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/smatch.h"
  10 #include "sbr/fmt_rfc2047.h"
  11 #include "sbr/brkstring.h"
  12 #include "sbr/ambigsw.h"
  13 #include "sbr/error.h"
  14 #include "h/tws.h"
  15 #include "h/picksbr.h"
  16 #include "h/utils.h"
  17
  18 #ifdef HAVE_SYS_TIME_H
  19 # include <sys/time.h>
  20 #endif
  21 #include <time.h>
  22
  23 #define PARSE_SWITCHES \
  24     X("and", 0, PRAND) \
  25     X("or", 0, PROR) \
  26     X("not", 0, PRNOT) \
  27     X("lbrace", 0, PRLBR) \
  28     X("rbrace", 0, PRRBR) \
  29     X("cc  pattern", 0, PRCC) \
  30     X("date  pattern", 0, PRDATE) \
  31     X("from  pattern", 0, PRFROM) \
  32     X("search  pattern", 0, PRSRCH) \
  33     X("subject  pattern", 0, PRSUBJ) \
  34     X("to  pattern", 0, PRTO) \
  35     X("-othercomponent  pattern", 15, PROTHR) \
  36     X("after date", 0, PRAFTR) \
  37     X("before date", 0, PRBEFR) \
  38     X("datefield field", 5, PRDATF) \
  39
  40 #define X(sw, minchars, id) id,
  41 DEFINE_SWITCH_ENUM(PARSE);
  42 #undef X
  43
  44 #define X(sw, minchars, id) { sw, minchars, id },
  45 DEFINE_SWITCH_ARRAY(PARSE, parswit);
  46 #undef X
  47
  48 /* DEFINITIONS FOR PATTERN MATCHING */
  49
  50 /*
  51  * We really should be using re_comp() and re_exec() here.  Unfortunately,
  52  * pick advertises that lowercase characters matches characters of both
  53  * cases.  Since re_exec() doesn't exhibit this behavior, we are stuck
  54  * with this version.  Furthermore, we need to be able to save and restore
  55  * the state of the pattern matcher in order to do things "efficiently".
  56  *
  57  * The matching power of this algorithm isn't as powerful as the re_xxx()
  58  * routines (no \(xxx\) and \n constructs).  Such is life.
  59  */
  60
  61 #define CCHR    2
  62 #define CDOT    4
  63 #define CCL     6
  64 #define NCCL    8
  65 #define CDOL    10
  66 #define CEOF    11
  67
  68 #define STAR    01
  69
  70 #define LBSIZE  NMH_BUFSIZ
  71 #define ESIZE   1024
  72
  73
  74 static char linebuf[LBSIZE + 1];
  75 static char decoded_linebuf[LBSIZE + 1];
  76
  77 /* the magic array for case-independence */
  78 static unsigned char cc[] = {
  79         0000,0001,0002,0003,0004,0005,0006,0007,
  80         0010,0011,0012,0013,0014,0015,0016,0017,
  81         0020,0021,0022,0023,0024,0025,0026,0027,
  82         0030,0031,0032,0033,0034,0035,0036,0037,
  83         0040,0041,0042,0043,0044,0045,0046,0047,
  84         0050,0051,0052,0053,0054,0055,0056,0057,
  85         0060,0061,0062,0063,0064,0065,0066,0067,
  86         0070,0071,0072,0073,0074,0075,0076,0077,
  87         0100,0141,0142,0143,0144,0145,0146,0147,
  88         0150,0151,0152,0153,0154,0155,0156,0157,
  89         0160,0161,0162,0163,0164,0165,0166,0167,
  90         0170,0171,0172,0133,0134,0135,0136,0137,
  91         0140,0141,0142,0143,0144,0145,0146,0147,
  92         0150,0151,0152,0153,0154,0155,0156,0157,
  93         0160,0161,0162,0163,0164,0165,0166,0167,
  94         0170,0171,0172,0173,0174,0175,0176,0177,
  95
  96         0200,0201,0202,0203,0204,0205,0206,0207,
  97         0210,0211,0212,0213,0214,0215,0216,0217,
  98         0220,0221,0222,0223,0224,0225,0226,0227,
  99         0230,0231,0232,0233,0234,0235,0236,0237,
 100         0240,0241,0242,0243,0244,0245,0246,0247,
 101         0250,0251,0252,0253,0254,0255,0256,0257,
 102         0260,0261,0262,0263,0264,0265,0266,0267,
 103         0270,0271,0272,0273,0274,0275,0276,0277,
 104         0300,0301,0302,0303,0304,0305,0306,0307,
 105         0310,0311,0312,0313,0314,0315,0316,0317,
 106         0320,0321,0322,0323,0324,0325,0326,0327,
