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     register char  *cp;
 218     register 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             return NULL;
 247
 248 header: ;
 249         default:
 250             prvarg ();
 251             return n;
 252     }
 253 }
 254
 255 static struct nexus *
 256 nexp1 (void)
 257 {
 258     register char *cp;
 259     register struct nexus *n, *o;
 260
 261     if ((n = nexp2 ()) == NULL || (cp = nxtarg ()) == NULL)
 262         return n;
 263
 264     if (*cp != '-') {
 265         padvise (NULL, "%s unexpected", cp);
 266         return NULL;
 267     }
 268
 269     if (*++cp == '-')
 270         goto header;
 271     switch (smatch (cp, parswit)) {
 272         case AMBIGSW:
 273             ambigsw (cp, parswit);
 274             talked++;
 275             return NULL;
 276         case UNKWNSW:
 277             fprintf (stderr, "-%s unknown\n", cp);
 278             talked++;
 279             return NULL;
 280
 281         case PRAND:
 282             o = newnexus (ANDaction);
 283             o->n_L_child = n;
 284             if ((o->n_R_child = nexp1 ()))
 285                 return o;
 286             padvise (NULL, "missing conjunctive");
 287             return NULL;
 288
 289 header: ;
 290         default:
 291             prvarg ();
 292             return n;
 293     }
 294 }
 295
 296
 297 static struct nexus *
 298 nexp2 (void)
 299 {
 300     register char *cp;
 301     register struct nexus *n;
 302
 303     if ((cp = nxtarg ()) == NULL)
 304         return NULL;
 305
 306     if (*cp != '-') {
 307         prvarg ();
 308         return nexp3 ();
 309     }
 310
 311     if (*++cp == '-')
 312         goto header;
 313     switch (smatch (cp, parswit)) {
 314         case AMBIGSW:
 315             ambigsw (cp, parswit);
 316             talked++;
 317             return NULL;
 318         case UNKWNSW:
 319             fprintf (stderr, "-%s unknown\n", cp);
 320             talked++;
 321             return NULL;
 322
 323         case PRNOT:
 324             n = newnexus (NOTaction);
 325             if ((n->n_L_child = nexp3 ()))
 326                 return n;
 327             padvise (NULL, "missing negation");
 328             return NULL;
 329
 330 header: ;
 331         default:
 332             prvarg ();
 333             return nexp3 ();
 334     }
 335 }
 336
 337 static struct nexus *
 338 nexp3 (void)
 339 {
 340     int i;
 341     register char *cp, *dp;
 342     char buffer[BUFSIZ], temp[64];
 343     register struct nexus *n;
 344
 345     if ((cp = nxtarg ()) == NULL)
 346         return NULL;
 347
 348     if (*cp != '-') {
 349         padvise (NULL, "%s unexpected", cp);
 350         return NULL;
 351     }
 352
 353     if (*++cp == '-') {
 354         dp = ++cp;
 355         goto header;
 356     }
 357     switch (i = smatch (cp, parswit)) {
 358         case AMBIGSW:
 359             ambigsw (cp, parswit);
 360             talked++;
 361             return NULL;
 362         case UNKWNSW:
 363             fprintf (stderr, "-%s unknown\n", cp);
 364             talked++;
 365             return NULL;
 366
 367         case PRLBR:
 368             if ((n = parse ()) == NULL) {
 369                 padvise (NULL, "missing group");
 370                 return NULL;
 371             }
 372             if ((cp = nxtarg ()) == NULL) {
 373                 padvise (NULL, "missing -rbrace");
 374                 return NULL;
 375             }
 376             if (*cp++ == '-' && smatch (cp, parswit) == PRRBR)
 377                 return n;
 378             padvise (NULL, "%s unexpected", --cp);
 379             return NULL;
 380
 381         default:
 382             prvarg ();
 383             return NULL;
 384
 385         case PRCC:
 386         case PRDATE:
 387         case PRFROM:
 388         case PRTO:
 389         case PRSUBJ:
 390             strncpy(temp, parswit[i].sw, sizeof(temp));
 391             temp[sizeof(temp) - 1] = '\0';
 392             dp = *brkstring (temp, " ", NULL);
 393     header: ;
 394             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 395                 padvise (NULL, "missing argument to %s", argp[-2]);
 396                 return NULL;
 397             }
 398             n = newnexus (GREPaction);
