diplodocus.org Git - nmh/blob - sbr/fmt_compile.c

   1
   2 /*
   3  * fmt_compile.c -- "compile" format strings for fmt_scan
   4  *
   5  * $Id$
   6  */
   7
   8 #include <h/mh.h>
   9 #include <h/addrsbr.h>
  10 #include <zotnet/tws/tws.h>
  11 #include <h/fmt_scan.h>
  12 #include <h/fmt_compile.h>
  13
  14 #ifdef TIME_WITH_SYS_TIME
  15 # include <sys/time.h>
  16 # include <time.h>
  17 #else
  18 # ifdef TM_IN_SYS_TIME
  19 #  include <sys/time.h>
  20 # else
  21 #  include <time.h>
  22 # endif
  23 #endif
  24
  25 /*
  26  * hash table for deciding if a component is "interesting"
  27  */
  28 struct comp *wantcomp[128];
  29
  30 static struct format *formatvec;        /* array to hold formats */
  31 static struct format *next_fp;          /* next free format slot */
  32 static struct format *fp;               /* current format slot   */
  33 static struct comp *cm;                 /* most recent comp ref  */
  34 static struct ftable *ftbl;             /* most recent func ref  */
  35 static int ncomp;
  36 static int infunction;                  /* function nesting cnt  */
  37
  38 extern struct mailname fmt_mnull;
  39
  40 /* ftable->type (argument type) */
  41 #define TF_COMP    0        /* component expected                 */
  42 #define TF_NUM     1        /* number expected                    */
  43 #define TF_STR     2        /* string expected                    */
  44 #define TF_EXPR    3        /* component or func. expected        */
  45 #define TF_NONE    4        /* no argument                        */
  46 #define TF_MYBOX   5        /* special - get current user's mbox  */
  47 #define TF_NOW     6        /* special - get current unix time    */
  48 #define TF_EXPR_SV 7        /* like expr but save current str reg */
  49 #define TF_NOP     8        /* like expr but no result            */
  50
  51 /* ftable->flags */
  52 #define TFL_PUTS   1        /* implicit putstr if top level */
  53 #define TFL_PUTN   2        /* implicit putnum if top level */
  54
  55 struct ftable {
  56     char *name;         /* function name                  */
  57     char type;          /* argument type                  */
  58     char f_type;        /* fmt type                       */
  59     char extra;         /* arg. type dependent extra info */
  60     char flags;
  61 };
  62
  63 static struct ftable functable[] = {
  64      { "nonzero",    TF_EXPR,   FT_V_NE,        FT_IF_V_NE,     0 },
  65      { "zero",       TF_EXPR,   FT_V_EQ,        FT_IF_V_EQ,     0 },
  66      { "eq",         TF_NUM,    FT_V_EQ,        FT_IF_V_EQ,     0 },
  67      { "ne",         TF_NUM,    FT_V_NE,        FT_IF_V_NE,     0 },
  68      { "gt",         TF_NUM,    FT_V_GT,        FT_IF_V_GT,     0 },
  69      { "null",       TF_EXPR,   FT_S_NULL,      FT_IF_S_NULL,   0 },
  70      { "nonnull",    TF_EXPR,   FT_S_NONNULL,   FT_IF_S,        0 },
  71      { "match",      TF_STR,    FT_V_MATCH,     FT_IF_MATCH,    0 },
  72      { "amatch",     TF_STR,    FT_V_AMATCH,    FT_IF_AMATCH,   0 },
  73
