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

   1
   2 /*
   3  * picksbr.c -- routines to help pick along...
   4  *
   5  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   6  * COPYRIGHT file in the root directory of the nmh distribution for
   7  * complete copyright information.
   8  */
   9
  10 #include <h/mh.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  1024
  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 padvise         if (!talked++) advise
 119
 120 struct nexus {
 121     int (*n_action)();
 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 (*)());
 186
 187 static int ORaction();
 188 static int ANDaction();
 189 static int NOTaction();
 190 static int GREPaction();
 191 static int TWSaction();
 192
 193
 194 int
 195 pcompile (char **vec, char *date)
 196 {
 197     argp = vec;
 198     if ((datesw = date) == NULL)
 199         datesw = "date";
 200     talked = 0;
 201
 202     if ((head = parse ()) == NULL)
 203         return (talked ? 0 : 1);
 204
 205     if (*argp) {
 206         padvise (NULL, "%s unexpected", *argp);
 207         return 0;
 208     }
 209
 210     return 1;
 211 }
 212
 213
 214 static struct nexus *
 215 parse (void)
 216 {
 217     char  *cp;
 218     struct nexus *n, *o;
 219
 220     if ((n = nexp1 ()) == NULL || (cp = nxtarg ()) == NULL)
 221         return n;
 222
 223     if (*cp != '-') {
 224         padvise (NULL, "%s unexpected", cp);
 225         return NULL;
 226     }
 227
 228     if (*++cp == '-')
 229         goto header;
 230     switch (smatch (cp, parswit)) {
 231         case AMBIGSW:
 232             ambigsw (cp, parswit);
 233             talked++;
 234             return NULL;
 235         case UNKWNSW:
 236             fprintf (stderr, "-%s unknown\n", cp);
 237             talked++;
 238             return NULL;
 239
 240         case PROR:
 241             o = newnexus (ORaction);
 242             o->n_L_child = n;
 243             if ((o->n_R_child = parse ()))
 244                 return o;
 245             padvise (NULL, "missing disjunctive");
 246             free (o);
 247             return NULL;
 248
 249 header: ;
 250         default:
 251             prvarg ();
 252             return n;
 253     }
 254 }
 255
 256 static struct nexus *
 257 nexp1 (void)
 258 {
 259     char *cp;
 260     struct nexus *n, *o;
 261
 262     if ((n = nexp2 ()) == NULL || (cp = nxtarg ()) == NULL)
 263         return n;
 264
 265     if (*cp != '-') {
 266         padvise (NULL, "%s unexpected", cp);
 267         free (n);
 268         return NULL;
 269     }
 270
 271     if (*++cp == '-')
 272         goto header;
 273     switch (smatch (cp, parswit)) {
 274         case AMBIGSW:
 275             ambigsw (cp, parswit);
 276             talked++;
 277             free (n);
 278             return NULL;
 279         case UNKWNSW:
 280             fprintf (stderr, "-%s unknown\n", cp);
 281             talked++;
 282             free (n);
 283             return NULL;
 284
 285         case PRAND:
 286             o = newnexus (ANDaction);
 287             o->n_L_child = n;
 288             if ((o->n_R_child = nexp1 ()))
 289                 return o;
 290             padvise (NULL, "missing conjunctive");
 291             free (o);
 292             return NULL;
 293
 294 header: ;
 295         default:
 296             prvarg ();
 297             return n;
 298     }
 299 }
 300
 301
 302 static struct nexus *
 303 nexp2 (void)
 304 {
 305     char *cp;
 306     struct nexus *n;
 307
 308     if ((cp = nxtarg ()) == NULL)
 309         return NULL;
 310
 311     if (*cp != '-') {
 312         prvarg ();
 313         return nexp3 ();
 314     }
 315
 316     if (*++cp == '-')
 317         goto header;
 318     switch (smatch (cp, parswit)) {
 319         case AMBIGSW:
 320             ambigsw (cp, parswit);
 321             talked++;
 322             return NULL;
 323         case UNKWNSW:
 324             fprintf (stderr, "-%s unknown\n", cp);
 325             talked++;