 399             n->n_header = 1;
 400             snprintf (buffer, sizeof(buffer), "^%s[ \t]*:.*%s", dp, cp);
 401             dp = buffer;
 402             goto pattern;
 403
 404         case PRSRCH:
 405             n = newnexus (GREPaction);
 406             n->n_header = 0;
 407             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 408                 padvise (NULL, "missing argument to %s", argp[-2]);
 409                 return NULL;
 410             }
 411             dp = cp;
 412     pattern: ;
 413             if (!gcompile (n, dp)) {
 414                 padvise (NULL, "pattern error in %s %s", argp[-2], cp);
 415                 return NULL;
 416             }
 417             n->n_patbuf = getcpy (dp);
 418             return n;
 419
 420         case PROTHR:
 421             padvise (NULL, "internal error!");
 422             return NULL;
 423
 424         case PRDATF:
 425             if (!(datesw = nxtarg ()) || *datesw == '-') {
 426                 padvise (NULL, "missing argument to %s", argp[-2]);
 427                 return NULL;
 428             }
 429             return nexp3 ();
 430
 431         case PRAFTR:
 432         case PRBEFR:
 433             if (!(cp = nxtarg ())) {/* allow -xyz arguments */
 434                 padvise (NULL, "missing argument to %s", argp[-2]);
 435                 return NULL;
 436             }
 437             n = newnexus (TWSaction);
 438             n->n_datef = datesw;
 439             if (!tcompile (cp, &n->n_tws, n->n_after = i == PRAFTR)) {
 440                 padvise (NULL, "unable to parse %s %s", argp[-2], cp);
 441                 return NULL;
 442             }
 443             return n;
 444     }
 445 }
 446
 447
 448 static struct nexus *
 449 newnexus (int (*action)())
 450 {
 451     register struct nexus *p;
 452
 453     if ((p = (struct nexus *) calloc ((size_t) 1, sizeof *p)) == NULL)
 454         adios (NULL, "unable to allocate component storage");
 455
 456     p->n_action = action;
 457     return p;
 458 }
 459
 460
 461 #define args(a) a, fp, msgnum, start, stop
 462 #define params  args (n)
 463 #define plist   \
 464             register struct nexus  *n; \
 465             register FILE *fp; \
 466             int msgnum; \
 467             long    start, \
 468                     stop;
 469
 470 int
 471 pmatches (FILE *fp, int msgnum, long start, long stop, int debug)
 472 {
 473     if (!head)
 474         return 1;
 475
 476     if (!talked++ && debug)
 477         PRaction (head, 0);
 478
 479     return (*head->n_action) (args (head));
 480 }
 481
 482
 483 static void
 484 PRaction (struct nexus *n, int level)
 485 {
 486     register int i;
 487
 488     for (i = 0; i < level; i++)
 489         fprintf (stderr, "| ");
 490
 491     if (n->n_action == ORaction) {
 492         fprintf (stderr, "OR\n");
 493         PRaction (n->n_L_child, level + 1);
 494         PRaction (n->n_R_child, level + 1);
 495         return;
 496     }
 497     if (n->n_action == ANDaction) {
 498         fprintf (stderr, "AND\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 == NOTaction) {
 504         fprintf (stderr, "NOT\n");
 505         PRaction (n->n_L_child, level + 1);
 506         return;
 507     }
 508     if (n->n_action == GREPaction) {
 509         fprintf (stderr, "PATTERN(%s) %s\n",
 510                 n->n_header ? "header" : "body", n->n_patbuf);
 511         return;
 512     }
 513     if (n->n_action == TWSaction) {
 514         fprintf (stderr, "TEMPORAL(%s) %s: %s\n",
 515                 n->n_after ? "after" : "before", n->n_datef,
 516                 dasctime (&n->n_tws, TW_NULL));
 517         return;
 518     }
 519     fprintf (stderr, "UNKNOWN(0x%x)\n",
 520              (unsigned int)(unsigned long) (*n->n_action));
 521 }
 522
 523
 524 static int
 525 ORaction (params)
 526 plist
 527 {
 528     if ((*n->n_L_child->n_action) (args (n->n_L_child)))
 529         return 1;
 530     return (*n->n_R_child->n_action) (args (n->n_R_child));
 531 }
 532
 533
 534 static int
 535 ANDaction (params)
 536 plist
 537 {
 538     if (!(*n->n_L_child->n_action) (args (n->n_L_child)))
 539         return 0;
 540     return (*n->n_R_child->n_action) (args (n->n_R_child));
 541 }
 542
 543
 544 static int
 545 NOTaction (params)