  74      { "putstr",     TF_EXPR,   FT_STR,         0,              0 },
  75      { "putstrf",    TF_EXPR,   FT_STRF,        0,              0 },
  76      { "putnum",     TF_EXPR,   FT_NUM,         0,              0 },
  77      { "putnumf",    TF_EXPR,   FT_NUMF,        0,              0 },
  78      { "putaddr",    TF_STR,    FT_PUTADDR,     0,              0 },
  79      { "void",       TF_NOP,    0,              0,              0 },
  80
  81      { "comp",       TF_COMP,   FT_LS_COMP,     0,              TFL_PUTS },
  82      { "lit",        TF_STR,    FT_LS_LIT,      0,              TFL_PUTS },
  83      { "getenv",     TF_STR,    FT_LS_GETENV,   0,              TFL_PUTS },
  84      { "profile",    TF_STR,    FT_LS_CFIND,    0,              TFL_PUTS },
  85      { "decodecomp", TF_COMP,   FT_LS_DECODECOMP, 0,            TFL_PUTS },
  86      { "decode",     TF_EXPR,   FT_LS_DECODE,   0,              TFL_PUTS },
  87      { "trim",       TF_EXPR,   FT_LS_TRIM,     0,              0 },
  88      { "compval",    TF_COMP,   FT_LV_COMP,     0,              TFL_PUTN },
  89      { "compflag",   TF_COMP,   FT_LV_COMPFLAG, 0,              TFL_PUTN },
  90      { "num",        TF_NUM,    FT_LV_LIT,      0,              TFL_PUTN },
  91      { "msg",        TF_NONE,   FT_LV_DAT,      0,              TFL_PUTN },
  92      { "cur",        TF_NONE,   FT_LV_DAT,      1,              TFL_PUTN },
  93      { "size",       TF_NONE,   FT_LV_DAT,      2,              TFL_PUTN },
  94      { "width",      TF_NONE,   FT_LV_DAT,      3,              TFL_PUTN },
  95      { "unseen",     TF_NONE,   FT_LV_DAT,      4,              TFL_PUTN },
  96      { "dat",        TF_NUM,    FT_LV_DAT,      0,              TFL_PUTN },
  97      { "strlen",     TF_NONE,   FT_LV_STRLEN,   0,              TFL_PUTN },
  98      { "me",         TF_MYBOX,  FT_LS_LIT,      0,              TFL_PUTS },
  99      { "plus",       TF_NUM,    FT_LV_PLUS_L,   0,              TFL_PUTN },
 100      { "minus",      TF_NUM,    FT_LV_MINUS_L,  0,              TFL_PUTN },
 101      { "divide",     TF_NUM,    FT_LV_DIVIDE_L, 0,              TFL_PUTN },
 102      { "modulo",     TF_NUM,    FT_LV_MODULO_L, 0,              TFL_PUTN },
 103      { "charleft",   TF_NONE,   FT_LV_CHAR_LEFT, 0,             TFL_PUTN },
 104      { "timenow",    TF_NOW,    FT_LV_LIT,      0,              TFL_PUTN },
 105
 106      { "month",      TF_COMP,   FT_LS_MONTH,    FT_PARSEDATE,   TFL_PUTS },
 107      { "lmonth",     TF_COMP,   FT_LS_LMONTH,   FT_PARSEDATE,   TFL_PUTS },
 108      { "tzone",      TF_COMP,   FT_LS_ZONE,     FT_PARSEDATE,   TFL_PUTS },
 109      { "day",        TF_COMP,   FT_LS_DAY,      FT_PARSEDATE,   TFL_PUTS },
 110      { "weekday",    TF_COMP,   FT_LS_WEEKDAY,  FT_PARSEDATE,   TFL_PUTS },
 111      { "tws",        TF_COMP,   FT_LS_822DATE,  FT_PARSEDATE,   TFL_PUTS },
 112      { "sec",        TF_COMP,   FT_LV_SEC,      FT_PARSEDATE,   TFL_PUTN },
 113      { "min",        TF_COMP,   FT_LV_MIN,      FT_PARSEDATE,   TFL_PUTN },
 114      { "hour",       TF_COMP,   FT_LV_HOUR,     FT_PARSEDATE,   TFL_PUTN },
