bin/sh/expand.c

   1 /*      $NetBSD: expand.c,v 1.93 2015/08/27 07:46:47 christos Exp $     */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993
   5  *      The Regents of the University of California.  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  * 3. 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 #include <sys/cdefs.h>
  36 #ifndef lint
  37 #if 0
  38 static char sccsid[] = "@(#)expand.c    8.5 (Berkeley) 5/15/95";
  39 #else
  40 __RCSID("$NetBSD: expand.c,v 1.93 2015/08/27 07:46:47 christos Exp $");
  41 #endif
  42 #endif /* not lint */
  43
  44 #include <sys/types.h>
  45 #include <sys/time.h>
  46 #include <sys/stat.h>
  47 #include <errno.h>
  48 #include <dirent.h>
  49 #include <unistd.h>
  50 #include <pwd.h>
  51 #include <limits.h>
  52 #include <stdlib.h>
  53 #include <stdio.h>
  54 #include <wctype.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 "builtins.h"
  71 #include "var.h"
  72 #include "input.h"
  73 #include "output.h"
  74 #include "memalloc.h"
  75 #include "error.h"
  76 #include "mystring.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 char *expdest;                  /* output of current string */
  93 struct nodelist *argbackq;      /* list of back quote expressions */
  94 struct ifsregion ifsfirst;      /* first struct in list of ifs regions */
  95 struct ifsregion *ifslastp;     /* last struct in list */
  96 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, 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 ifsfree(void);
 109 STATIC void expandmeta(struct strlist *, int);
 110 STATIC void expmeta(char *, char *);
 111 STATIC void addfname(char *);
 112 STATIC struct strlist *expsort(struct strlist *);
 113 STATIC struct strlist *msort(struct strlist *, int);
 114 STATIC int pmatch(char *, char *, int);
 115 STATIC char *cvtnum(int, char *);
 116
 117 /*
 118  * Expand shell variables and backquotes inside a here document.
 119  */
 120
 121 void
 122 expandhere(union node *arg, int fd)
 123 {
 124         herefd = fd;
 125         expandarg(arg, NULL, 0);
 126         xwrite(fd, stackblock(), expdest - stackblock());
 127 }
 128
 129
 130 /*
 131  * Perform variable substitution and command substitution on an argument,
 132  * placing the resulting list of arguments in arglist.  If EXP_FULL is true,
 133  * perform splitting and file name expansion.  When arglist is NULL, perform
 134  * here document expansion.
 135  */
 136
 137 void
 138 expandarg(union node *arg, struct arglist *arglist, int flag)
 139 {
 140         struct strlist *sp;
 141         char *p;
 142
 143         argbackq = arg->narg.backquote;
 144         STARTSTACKSTR(expdest);
 145         ifsfirst.next = NULL;
 146         ifslastp = NULL;
 147         argstr(arg->narg.text, flag);
 148         if (arglist == NULL) {
 149                 return;                 /* here document expanded */
 150         }
 151         STPUTC('\0', expdest);
 152         p = grabstackstr(expdest);
 153         exparg.lastp = &exparg.list;
 154         /*
 155          * TODO - EXP_REDIR
 156          */
 157         if (flag & EXP_FULL) {
 158                 ifsbreakup(p, &exparg);
 159                 *exparg.lastp = NULL;
 160                 exparg.lastp = &exparg.list;
 161                 expandmeta(exparg.list, flag);
 162         } else {
 163                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
 164                         rmescapes(p);
 165                 sp = (struct strlist *)stalloc(sizeof (struct strlist));
 166                 sp->text = p;
 167                 *exparg.lastp = sp;
 168                 exparg.lastp = &sp->next;
 169         }
 170         ifsfree();
 171         *exparg.lastp = NULL;
 172         if (exparg.list) {
 173                 *arglist->lastp = exparg.list;
 174                 arglist->lastp = exparg.lastp;
 175         }
 176 }
 177
 178
 179
 180 /*
 181  * Perform variable and command substitution.
 182  * If EXP_FULL is set, output CTLESC characters to allow for further processing.
 183  * Otherwise treat $@ like $* since no splitting will be performed.