 326             return NULL;
 327
 328         case PRNOT:
 329             n = newnexus (NOTaction);
 330             if ((n->n_L_child = nexp3 ()))
 331                 return n;
 332             padvise (NULL, "missing negation");
 333             free (n);
 334             return NULL;
 335
 336 header: ;
 337         default:
 338             prvarg ();
 339             return nexp3 ();
 340     }
 341 }
 342
 343 static struct nexus *
 344 nexp3 (void)
 345 {
 346     int i;
 347     char *cp, *dp;
 348     char buffer[BUFSIZ], temp[64];
 349     struct nexus *n;
 350
 351     if ((cp = nxtarg ()) == NULL)
 352         return NULL;
 353
 354     if (*cp != '-') {
 355         padvise (NULL, "%s unexpected", cp);
 356         return NULL;
 357     }
 358
 359     if (*++cp == '-') {
 360         dp = ++cp;
 361         goto header;
 362     }
 363     switch (i = smatch (cp, parswit)) {
 364         case AMBIGSW:
 365             ambigsw (cp, parswit);
 366             talked++;
 367             return NULL;
 368         case UNKWNSW:
 369             fprintf (stderr, "-%s unknown\n", cp);
 370             talked++;
 371             return NULL;
 372
 373         case PRLBR:
 374             if ((n = parse ()) == NULL) {
 375                 padvise (NULL, "missing group");
 376                 return NULL;
 377             }
 378             if ((cp = nxtarg ()) == NULL) {
 379                 padvise (NULL, "missing -rbrace");
 380                 return NULL;
 381             }
 382             if (*cp++ == '-' && smatch (cp, parswit) == PRRBR)
 383                 return n;
 384             padvise (NULL, "%s unexpected", --cp);
 385             return NULL;
 386
 387         default:
 388             prvarg ();
 389             return NULL;
 390
 391         case PRCC:
 392         case PRDATE:
 393         case PRFROM:
 394         case PRTO:
 395         case PRSUBJ:
 396             strncpy(temp, parswit[i].sw, sizeof(temp));
 397             temp[sizeof(temp) - 1] = '\0';
 398             dp = *brkstring (temp, " ", NULL);
 399     header: ;
 400             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 401                 padvise (NULL, "missing argument to %s", argp[-2]);
 402                 return NULL;
 403             }
 404             n = newnexus (GREPaction);
 405             n->n_header = 1;
 406             snprintf (buffer, sizeof(buffer), "^%s[ \t]*:.*%s", dp, cp);
 407             dp = buffer;
 408             goto pattern;
 409
 410         case PRSRCH:
 411             n = newnexus (GREPaction);
 412             n->n_header = 0;
 413             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 414                 padvise (NULL, "missing argument to %s", argp[-2]);
 415                 free (n);
 416                 return NULL;
 417             }
 418             dp = cp;
 419     pattern: ;
 420             if (!gcompile (n, dp)) {
 421                 padvise (NULL, "pattern error in %s %s", argp[-2], cp);
 422                 free (n);
 423                 return NULL;
 424             }
 425             n->n_patbuf = mh_xstrdup(dp);
 426             return n;
 427
 428         case PROTHR:
 429             padvise (NULL, "internal error!");
 430             return NULL;
 431
 432         case PRDATF:
 433             if (!(datesw = nxtarg ()) || *datesw == '-') {
 434                 padvise (NULL, "missing argument to %s", argp[-2]);
 435                 return NULL;
 436             }
 437             return nexp3 ();
 438
 439         case PRAFTR:
 440         case PRBEFR:
 441             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 442                 padvise (NULL, "missing argument to %s", argp[-2]);
 443                 return NULL;
 444             }
 445             n = newnexus (TWSaction);
 446             n->n_datef = datesw;
 447             if (!tcompile (cp, &n->n_tws, n->n_after = i == PRAFTR)) {
 448                 padvise (NULL, "unable to parse %s %s", argp[-2], cp);
 449                 free (n);
