bin/sh/expand.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1997-2005
   5  *      Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Kenneth Almquist.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #ifndef lint
  36 #if 0
  37 static char sccsid[] = "@(#)expand.c    8.5 (Berkeley) 5/15/95";
  38 #endif
  39 #endif /* not lint */
  40 #include <sys/cdefs.h>
  41 __FBSDID("$FreeBSD$");
  42
  43 #include <sys/types.h>
  44 #include <sys/time.h>
  45 #include <sys/stat.h>
  46 #include <dirent.h>
  47 #include <errno.h>
  48 #include <inttypes.h>
  49 #include <limits.h>
  50 #include <pwd.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55
  56 /*
  57  * Routines to expand arguments to commands.  We have to deal with
  58  * backquotes, shell variables, and file metacharacters.
  59  */
  60
  61 #include "shell.h"
  62 #include "main.h"
  63 #include "nodes.h"
  64 #include "eval.h"
  65 #include "expand.h"
  66 #include "syntax.h"
  67 #include "parser.h"
  68 #include "jobs.h"
  69 #include "options.h"
  70 #include "var.h"
  71 #include "input.h"
  72 #include "output.h"
  73 #include "memalloc.h"
  74 #include "error.h"
  75 #include "mystring.h"
  76 #include "arith.h"
  77 #include "show.h"
  78
  79 /*
  80  * Structure specifying which parts of the string should be searched
  81  * for IFS characters.
  82  */
  83
  84 struct ifsregion {
  85         struct ifsregion *next; /* next region in list */
  86         int begoff;             /* offset of start of region */
  87         int endoff;             /* offset of end of region */
  88         int inquotes;           /* search for nul bytes only */
  89 };
  90
  91
  92 static char *expdest;                   /* output of current string */
  93 static struct nodelist *argbackq;       /* list of back quote expressions */
  94 static struct ifsregion ifsfirst;       /* first struct in list of ifs regions */
  95 static struct ifsregion *ifslastp;      /* last struct in list */
  96 static struct arglist exparg;           /* holds expanded arg list */
  97
  98 static void argstr(char *, int);
  99 static char *exptilde(char *, int);
 100 static void expbackq(union node *, int, int);
 101 static int subevalvar(char *, char *, int, int, int, int);
 102 static char *evalvar(char *, int);
 103 static int varisset(char *, int);
 104 static void varvalue(char *, int, int, int);
 105 static void recordregion(int, int, int);
 106 static void removerecordregions(int);
 107 static void ifsbreakup(char *, struct arglist *);
 108 static void expandmeta(struct strlist *, int);
 109 static void expmeta(char *, char *);
 110 static void addfname(char *);
 111 static struct strlist *expsort(struct strlist *);
 112 static struct strlist *msort(struct strlist *, int);
 113 static char *cvtnum(int, char *);
 114 static int collate_range_cmp(int, int);
 115
 116 static int
 117 collate_range_cmp(int c1, int c2)
 118 {
 119         static char s1[2], s2[2];
 120
 121         s1[0] = c1;
 122         s2[0] = c2;
 123         return (strcoll(s1, s2));
 124 }
 125
 126 /*
 127  * Expand shell variables and backquotes inside a here document.
 128  *      union node *arg         the document
 129  *      int fd;                 where to write the expanded version
 130  */
 131
 132 void
 133 expandhere(union node *arg, int fd)
 134 {
 135         herefd = fd;
 136         expandarg(arg, (struct arglist *)NULL, 0);
 137         xwrite(fd, stackblock(), expdest - stackblock());
 138 }
 139
 140
 141 /*
 142  * Perform expansions on an argument, placing the resulting list of arguments
 143  * in arglist.  Parameter expansion, command substitution and arithmetic
 144  * expansion are always performed; additional expansions can be requested
 145  * via flag (EXP_*).
 146  * The result is left in the stack string.
 147  * When arglist is NULL, perform here document expansion.  A partial result
 148  * may be written to herefd, which is then not included in the stack string.
 149  *
 150  * Caution: this function uses global state and is not reentrant.
 151  * However, a new invocation after an interrupted invocation is safe
 152  * and will reset the global state for the new call.
 153  */
 154 void
 155 expandarg(union node *arg, struct arglist *arglist, int flag)
 156 {
 157         struct strlist *sp;
 158         char *p;
 159
 160         argbackq = arg->narg.backquote;
 161         STARTSTACKSTR(expdest);
 162         ifsfirst.next = NULL;
 163         ifslastp = NULL;
 164         argstr(arg->narg.text, flag);
 165         if (arglist == NULL) {
 166                 return;                 /* here document expanded */
 167         }
 168         STPUTC('\0', expdest);
 169         p = grabstackstr(expdest);
 170         exparg.lastp = &exparg.list;
 171         /*
 172          * TODO - EXP_REDIR
 173          */
 174         if (flag & EXP_FULL) {
 175                 ifsbreakup(p, &exparg);
 176                 *exparg.lastp = NULL;
 177                 exparg.lastp = &exparg.list;
 178                 expandmeta(exparg.list, flag);
 179         } else {
 180                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
 181                         rmescapes(p);
 182                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 183                 sp->text = p;
 184                 *exparg.lastp = sp;
 185                 exparg.lastp = &sp->next;
 186         }
 187         while (ifsfirst.next != NULL) {
 188                 struct ifsregion *ifsp;
 189                 INTOFF;
 190                 ifsp = ifsfirst.next->next;
 191                 ckfree(ifsfirst.next);
 192                 ifsfirst.next = ifsp;
 193                 INTON;
 194         }
 195         *exparg.lastp = NULL;
 196         if (exparg.list) {
 197                 *arglist->lastp = exparg.list;
 198                 arglist->lastp = exparg.lastp;
 199         }
 200 }
 201
 202
 203
 204 /*
 205  * Perform parameter expansion, command substitution and arithmetic
 206  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
 207  * Processing ends at a CTLENDVAR character as well as '\0'.
 208  * This is used to expand word in ${var+word} etc.
 209  * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC
 210  * characters to allow for further processing.