 184  */
 185
 186 STATIC void
 187 argstr(char *p, int flag)
 188 {
 189         char c;
 190         int quotes = flag & (EXP_FULL | EXP_CASE);      /* do CTLESC */
 191         int firsteq = 1;
 192         const char *ifs = NULL;
 193         int ifs_split = EXP_IFS_SPLIT;
 194
 195         if (flag & EXP_IFS_SPLIT)
 196                 ifs = ifsset() ? ifsval() : " \t\n";
 197
 198         if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
 199                 p = exptilde(p, flag);
 200         for (;;) {
 201                 switch (c = *p++) {
 202                 case '\0':
 203                 case CTLENDVAR: /* end of expanding yyy in ${xxx-yyy} */
 204                         return;
 205                 case CTLQUOTEMARK:
 206                         /* "$@" syntax adherence hack */
 207                         if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
 208                                 break;
 209                         if ((flag & EXP_FULL) != 0)
 210                                 STPUTC(c, expdest);
 211                         ifs_split = 0;
 212                         break;
 213                 case CTLQUOTEEND:
 214                         ifs_split = EXP_IFS_SPLIT;
 215                         break;
 216                 case CTLESC:
 217                         if (quotes)
 218                                 STPUTC(c, expdest);
 219                         c = *p++;
 220                         STPUTC(c, expdest);
 221                         break;
 222                 case CTLVAR:
 223                         p = evalvar(p, (flag & ~EXP_IFS_SPLIT) | (flag & ifs_split));
 224                         break;
 225                 case CTLBACKQ:
 226                 case CTLBACKQ|CTLQUOTE:
 227                         expbackq(argbackq->n, c & CTLQUOTE, flag);
 228                         argbackq = argbackq->next;
 229                         break;
 230                 case CTLENDARI:
 231                         expari(flag);
 232                         break;
 233                 case ':':
 234                 case '=':
 235                         /*
 236                          * sort of a hack - expand tildes in variable
 237                          * assignments (after the first '=' and after ':'s).
 238                          */
 239                         STPUTC(c, expdest);
 240                         if (flag & EXP_VARTILDE && *p == '~') {
 241                                 if (c == '=') {
 242                                         if (firsteq)
 243                                                 firsteq = 0;
 244                                         else
 245                                                 break;
 246                                 }
 247                                 p = exptilde(p, flag);
 248                         }
 249                         break;
 250                 default:
 251                         STPUTC(c, expdest);
 252                         if (flag & ifs_split && strchr(ifs, c) != NULL) {
 253                                 /* We need to get the output split here... */
 254                                 recordregion(expdest - stackblock() - 1,
 255                                                 expdest - stackblock(), 0);
 256                         }
 257                         break;
 258                 }
 259         }
 260 }
 261
 262 STATIC char *
 263 exptilde(char *p, int flag)
 264 {
 265         char c, *startp = p;
 266         struct passwd *pw;
 267         const char *home;
 268         int quotes = flag & (EXP_FULL | EXP_CASE);
 269
 270         while ((c = *p) != '\0') {
 271                 switch(c) {
 272                 case CTLESC:
 273                         return (startp);
 274                 case CTLQUOTEMARK:
 275                         return (startp);
 276                 case ':':
 277                         if (flag & EXP_VARTILDE)
 278                                 goto done;
 279                         break;
 280                 case '/':
 281                         goto done;
 282                 }
 283                 p++;
 284         }
 285 done:
 286         *p = '\0';
 287         if (*(startp+1) == '\0') {
 288                 if ((home = lookupvar("HOME")) == NULL)
 289                         goto lose;