 115      { "mday",       TF_COMP,   FT_LV_MDAY,     FT_PARSEDATE,   TFL_PUTN },
 116      { "mon",        TF_COMP,   FT_LV_MON,      FT_PARSEDATE,   TFL_PUTN },
 117      { "year",       TF_COMP,   FT_LV_YEAR,     FT_PARSEDATE,   TFL_PUTN },
 118      { "yday",       TF_COMP,   FT_LV_YDAY,     FT_PARSEDATE,   TFL_PUTN },
 119      { "wday",       TF_COMP,   FT_LV_WDAY,     FT_PARSEDATE,   TFL_PUTN },
 120      { "zone",       TF_COMP,   FT_LV_ZONE,     FT_PARSEDATE,   TFL_PUTN },
 121      { "clock",      TF_COMP,   FT_LV_CLOCK,    FT_PARSEDATE,   TFL_PUTN },
 122      { "rclock",     TF_COMP,   FT_LV_RCLOCK,   FT_PARSEDATE,   TFL_PUTN },
 123      { "sday",       TF_COMP,   FT_LV_DAYF,     FT_PARSEDATE,   TFL_PUTN },
 124      { "szone",      TF_COMP,   FT_LV_ZONEF,    FT_PARSEDATE,   TFL_PUTN },
 125      { "dst",        TF_COMP,   FT_LV_DST,      FT_PARSEDATE,   TFL_PUTN },
 126      { "pretty",     TF_COMP,   FT_LS_PRETTY,   FT_PARSEDATE,   TFL_PUTS },
 127      { "nodate",     TF_COMP,   FT_LV_COMPFLAG, FT_PARSEDATE,   TFL_PUTN },
 128      { "date2local", TF_COMP,   FT_LOCALDATE,   FT_PARSEDATE,   0 },
 129      { "date2gmt",   TF_COMP,   FT_GMTDATE,     FT_PARSEDATE,   0 },
 130
 131      { "pers",       TF_COMP,   FT_LS_PERS,     FT_PARSEADDR,   TFL_PUTS },
 132      { "mbox",       TF_COMP,   FT_LS_MBOX,     FT_PARSEADDR,   TFL_PUTS },
 133      { "host",       TF_COMP,   FT_LS_HOST,     FT_PARSEADDR,   TFL_PUTS },
 134      { "path",       TF_COMP,   FT_LS_PATH,     FT_PARSEADDR,   TFL_PUTS },
 135      { "gname",      TF_COMP,   FT_LS_GNAME,    FT_PARSEADDR,   TFL_PUTS },
 136      { "note",       TF_COMP,   FT_LS_NOTE,     FT_PARSEADDR,   TFL_PUTS },
 137      { "addr",       TF_COMP,   FT_LS_ADDR,     FT_PARSEADDR,   TFL_PUTS },
 138      { "proper",     TF_COMP,   FT_LS_822ADDR,  FT_PARSEADDR,   TFL_PUTS },
 139      { "type",       TF_COMP,   FT_LV_HOSTTYPE, FT_PARSEADDR,   TFL_PUTN },
 140      { "ingrp",      TF_COMP,   FT_LV_INGRPF,   FT_PARSEADDR,   TFL_PUTN },
 141      { "nohost",     TF_COMP,   FT_LV_NOHOSTF,  FT_PARSEADDR,   TFL_PUTN },
 142      { "formataddr", TF_EXPR_SV,FT_FORMATADDR,  FT_FORMATADDR,  0 },
 143      { "friendly",   TF_COMP,   FT_LS_FRIENDLY, FT_PARSEADDR,   TFL_PUTS },
 144
 145      { "mymbox",     TF_COMP,   FT_LV_COMPFLAG, FT_MYMBOX,      TFL_PUTN },
 146      { "addtoseq",   TF_STR,    FT_ADDTOSEQ,    0,              0 },
 147
 148      { NULL,         0,         0,              0,              0 }
 149 };
 150
 151 /* Add new component to the hash table */
 152 #define NEWCOMP(cm,name)\
 153         cm = ((struct comp *) calloc(1, sizeof (struct comp)));\
 154         cm->c_name = name;\
 155         ncomp++;\
 156         i = CHASH(name);\
 157         cm->c_next = wantcomp[i];\
 158         wantcomp[i] = cm;
 159
 160 #define NEWFMT (next_fp++)
 161 #define NEW(type,fill,wid)\
 162         fp=NEWFMT; fp->f_type=(type); fp->f_fill=(fill); fp->f_width=(wid);
 163
 164 /* Add (possibly new) component to the hash table */
 165 #define ADDC(name)\
 166         FINDCOMP(cm, name);\