 211  * If EXP_FULL is set, also preserve CTLQUOTEMARK characters.
 212  */
 213 static void
 214 argstr(char *p, int flag)
 215 {
 216         char c;
 217         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);  /* do CTLESC */
 218         int firsteq = 1;
 219         int split_lit;
 220         int lit_quoted;
 221
 222         split_lit = flag & EXP_SPLIT_LIT;
 223         lit_quoted = flag & EXP_LIT_QUOTED;
 224         flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
 225         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 226                 p = exptilde(p, flag);
 227         for (;;) {
 228                 switch (c = *p++) {
 229                 case '\0':
 230                 case CTLENDVAR:
 231                         goto breakloop;
 232                 case CTLQUOTEMARK:
 233                         lit_quoted = 1;
 234                         /* "$@" syntax adherence hack */
 235                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 236                                 break;
 237                         if ((flag & EXP_FULL) != 0)
 238                                 STPUTC(c, expdest);
 239                         break;
 240                 case CTLQUOTEEND:
 241                         lit_quoted = 0;
 242                         break;
 243                 case CTLESC:
 244                         if (quotes)
 245                                 STPUTC(c, expdest);
 246                         c = *p++;
 247                         STPUTC(c, expdest);
 248                         if (split_lit && !lit_quoted)
 249                                 recordregion(expdest - stackblock() -
 250                                     (quotes ? 2 : 1),
 251                                     expdest - stackblock(), 0);
 252                         break;
 253                 case CTLVAR:
 254                         p = evalvar(p, flag);
 255                         break;
 256                 case CTLBACKQ:
 257                 case CTLBACKQ|CTLQUOTE:
 258                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 259                         argbackq = argbackq->next;
 260                         break;
 261                 case CTLENDARI:
 262                         expari(flag);
 263                         break;
 264                 case ':':
 265                 case '=':
 266                         /*
 267                          * sort of a hack - expand tildes in variable
 268                          * assignments (after the first '=' and after ':'s).
 269                          */
 270                         STPUTC(c, expdest);
 271                         if (split_lit && !lit_quoted)
 272                                 recordregion(expdest - stackblock() - 1,
 273                                     expdest - stackblock(), 0);
 274                         if (flag & EXP_VARTILDE && *p == '~' &&
 275                             (c != '=' || firsteq)) {
 276                                 if (c == '=')
 277                                         firsteq = 0;
 278                                 p = exptilde(p, flag);
 279                         }
 280                         break;
 281                 default:
 282                         STPUTC(c, expdest);
 283                         if (split_lit && !lit_quoted)
 284                                 recordregion(expdest - stackblock() - 1,
 285                                     expdest - stackblock(), 0);
 286                 }
 287         }
 288 breakloop:;
 289 }
 290
 291 /*
 292  * Perform tilde expansion, placing the result in the stack string and
 293  * returning the next position in the input string to process.
 294  */
 295 static char *
 296 exptilde(char *p, int flag)
 297 {
 298         char c, *startp = p;
 299         struct passwd *pw;
 300         char *home;
 301         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 302
 303         while ((c = *p) != '\0') {
 304                 switch(c) {
 305                 case CTLESC: /* This means CTL* are always considered quoted. */
 306                 case CTLVAR:
 307                 case CTLBACKQ:
 308                 case CTLBACKQ | CTLQUOTE:
 309                 case CTLARI:
 310                 case CTLENDARI:
 311                 case CTLQUOTEMARK:
 312                         return (startp);
 313                 case ':':
 314                         if (flag & EXP_VARTILDE)
 315                                 goto done;
 316                         break;
 317                 case '/':
 318                 case CTLENDVAR:
 319                         goto done;
 320                 }
 321                 p++;
 322         }
 323 done:
 324         *p = '\0';
 325         if (*(startp+1) == '\0') {
 326                 if ((home = lookupvar("HOME")) == NULL)
 327                         goto lose;
 328         } else {
 329                 if ((pw = getpwnam(startp+1)) == NULL)
 330                         goto lose;
 331                 home = pw->pw_dir;
 332         }
 333         if (*home == '\0')
 334                 goto lose;
 335         *p = c;
 336         while ((c = *home++) != '\0') {
 337                 if (quotes && SQSYNTAX[(int)c] == CCTL)
 338                         STPUTC(CTLESC, expdest);
 339                 STPUTC(c, expdest);
 340         }
 341         return (p);
 342 lose:
 343         *p = c;
 344         return (startp);
 345 }
 346
 347
 348 static void
 349 removerecordregions(int endoff)
 350 {
 351         if (ifslastp == NULL)
 352                 return;
 353
 354         if (ifsfirst.endoff > endoff) {
 355                 while (ifsfirst.next != NULL) {
 356                         struct ifsregion *ifsp;
 357                         INTOFF;
 358                         ifsp = ifsfirst.next->next;
 359                         ckfree(ifsfirst.next);
 360                         ifsfirst.next = ifsp;
 361                         INTON;
 362                 }
 363                 if (ifsfirst.begoff > endoff)
 364                         ifslastp = NULL;
 365                 else {
 366                         ifslastp = &ifsfirst;
 367                         ifsfirst.endoff = endoff;
 368                 }
 369                 return;
 370         }
 371
 372         ifslastp = &ifsfirst;
 373         while (ifslastp->next && ifslastp->next->begoff < endoff)
 374                 ifslastp=ifslastp->next;
 375         while (ifslastp->next != NULL) {
 376                 struct ifsregion *ifsp;
 377                 INTOFF;
 378                 ifsp = ifslastp->next->next;
 379                 ckfree(ifslastp->next);
 380                 ifslastp->next = ifsp;
 381                 INTON;
 382         }
 383         if (ifslastp->endoff > endoff)
 384                 ifslastp->endoff = endoff;
 385 }
 386
 387 /*
 388  * Expand arithmetic expression.  Backup to start of expression,
 389  * evaluate, place result in (backed up) result, adjust string position.