 290         } else {
 291                 if ((pw = getpwnam(startp+1)) == NULL)
 292                         goto lose;
 293                 home = pw->pw_dir;
 294         }
 295         if (*home == '\0')
 296                 goto lose;
 297         *p = c;
 298         while ((c = *home++) != '\0') {
 299                 if (quotes && SQSYNTAX[(int)c] == CCTL)
 300                         STPUTC(CTLESC, expdest);
 301                 STPUTC(c, expdest);
 302         }
 303         return (p);
 304 lose:
 305         *p = c;
 306         return (startp);
 307 }
 308
 309
 310 STATIC void
 311 removerecordregions(int endoff)
 312 {
 313         if (ifslastp == NULL)
 314                 return;
 315
 316         if (ifsfirst.endoff > endoff) {
 317                 while (ifsfirst.next != NULL) {
 318                         struct ifsregion *ifsp;
 319                         INTOFF;
 320                         ifsp = ifsfirst.next->next;
 321                         ckfree(ifsfirst.next);
 322                         ifsfirst.next = ifsp;
 323                         INTON;
 324                 }
 325                 if (ifsfirst.begoff > endoff)
 326                         ifslastp = NULL;
 327                 else {
 328                         ifslastp = &ifsfirst;
 329                         ifsfirst.endoff = endoff;
 330                 }
 331                 return;
 332         }
 333
 334         ifslastp = &ifsfirst;
 335         while (ifslastp->next && ifslastp->next->begoff < endoff)
 336                 ifslastp=ifslastp->next;
 337         while (ifslastp->next != NULL) {
 338                 struct ifsregion *ifsp;
 339                 INTOFF;
 340                 ifsp = ifslastp->next->next;
 341                 ckfree(ifslastp->next);
 342                 ifslastp->next = ifsp;
 343                 INTON;
 344         }
 345         if (ifslastp->endoff > endoff)
 346                 ifslastp->endoff = endoff;
 347 }
 348
 349
 350 /*
 351  * Expand arithmetic expression.  Backup to start of expression,
 352  * evaluate, place result in (backed up) result, adjust string position.
 353  */
 354 void
 355 expari(int flag)
 356 {
 357         char *p, *start;
 358         intmax_t result;
 359         int adjustment;
 360         int begoff;
 361         int quotes = flag & (EXP_FULL | EXP_CASE);
 362         int quoted;
 363
 364         /*      ifsfree(); */
 365
 366         /*
 367          * This routine is slightly over-complicated for
 368          * efficiency.  First we make sure there is
 369          * enough space for the result, which may be bigger
 370          * than the expression if we add exponentation.  Next we
 371          * scan backwards looking for the start of arithmetic.  If the
 372          * next previous character is a CTLESC character, then we
 373          * have to rescan starting from the beginning since CTLESC
 374          * characters have to be processed left to right.
 375          */
 376 /* SPACE_NEEDED is enough for all digits, plus possible "-", plus 2 (why?) */
 377 #define SPACE_NEEDED ((sizeof(intmax_t) * CHAR_BIT + 2) / 3 + 1 + 2)
 378         CHECKSTRSPACE((int)(SPACE_NEEDED - 2), expdest);
 379         USTPUTC('\0', expdest);
 380         start = stackblock();
 381         p = expdest - 1;
 382         while (*p != CTLARI && p >= start)
 383                 --p;
 384         if (*p != CTLARI)
 385                 error("missing CTLARI (shouldn't happen)");
 386         if (p > start && *(p-1) == CTLESC)
 387                 for (p = start; *p != CTLARI; p++)
 388                         if (*p == CTLESC)
 389                                 p++;
 390
 391         if (p[1] == '"')
 392                 quoted=1;
 393         else
 394                 quoted=0;
 395         begoff = p - start;
 396         removerecordregions(begoff);
 397         if (quotes)
 398                 rmescapes(p+2);
 399         result = arith(p+2);
 400         fmtstr(p, SPACE_NEEDED, "%"PRIdMAX, result);
 401
 402         while (*p++)
 403                 ;
 404
 405         if (quoted == 0)
 406                 recordregion(begoff, p - 1 - start, 0);
 407         adjustment = expdest - p + 1;
 408         STADJUST(-adjustment, expdest);
 409 }
 410
 411
 412 /*
 413  * Expand stuff in backwards quotes.