 546 plist
 547 {
 548     return (!(*n->n_L_child->n_action) (args (n->n_L_child)));
 549 }
 550
 551
 552 static int
 553 gcompile (struct nexus *n, char *astr)
 554 {
 555     register int c;
 556     int cclcnt;
 557     register unsigned char *ep, *dp, *sp, *lastep = 0;
 558
 559     dp = (ep = (unsigned char *) n->n_expbuf) + sizeof n->n_expbuf;
 560     sp = (unsigned char *) astr;
 561     if (*sp == '^') {
 562         n->n_circf = 1;
 563         sp++;
 564     }
 565     else
 566         n->n_circf = 0;
 567     for (;;) {
 568         if (ep >= dp)
 569             goto cerror;
 570         if ((c = *sp++) != '*')
 571             lastep = ep;
 572         switch (c) {
 573             case '\0':
 574                 *ep++ = CEOF;
 575                 return 1;
 576
 577             case '.':
 578                 *ep++ = CDOT;
 579                 continue;
 580
 581             case '*':
 582                 if (lastep == 0)
 583                     goto defchar;
 584                 *lastep |= STAR;
 585                 continue;
 586
 587             case '$':
 588                 if (*sp != '\0')
 589                     goto defchar;
 590                 *ep++ = CDOL;
 591                 continue;
 592
 593             case '[':
 594                 *ep++ = CCL;
 595                 *ep++ = 0;
 596                 cclcnt = 0;
 597                 if ((c = *sp++) == '^') {
 598                     c = *sp++;
 599                     ep[-2] = NCCL;
 600                 }
 601                 if (c == '-') {
 602                     *ep++ = c;
 603                     cclcnt++;
 604                     c = *sp++;
 605                 }
 606                 do {
 607                     if (c == '-' && *sp != '\0' && *sp != ']') {
 608                         for (c = ep[-1]+1; c < *sp; c++) {
 609                             *ep++ = c;
 610                             cclcnt++;
 611                             if (c == '\0' || ep >= dp)
 612                                 goto cerror;
 613                         }
 614                     } else {
 615                         *ep++ = c;
 616                         cclcnt++;
 617                         if (c == '\0' || ep >= dp)
 618                             goto cerror;
 619                     }
 620                 } while ((c = *sp++) != ']');
 621                 if (cclcnt > 255)
 622                     goto cerror;
 623                 lastep[1] = cclcnt;
 624                 continue;
 625
 626             case '\\':
 627                 if ((c = *sp++) == '\0')
 628                     goto cerror;
 629         defchar:
 630             default:
 631                 *ep++ = CCHR;
 632                 *ep++ = c;
 633         }
 634     }
 635
 636 cerror: ;
 637     return 0;
 638 }
 639
 640
 641 static int
 642 GREPaction (params)
 643 plist
 644 {
 645     int c, body, lf;
 646     long pos = start;
 647     register char *p1, *p2, *ebp, *cbp;
 648     char ibuf[BUFSIZ];
 649     NMH_UNUSED (msgnum);
 650
 651     fseek (fp, start, SEEK_SET);
 652     body = 0;
 653     ebp = cbp = ibuf;
 654     for (;;) {
 655         if (body && n->n_header)
 656             return 0;
 657         p1 = linebuf;
 658         p2 = cbp;
 659         lf = 0;
 660         for (;;) {
 661             if (p2 >= ebp) {
 662                 if (fgets (ibuf, sizeof ibuf, fp) == NULL
 663                         || (stop && pos >= stop)) {
 664                     if (lf)
 665                         break;
 666                     return 0;
 667                 }
 668                 pos += (long) strlen (ibuf);
 669                 p2 = ibuf;
 670                 ebp = ibuf + strlen (ibuf);
 671             }
 672             c = *p2++;
 673             if (lf && c != '\n') {
 674                 if (c != ' ' && c != '\t') {
 675                     --p2;
 676                     break;
 677                 }
 678                 else
 679                     lf = 0;
 680             }
 681             if (c == '\n') {
 682                 if (body)
 683                     break;
 684                 else {
 685                     if (lf) {
 686                         body++;
 687                         break;
 688                     }
 689                     lf++;