 107         0330,0331,0332,0333,0334,0335,0336,0337,
 108         0340,0341,0342,0343,0344,0345,0346,0347,
 109         0350,0351,0352,0353,0354,0355,0356,0357,
 110         0360,0361,0362,0363,0364,0365,0366,0367,
 111         0370,0371,0372,0373,0374,0375,0376,0377,
 112 };
 113
 114 /*
 115  * DEFINITIONS FOR NEXUS
 116  */
 117
 118 #define nxtarg()        (*argp ? *argp++ : NULL)
 119 #define prvarg()        argp--
 120
 121 #define pinform         if (!talked++) inform
 122
 123 struct nexus {
 124     int (*n_action)(struct nexus *n, FILE *fp, int msgnum, long start, long stop);
 125
 126     union {
 127         /* for {OR,AND,NOT}action */
 128         struct {
 129             struct nexus *un_L_child;
 130             struct nexus *un_R_child;
 131         } st1;
 132
 133         /* for GREPaction */
 134         struct {
 135             int   un_header;
 136             int   un_circf;
 137             char  un_expbuf[ESIZE];
 138             char *un_patbuf;
 139         } st2;
 140
 141         /* for TWSaction */
 142         struct {
 143             char *un_datef;
 144             int   un_after;
 145             struct tws un_tws;
 146         } st3;
 147     } un;
 148 };
 149
 150 #define n_L_child un.st1.un_L_child
 151 #define n_R_child un.st1.un_R_child
 152
 153 #define n_header un.st2.un_header
 154 #define n_circf  un.st2.un_circf
 155 #define n_expbuf un.st2.un_expbuf
 156 #define n_patbuf un.st2.un_patbuf
 157
 158 #define n_datef  un.st3.un_datef
 159 #define n_after  un.st3.un_after
 160 #define n_tws    un.st3.un_tws
 161
 162 static int talked;
 163
 164 static char *datesw;
 165 static char **argp;
 166
 167 static struct nexus *head;
 168
 169 /*
 170  * prototypes for date routines
 171  */
 172 static struct tws *tws_parse(char *, int);
 173 static struct tws *tws_special(char *);
 174
 175 /*
 176  * static prototypes
 177  */
 178 static void PRaction(struct nexus *, int);
 179 static int gcompile(struct nexus *, char *);
 180 static int advance(char *, char *);
 181 static int cclass(unsigned char *, int, int);
 182 static int tcompile(char *, struct tws *, int);
 183
 184 static struct nexus *parse(void);
 185 static struct nexus *nexp1(void);
 186 static struct nexus *nexp2(void);
 187 static struct nexus *nexp3(void);
 188 static struct nexus *newnexus(int (*action)(struct nexus *n,
 189     FILE *fp, int msgnum, long start, long stop));
 190
 191 static int ORaction(struct nexus *n, FILE *fp, int msgnum,
 192     long start, long stop);
 193 static int ANDaction(struct nexus *n, FILE *fp, int msgnum,
 194     long start, long stop);
 195 static int NOTaction(struct nexus *n, FILE *fp, int msgnum,
 196     long start, long stop);
 197 static int GREPaction(struct nexus *n, FILE *fp, int msgnum,
 198     long start, long stop);
 199 static int TWSaction(struct nexus *n, FILE *fp, int msgnum,
 200     long start, long stop);
 201
 202
 203 int
 204 pcompile (char **vec, char *date)
 205 {
 206     argp = vec;
 207     if ((datesw = date) == NULL)
 208         datesw = "date";
 209     talked = 0;
 210
 211     if ((head = parse ()) == NULL)
 212         return !talked;
 213
 214     if (*argp) {
 215         inform("%s unexpected", *argp);
 216         return 0;
 217     }
 218
 219     return 1;
 220 }
 221
 222
 223 static struct nexus *
 224 parse (void)
 225 {
 226     char  *cp;
 227     struct nexus *n, *o;
 228
 229     if ((n = nexp1 ()) == NULL || (cp = nxtarg ()) == NULL)
 230         return n;
 231
 232     if (*cp != '-') {
 233         pinform("%s unexpected", cp);
 234         return NULL;
 235     }