 414  */
 415
 416 STATIC void
 417 expbackq(union node *cmd, int quoted, int flag)
 418 {
 419         struct backcmd in;
 420         int i;
 421         char buf[128];
 422         char *p;
 423         char *dest = expdest;
 424         struct ifsregion saveifs, *savelastp;
 425         struct nodelist *saveargbackq;
 426         char lastc;
 427         int startloc = dest - stackblock();
 428         char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
 429         int saveherefd;
 430         int quotes = flag & (EXP_FULL | EXP_CASE);
 431         int nnl;
 432
 433         INTOFF;
 434         saveifs = ifsfirst;
 435         savelastp = ifslastp;
 436         saveargbackq = argbackq;
 437         saveherefd = herefd;
 438         herefd = -1;
 439         p = grabstackstr(dest);
 440         evalbackcmd(cmd, &in);
 441         ungrabstackstr(p, dest);
 442         ifsfirst = saveifs;
 443         ifslastp = savelastp;
 444         argbackq = saveargbackq;
 445         herefd = saveherefd;
 446
 447         p = in.buf;
 448         lastc = '\0';
 449         nnl = 0;
 450         for (;;) {
 451                 if (--in.nleft < 0) {
 452                         if (in.fd < 0)
 453                                 break;
 454                         while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR)
 455                                 continue;
 456                         TRACE(("expbackq: read returns %d\n", i));
 457                         if (i <= 0)
 458                                 break;
 459                         p = buf;
 460                         in.nleft = i - 1;
 461                 }
 462                 lastc = *p++;
 463                 if (lastc != '\0') {
 464                         if (lastc == '\n')
 465                                 nnl++;
 466                         else {
 467                                 CHECKSTRSPACE(nnl + 2, dest);
 468                                 while (nnl > 0) {
 469                                         nnl--;
 470                                         USTPUTC('\n', dest);
 471                                 }
 472                                 if (quotes && syntax[(int)lastc] == CCTL)
 473                                         USTPUTC(CTLESC, dest);
 474                                 USTPUTC(lastc, dest);
 475                         }
 476                 }
 477         }
 478
 479         if (in.fd >= 0)
 480                 close(in.fd);
 481         if (in.buf)
 482                 ckfree(in.buf);
 483         if (in.jp)
 484                 back_exitstatus = waitforjob(in.jp);
 485         if (quoted == 0)
 486                 recordregion(startloc, dest - stackblock(), 0);
 487         TRACE(("evalbackq: size=%d: \"%.*s\"\n",
 488                 (int)((dest - stackblock()) - startloc),
 489                 (int)((dest - stackblock()) - startloc),
 490                 stackblock() + startloc));
 491         expdest = dest;
 492         INTON;
 493 }
 494
 495
 496
 497 STATIC int
 498 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags, int quotes)
 499 {
 500         char *startp;
 501         char *loc = NULL;
 502         char *q;
 503         int c = 0;
 504         int saveherefd = herefd;
 505         struct nodelist *saveargbackq = argbackq;
 506         int amount, how;
 507
 508         herefd = -1;
 509         switch (subtype) {
 510         case VSTRIMLEFT:
 511         case VSTRIMLEFTMAX:
 512         case VSTRIMRIGHT:
 513         case VSTRIMRIGHTMAX:
 514                 how = (varflags & VSQUOTE) ? 0 : EXP_CASE;
 515                 break;
 516         default:
 517                 how = 0;
 518                 break;
 519         }
 520         argstr(p, how);
 521         STACKSTRNUL(expdest);
 522         herefd = saveherefd;
 523         argbackq = saveargbackq;
 524         startp = stackblock() + startloc;
 525         if (str == NULL)
 526             str = stackblock() + strloc;
 527
 528         switch (subtype) {
 529         case VSASSIGN:
 530                 setvar(str, startp, 0);
 531                 amount = startp - expdest;
 532                 STADJUST(amount, expdest);
 533                 varflags &= ~VSNUL;
 534                 return 1;
 535
 536         case VSQUESTION:
 537                 if (*p != CTLENDVAR) {
 538                         outfmt(&errout, "%s\n", startp);
 539                         error(NULL);
 540                 }
 541                 error("%.*s: parameter %snot set",
 542                       (int)(p - str - 1),
 543                       str, (varflags & VSNUL) ? "null or "
 544                                               : nullstr);
 545                 /* NOTREACHED */
 546
 547         case VSTRIMLEFT:
 548                 for (loc = startp; loc < str; loc++) {
 549                         c = *loc;
 550                         *loc = '\0';
 551                         if (patmatch(str, startp, quotes))
 552                                 goto recordleft;
 553                         *loc = c;
 554                         if (quotes && *loc == CTLESC)
 555                                 loc++;
 556                 }
 557                 return 0;