 167         if (!cm) {\
 168             NEWCOMP(cm,name);\
 169         }\
 170         fp->f_comp = cm;
 171
 172 #define LV(type, value)         NEW(type,0,0); fp->f_value = (value);
 173 #define LS(type, str)           NEW(type,0,0); fp->f_text = (str);
 174
 175 #define PUTCOMP(comp)           NEW(FT_COMP,0,0); ADDC(comp);
 176 #define PUTLIT(str)             NEW(FT_LIT,0,0); fp->f_text = (str);
 177 #define PUTC(c)                 NEW(FT_CHAR,0,0); fp->f_char = (c);
 178
 179 static char *format_string;
 180 static char *usr_fstring;       /* for CERROR */
 181
 182 #define CERROR(str) compile_error (str, cp)
 183
 184 /*
 185  * external prototypes
 186  */
 187 extern char *getusername(void);
 188
 189 /*
 190  * static prototypes
 191  */
 192 static struct ftable *lookup(char *);
 193 static void compile_error(char *, char *);
 194 static char *compile (char *);
 195 static char *do_spec(char *);
 196 static char *do_name(char *, int);
 197 static char *do_func(char *);
 198 static char *do_expr (char *, int);
 199 static char *do_loop(char *);
 200 static char *do_if(char *);
 201
 202
 203 static struct ftable *
 204 lookup(char *name)
 205 {
 206     register struct ftable *t = functable;
 207     register char *nm;
 208     register char c = *name;
 209
 210     while ((nm = t->name)) {
 211         if (*nm == c && strcmp (nm, name) == 0)
 212             return (ftbl = t);
 213
 214         t++;
 215     }
 216     return (struct ftable *) 0;
 217 }
 218
 219
 220 static void
 221 compile_error(char *str, char *cp)
 222 {
 223     int i, errpos, errctx;
 224
 225     errpos = cp - format_string;
 226     errctx = errpos > 20 ? 20 : errpos;
 227     usr_fstring[errpos] = '\0';
 228
 229     for (i = errpos-errctx; i < errpos; i++) {
 230 #ifdef LOCALE
 231         if (iscntrl(usr_fstring[i]))
 232 #else
 233         if (usr_fstring[i] < 32)
 234 #endif
 235             usr_fstring[i] = '_';
 236     }
 237
 238     advise(NULL, "\"%s\": format compile error - %s",
 239            &usr_fstring[errpos-errctx], str);
 240     adios (NULL, "%*s", errctx+1, "^");
 241 }
 242
 243 /*
 244  * Compile format string "fstring" into format list "fmt".
 245  * Return the number of header components found in the format
 246  * string.
 247  */
 248
 249 int
 250 fmt_compile(char *fstring, struct format **fmt)
 251 {
 252     register char *cp;
 253     int i;
 254
 255     if (format_string)
 256         free (format_string);
 257     format_string = getcpy (fstring);
 258     usr_fstring = fstring;
 259
 260     /* init the component hash table. */
 261     for (i = 0; i < sizeof(wantcomp)/sizeof(wantcomp[0]); i++)
 262         wantcomp[i] = 0;
 263
 264     memset((char *) &fmt_mnull, 0, sizeof(fmt_mnull));
 265
 266     /* it takes at least 4 char to generate one format so we
 267      * allocate a worst-case format array using 1/4 the length
 268      * of the format string.  We actually need twice this much
 269      * to handle both pre-processing (e.g., address parsing) and
 270      * normal processing.