 390  */
 391 void
 392 expari(int flag)
 393 {
 394         char *p, *q, *start;
 395         arith_t result;
 396         int begoff;
 397         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 398         int quoted;
 399
 400         /*
 401          * This routine is slightly over-complicated for
 402          * efficiency.  First we make sure there is
 403          * enough space for the result, which may be bigger
 404          * than the expression.  Next we
 405          * scan backwards looking for the start of arithmetic.  If the
 406          * next previous character is a CTLESC character, then we
 407          * have to rescan starting from the beginning since CTLESC
 408          * characters have to be processed left to right.
 409          */
 410         CHECKSTRSPACE(DIGITS(result) - 2, expdest);
 411         USTPUTC('\0', expdest);
 412         start = stackblock();
 413         p = expdest - 2;
 414         while (p >= start && *p != CTLARI)
 415                 --p;
 416         if (p < start || *p != CTLARI)
 417                 error("missing CTLARI (shouldn't happen)");
 418         if (p > start && *(p - 1) == CTLESC)
 419                 for (p = start; *p != CTLARI; p++)
 420                         if (*p == CTLESC)
 421                                 p++;
 422
 423         if (p[1] == '"')
 424                 quoted=1;
 425         else
 426                 quoted=0;
 427         begoff = p - start;
 428         removerecordregions(begoff);
 429         if (quotes)
 430                 rmescapes(p+2);
 431         q = grabstackstr(expdest);
 432         result = arith(p+2);
 433         ungrabstackstr(q, expdest);
 434         fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result);
 435         while (*p++)
 436                 ;
 437         if (quoted == 0)
 438                 recordregion(begoff, p - 1 - start, 0);
 439         result = expdest - p + 1;
 440         STADJUST(-result, expdest);
 441 }
 442
 443
 444 /*
 445  * Perform command substitution.
 446  */
 447 static void
 448 expbackq(union node *cmd, int quoted, int flag)
 449 {
 450         struct backcmd in;
 451         int i;
 452         char buf[128];
 453         char *p;
 454         char *dest = expdest;
 455         struct ifsregion saveifs, *savelastp;
 456         struct nodelist *saveargbackq;
 457         char lastc;
 458         int startloc = dest - stackblock();
 459         char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
 460         int saveherefd;
 461         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 462         int nnl;
 463
 464         INTOFF;
 465         saveifs = ifsfirst;
 466         savelastp = ifslastp;
 467         saveargbackq = argbackq;
 468         saveherefd = herefd;
 469         herefd = -1;
 470         p = grabstackstr(dest);
 471         evalbackcmd(cmd, &in);
 472         ungrabstackstr(p, dest);
 473         ifsfirst = saveifs;
 474         ifslastp = savelastp;
 475         argbackq = saveargbackq;
 476         herefd = saveherefd;
 477
 478         p = in.buf;
 479         lastc = '\0';
 480         nnl = 0;
 481         /* Don't copy trailing newlines */
 482         for (;;) {
 483                 if (--in.nleft < 0) {
 484                         if (in.fd < 0)
 485                                 break;
 486                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
 487                         TRACE(("expbackq: read returns %d\n", i));
 488                         if (i <= 0)
 489                                 break;
 490                         p = buf;
 491                         in.nleft = i - 1;
 492                 }
 493                 lastc = *p++;
 494                 if (lastc != '\0') {
 495                         if (quotes && syntax[(int)lastc] == CCTL)
 496                                 STPUTC(CTLESC, dest);
 497                         if (lastc == '\n') {
 498                                 nnl++;
 499                         } else {
 500                                 while (nnl > 0) {
 501                                         nnl--;
 502                                         STPUTC('\n', dest);
 503                                 }
 504                                 STPUTC(lastc, dest);
 505                         }
 506                 }
 507         }
 508
 509         if (in.fd >= 0)
 510                 close(in.fd);
 511         if (in.buf)
 512                 ckfree(in.buf);
 513         if (in.jp)
 514                 exitstatus = waitforjob(in.jp, (int *)NULL);
 515         if (quoted == 0)
 516                 recordregion(startloc, dest - stackblock(), 0);
 517         TRACE(("expbackq: size=%td: \"%.*s\"\n",
 518                 ((dest - stackblock()) - startloc),
 519                 (int)((dest - stackblock()) - startloc),
 520                 stackblock() + startloc));
 521         expdest = dest;
 522         INTON;
 523 }
 524
 525
 526
 527 static int
 528 subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
 529   int varflags)
 530 {
 531         char *startp;
 532         char *loc = NULL;
 533         char *q;
 534         int c = 0;
 535         int saveherefd = herefd;
 536         struct nodelist *saveargbackq = argbackq;
 537         int amount;
 538
 539         herefd = -1;
 540         argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
 541             subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ?