 690                     /* Unfold by skipping the newline. */
 691                     c = 0;
 692                 }
 693             }
 694             if (c && p1 < &linebuf[LBSIZE - 1])
 695                 *p1++ = c;
 696         }
 697
 698         *p1++ = 0;
 699         cbp = p2;
 700         p1 = linebuf;
 701         p2 = n->n_expbuf;
 702
 703         /* Attempt to decode as a MIME header.  If it's the last header,
 704            body will be 1 and lf will be at least 1. */
 705         if ((body == 0 || lf > 0)  &&
 706             decode_rfc2047 (linebuf, decoded_linebuf, sizeof decoded_linebuf)) {
 707             p1 = decoded_linebuf;
 708         }
 709
 710         if (n->n_circf) {
 711             if (advance (p1, p2))
 712                 return 1;
 713             continue;
 714         }
 715
 716         if (*p2 == CCHR) {
 717             c = p2[1];
 718             do {
 719                 if (*p1 == c || cc[(unsigned char)*p1] == c)
 720                     if (advance (p1, p2))
 721                         return 1;
 722             } while (*p1++);
 723             continue;
 724         }
 725
 726         do {
 727             if (advance (p1, p2))
 728                 return 1;
 729         } while (*p1++);
 730     }
 731 }
 732
 733
 734 static int
 735 advance (char *alp, char *aep)
 736 {
 737     register unsigned char *lp, *ep, *curlp;
 738
 739     lp = (unsigned char *)alp;
 740     ep = (unsigned char *)aep;
 741     for (;;)
 742         switch (*ep++) {
 743             case CCHR:
 744                 if (*ep++ == *lp++ || ep[-1] == cc[lp[-1]])
 745                     continue;
 746                 return 0;
 747
 748             case CDOT:
 749                 if (*lp++)
 750                     continue;
 751                 return 0;
 752
 753             case CDOL:
 754                 if (*lp == 0)
 755                     continue;
 756                 return 0;
 757
 758             case CEOF:
 759                 return 1;
 760
 761             case CCL:
 762                 if (cclass (ep, *lp++, 1)) {
 763                     ep += *ep + 1;
 764                     continue;
 765                 }
 766                 return 0;
 767
 768             case NCCL:
 769                 if (cclass (ep, *lp++, 0)) {
 770                     ep += *ep + 1;
 771                     continue;
 772                 }
 773                 return 0;
 774
 775             case CDOT | STAR:
 776                 curlp = lp;
 777                 while (*lp++)
 778                     continue;
 779                 goto star;
 780
 781             case CCHR | STAR:
 782                 curlp = lp;
 783                 while (*lp++ == *ep || cc[lp[-1]] == *ep)
 784                     continue;
 785                 ep++;
 786                 goto star;
 787
 788             case CCL | STAR:
 789             case NCCL | STAR:
 790                 curlp = lp;
 791                 while (cclass (ep, *lp++, ep[-1] == (CCL | STAR)))
 792                     continue;
 793                 ep += *ep + 1;
 794                 goto star;
 795
 796         star:
 797                 do {
 798                     lp--;
 799                     if (advance ((char *) lp, (char *) ep))
 800                         return (1);
 801                 } while (lp > curlp);
 802                 return 0;
 803
 804             default:
 805                 admonish (NULL, "advance() botch -- you lose big");
 806                 return 0;
 807         }
 808 }
 809
 810
 811 static int
 812 cclass (unsigned char *aset, int ac, int af)
 813 {
 814     register unsigned int    n;
 815     register unsigned char   c, *set;
 816
 817     set = aset;
 818     if ((c = ac) == 0)
 819         return (0);
 820
 821     n = *set++;
 822     while (n--)
 823         if (*set++ == c || set[-1] == cc[c])
 824             return (af);
 825
 826     return (!af);
 827 }
 828
 829
 830 static int
 831 tcompile (char *ap, struct tws *tb, int isafter)
 832 {
 833     register struct tws *tw;
 834
 835     if ((tw = tws_parse (ap, isafter)) == NULL)
 836         return 0;
 837
 838     twscopy (tb, tw);
 839     return 1;
 840 }
 841
 842
 843 static struct tws *
 844 tws_parse (char *ap, int isafter)
 845 {
 846     char buffer[BUFSIZ];