 450                 return NULL;
 451             }
 452             return n;
 453     }
 454 }
 455
 456
 457 static struct nexus *
 458 newnexus (int (*action)())
 459 {
 460     struct nexus *p;
 461
 462     NEW0(p);
 463     p->n_action = action;
 464     return p;
 465 }
 466
 467
 468 #define args(a) a, fp, msgnum, start, stop
 469 #define params  args (n)
 470 #define plist   \
 471             struct nexus  *n; \
 472             FILE *fp; \
 473             int msgnum; \
 474             long    start, \
 475                     stop;
 476
 477 int
 478 pmatches (FILE *fp, int msgnum, long start, long stop, int debug)
 479 {
 480     if (!head)
 481         return 1;
 482
 483     if (!talked++ && debug)
 484         PRaction (head, 0);
 485
 486     return (*head->n_action) (args (head));
 487 }
 488
 489
 490 static void
 491 PRaction (struct nexus *n, int level)
 492 {
 493     int i;
 494
 495     for (i = 0; i < level; i++)
 496         fprintf (stderr, "| ");
 497
 498     if (n->n_action == ORaction) {
 499         fprintf (stderr, "OR\n");
 500         PRaction (n->n_L_child, level + 1);
 501         PRaction (n->n_R_child, level + 1);
 502         return;
 503     }
 504     if (n->n_action == ANDaction) {
 505         fprintf (stderr, "AND\n");
 506         PRaction (n->n_L_child, level + 1);
 507         PRaction (n->n_R_child, level + 1);
 508         return;
 509     }
 510     if (n->n_action == NOTaction) {
 511         fprintf (stderr, "NOT\n");
 512         PRaction (n->n_L_child, level + 1);
 513         return;
 514     }
 515     if (n->n_action == GREPaction) {
 516         fprintf (stderr, "PATTERN(%s) %s\n",
 517                 n->n_header ? "header" : "body", n->n_patbuf);
 518         return;
 519     }
 520     if (n->n_action == TWSaction) {
 521         fprintf (stderr, "TEMPORAL(%s) %s: %s\n",
 522                 n->n_after ? "after" : "before", n->n_datef,
 523                 dasctime (&n->n_tws, TW_NULL));
 524         return;
 525     }
 526     fprintf (stderr, "UNKNOWN(0x%x)\n",
 527              (unsigned int)(unsigned long) (*n->n_action));
 528 }
 529
 530
 531 static int
 532 ORaction (params)
 533 plist
 534 {
 535     if ((*n->n_L_child->n_action) (args (n->n_L_child)))
 536         return 1;
 537     return (*n->n_R_child->n_action) (args (n->n_R_child));
 538 }
 539
 540
 541 static int
 542 ANDaction (params)
 543 plist
 544 {
 545     if (!(*n->n_L_child->n_action) (args (n->n_L_child)))
 546         return 0;
 547     return (*n->n_R_child->n_action) (args (n->n_R_child));
 548 }
 549
 550
 551 static int
 552 NOTaction (params)
 553 plist
 554 {
 555     return (!(*n->n_L_child->n_action) (args (n->n_L_child)));
 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         defchar:
 637             default:
 638                 *ep++ = CCHR;
 639                 *ep++ = c;
 640         }
 641     }
 642
 643 cerror: ;
 644     return 0;
 645 }
 646
 647
 648 static int
 649 GREPaction (params)
 650 plist
 651 {
 652     int c, body, 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 = 0;
 660     ebp = cbp = ibuf;
 661     for (;;) {
 662         if (body && n->n_header)
 663             return 0;
 664         p1 = linebuf;
 665         p2 = cbp;
 666         lf = 0;
 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                 else
 686                     lf = 0;
 687             }
 688             if (c == '\n') {
 689                 if (body)
 690                     break;
 691                 else {
 692                     if (lf) {
 693                         body++;
 694                         break;
 695                     }
 696                     lf++;
 697                     /* Unfold by skipping the newline. */
 698                     c = 0;
 699                 }
 700             }
 701             if (c && p1 < &linebuf[LBSIZE - 1])
 702                 *p1++ = c;
 703         }
 704
 705         *p1++ = 0;
 706         cbp = p2;
 707         p1 = linebuf;
 708         p2 = n->n_expbuf;