 542             EXP_CASE : 0) | EXP_TILDE);
 543         STACKSTRNUL(expdest);
 544         herefd = saveherefd;
 545         argbackq = saveargbackq;
 546         startp = stackblock() + startloc;
 547         if (str == NULL)
 548             str = stackblock() + strloc;
 549
 550         switch (subtype) {
 551         case VSASSIGN:
 552                 setvar(str, startp, 0);
 553                 amount = startp - expdest;
 554                 STADJUST(amount, expdest);
 555                 varflags &= ~VSNUL;
 556                 if (c != 0)
 557                         *loc = c;
 558                 return 1;
 559
 560         case VSQUESTION:
 561                 if (*p != CTLENDVAR) {
 562                         outfmt(out2, "%s\n", startp);
 563                         error((char *)NULL);
 564                 }
 565                 error("%.*s: parameter %snot set", (int)(p - str - 1),
 566                       str, (varflags & VSNUL) ? "null or "
 567                                               : nullstr);
 568                 return 0;
 569
 570         case VSTRIMLEFT:
 571                 for (loc = startp; loc < str; loc++) {
 572                         c = *loc;
 573                         *loc = '\0';
 574                         if (patmatch(str, startp, varflags & VSQUOTE)) {
 575                                 *loc = c;
 576                                 goto recordleft;
 577                         }
 578                         *loc = c;
 579                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 580                                 loc++;
 581                 }
 582                 return 0;
 583
 584         case VSTRIMLEFTMAX:
 585                 for (loc = str - 1; loc >= startp;) {
 586                         c = *loc;
 587                         *loc = '\0';
 588                         if (patmatch(str, startp, varflags & VSQUOTE)) {
 589                                 *loc = c;
 590                                 goto recordleft;
 591                         }
 592                         *loc = c;
 593                         loc--;
 594                         if ((varflags & VSQUOTE) && loc > startp &&
 595                             *(loc - 1) == CTLESC) {
 596                                 for (q = startp; q < loc; q++)
 597                                         if (*q == CTLESC)
 598                                                 q++;
 599                                 if (q > loc)
 600                                         loc--;
 601                         }
 602                 }
 603                 return 0;
 604
 605         case VSTRIMRIGHT:
 606                 for (loc = str - 1; loc >= startp;) {
 607                         if (patmatch(str, loc, varflags & VSQUOTE)) {
 608                                 amount = loc - expdest;
 609                                 STADJUST(amount, expdest);
 610                                 return 1;
 611                         }
 612                         loc--;
 613                         if ((varflags & VSQUOTE) && loc > startp &&
 614                             *(loc - 1) == CTLESC) {
 615                                 for (q = startp; q < loc; q++)
 616                                         if (*q == CTLESC)
 617                                                 q++;
 618                                 if (q > loc)
 619                                         loc--;
 620                         }
 621                 }
 622                 return 0;
 623
 624         case VSTRIMRIGHTMAX:
 625                 for (loc = startp; loc < str - 1; loc++) {
 626                         if (patmatch(str, loc, varflags & VSQUOTE)) {
 627                                 amount = loc - expdest;
 628                                 STADJUST(amount, expdest);
 629                                 return 1;
 630                         }
 631                         if ((varflags & VSQUOTE) && *loc == CTLESC)
 632                                 loc++;
 633                 }
 634                 return 0;
 635
 636
 637         default:
 638                 abort();
 639         }
 640
 641 recordleft:
 642         amount = ((str - 1) - (loc - startp)) - expdest;
 643         STADJUST(amount, expdest);
 644         while (loc != str - 1)
 645                 *startp++ = *loc++;
 646         return 1;
 647 }
 648
 649
 650 /*
 651  * Expand a variable, and return a pointer to the next character in the
 652  * input string.
 653  */
 654
 655 static char *
 656 evalvar(char *p, int flag)
 657 {
 658         int subtype;
 659         int varflags;
 660         char *var;
 661         char *val;
 662         int patloc;
 663         int c;
 664         int set;
 665         int special;
 666         int startloc;
 667         int varlen;
 668         int easy;
 669         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
 670
 671         varflags = (unsigned char)*p++;
 672         subtype = varflags & VSTYPE;
 673         var = p;
 674         special = 0;
 675         if (! is_name(*p))
 676                 special = 1;
 677         p = strchr(p, '=') + 1;
 678 again: /* jump here after setting a variable with ${var=text} */
 679         if (varflags & VSLINENO) {
 680                 set = 1;
 681                 special = 0;
 682                 val = var;
 683                 p[-1] = '\0';   /* temporarily overwrite '=' to have \0
 684                                    terminated string */
 685         } else if (special) {
 686                 set = varisset(var, varflags & VSNUL);
 687                 val = NULL;
 688         } else {
 689                 val = bltinlookup(var, 1);
 690                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 691                         val = NULL;
 692                         set = 0;
 693                 } else
 694                         set = 1;
 695         }
 696         varlen = 0;
 697         startloc = expdest - stackblock();
 698         if (!set && uflag && *var != '@' && *var != '*') {
 699                 switch (subtype) {
 700                 case VSNORMAL:
 701                 case VSTRIMLEFT:
 702                 case VSTRIMLEFTMAX:
 703                 case VSTRIMRIGHT:
 704                 case VSTRIMRIGHTMAX:
 705                 case VSLENGTH:
 706                         error("%.*s: parameter not set", (int)(p - var - 1),
 707                             var);
 708                 }
 709         }
 710         if (set && subtype != VSPLUS) {
 711                 /* insert the value of the variable */
 712                 if (special) {
 713                         varvalue(var, varflags & VSQUOTE, subtype, flag);
 714                         if (subtype == VSLENGTH) {
 715                                 varlen = expdest - stackblock() - startloc;
 716                                 STADJUST(-varlen, expdest);
 717                         }
 718                 } else {
 719                         char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
 720                                                                   : BASESYNTAX;
 721
 722                         if (subtype == VSLENGTH) {
 723                                 for (;*val; val++)
 724                                         varlen++;
 725                         }
 726                         else {
 727                                 while (*val) {
 728                                         if (quotes &&
 729                                             syntax[(int)*val] == CCTL)
 730                                                 STPUTC(CTLESC, expdest);
 731                                         STPUTC(*val++, expdest);
 732                                 }
 733
 734                         }
 735                 }
 736         }
 737
 738         if (subtype == VSPLUS)
 739                 set = ! set;
 740
 741         easy = ((varflags & VSQUOTE) == 0 ||
 742                 (*var == '@' && shellparam.nparam != 1));
 743
 744
 745         switch (subtype) {
