {
 515         fprintf (stderr, "PATTERN(%s) %s\n",
 516                 n->n_header ? "header" : "body", n->n_patbuf);
 517         return;
 518     }
 519     if (n->n_action == TWSaction) {
 520         fprintf (stderr, "TEMPORAL(%s) %s: %s\n",
 521                 n->n_after ? "after" : "before", n->n_datef,
 522                 dasctime (&n->n_tws, TW_NULL));
 523         return;
 524     }
 525
 526     generic_pointer gp;
 527     gp.f = (void (*)(void))n->n_action;
 528     fprintf(stderr, "UNKNOWN(%p)\n", gp.v);
 529 }
 530
 531
 532 static int
 533 ORaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 534 {
 535     if ((*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop))
 536         return 1;
 537     return (*n->n_R_child->n_action)(n->n_R_child, fp, msgnum, start, stop);
 538 }
 539
 540
 541 static int
 542 ANDaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 543 {
 544     if (!(*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop))
 545         return 0;
 546     return (*n->n_R_child->n_action)(n->n_R_child, fp, msgnum, start, stop);
 547 }
 548
 549
 550 static int
 551 NOTaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 552 {
 553     return (!(*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop));
 554 }
 555
 556
 557 static int
 558 gcompile (struct nexus *n, char *astr)
 559 {
 560     int c;
 561     int cclcnt;
 562     unsigned char *ep, *dp, *sp, *lastep = 0;
 563
 564     dp = (ep = (unsigned char *) n->n_expbuf) + sizeof n->n_expbuf;
 565     sp = (unsigned char *) astr;
 566     if (*sp == '^') {
 567         n->n_circf = 1;
 568         sp++;
 569     }
 570     else
 571         n->n_circf = 0;
 572     for (;;) {
 573         if (ep >= dp)
 574             goto cerror;
 575         if ((c = *sp++) != '*')
 576             lastep = ep;
 577         switch (c) {
 578             case '\0':
 579                 *ep++ = CEOF;
 580                 return 1;
 581
 582             case '.':
 583                 *ep++ = CDOT;
 584                 continue;
 585
 586             case '*':
 587                 if (lastep == 0)
 588                     goto defchar;
 589                 *lastep |= STAR;
 590                 continue;
 591
 592             case '$':
 593                 if (*sp != '\0')
 594                     goto defchar;
 595                 *ep++ = CDOL;
 596                 continue;
 597
 598             case '[':
 599                 *ep++ = CCL;
 600                 *ep++ = 0;
 601                 cclcnt = 0;
 602                 if ((c = *sp++) == '^') {
 603                     c = *sp++;
 604                     ep[-2] = NCCL;
 605                 }
 606                 if (c == '-') {
 607                     *ep++ = c;
 608                     cclcnt++;
 609                     c = *sp++;
 610                 }
 611                 do {
 612                     if (c == '-' && *sp != '\0' && *sp != ']') {
 613                         for (c = ep[-1]+1; c < *sp; c++) {
 614                             *ep++ = c;
 615                             cclcnt++;
 616                             if (c == '\0' || ep >= dp)
 617                                 goto cerror;
 618                         }
 619                     } else {
 620                         *ep++ = c;
 621                         cclcnt++;
 622                         if (c == '\0' || ep >= dp)
 623                             goto cerror;
 624                     }
 625                 } while ((c = *sp++) != ']');
 626                 if (cclcnt > 255)
 627                     goto cerror;
 628                 lastep[1] = cclcnt;
 629                 continue;
 630
 631             case '\\':
 632                 if ((c = *sp++) == '\0')
 633                     goto cerror;
 634                 /* FALLTHRU */
 635         defchar:
 636             default:
 637                 *ep++ = CCHR;
 638                 *ep++ = c;
 639         }
 640     }
 641
 642 cerror: ;
 643     return 0;
 644 }
 645
 646
 647 static int
 648 GREPaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 649 {
 650     int c;
 651     bool body;
 652     bool lf;
 653     long pos = start;
 654     char *p1, *p2, *ebp, *cbp;
 655     char ibuf[BUFSIZ];
 656     NMH_UNUSED (msgnum);
 657
 658     fseek (fp, start, SEEK_SET);
 659     body = false;
 660     ebp = cbp = ibuf;
 661     for (;;) {
 662         if (body && n->n_header)
 663             return 0;
 664         p1 = linebuf;
 665         p2 = cbp;
 666         lf = false;
 667         for (;;) {
 668             if (p2 >= ebp) {
 669                 if (fgets (ibuf, sizeof ibuf, fp) == NULL