 709
 710         /* Attempt to decode as a MIME header.  If it's the last header,
 711            body will be 1 and lf will be at least 1. */
 712         if ((body == 0 || lf > 0)  &&
 713             decode_rfc2047 (linebuf, decoded_linebuf, sizeof decoded_linebuf)) {
 714             p1 = decoded_linebuf;
 715         }
 716
 717         if (n->n_circf) {
 718             if (advance (p1, p2))
 719                 return 1;
 720             continue;
 721         }
 722
 723         if (*p2 == CCHR) {
 724             c = p2[1];
 725             do {
 726                 if (*p1 == c || cc[(unsigned char)*p1] == c)
 727                     if (advance (p1, p2))
 728                         return 1;
 729             } while (*p1++);
 730             continue;
 731         }
 732
 733         do {
 734             if (advance (p1, p2))
 735                 return 1;
 736         } while (*p1++);
 737     }
 738 }
 739
 740
 741 static int
 742 advance (char *alp, char *aep)
 743 {
 744     unsigned char *lp, *ep, *curlp;
 745
 746     lp = (unsigned char *)alp;
 747     ep = (unsigned char *)aep;
 748     for (;;)
 749         switch (*ep++) {
 750             case CCHR:
 751                 if (*ep++ == *lp++ || ep[-1] == cc[lp[-1]])
 752                     continue;
 753                 return 0;
 754
 755             case CDOT:
 756                 if (*lp++)
 757                     continue;
 758                 return 0;
 759
 760             case CDOL:
 761                 if (*lp == 0)
 762                     continue;
 763                 return 0;
 764
 765             case CEOF:
 766                 return 1;
 767
 768             case CCL:
 769                 if (cclass (ep, *lp++, 1)) {
 770                     ep += *ep + 1;
 771                     continue;
 772                 }
 773                 return 0;
 774
 775             case NCCL:
 776                 if (cclass (ep, *lp++, 0)) {
 777                     ep += *ep + 1;
 778                     continue;
 779                 }
 780                 return 0;
 781
 782             case CDOT | STAR:
 783                 curlp = lp;
 784                 while (*lp++)
 785                     continue;
 786                 goto star;
 787
 788             case CCHR | STAR:
 789                 curlp = lp;
 790                 while (*lp++ == *ep || cc[lp[-1]] == *ep)
 791                     continue;
 792                 ep++;
 793                 goto star;
 794
 795             case CCL | STAR:
 796             case NCCL | STAR:
 797                 curlp = lp;
 798                 while (cclass (ep, *lp++, ep[-1] == (CCL | STAR)))
 799                     continue;
 800                 ep += *ep + 1;
 801                 goto star;
 802
 803         star:
 804                 do {
 805                     lp--;
 806                     if (advance ((char *) lp, (char *) ep))
 807                         return (1);
 808                 } while (lp > curlp);
 809                 return 0;
 810
 811             default:
 812                 admonish (NULL, "advance() botch -- you lose big");
 813                 return 0;
 814         }
 815 }
 816
 817
 818 static int
 819 cclass (unsigned char *aset, int ac, int af)
 820 {
 821     unsigned int    n;
 822     unsigned char   c, *set;
 823
 824     set = aset;
 825     if ((c = ac) == 0)
 826         return (0);
 827
 828     n = *set++;
 829     while (n--)
 830         if (*set++ == c || set[-1] == cc[c])
 831             return (af);
 832
 833     return (!af);
 834 }
 835
 836
 837 static int
 838 tcompile (char *ap, struct tws *tb, int isafter)
 839 {
 840     struct tws *tw;
 841
 842     if ((tw = tws_parse (ap, isafter)) == NULL)
 843         return 0;
 844
 845     twscopy (tb, tw);
 846     return 1;
 847 }
 848
 849
 850 static struct tws *
 851 tws_parse (char *ap, int isafter)
 852 {
 853     char buffer[BUFSIZ];
 854     struct tws *tw, *ts;
 855
 856     if ((tw = tws_special (ap)) != NULL) {
 857         tw->tw_sec = tw->tw_min = isafter ? 59 : 0;