 746         case VSLENGTH:
 747                 expdest = cvtnum(varlen, expdest);
 748                 goto record;
 749
 750         case VSNORMAL:
 751                 if (!easy)
 752                         break;
 753 record:
 754                 recordregion(startloc, expdest - stackblock(),
 755                              varflags & VSQUOTE);
 756                 break;
 757
 758         case VSPLUS:
 759         case VSMINUS:
 760                 if (!set) {
 761                         argstr(p, flag | (flag & EXP_FULL ? EXP_SPLIT_LIT : 0) |
 762                             (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0));
 763                         break;
 764                 }
 765                 if (easy)
 766                         goto record;
 767                 break;
 768
 769         case VSTRIMLEFT:
 770         case VSTRIMLEFTMAX:
 771         case VSTRIMRIGHT:
 772         case VSTRIMRIGHTMAX:
 773                 if (!set)
 774                         break;
 775                 /*
 776                  * Terminate the string and start recording the pattern
 777                  * right after it
 778                  */
 779                 STPUTC('\0', expdest);
 780                 patloc = expdest - stackblock();
 781                 if (subevalvar(p, NULL, patloc, subtype,
 782                                startloc, varflags) == 0) {
 783                         int amount = (expdest - stackblock() - patloc) + 1;
 784                         STADJUST(-amount, expdest);
 785                 }
 786                 /* Remove any recorded regions beyond start of variable */
 787                 removerecordregions(startloc);
 788                 goto record;
 789
 790         case VSASSIGN:
 791         case VSQUESTION:
 792                 if (!set) {
 793                         if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
 794                                 varflags &= ~VSNUL;
 795                                 /*
 796                                  * Remove any recorded regions beyond
 797                                  * start of variable
 798                                  */
 799                                 removerecordregions(startloc);
 800                                 goto again;
 801                         }
 802                         break;
 803                 }
 804                 if (easy)
 805                         goto record;
 806                 break;
 807
 808         case VSERROR:
 809                 c = p - var - 1;
 810                 error("${%.*s%s}: Bad substitution", c, var,
 811                     (c > 0 && *p != CTLENDVAR) ? "..." : "");
 812
 813         default:
 814                 abort();
 815         }
 816         p[-1] = '=';    /* recover overwritten '=' */
 817
 818         if (subtype != VSNORMAL) {      /* skip to end of alternative */
 819                 int nesting = 1;
 820                 for (;;) {
 821                         if ((c = *p++) == CTLESC)
 822                                 p++;
 823                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
 824                                 if (set)
 825                                         argbackq = argbackq->next;
 826                         } else if (c == CTLVAR) {
 827                                 if ((*p++ & VSTYPE) != VSNORMAL)
 828                                         nesting++;
 829                         } else if (c == CTLENDVAR) {
 830                                 if (--nesting == 0)
 831                                         break;
 832                         }
 833                 }
 834         }
 835         return p;
 836 }
 837
 838
 839
 840 /*
 841  * Test whether a specialized variable is set.
 842  */
 843
 844 static int
 845 varisset(char *name, int nulok)
 846 {
 847
 848         if (*name == '!')
 849                 return backgndpidset();
 850         else if (*name == '@' || *name == '*') {
 851                 if (*shellparam.p == NULL)
 852                         return 0;
 853
 854                 if (nulok) {
 855                         char **av;
 856
 857                         for (av = shellparam.p; *av; av++)
 858                                 if (**av != '\0')
 859                                         return 1;
 860                         return 0;
 861                 }
 862         } else if (is_digit(*name)) {
 863                 char *ap;
 864                 int num = atoi(name);
 865
 866                 if (num > shellparam.nparam)
 867                         return 0;
 868
 869                 if (num == 0)
 870                         ap = arg0;
 871                 else
 872                         ap = shellparam.p[num - 1];
 873
 874                 if (nulok && (ap == NULL || *ap == '\0'))
 875                         return 0;
 876         }
 877         return 1;
 878 }
 879
 880
 881
 882 /*
 883  * Add the value of a specialized variable to the stack string.
 884  */
 885
 886 static void
 887 varvalue(char *name, int quoted, int subtype, int flag)
 888 {
 889         int num;
 890         char *p;
 891         int i;
 892         char sep;
 893         char **ap;
 894         char const *syntax;
 895
 896 #define STRTODEST(p) \
 897         do {\
 898         if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
 899                 syntax = quoted? DQSYNTAX : BASESYNTAX; \
 900                 while (*p) { \
 901                         if (syntax[(int)*p] == CCTL) \
 902                                 STPUTC(CTLESC, expdest); \
 903                         STPUTC(*p++, expdest); \
 904                 } \
 905         } else \
 906                 while (*p) \
 907                         STPUTC(*p++, expdest); \
 908         } while (0)
 909
 910
 911         switch (*name) {
 912         case '$':
 913                 num = rootpid;
 914                 goto numvar;
 915         case '?':
 916                 num = oexitstatus;
 917                 goto numvar;
 918         case '#':
 919                 num = shellparam.nparam;
 920                 goto numvar;
 921         case '!':
 922                 num = backgndpidval();
 923 numvar:
 924                 expdest = cvtnum(num, expdest);
 925                 break;
 926         case '-':
 927                 for (i = 0 ; i < NOPTS ; i++) {
 928                         if (optlist[i].val)
 929                                 STPUTC(optlist[i].letter, expdest);
 930                 }
 931                 break;
 932         case '@':
 933                 if (flag & EXP_FULL && quoted) {
 934                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 935                                 STRTODEST(p);
 936                                 if (*ap)
 937                                         STPUTC('\0', expdest);
 938                         }
 939                         break;
 940                 }
 941                 /* FALLTHROUGH */
 942         case '*':
 943                 if (ifsset())
 944                         sep = ifsval()[0];
 945                 else
 946                         sep = ' ';
 947                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 948                         STRTODEST(p);
 949                         if (*ap && sep)
 950                                 STPUTC(sep, expdest);
 951                 }
 952                 break;
 953         case '0':
 954                 p = arg0;
 955                 STRTODEST(p);
 956                 break;
 957         default:
 958                 if (is_digit(*name)) {
 959                         num = atoi(name);
 960                         if (num > 0 && num <= shellparam.nparam) {
 961                                 p = shellparam.p[num - 1];
 962                                 STRTODEST(p);
 963                         }
 964                 }
 965                 break;
 966         }
 967 }
 968
 969
 970
 971 /*
 972  * Record the the fact that we have to scan this region of the
 973  * string for IFS characters.