 670                         || (stop && pos >= stop)) {
 671                     if (lf)
 672                         break;
 673                     return 0;
 674                 }
 675                 pos += (long) strlen (ibuf);
 676                 p2 = ibuf;
 677                 ebp = ibuf + strlen (ibuf);
 678             }
 679             c = *p2++;
 680             if (lf && c != '\n') {
 681                 if (c != ' ' && c != '\t') {
 682                     --p2;
 683                     break;
 684                 }
 685                 lf = false;
 686             }
 687             if (c == '\n') {
 688                 if (body)
 689                     break;
 690                 if (lf) {
 691                     body = true;
 692                     break;
 693                 }
 694                 lf = true;
 695                 /* Unfold by skipping the newline. */
 696                 c = 0;
 697             }
 698             if (c && p1 < &linebuf[LBSIZE - 1])
 699                 *p1++ = c;
 700         }
 701
 702         *p1++ = 0;
 703         cbp = p2;
 704         p1 = linebuf;
 705         p2 = n->n_expbuf;
 706
 707         /* Attempt to decode as a MIME header.  If it's the last header,
 708            body will be 1 and lf will be at least 1. */
 709         if ((!body || lf)  &&
 710             decode_rfc2047 (linebuf, decoded_linebuf, sizeof decoded_linebuf)) {
 711             p1 = decoded_linebuf;
 712         }
 713
 714         if (n->n_circf) {
 715             if (advance (p1, p2))
 716                 return 1;
 717             continue;
 718         }
 719
 720         if (*p2 == CCHR) {
 721             c = p2[1];
 722             do {
 723                 if (*p1 == c || cc[(unsigned char)*p1] == c)
 724                     if (advance (p1, p2))
 725                         return 1;
 726             } while (*p1++);
 727             continue;
 728         }
 729
 730         do {
 731             if (advance (p1, p2))
 732                 return 1;
 733         } while (*p1++);
 734     }
 735 }
 736
 737
 738 static int
 739 advance (char *alp, char *aep)
 740 {
 741     unsigned char *lp, *ep, *curlp;
 742
 743     lp = (unsigned char *)alp;
 744     ep = (unsigned char *)aep;
 745     for (;;)
 746         switch (*ep++) {
 747             case CCHR:
 748                 if (*ep++ == *lp++ || ep[-1] == cc[lp[-1]])
 749                     continue;
 750                 return 0;
 751
 752             case CDOT:
 753                 if (*lp++)
 754                     continue;
 755                 return 0;
 756
 757             case CDOL:
 758                 if (*lp == 0)
 759                     continue;
 760                 return 0;
 761
 762             case CEOF:
 763                 return 1;
 764
 765             case CCL:
 766                 if (cclass (ep, *lp++, 1)) {
 767                     ep += *ep + 1;
 768                     continue;
 769                 }
 770                 return 0;
 771
 772             case NCCL:
 773                 if (cclass (ep, *lp++, 0)) {
 774                     ep += *ep + 1;
 775                     continue;
 776                 }
 777                 return 0;
 778
 779             case CDOT | STAR:
 780                 curlp = lp;
 781                 while (*lp++)
 782                     continue;
 783                 goto star;
 784
 785             case CCHR | STAR:
 786                 curlp = lp;
 787                 while (*lp++ == *ep || cc[lp[-1]] == *ep)
 788                     continue;
 789                 ep++;
 790                 goto star;
 791
 792             case CCL | STAR:
 793             case NCCL | STAR:
 794                 curlp = lp;
 795                 while (cclass (ep, *lp++, ep[-1] == (CCL | STAR)))
 796                     continue;
 797                 ep += *ep + 1;
 798                 goto star;
 799
 800         star:
 801                 do {
 802                     lp--;
 803                     if (advance ((char *) lp, (char *) ep))
 804                         return 1;
 805                 } while (lp > curlp);
 806                 return 0;
 807
 808             default:
 809                 inform("advance() botch -- you lose big, continuing...");
 810                 return 0;
 811         }
 812 }
 813
 814
 815 static int
 816 cclass (unsigned char *aset, int ac, int af)
 817 {
 818     unsigned int    n;
 819     unsigned char   c, *set;
 820
 821     set = aset;
 822     if ((c = ac) == 0)
 823         return 0;
 824
 825     n = *set++;
 826     while (n--)