 858         tw->tw_hour = isafter ? 23 : 0;
 859         return tw;
 860     }
 861     if ((tw = dparsetime (ap)) != NULL)
 862         return tw;
 863
 864     if ((ts = dlocaltimenow ()) == NULL)
 865         return NULL;
 866
 867     snprintf (buffer, sizeof(buffer), "%s %s", ap, dtwszone (ts));
 868     if ((tw = dparsetime (buffer)) != NULL)
 869         return tw;
 870
 871     snprintf (buffer, sizeof(buffer), "%s %02d:%02d:%02d %s", ap,
 872             ts->tw_hour, ts->tw_min, ts->tw_sec, dtwszone (ts));
 873     if ((tw = dparsetime (buffer)) != NULL)
 874         return tw;
 875
 876     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s",
 877             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year, ap);
 878     if ((tw = dparsetime (buffer)) != NULL)
 879         return tw;
 880
 881     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s %s",
 882             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year,
 883             ap, dtwszone (ts));
 884     if ((tw = dparsetime (buffer)) != NULL)
 885         return tw;
 886
 887     return NULL;
 888 }
 889
 890
 891 static struct tws *
 892 tws_special (char *ap)
 893 {
 894     int i;
 895     time_t clock;
 896     struct tws *tw;
 897
 898     time (&clock);
 899     if (!strcasecmp (ap, "today"))
 900         return dlocaltime (&clock);
 901     if (!strcasecmp (ap, "yesterday")) {
 902         clock -= (long) (60 * 60 * 24);
 903         return dlocaltime (&clock);
 904     }
 905     if (!strcasecmp (ap, "tomorrow")) {
 906         clock += (long) (60 * 60 * 24);
 907         return dlocaltime (&clock);
 908     }
 909
 910     for (i = 0; tw_ldotw[i]; i++)
 911         if (!strcasecmp (ap, tw_ldotw[i]))
 912             break;
 913     if (tw_ldotw[i]) {
 914         if ((tw = dlocaltime (&clock)) == NULL)
 915             return NULL;
 916         if ((i -= tw->tw_wday) > 0)
 917             i -= 7;
 918     }
 919     else {
 920         if (*ap != '-')
 921             return NULL;
 922         /* -ddd days ago */
 923         i = atoi (ap);  /* we should error check this */
 924     }
 925
 926     clock += (long) ((60 * 60 * 24) * i);
 927     return dlocaltime (&clock);
 928 }
 929
 930
 931 static int
 932 TWSaction (params)
 933 plist
 934 {
 935     int state;
 936     char *bp;
 937     char buf[BUFSIZ], name[NAMESZ];
 938     struct tws *tw;
 939     m_getfld_state_t gstate = 0;
 940     NMH_UNUSED (stop);
 941
 942     fseek (fp, start, SEEK_SET);
 943     for (bp = NULL;;) {
 944         int bufsz = sizeof buf;
 945         switch (state = m_getfld (&gstate, name, buf, &bufsz, fp)) {
 946             case FLD:
 947             case FLDPLUS:
 948                 mh_xfree(bp);
 949                 bp = add (buf, NULL);
 950                 while (state == FLDPLUS) {
 951                     bufsz = sizeof buf;
 952                     state = m_getfld (&gstate, name, buf, &bufsz, fp);
 953                     bp = add (buf, bp);
 954                 }
 955                 if (!strcasecmp (name, n->n_datef))
 956                     break;
 957                 continue;
 958
 959             case BODY:
 960             case FILEEOF:
 961             case LENERR:
 962             case FMTERR:
 963                 if (state == LENERR || state == FMTERR)
 964                     advise (NULL, "format error in message %d", msgnum);
 965                 mh_xfree(bp);
 966                 return 0;
 967
 968             default:
 969                 adios (NULL, "internal error -- you lose");
 970         }
 971         break;
 972     }
 973     m_getfld_state_destroy (&gstate);
 974
 975     if ((tw = dparsetime (bp)) == NULL)
 976         advise (NULL, "unable to parse %s field in message %d, matching...",
 977                 n->n_datef, msgnum), state = 1;
 978     else
 979         state = n->n_after ? (twsort (tw, &n->n_tws) > 0)
 980             : (twsort (tw, &n->n_tws) < 0);
 981
 982     mh_xfree(bp);
 983     return state;
 984 }