 974  */
 975
 976 static void
 977 recordregion(int start, int end, int inquotes)
 978 {
 979         struct ifsregion *ifsp;
 980
 981         if (ifslastp == NULL) {
 982                 ifsp = &ifsfirst;
 983         } else {
 984                 if (ifslastp->endoff == start
 985                     && ifslastp->inquotes == inquotes) {
 986                         /* extend previous area */
 987                         ifslastp->endoff = end;
 988                         return;
 989                 }
 990                 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
 991                 ifslastp->next = ifsp;
 992         }
 993         ifslastp = ifsp;
 994         ifslastp->next = NULL;
 995         ifslastp->begoff = start;
 996         ifslastp->endoff = end;
 997         ifslastp->inquotes = inquotes;
 998 }
 999
1000
1001
1002 /*
1003  * Break the argument string into pieces based upon IFS and add the
1004  * strings to the argument list.  The regions of the string to be
1005  * searched for IFS characters have been stored by recordregion.
1006  * CTLESC characters are preserved but have little effect in this pass
1007  * other than escaping CTL* characters.  In particular, they do not escape
1008  * IFS characters: that should be done with the ifsregion mechanism.
1009  * CTLQUOTEMARK characters are used to preserve empty quoted strings.
1010  * This pass treats them as a regular character, making the string non-empty.
1011  * Later, they are removed along with the other CTL* characters.
1012  */
1013 static void
1014 ifsbreakup(char *string, struct arglist *arglist)
1015 {
1016         struct ifsregion *ifsp;
1017         struct strlist *sp;
1018         char *start;
1019         char *p;
1020         char *q;
1021         const char *ifs;
1022         const char *ifsspc;
1023         int had_param_ch = 0;
1024
1025         start = string;
1026
1027         if (ifslastp == NULL) {
1028                 /* Return entire argument, IFS doesn't apply to any of it */
1029                 sp = (struct strlist *)stalloc(sizeof *sp);
1030                 sp->text = start;
1031                 *arglist->lastp = sp;
1032                 arglist->lastp = &sp->next;
1033                 return;
1034         }
1035
1036         ifs = ifsset() ? ifsval() : " \t\n";
1037
1038         for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
1039                 p = string + ifsp->begoff;
1040                 while (p < string + ifsp->endoff) {
1041                         q = p;
1042                         if (*p == CTLESC)
1043                                 p++;
1044                         if (ifsp->inquotes) {
1045                                 /* Only NULs (should be from "$@") end args */
1046                                 had_param_ch = 1;
1047                                 if (*p != 0) {
1048                                         p++;
1049                                         continue;
1050                                 }
1051                                 ifsspc = NULL;
1052                         } else {
1053                                 if (!strchr(ifs, *p)) {
1054                                         had_param_ch = 1;
1055                                         p++;
1056                                         continue;
1057                                 }
1058                                 ifsspc = strchr(" \t\n", *p);
1059
1060                                 /* Ignore IFS whitespace at start */
1061                                 if (q == start && ifsspc != NULL) {
1062                                         p++;
1063                                         start = p;
1064                                         continue;
1065                                 }
1066                                 had_param_ch = 0;
1067                         }
1068
1069                         /* Save this argument... */
1070                         *q = '\0';
1071                         sp = (struct strlist *)stalloc(sizeof *sp);
1072                         sp->text = start;
1073                         *arglist->lastp = sp;
1074                         arglist->lastp = &sp->next;
1075                         p++;
1076
1077                         if (ifsspc != NULL) {
1078                                 /* Ignore further trailing IFS whitespace */
1079                                 for (; p < string + ifsp->endoff; p++) {
1080                                         q = p;
1081                                         if (*p == CTLESC)
1082                                                 p++;
1083                                         if (strchr(ifs, *p) == NULL) {
1084                                                 p = q;
1085                                                 break;
1086                                         }
1087                                         if (strchr(" \t\n", *p) == NULL) {
1088                                                 p++;
1089                                                 break;
1090                                         }
1091                                 }
1092                         }
1093                         start = p;
1094                 }
1095         }
1096
1097         /*
1098          * Save anything left as an argument.
1099          * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1100          * generating 2 arguments, the second of which is empty.
1101          * Some recent clarification of the Posix spec say that it
1102          * should only generate one....
1103          */
1104         if (had_param_ch || *start != 0) {
1105                 sp = (struct strlist *)stalloc(sizeof *sp);
1106                 sp->text = start;
1107                 *arglist->lastp = sp;
1108                 arglist->lastp = &sp->next;
1109         }
1110 }
1111
1112
1113 static char expdir[PATH_MAX];
1114 #define expdir_end (expdir + sizeof(expdir))
1115
1116 /*
1117  * Perform pathname generation and remove control characters.
1118  * At this point, the only control characters should be CTLESC and CTLQUOTEMARK.
1119  * The results are stored in the list exparg.
1120  */
1121 static void
1122 expandmeta(struct strlist *str, int flag __unused)
1123 {
1124         char *p;
1125         struct strlist **savelastp;
1126         struct strlist *sp;
1127         char c;
1128         /* TODO - EXP_REDIR */
1129
1130         while (str) {
1131                 if (fflag)
1132                         goto nometa;
1133                 p = str->text;
1134                 for (;;) {                      /* fast check for meta chars */
1135                         if ((c = *p++) == '\0')
1136                                 goto nometa;
1137                         if (c == '*' || c == '?' || c == '[')
1138                                 break;
1139                 }
1140                 savelastp = exparg.lastp;
1141                 INTOFF;
1142                 expmeta(expdir, str->text);
1143                 INTON;
1144                 if (exparg.lastp == savelastp) {
1145                         /*
1146                          * no matches
1147                          */
1148 nometa:
1149                         *exparg.lastp = str;
1150                         rmescapes(str->text);
1151                         exparg.lastp = &str->next;
1152                 } else {
1153                         *exparg.lastp = NULL;
1154                         *savelastp = sp = expsort(*savelastp);
1155                         while (sp->next != NULL)
1156                                 sp = sp->next;
1157                         exparg.lastp = &sp->next;
1158                 }
1159                 str = str->next;
1160         }
1161 }
1162
1163
1164 /*
1165  * Do metacharacter (i.e. *, ?, [...]) expansion.