 271      */
 272     i = strlen(fstring)/2 + 1;
 273     next_fp = formatvec = (struct format *)calloc ((size_t) i,
 274                                                    sizeof(struct format));
 275     if (next_fp == NULL)
 276         adios (NULL, "unable to allocate format storage");
 277
 278     ncomp = 0;
 279     infunction = 0;
 280
 281     cp = compile(format_string);
 282     if (*cp) {
 283         CERROR("extra '%>', '%|' or '%?'");
 284     }
 285     LV(FT_DONE, 0);             /* really done */
 286     *fmt = formatvec;
 287
 288     return (ncomp);
 289 }
 290
 291 static char *
 292 compile (char *sp)
 293 {
 294     register char *cp = sp;
 295     register int  c;
 296
 297     for (;;) {
 298         sp = cp;
 299         while ((c = *cp) && c != '%')
 300             cp++;
 301         *cp = 0;
 302         switch (cp-sp) {
 303         case 0:
 304             break;
 305         case 1:
 306             PUTC(*sp);
 307             break;
 308         default:
 309             PUTLIT(sp);
 310             break;
 311         }
 312         if (c == 0)
 313             return (cp);
 314
 315         switch (c = *++cp) {
 316         case '%':
 317             PUTC (*cp);
 318             cp++;
 319             break;
 320
 321         case '|':
 322         case '>':
 323         case '?':
 324         case ']':
 325             return (cp);
 326
 327         case '<':
 328             cp = do_if(++cp);
 329             break;
 330
 331         case '[':       /* ] */
 332             cp = do_loop(++cp);
 333             break;
 334
 335         case ';':       /* comment line */
 336             cp++;
 337             while ((c = *cp++) && c != '\n')
 338                 continue;
 339             break;
 340
 341         default:
 342             cp = do_spec(cp);
 343             break;
 344         }
 345     }
 346 }
 347
 348
 349 static char *
 350 do_spec(char *sp)
 351 {
 352     register char *cp = sp;
 353     register int c;
 354 #ifndef lint
 355     register int ljust = 0;
 356 #endif  /* not lint */
 357     register int wid = 0;
 358     register char fill = ' ';
 359
 360     c = *cp++;
 361     if (c == '-') {
 362         ljust++;
 363         c = *cp++;
 364     }
 365     if (c == '0') {
 366         fill = c;
 367         c = *cp++;
 368     }
 369     while (isdigit(c)) {
 370         wid = wid*10 + (c - '0');
 371         c = *cp++;
 372     }
 373     if (c == '{') {
 374         cp = do_name(cp, 0);
 375         if (! infunction)
 376             fp->f_type = wid? FT_COMPF : FT_COMP;
 377     }
 378     else if (c == '(') {
 379         cp = do_func(cp);
 380         if (! infunction) {
 381             if (ftbl->flags & TFL_PUTS) {
 382                 LV( wid? FT_STRF : FT_STR, ftbl->extra);
 383             }
 384             else if (ftbl->flags & TFL_PUTN) {
 385                 LV( wid? FT_NUMF : FT_NUM, ftbl->extra);
 386             }
 387         }
 388     }
 389     else {
 390         CERROR("component or function name expected");
 391     }
 392     if (ljust)
 393         wid = -wid;
 394     fp->f_width = wid;
 395     fp->f_fill = fill;
 396
 397     return (cp);
 398 }
 399
 400 static char *
 401 do_name(char *sp, int preprocess)
 402 {
 403     register char *cp = sp;
 404     register int c;
 405     register int i;
 406     static int primed = 0;
 407
 408     while (isalnum(c = *cp++) || c == '-' || c == '_')
 409         ;
 410     if (c != '}') {