 847     register struct tws *tw, *ts;
 848
 849     if ((tw = tws_special (ap)) != NULL) {
 850         tw->tw_sec = tw->tw_min = isafter ? 59 : 0;
 851         tw->tw_hour = isafter ? 23 : 0;
 852         return tw;
 853     }
 854     if ((tw = dparsetime (ap)) != NULL)
 855         return tw;
 856
 857     if ((ts = dlocaltimenow ()) == NULL)
 858         return NULL;
 859
 860     snprintf (buffer, sizeof(buffer), "%s %s", ap, dtwszone (ts));
 861     if ((tw = dparsetime (buffer)) != NULL)
 862         return tw;
 863
 864     snprintf (buffer, sizeof(buffer), "%s %02d:%02d:%02d %s", ap,
 865             ts->tw_hour, ts->tw_min, ts->tw_sec, dtwszone (ts));
 866     if ((tw = dparsetime (buffer)) != NULL)
 867         return tw;
 868
 869     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s",
 870             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year, ap);
 871     if ((tw = dparsetime (buffer)) != NULL)
 872         return tw;
 873
 874     snprintf (buffer, sizeof(buffer), "%02d %s %04d %s %s",
 875             ts->tw_mday, tw_moty[ts->tw_mon], ts->tw_year,
 876             ap, dtwszone (ts));
 877     if ((tw = dparsetime (buffer)) != NULL)
 878         return tw;
 879
 880     return NULL;
 881 }
 882
 883
 884 static struct tws *
 885 tws_special (char *ap)
 886 {
 887     int i;
 888     time_t clock;
 889     register struct tws *tw;
 890
 891     time (&clock);
 892     if (!strcasecmp (ap, "today"))
 893         return dlocaltime (&clock);
 894     if (!strcasecmp (ap, "yesterday")) {
 895         clock -= (long) (60 * 60 * 24);
 896         return dlocaltime (&clock);
 897     }
 898     if (!strcasecmp (ap, "tomorrow")) {
 899         clock += (long) (60 * 60 * 24);
 900         return dlocaltime (&clock);
 901     }
 902
 903     for (i = 0; tw_ldotw[i]; i++)
 904         if (!strcasecmp (ap, tw_ldotw[i]))
 905             break;
 906     if (tw_ldotw[i]) {
 907         if ((tw = dlocaltime (&clock)) == NULL)
 908             return NULL;
 909         if ((i -= tw->tw_wday) > 0)
 910             i -= 7;
 911     }
 912     else
 913         if (*ap != '-')
 914             return NULL;
 915         else                    /* -ddd days ago */
 916             i = atoi (ap);      /* we should error check this */
 917
 918     clock += (long) ((60 * 60 * 24) * i);
 919     return dlocaltime (&clock);
 920 }
 921
 922
 923 static int
 924 TWSaction (params)
 925 plist
 926 {
 927     int state;
 928     register char *bp;
 929     char buf[BUFSIZ], name[NAMESZ];
 930     register struct tws *tw;
 931     m_getfld_state_t gstate = 0;
 932     NMH_UNUSED (stop);
 933
 934     fseek (fp, start, SEEK_SET);
 935     for (bp = NULL;;) {
 936         int bufsz = sizeof buf;
 937         switch (state = m_getfld (&gstate, name, buf, &bufsz, fp)) {
 938             case FLD:
 939             case FLDPLUS:
 940                 if (bp != NULL)
 941                     free (bp), bp = NULL;
 942                 bp = add (buf, NULL);
 943                 while (state == FLDPLUS) {
 944                     bufsz = sizeof buf;
 945                     state = m_getfld (&gstate, name, buf, &bufsz, fp);
 946                     bp = add (buf, bp);
 947                 }
 948                 if (!strcasecmp (name, n->n_datef))
 949                     break;
 950                 continue;
 951
 952             case BODY:
 953             case FILEEOF:
 954             case LENERR:
 955             case FMTERR:
 956                 if (state == LENERR || state == FMTERR)
 957                     advise (NULL, "format error in message %d", msgnum);
 958                 if (bp != NULL)
 959                     free (bp);
 960                 return 0;
 961
 962             default:
 963                 adios (NULL, "internal error -- you lose");
 964         }
 965         break;
 966     }
 967     m_getfld_state_destroy (&gstate);
 968
 969     if ((tw = dparsetime (bp)) == NULL)
 970         advise (NULL, "unable to parse %s field in message %d, matching...",
 971                 n->n_datef, msgnum), state = 1;
 972     else
 973         state = n->n_after ? (twsort (tw, &n->n_tws) > 0)
 974             : (twsort (tw, &n->n_tws) < 0);
 975
 976     if (bp != NULL)
 977         free (bp);
 978     return state;
 979 }