1166  */
1167
1168 static void
1169 expmeta(char *enddir, char *name)
1170 {
1171         char *p;
1172         char *q;
1173         char *start;
1174         char *endname;
1175         int metaflag;
1176         struct stat statb;
1177         DIR *dirp;
1178         struct dirent *dp;
1179         int atend;
1180         int matchdot;
1181         int esc;
1182
1183         metaflag = 0;
1184         start = name;
1185         for (p = name; esc = 0, *p; p += esc + 1) {
1186                 if (*p == '*' || *p == '?')
1187                         metaflag = 1;
1188                 else if (*p == '[') {
1189                         q = p + 1;
1190                         if (*q == '!' || *q == '^')
1191                                 q++;
1192                         for (;;) {
1193                                 while (*q == CTLQUOTEMARK)
1194                                         q++;
1195                                 if (*q == CTLESC)
1196                                         q++;
1197                                 if (*q == '/' || *q == '\0')
1198                                         break;
1199                                 if (*++q == ']') {
1200                                         metaflag = 1;
1201                                         break;
1202                                 }
1203                         }
1204                 } else if (*p == '\0')
1205                         break;
1206                 else if (*p == CTLQUOTEMARK)
1207                         continue;
1208                 else {
1209                         if (*p == CTLESC)
1210                                 esc++;
1211                         if (p[esc] == '/') {
1212                                 if (metaflag)
1213                                         break;
1214                                 start = p + esc + 1;
1215                         }
1216                 }
1217         }
1218         if (metaflag == 0) {    /* we've reached the end of the file name */
1219                 if (enddir != expdir)
1220                         metaflag++;
1221                 for (p = name ; ; p++) {
1222                         if (*p == CTLQUOTEMARK)
1223                                 continue;
1224                         if (*p == CTLESC)
1225                                 p++;
1226                         *enddir++ = *p;
1227                         if (*p == '\0')
1228                                 break;
1229                         if (enddir == expdir_end)
1230                                 return;
1231                 }
1232                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1233                         addfname(expdir);
1234                 return;
1235         }
1236         endname = p;
1237         if (start != name) {
1238                 p = name;
1239                 while (p < start) {
1240                         while (*p == CTLQUOTEMARK)
1241                                 p++;
1242                         if (*p == CTLESC)
1243                                 p++;
1244                         *enddir++ = *p++;
1245                         if (enddir == expdir_end)
1246                                 return;
1247                 }
1248         }
1249         if (enddir == expdir) {
1250                 p = ".";
1251         } else if (enddir == expdir + 1 && *expdir == '/') {
1252                 p = "/";
1253         } else {
1254                 p = expdir;
1255                 enddir[-1] = '\0';
1256         }
1257         if ((dirp = opendir(p)) == NULL)
1258                 return;
1259         if (enddir != expdir)
1260                 enddir[-1] = '/';
1261         if (*endname == 0) {
1262                 atend = 1;
1263         } else {
1264                 atend = 0;
1265                 *endname = '\0';
1266                 endname += esc + 1;
1267         }
1268         matchdot = 0;
1269         p = start;
1270         while (*p == CTLQUOTEMARK)
1271                 p++;
1272         if (*p == CTLESC)
1273                 p++;
1274         if (*p == '.')
1275                 matchdot++;
1276         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1277                 if (dp->d_name[0] == '.' && ! matchdot)
1278                         continue;
1279                 if (patmatch(start, dp->d_name, 0)) {
1280                         if (enddir + dp->d_namlen + 1 > expdir_end)
1281                                 continue;
1282                         memcpy(enddir, dp->d_name, dp->d_namlen + 1);
1283                         if (atend)
1284                                 addfname(expdir);
1285                         else {
1286                                 if (enddir + dp->d_namlen + 2 > expdir_end)
1287                                         continue;
1288                                 enddir[dp->d_namlen] = '/';
1289                                 enddir[dp->d_namlen + 1] = '\0';
1290                                 expmeta(enddir + dp->d_namlen + 1, endname);
1291                         }
1292                 }
1293         }
1294         closedir(dirp);
1295         if (! atend)
1296                 endname[-esc - 1] = esc ? CTLESC : '/';
1297 }
1298
1299
1300 /*
1301  * Add a file name to the list.
1302  */
1303
1304 static void
1305 addfname(char *name)
1306 {
1307         char *p;
1308         struct strlist *sp;
1309
1310         p = stalloc(strlen(name) + 1);
1311         scopy(name, p);
1312         sp = (struct strlist *)stalloc(sizeof *sp);
1313         sp->text = p;
1314         *exparg.lastp = sp;
1315         exparg.lastp = &sp->next;
1316 }
1317
1318
1319 /*
1320  * Sort the results of file name expansion.  It calculates the number of
1321  * strings to sort and then calls msort (short for merge sort) to do the
1322  * work.
1323  */
1324
1325 static struct strlist *
1326 expsort(struct strlist *str)
1327 {
1328         int len;
1329         struct strlist *sp;
1330
1331         len = 0;
1332         for (sp = str ; sp ; sp = sp->next)
1333                 len++;
1334         return msort(str, len);
1335 }
1336
1337
1338 static struct strlist *
1339 msort(struct strlist *list, int len)
1340 {
1341         struct strlist *p, *q = NULL;
1342         struct strlist **lpp;
1343         int half;
1344         int n;
1345
1346         if (len <= 1)
1347                 return list;
1348         half = len >> 1;
1349         p = list;
1350         for (n = half ; --n >= 0 ; ) {
1351                 q = p;
1352                 p = p->next;
1353         }
1354         q->next = NULL;                 /* terminate first half of list */
1355         q = msort(list, half);          /* sort first half of list */
1356         p = msort(p, len - half);               /* sort second half */
1357         lpp = &list;
1358         for (;;) {
1359                 if (strcmp(p->text, q->text) < 0) {
1360                         *lpp = p;
1361                         lpp = &p->next;
1362                         if ((p = *lpp) == NULL) {
1363                                 *lpp = q;
1364                                 break;
1365                         }
1366                 } else {
1367                         *lpp = q;
1368                         lpp = &q->next;
1369                         if ((q = *lpp) == NULL) {
1370                                 *lpp = p;
1371                                 break;
1372                         }
1373                 }
1374         }
1375         return list;
1376 }
1377
1378
1379
1380 /*
1381  * Returns true if the pattern matches the string.