 411         CERROR("'}' expected");
 412     }
 413     cp[-1] = '\0';
 414     PUTCOMP(sp);
 415     switch (preprocess) {
 416
 417     case FT_PARSEDATE:
 418         if (cm->c_type & CT_ADDR) {
 419             CERROR("component used as both date and address");
 420         }
 421         if (! (cm->c_type & CT_DATE)) {
 422             cm->c_tws = (struct tws *)
 423                                 calloc((size_t) 1, sizeof(*cm->c_tws));
 424             fp->f_type = preprocess;
 425             PUTCOMP(sp);
 426             cm->c_type |= CT_DATE;
 427         }
 428         break;
 429
 430     case FT_MYMBOX:
 431         if (!primed) {
 432             ismymbox ((struct mailname *) 0);
 433             primed++;
 434         }
 435         cm->c_type |= CT_MYMBOX;
 436         /* fall through */
 437     case FT_PARSEADDR:
 438         if (cm->c_type & CT_DATE) {
 439             CERROR("component used as both date and address");
 440         }
 441         if (! (cm->c_type & CT_ADDRPARSE)) {
 442             cm->c_mn = &fmt_mnull;
 443             fp->f_type = preprocess;
 444             PUTCOMP(sp);
 445             cm->c_type |= (CT_ADDR | CT_ADDRPARSE);
 446         }
 447         break;
 448
 449     case FT_FORMATADDR:
 450         if (cm->c_type & CT_DATE) {
 451             CERROR("component used as both date and address");
 452         }
 453         cm->c_type |= CT_ADDR;
 454         break;
 455     }
 456     return (cp);
 457 }
 458
 459 static char *
 460 do_func(char *sp)
 461 {
 462     register char *cp = sp;
 463     register int c;
 464     register struct ftable *t;
 465     register int n;
 466     int mflag;          /* minus sign in NUM */
 467
 468     infunction++;
 469
 470     while (isalnum(c = *cp++))
 471         ;
 472     if (c != '(' && c != '{' && c != ' ' && c != ')') {
 473         CERROR("'(', '{', ' ' or ')' expected");
 474     }
 475     cp[-1] = '\0';
 476     if ((t = lookup (sp)) == 0) {
 477         CERROR("unknown function");
 478     }
 479     if (isspace(c))
 480         c = *cp++;
 481
 482     switch (t->type) {
 483
 484     case TF_COMP:
 485         if (c != '{') {
 486             CERROR("component name expected");
 487         }
 488         cp = do_name(cp, t->extra);
 489         fp->f_type = t->f_type;
 490         c = *cp++;
 491         break;
 492
 493     case TF_NUM:
 494         if ((mflag = (c == '-')))
 495             c = *cp++;
 496         n = 0;
 497         while (isdigit(c)) {
 498             n = n*10 + (c - '0');
 499             c = *cp++;
 500         }
 501         if (mflag)
 502             n = (-n);
 503         LV(t->f_type,n);
 504         break;
 505
 506     case TF_STR:
 507         sp = cp - 1;
 508         while (c && c != ')')
 509             c = *cp++;
 510         cp[-1] = '\0';
 511         LS(t->f_type,sp);
 512         break;
 513
 514     case TF_NONE:
 515         LV(t->f_type,t->extra);
 516         break;
 517
 518     case TF_MYBOX:
 519         LS(t->f_type, getusername());
 520         break;
 521
 522     case TF_NOW:
 523         LV(t->f_type, time((time_t *) 0));
 524         break;
 525
 526     case TF_EXPR_SV:
 527         LV(FT_SAVESTR, 0);
 528         /* fall through */
 529     case TF_EXPR:
 530         *--cp = c;
 531         cp = do_expr(cp, t->extra);
 532         LV(t->f_type, 0);
 533         c = *cp++;
 534         ftbl = t;
 535         break;
 536
 537     case TF_NOP:
 538         *--cp = c;