 236
 237     if (*++cp == '-')
 238         goto header;
 239     switch (smatch (cp, parswit)) {
 240         case AMBIGSW:
 241             ambigsw (cp, parswit);
 242             talked++;
 243             return NULL;
 244         case UNKWNSW:
 245             fprintf (stderr, "-%s unknown\n", cp);
 246             talked++;
 247             return NULL;
 248
 249         case PROR:
 250             o = newnexus (ORaction);
 251             o->n_L_child = n;
 252             if ((o->n_R_child = parse ()))
 253                 return o;
 254             pinform("missing disjunctive");
 255             free (o);
 256             return NULL;
 257
 258 header: ;
 259         default:
 260             prvarg ();
 261             return n;
 262     }
 263 }
 264
 265 static struct nexus *
 266 nexp1 (void)
 267 {
 268     char *cp;
 269     struct nexus *n, *o;
 270
 271     if ((n = nexp2 ()) == NULL || (cp = nxtarg ()) == NULL)
 272         return n;
 273
 274     if (*cp != '-') {
 275         pinform("%s unexpected", cp);
 276         free (n);
 277         return NULL;
 278     }
 279
 280     if (*++cp == '-')
 281         goto header;
 282     switch (smatch (cp, parswit)) {
 283         case AMBIGSW:
 284             ambigsw (cp, parswit);
 285             talked++;
 286             free (n);
 287             return NULL;
 288         case UNKWNSW:
 289             fprintf (stderr, "-%s unknown\n", cp);
 290             talked++;
 291             free (n);
 292             return NULL;
 293
 294         case PRAND:
 295             o = newnexus (ANDaction);
 296             o->n_L_child = n;
 297             if ((o->n_R_child = nexp1 ()))
 298                 return o;
 299             pinform("missing conjunctive");
 300             free (o);
 301             return NULL;
 302
 303 header: ;
 304         default:
 305             prvarg ();
 306             return n;
 307     }
 308 }
 309
 310
 311 static struct nexus *
 312 nexp2 (void)
 313 {
 314     char *cp;
 315     struct nexus *n;
 316
 317     if ((cp = nxtarg ()) == NULL)
 318         return NULL;
 319
 320     if (*cp != '-') {
 321         prvarg ();
 322         return nexp3 ();
 323     }
 324
 325     if (*++cp == '-')
 326         goto header;
 327     switch (smatch (cp, parswit)) {
 328         case AMBIGSW:
 329             ambigsw (cp, parswit);
 330             talked++;
 331             return NULL;
 332         case UNKWNSW:
 333             fprintf (stderr, "-%s unknown\n", cp);
 334             talked++;
 335             return NULL;
 336
 337         case PRNOT:
 338             n = newnexus (NOTaction);
 339             if ((n->n_L_child = nexp3 ()))
 340                 return n;
 341             pinform("missing negation");
 342             free (n);
 343             return NULL;
 344
 345 header: ;
 346         default:
 347             prvarg ();
 348             return nexp3 ();
 349     }
 350 }
 351
 352 static struct nexus *
 353 nexp3 (void)
 354 {
 355     int i;
 356     char *cp, *dp;
 357     char buffer[BUFSIZ], temp[64];
 358     struct nexus *n;
 359
 360     if ((cp = nxtarg ()) == NULL)
 361         return NULL;
 362
 363     if (*cp != '-') {
 364         pinform("%s unexpected", cp);
 365         return NULL;
 366     }
 367
 368     if (*++cp == '-') {
 369         dp = ++cp;
 370         goto header;
 371     }
 372     switch (i = smatch (cp, parswit)) {
 373         case AMBIGSW:
 374             ambigsw (cp, parswit);
 375             talked++;
 376             return NULL;
 377         case UNKWNSW:
 378             fprintf (stderr, "-%s unknown\n", cp);