 827         if (*set++ == c || set[-1] == cc[c])
 828             return af;
 829
 830     return !af;
 831 }
 832
 833
 834 static int
 835 tcompile (char *ap, struct tws *tb, int isafter)
 836 {
 837     struct tws *tw;
 838
 839     if ((tw = tws_parse (ap, isafter)) == NULL)
 840         return 0;
 841
 842     *tb = *tw;
 843     return 1;
 844 }
 845
 846
 847 static struct tws *
 848 tws_parse (char *ap, int isafter)
 849 {
 850     char buffer[BUFSIZ];
 851     struct tws *tw, *ts;
 852
 853     if ((tw = tws_special (ap)) != NULL) {
 854         tw->tw_sec = tw->tw_min = isafter ? 59 : 0;
 855         tw->tw_hour = isafter ? 23 : 0;
 856         return tw;
 857     }
 858     if ((tw = dparsetime (ap)) != NULL)
 859         return tw;
 860
 861     if ((ts = dlocaltimenow ()) == NULL)
 862         return NULL;
 863
 864     snprintf (buffer, sizeof(buffer), "%s %s", ap, dtwszone (ts));
 865     if ((tw = dparsetime (buffer)) != NULL)
 866         return tw;
 867
 868     snprintf (buffer, sizeof(buffer), "%s %02d:%02d:%02d %s", ap,
 869             ts->tw_hour, ts->tw_min, ts->tw_sec, dtwszone (ts));
 870     if ((tw = dparsetime (buffer)) != NULL)
 871         return tw;
 872
 873     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s",
 874             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year, ap);
 875     if ((tw = dparsetime (buffer)) != NULL)
 876         return tw;
 877
 878     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s %s",
 879             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year,
 880             ap, dtwszone (ts));
 881     if ((tw = dparsetime (buffer)) != NULL)
 882         return tw;
 883
 884     return NULL;
 885 }
 886
 887
 888 static struct tws *
 889 tws_special (char *ap)
 890 {
 891     int i;
 892     time_t clock;
 893     struct tws *tw;
 894
 895     time (&clock);
 896     if (!strcasecmp (ap, "today"))
 897         return dlocaltime (&clock);
 898     if (!strcasecmp (ap, "yesterday")) {
 899         clock -= (long) (60 * 60 * 24);
 900         return dlocaltime (&clock);
 901     }
 902     if (!strcasecmp (ap, "tomorrow")) {
 903         clock += (long) (60 * 60 * 24);
 904         return dlocaltime (&clock);
 905     }
 906
 907     for (i = 0; tw_ldotw[i]; i++)
 908         if (!strcasecmp (ap, tw_ldotw[i]))
 909             break;
 910     if (tw_ldotw[i]) {
 911         if ((tw = dlocaltime (&clock)) == NULL)
 912             return NULL;
 913         if ((i -= tw->tw_wday) > 0)
 914             i -= 7;
 915     }
 916     else {
 917         if (*ap != '-')
 918             return NULL;
 919         /* -ddd days ago */
 920         i = atoi (ap);  /* we should error check this */
 921     }
 922
 923     clock += (long) ((60 * 60 * 24) * i);
 924     return dlocaltime (&clock);
 925 }
 926
 927
 928 static int
 929 TWSaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 930 {
 931     int state;
 932     char *bp;
 933     char buf[NMH_BUFSIZ], name[NAMESZ];
 934     struct tws *tw;
 935     m_getfld_state_t gstate;
 936     NMH_UNUSED (stop);
 937
 938     fseek (fp, start, SEEK_SET);
 939     gstate = m_getfld_state_init(fp);
 940     for (bp = NULL;;) {
 941         int bufsz = sizeof buf;
 942         switch (state = m_getfld2(&gstate, name, buf, &bufsz)) {
 943             case FLD:
 944             case FLDPLUS:
 945                 free(bp);
 946                 bp = mh_xstrdup(buf);
 947                 while (state == FLDPLUS) {
 948                     bufsz = sizeof buf;
 949                     state = m_getfld2(&gstate, name, buf, &bufsz);
 950                     bp = add (buf, bp);
 951                 }
 952                 if (!strcasecmp (name, n->n_datef))
 953                     break;
 954                 continue;
 955
 956             case BODY:
 957             case FILEEOF:
 958             case LENERR:
 959             case FMTERR:
 960                 if (state == LENERR || state == FMTERR)
 961                     inform("format error in message %d", msgnum);
 962                 free(bp);
 963                 return 0;
 964
 965             default:
 966                 die("internal error -- you lose");
 967         }
 968         break;
 969     }
 970     m_getfld_state_destroy (&gstate);
 971
 972     if ((tw = dparsetime (bp)) == NULL)
 973         inform("unable to parse %s field in message %d, matching...",
 974                 n->n_datef, msgnum), state = 1;
 975     else
 976         state = n->n_after ? (twsort (tw, &n->n_tws) > 0)
 977             : (twsort (tw, &n->n_tws) < 0);
 978
 979     free(bp);
 980     return state;
 981 }