1382  */
1383
1384 int
1385 patmatch(const char *pattern, const char *string, int squoted)
1386 {
1387         const char *p, *q;
1388         char c;
1389
1390         p = pattern;
1391         q = string;
1392         for (;;) {
1393                 switch (c = *p++) {
1394                 case '\0':
1395                         goto breakloop;
1396                 case CTLESC:
1397                         if (squoted && *q == CTLESC)
1398                                 q++;
1399                         if (*q++ != *p++)
1400                                 return 0;
1401                         break;
1402                 case CTLQUOTEMARK:
1403                         continue;
1404                 case '?':
1405                         if (squoted && *q == CTLESC)
1406                                 q++;
1407                         if (*q++ == '\0')
1408                                 return 0;
1409                         break;
1410                 case '*':
1411                         c = *p;
1412                         while (c == CTLQUOTEMARK || c == '*')
1413                                 c = *++p;
1414                         if (c != CTLESC &&  c != CTLQUOTEMARK &&
1415                             c != '?' && c != '*' && c != '[') {
1416                                 while (*q != c) {
1417                                         if (squoted && *q == CTLESC &&
1418                                             q[1] == c)
1419                                                 break;
1420                                         if (*q == '\0')
1421                                                 return 0;
1422                                         if (squoted && *q == CTLESC)
1423                                                 q++;
1424                                         q++;
1425                                 }
1426                         }
1427                         do {
1428                                 if (patmatch(p, q, squoted))
1429                                         return 1;
1430                                 if (squoted && *q == CTLESC)
1431                                         q++;
1432                         } while (*q++ != '\0');
1433                         return 0;
1434                 case '[': {
1435                         const char *endp;
1436                         int invert, found;
1437                         char chr;
1438
1439                         endp = p;
1440                         if (*endp == '!' || *endp == '^')
1441                                 endp++;
1442                         for (;;) {
1443                                 while (*endp == CTLQUOTEMARK)
1444                                         endp++;
1445                                 if (*endp == '\0')
1446                                         goto dft;               /* no matching ] */
1447                                 if (*endp == CTLESC)
1448                                         endp++;
1449                                 if (*++endp == ']')
1450                                         break;
1451                         }
1452                         invert = 0;
1453                         if (*p == '!' || *p == '^') {
1454                                 invert++;
1455                                 p++;
1456                         }
1457                         found = 0;
1458                         chr = *q++;
1459                         if (squoted && chr == CTLESC)
1460                                 chr = *q++;
1461                         if (chr == '\0')
1462                                 return 0;
1463                         c = *p++;
1464                         do {
1465                                 if (c == CTLQUOTEMARK)
1466                                         continue;
1467                                 if (c == CTLESC)
1468                                         c = *p++;
1469                                 if (*p == '-' && p[1] != ']') {
1470                                         p++;
1471                                         while (*p == CTLQUOTEMARK)
1472                                                 p++;
1473                                         if (*p == CTLESC)
1474                                                 p++;
1475                                         if (   collate_range_cmp(chr, c) >= 0
1476                                             && collate_range_cmp(chr, *p) <= 0
1477                                            )
1478                                                 found = 1;
1479                                         p++;
1480                                 } else {
1481                                         if (chr == c)
1482                                                 found = 1;
1483                                 }
1484                         } while ((c = *p++) != ']');
1485                         if (found == invert)
1486                                 return 0;
1487                         break;
1488                 }
1489 dft:            default:
1490                         if (squoted && *q == CTLESC)
1491                                 q++;
1492                         if (*q++ != c)
1493                                 return 0;
1494                         break;
1495                 }
1496         }
1497 breakloop:
1498         if (*q != '\0')
1499                 return 0;
1500         return 1;
1501 }
1502
1503
1504
1505 /*
1506  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1507  */
1508
1509 void
1510 rmescapes(char *str)
1511 {
1512         char *p, *q;
1513
1514         p = str;
1515         while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1516                 if (*p++ == '\0')
1517                         return;
1518         }
1519         q = p;
1520         while (*p) {
1521                 if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1522                         p++;
1523                         continue;
1524                 }
1525                 if (*p == CTLESC)
1526                         p++;
1527                 *q++ = *p++;
1528         }
1529         *q = '\0';
1530 }
1531
1532
1533
1534 /*
1535  * See if a pattern matches in a case statement.
1536  */
1537
1538 int
1539 casematch(union node *pattern, const char *val)
1540 {
1541         struct stackmark smark;
1542         int result;
1543         char *p;
1544
1545         setstackmark(&smark);
1546         argbackq = pattern->narg.backquote;
1547         STARTSTACKSTR(expdest);
1548         ifslastp = NULL;
1549         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1550         STPUTC('\0', expdest);
1551         p = grabstackstr(expdest);
1552         result = patmatch(p, val, 0);
1553         popstackmark(&smark);
1554         return result;
1555 }
1556
1557 /*
1558  * Our own itoa().
1559  */
1560
1561 static char *
1562 cvtnum(int num, char *buf)
1563 {
1564         char temp[32];
1565         int neg = num < 0;
1566         char *p = temp + 31;
1567
1568         temp[31] = '\0';
1569
1570         do {
1571                 *--p = num % 10 + '0';
1572         } while ((num /= 10) != 0);
1573
1574         if (neg)
1575                 *--p = '-';
1576
1577         while (*p)
1578                 STPUTC(*p++, buf);
1579         return buf;
1580 }
1581
1582 /*
1583  * Do most of the work for wordexp(3).
1584  */
1585
1586 int
1587 wordexpcmd(int argc, char **argv)
1588 {
1589         size_t len;
1590         int i;
1591
1592         out1fmt("%08x", argc - 1);
1593         for (i = 1, len = 0; i < argc; i++)
1594                 len += strlen(argv[i]);
1595         out1fmt("%08x", (int)len);
1596         for (i = 1; i < argc; i++) {
1597                 out1str(argv[i]);
1598                 out1c('\0');
1599         }
1600         return (0);
1601 }