 379             talked++;
 380             return NULL;
 381
 382         case PRLBR:
 383             if ((n = parse ()) == NULL) {
 384                 pinform("missing group");
 385                 return NULL;
 386             }
 387             if ((cp = nxtarg ()) == NULL) {
 388                 pinform("missing -rbrace");
 389                 return NULL;
 390             }
 391             if (*cp++ == '-' && smatch (cp, parswit) == PRRBR)
 392                 return n;
 393             pinform("%s unexpected", --cp);
 394             return NULL;
 395
 396         default:
 397             prvarg ();
 398             return NULL;
 399
 400         case PRCC:
 401         case PRDATE:
 402         case PRFROM:
 403         case PRTO:
 404         case PRSUBJ:
 405             strncpy(temp, parswit[i].sw, sizeof(temp));
 406             temp[sizeof(temp) - 1] = '\0';
 407             dp = *brkstring (temp, " ", NULL);
 408     header: ;
 409             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 410                 pinform("missing argument to %s", argp[-2]);
 411                 return NULL;
 412             }
 413             n = newnexus (GREPaction);
 414             n->n_header = 1;
 415             snprintf (buffer, sizeof(buffer), "^%s[ \t]*:.*%s", dp, cp);
 416             dp = buffer;
 417             goto pattern;
 418
 419         case PRSRCH:
 420             n = newnexus (GREPaction);
 421             n->n_header = 0;
 422             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 423                 pinform("missing argument to %s", argp[-2]);
 424                 free (n);
 425                 return NULL;
 426             }
 427             dp = cp;
 428     pattern: ;
 429             if (!gcompile (n, dp)) {
 430                 pinform("pattern error in %s %s", argp[-2], cp);
 431                 free (n);
 432                 return NULL;
 433             }
 434             n->n_patbuf = mh_xstrdup(dp);
 435             return n;
 436
 437         case PROTHR:
 438             pinform("internal error!");
 439             return NULL;
 440
 441         case PRDATF:
 442             if (!(datesw = nxtarg ()) || *datesw == '-') {
 443                 pinform("missing argument to %s", argp[-2]);
 444                 return NULL;
 445             }
 446             return nexp3 ();
 447
 448         case PRAFTR:
 449         case PRBEFR:
 450             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 451                 pinform("missing argument to %s", argp[-2]);
 452                 return NULL;
 453             }
 454             n = newnexus (TWSaction);
 455             n->n_datef = datesw;
 456             if (!tcompile (cp, &n->n_tws, n->n_after = i == PRAFTR)) {
 457                 pinform("unable to parse %s %s", argp[-2], cp);
 458                 free (n);
 459                 return NULL;
 460             }
 461             return n;
 462     }
 463 }
 464
 465
 466 static struct nexus *
 467 newnexus(int (*action)(struct nexus *n, FILE *fp, int msgnum,
 468     long start, long stop))
 469 {
 470     struct nexus *p;
 471
 472     NEW0(p);
 473     p->n_action = action;
 474     return p;
 475 }
 476
 477
 478 int
 479 pmatches (FILE *fp, int msgnum, long start, long stop, int debug)
 480 {
 481     if (!head)
 482         return 1;
 483
 484     if (!talked++ && debug)
 485         PRaction (head, 0);
 486
 487     return (*head->n_action)(head, fp, msgnum, start, stop);
 488 }
 489
 490
 491 static void
 492 PRaction (struct nexus *n, int level)
 493 {
 494     int i;
 495
 496     for (i = 0; i < level; i++)
 497         fprintf (stderr, "| ");