 539         cp = do_expr(cp, t->extra);
 540         c = *cp++;
 541         ftbl = t;
 542         break;
 543     }
 544     if (c != ')') {
 545         CERROR("')' expected");
 546     }
 547     --infunction;
 548     return (cp);
 549 }
 550
 551 static char *
 552 do_expr (char *sp, int preprocess)
 553 {
 554     register char *cp = sp;
 555     register int  c;
 556
 557     if ((c = *cp++) == '{') {
 558         cp = do_name (cp, preprocess);
 559         fp->f_type = FT_LS_COMP;
 560     } else if (c == '(') {
 561         cp = do_func (cp);
 562     } else if (c == ')') {
 563         return (--cp);
 564     } else if (c == '%' && *cp == '<') {
 565         cp = do_if (cp+1);
 566     } else {
 567         CERROR ("'(', '{', '%<' or ')' expected");
 568     }
 569     return (cp);
 570 }
 571
 572 static char *
 573 do_loop(char *sp)
 574 {
 575     register char *cp = sp;
 576     struct format *floop;
 577
 578     floop = next_fp;
 579     cp = compile (cp);
 580     if (*cp++ != ']')
 581         CERROR ("']' expected");
 582
 583     LV(FT_DONE, 1);             /* not yet done */
 584     LV(FT_GOTO, 0);
 585     fp->f_skip = floop - fp;    /* skip backwards */
 586
 587     return cp;
 588 }
 589
 590 static char *
 591 do_if(char *sp)
 592 {
 593     register char *cp = sp;
 594     register struct format *fexpr,
 595                            *fif = (struct format *)NULL;
 596     register int c = '<';
 597
 598     for (;;) {
 599         if (c == '<') {                 /* doing an IF */
 600             if ((c = *cp++) == '{') /*}*/{
 601                 cp = do_name(cp, 0);
 602                 fp->f_type = FT_LS_COMP;
 603                 LV (FT_IF_S, 0);
 604             }
 605             else if (c == '(') {
 606                 cp = do_func(cp);
 607                 /* see if we can merge the load and the "if" */
 608                 if (ftbl->f_type >= IF_FUNCS)
 609                     fp->f_type = ftbl->extra;
 610                 else {
 611                     LV (FT_IF_V_NE, 0);
 612                 }
 613             }
 614             else {
 615                 CERROR("'(' or '{' expected");  /*}*/
 616             }
 617         }
 618
 619         fexpr = fp;                     /* loc of [ELS]IF */
 620         cp = compile (cp);              /* compile IF TRUE stmts */
 621         if (fif)
 622             fif->f_skip = next_fp - fif;
 623
 624         if ((c = *cp++) == '|') {       /* the last ELSE */
 625             LV(FT_GOTO, 0);
 626             fif = fp;                   /* loc of GOTO */
 627             fexpr->f_skip = next_fp - fexpr;
 628
 629             fexpr = (struct format *)NULL;/* no extra ENDIF */
 630
 631             cp = compile (cp);          /* compile ELSE stmts */
 632             fif->f_skip = next_fp - fif;
 633             c = *cp++;
 634         }
 635         else if (c == '?') {            /* another ELSIF */
 636             LV(FT_GOTO, 0);
 637             fif = fp;                   /* loc of GOTO */
 638             fexpr->f_skip = next_fp - fexpr;
 639
 640             c = '<';                    /* impersonate an IF */
 641             continue;
 642         }
 643         break;
 644     }
 645
 646     if (c != '>') {
 647         CERROR("'>' expected.");
 648     }
 649
 650     if (fexpr)                          /* IF ... [ELSIF ...] ENDIF */
 651         fexpr->f_skip = next_fp - fexpr;
 652
 653     return (cp);
 654 }