 498
 499     if (n->n_action == ORaction) {
 500         fprintf (stderr, "OR\n");
 501         PRaction (n->n_L_child, level + 1);
 502         PRaction (n->n_R_child, level + 1);
 503         return;
 504     }
 505     if (n->n_action == ANDaction) {
 506         fprintf (stderr, "AND\n");
 507         PRaction (n->n_L_child, level + 1);
 508         PRaction (n->n_R_child, level + 1);
 509         return;
 510     }
 511     if (n->n_action == NOTaction) {
 512         fprintf (stderr, "NOT\n");
 513         PRaction (n->n_L_child, level + 1);
 514         return;
 515     }
 516     if (n->n_action == GREPaction) {
 517         fprintf (stderr, "PATTERN(%s) %s\n",
 518                 n->n_header ? "header" : "body", n->n_patbuf);
 519         return;
 520     }
 521     if (n->n_action == TWSaction) {
 522         fprintf (stderr, "TEMPORAL(%s) %s: %s\n",
 523                 n->n_after ? "after" : "before", n->n_datef,
 524                 dasctime (&n->n_tws, TW_NULL));
 525         return;
 526     }
 527
 528     generic_pointer gp;
 529     gp.f = (void (*)(void))n->n_action;
 530     fprintf(stderr, "UNKNOWN(%p)\n", gp.v);
 531 }
 532
 533
 534 static int
 535 ORaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 536 {
 537     if ((*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop))
 538         return 1;
 539     return (*n->n_R_child->n_action)(n->n_R_child, fp, msgnum, start, stop);
 540 }
 541
 542
 543 static int
 544 ANDaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 545 {
 546     if (!(*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop))
 547         return 0;
 548     return (*n->n_R_child->n_action)(n->n_R_child, fp, msgnum, start, stop);
 549 }
 550
 551
 552 static int
 553 NOTaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 554 {
 555     return (!(*n->n_L_child->n_action)(n->n_L_child, fp, msgnum, start, stop));
 556 }
 557
 558
 559 static int
 560 gcompile (struct nexus *n, char *astr)
 561 {
 562     int c;
 563     int cclcnt;
 564     unsigned char *ep, *dp, *sp, *lastep = 0;
 565
 566     dp = (ep = (unsigned char *) n->n_expbuf) + sizeof n->n_expbuf;
 567     sp = (unsigned char *) astr;
 568     if (*sp == '^') {
 569         n->n_circf = 1;
 570         sp++;
 571     }
 572     else
 573         n->n_circf = 0;
 574     for (;;) {
 575         if (ep >= dp)
 576             goto cerror;
 577         if ((c = *sp++) != '*')
 578             lastep = ep;
 579         switch (c) {
 580             case '\0':
 581                 *ep++ = CEOF;
 582                 return 1;
 583
 584             case '.':
 585                 *ep++ = CDOT;
 586                 continue;
 587
 588             case '*':
 589                 if (lastep == 0)
 590                     goto defchar;
 591                 *lastep |= STAR;
 592                 continue;
 593
 594             case '$':
 595                 if (*sp != '\0')
 596                     goto defchar;
 597                 *ep++ = CDOL;
 598                 continue;
 599
 600             case '[':
 601                 *ep++ = CCL;
 602                 *ep++ = 0;
 603                 cclcnt = 0;
 604                 if ((c = *sp++) == '^') {
 605                     c = *sp++;
 606                     ep[-2] = NCCL;
 607                 }
 608                 if (c == '-') {
 609                     *ep++ = c;
 610                     cclcnt++;
 611                     c = *sp++;
 612                 }
 613                 do {
 614                     if (c == '-' && *sp != '\0' && *sp != ']') {
 615                         for (c = ep[-1]+1; c < *sp; c++) {
 616                             *ep++ = c;
 617                             cclcnt++;
 618                             if (c == '\0' || ep >= dp)
 619                                 goto cerror;
 620                         }
 621                     } else {
 622                         *ep++ = c;
 623                         cclcnt++;
 624                         if (c == '\0' || ep >= dp)
 625                             goto cerror;
 626                     }
 627                 } while ((c = *sp++) != ']');
 628                 if (cclcnt > 255)
 629                     goto cerror;
 630                 lastep[1] = cclcnt;
 631                 continue;
 632
 633             case '\\':
 634                 if ((c = *sp++) == '\0')
 635                     goto cerror;
 636                 /* FALLTHRU */
 637         defchar:
 638             default:
 639                 *ep++ = CCHR;
 640                 *ep++ = c;
 641         }
 642     }
 643
 644 cerror: ;
 645     return 0;
 646 }
 647
 648
 649 static int
 650 GREPaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 651 {
 652     int c;
 653     bool body;
 654     bool lf;
 655     long pos = start;
 656     char *p1, *p2, *ebp, *cbp;
 657     char ibuf[BUFSIZ];
 658     NMH_UNUSED (msgnum);
 659
 660     fseek (fp, start, SEEK_SET);
 661     body = false;
 662     ebp = cbp = ibuf;
 663     for (;;) {
 664         if (body && n->n_header)
 665             return 0;
 666         p1 = linebuf;
 667         p2 = cbp;
 668         lf = false;
 669         for (;;) {
 670             if (p2 >= ebp) {
 671                 if (fgets (ibuf, sizeof ibuf, fp) == NULL
 672                         || (stop && pos >= stop)) {
 673                     if (lf)
 674                         break;
 675                     return 0;
 676                 }
 677                 pos += (long) strlen (ibuf);
 678                 p2 = ibuf;
 679                 ebp = ibuf + strlen (ibuf);
 680             }
 681             c = *p2++;
 682             if (lf && c != '\n') {
 683                 if (c != ' ' && c != '\t') {
 684                     --p2;
 685                     break;
 686                 }
 687                 lf = false;
 688             }
 689             if (c == '\n') {
 690                 if (body)
 691                     break;
 692                 if (lf) {
 693                     body = true;
 694                     break;
 695                 }
 696                 lf = true;
 697                 /* Unfold by skipping the newline. */
 698                 c = 0;
 699             }
 700             if (c && p1 < &linebuf[LBSIZE - 1])
 701                 *p1++ = c;
 702         }
 703
 704         *p1++ = 0;
 705         cbp = p2;
 706         p1 = linebuf;
 707         p2 = n->n_expbuf;
 708
 709         /* Attempt to decode as a MIME header.  If it's the last header,
 710            body will be 1 and lf will be at least 1. */
 711         if ((!body || lf)  &&
 712             decode_rfc2047 (linebuf, decoded_linebuf, sizeof decoded_linebuf)) {
 713             p1 = decoded_linebuf;
 714         }
 715
 716         if (n->n_circf) {
 717             if (advance (p1, p2))
 718                 return 1;
 719             continue;
 720         }
 721
 722         if (*p2 == CCHR) {
 723             c = p2[1];
 724             do {
 725                 if (*p1 == c || cc[(unsigned char)*p1] == c)
 726                     if (advance (p1, p2))
 727                         return 1;
 728             } while (*p1++);
 729             continue;
 730         }
 731
 732         do {
 733             if (advance (p1, p2))
 734                 return 1;
 735         } while (*p1++);
 736     }
 737 }
 738
 739
 740 static int
 741 advance (char *alp, char *aep)
 742 {
 743     unsigned char *lp, *ep, *curlp;
 744
 745     lp = (unsigned char *)alp;
 746     ep = (unsigned char *)aep;
 747     for (;;)
 748         switch (*ep++) {
 749             case CCHR:
 750                 if (*ep++ == *lp++ || ep[-1] == cc[lp[-1]])
 751                     continue;
 752                 return 0;
 753
 754             case CDOT:
 755                 if (*lp++)
 756                     continue;
 757                 return 0;
 758
 759             case CDOL:
 760                 if (*lp == 0)
 761                     continue;
 762                 return 0;
 763
 764             case CEOF:
 765                 return 1;
 766
 767             case CCL:
 768                 if (cclass (ep, *lp++, 1)) {
 769                     ep += *ep + 1;
 770                     continue;
 771                 }
 772                 return 0;
 773
 774             case NCCL:
 775                 if (cclass (ep, *lp++, 0)) {
 776                     ep += *ep + 1;
 777                     continue;
 778                 }
 779                 return 0;
 780
 781             case CDOT | STAR:
 782                 curlp = lp;
 783                 while (*lp++)
 784                     continue;
 785                 goto star;
 786
 787             case CCHR | STAR:
 788                 curlp = lp;
 789                 while (*lp++ == *ep || cc[lp[-1]] == *ep)
 790                     continue;
 791                 ep++;
 792                 goto star;
 793
 794             case CCL | STAR:
 795             case NCCL | STAR:
 796                 curlp = lp;
 797                 while (cclass (ep, *lp++, ep[-1] == (CCL | STAR)))
 798                     continue;
 799                 ep += *ep + 1;
 800                 goto star;
 801
 802         star:
 803                 do {
 804                     lp--;
 805                     if (advance ((char *) lp, (char *) ep))
 806                         return 1;
 807                 } while (lp > curlp);
 808                 return 0;
 809
 810             default:
 811                 inform("advance() botch -- you lose big, continuing...");
 812                 return 0;
 813         }
 814 }
 815
 816
 817 static int
 818 cclass (unsigned char *aset, int ac, int af)
 819 {
 820     unsigned int    n;
 821     unsigned char   c, *set;
 822
 823     set = aset;
 824     if ((c = ac) == 0)
 825         return 0;
 826
 827     n = *set++;
 828     while (n--)
 829         if (*set++ == c || set[-1] == cc[c])
 830             return af;
 831
 832     return !af;
 833 }
 834
 835
 836 static int
 837 tcompile (char *ap, struct tws *tb, int isafter)
 838 {
 839     struct tws *tw;
 840
 841     if ((tw = tws_parse (ap, isafter)) == NULL)
 842         return 0;
 843
 844     *tb = *tw;
 845     return 1;
 846 }
 847
 848
 849 static struct tws *
 850 tws_parse (char *ap, int isafter)
 851 {
 852     char buffer[BUFSIZ];
 853     struct tws *tw, *ts;
 854
 855     if ((tw = tws_special (ap)) != NULL) {
 856         tw->tw_sec = tw->tw_min = isafter ? 59 : 0;
 857         tw->tw_hour = isafter ? 23 : 0;
 858         return tw;
 859     }
 860     if ((tw = dparsetime (ap)) != NULL)
 861         return tw;
 862
 863     if ((ts = dlocaltimenow ()) == NULL)
 864         return NULL;
 865
 866     snprintf (buffer, sizeof(buffer), "%s %s", ap, dtwszone (ts));
 867     if ((tw = dparsetime (buffer)) != NULL)
 868         return tw;
 869
 870     snprintf (buffer, sizeof(buffer), "%s %02d:%02d:%02d %s", ap,
 871             ts->tw_hour, ts->tw_min, ts->tw_sec, dtwszone (ts));
 872     if ((tw = dparsetime (buffer)) != NULL)
 873         return tw;
 874
 875     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s",
 876             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year, ap);
 877     if ((tw = dparsetime (buffer)) != NULL)
 878         return tw;
 879
 880     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s %s",
 881             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year,
 882             ap, dtwszone (ts));
 883     if ((tw = dparsetime (buffer)) != NULL)
 884         return tw;
 885
 886     return NULL;
 887 }
 888
 889
 890 static struct tws *
 891 tws_special (char *ap)
 892 {
 893     int i;
 894     time_t clock;
 895     struct tws *tw;
 896
 897     time (&clock);
 898     if (!strcasecmp (ap, "today"))
 899         return dlocaltime (&clock);
 900     if (!strcasecmp (ap, "yesterday")) {
 901         clock -= (long) (60 * 60 * 24);
 902         return dlocaltime (&clock);
 903     }
 904     if (!strcasecmp (ap, "tomorrow")) {
 905         clock += (long) (60 * 60 * 24);
 906         return dlocaltime (&clock);
 907     }
 908
 909     for (i = 0; tw_ldotw[i]; i++)
 910         if (!strcasecmp (ap, tw_ldotw[i]))
 911             break;
 912     if (tw_ldotw[i]) {
 913         if ((tw = dlocaltime (&clock)) == NULL)
 914             return NULL;
 915         if ((i -= tw->tw_wday) > 0)
 916             i -= 7;
 917     }
 918     else {
 919         if (*ap != '-')
 920             return NULL;
 921         /* -ddd days ago */
 922         i = atoi (ap);  /* we should error check this */
 923     }
 924
 925     clock += (long) ((60 * 60 * 24) * i);
 926     return dlocaltime (&clock);
 927 }
 928
 929
 930 static int
 931 TWSaction(struct nexus *n, FILE *fp, int msgnum, long start, long stop)
 932 {
 933     int state;
 934     char *bp;
 935     char buf[NMH_BUFSIZ], name[NAMESZ];
 936     struct tws *tw;
 937     m_getfld_state_t gstate;
 938     NMH_UNUSED (stop);
 939
 940     fseek (fp, start, SEEK_SET);
 941     gstate = m_getfld_state_init(fp);
 942     for (bp = NULL;;) {
 943         int bufsz = sizeof buf;
 944         switch (state = m_getfld2(&gstate, name, buf, &bufsz)) {
 945             case FLD:
 946             case FLDPLUS:
 947                 free(bp);
 948                 bp = mh_xstrdup(buf);
 949                 while (state == FLDPLUS) {
 950                     bufsz = sizeof buf;
 951                     state = m_getfld2(&gstate, name, buf, &bufsz);
 952                     bp = add (buf, bp);
 953                 }
 954                 if (!strcasecmp (name, n->n_datef))
 955                     break;
 956                 continue;
 957
 958             case BODY:
 959             case FILEEOF:
 960             case LENERR:
 961             case FMTERR:
 962                 if (state == LENERR || state == FMTERR)
 963                     inform("format error in message %d", msgnum);
 964                 free(bp);
 965                 return 0;
 966
 967             default:
 968                 die("internal error -- you lose");
 969         }
 970         break;
 971     }
 972     m_getfld_state_destroy (&gstate);
 973
 974     if ((tw = dparsetime (bp)) == NULL)
 975         inform("unable to parse %s field in message %d, matching...",
 976                 n->n_datef, msgnum), state = 1;
 977     else
 978         state = n->n_after ? (twsort (tw, &n->n_tws) > 0)
 979             : (twsort (tw, &n->n_tws) < 0);
 980
 981     free(bp);
 982     return state;
 983 }