 558
 559         case VSTRIMLEFTMAX:
 560                 for (loc = str - 1; loc >= startp;) {
 561                         c = *loc;
 562                         *loc = '\0';
 563                         if (patmatch(str, startp, quotes))
 564                                 goto recordleft;
 565                         *loc = c;
 566                         loc--;
 567                         if (quotes && loc > startp &&
 568                             *(loc - 1) == CTLESC) {
 569                                 for (q = startp; q < loc; q++)
 570                                         if (*q == CTLESC)
 571                                                 q++;
 572                                 if (q > loc)
 573                                         loc--;
 574                         }
 575                 }
 576                 return 0;
 577
 578         case VSTRIMRIGHT:
 579                 for (loc = str - 1; loc >= startp;) {
 580                         if (patmatch(str, loc, quotes))
 581                                 goto recordright;
 582                         loc--;
 583                         if (quotes && loc > startp &&
 584                             *(loc - 1) == CTLESC) {
 585                                 for (q = startp; q < loc; q++)
 586                                         if (*q == CTLESC)
 587                                                 q++;
 588                                 if (q > loc)
 589                                         loc--;
 590                         }
 591                 }
 592                 return 0;
 593
 594         case VSTRIMRIGHTMAX:
 595                 for (loc = startp; loc < str - 1; loc++) {
 596                         if (patmatch(str, loc, quotes))
 597                                 goto recordright;
 598                         if (quotes && *loc == CTLESC)
 599                                 loc++;
 600                 }
 601                 return 0;
 602
 603         default:
 604                 abort();
 605         }
 606
 607 recordleft:
 608         *loc = c;
 609         amount = ((str - 1) - (loc - startp)) - expdest;
 610         STADJUST(amount, expdest);
 611         while (loc != str - 1)
 612                 *startp++ = *loc++;
 613         return 1;
 614
 615 recordright:
 616         amount = loc - expdest;
 617         STADJUST(amount, expdest);
 618         STPUTC('\0', expdest);
 619         STADJUST(-1, expdest);
 620         return 1;
 621 }
 622
 623
 624 /*
 625  * Expand a variable, and return a pointer to the next character in the
 626  * input string.
 627  */
 628
 629 STATIC char *
 630 evalvar(char *p, int flag)
 631 {
 632         int subtype;
 633         int varflags;
 634         char *var;
 635         char *val;
 636         int patloc;
 637         int c;
 638         int set;
 639         int special;
 640         int startloc;
 641         int varlen;
 642         int apply_ifs;
 643         int quotes = flag & (EXP_FULL | EXP_CASE);
 644
 645         varflags = (unsigned char)*p++;
 646         subtype = varflags & VSTYPE;
 647         var = p;
 648         special = !is_name(*p);
 649         p = strchr(p, '=') + 1;
 650
 651 again: /* jump here after setting a variable with ${var=text} */
 652         if (varflags & VSLINENO) {
 653                 set = 1;
 654                 special = 0;
 655                 val = var;
 656                 p[-1] = '\0';
 657         } else if (special) {
 658                 set = varisset(var, varflags & VSNUL);
 659                 val = NULL;
 660         } else {
 661                 val = lookupvar(var);
 662                 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
 663                         val = NULL;
 664                         set = 0;
 665                 } else
 666                         set = 1;
 667         }
 668
 669         varlen = 0;
 670         startloc = expdest - stackblock();
 671
 672         if (!set && uflag && *var != '@' && *var != '*') {
 673                 switch (subtype) {
 674                 case VSNORMAL:
 675                 case VSTRIMLEFT:
 676                 case VSTRIMLEFTMAX:
 677                 case VSTRIMRIGHT:
 678                 case VSTRIMRIGHTMAX:
 679                 case VSLENGTH:
 680                         error("%.*s: parameter not set",
 681                             (int)(p - var - 1), var);
 682                         /* NOTREACHED */
 683                 }
 684         }
 685
 686         if (set && subtype != VSPLUS) {
 687                 /* insert the value of the variable */
 688                 if (special) {
 689                         varvalue(var, varflags & VSQUOTE, subtype, flag);
 690                         if (subtype == VSLENGTH) {
 691                                 varlen = expdest - stackblock() - startloc;
 692                                 STADJUST(-varlen, expdest);
 693                         }
 694                 } else {
 695                         char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
 696                                                                   : BASESYNTAX;
 697
 698                         if (subtype == VSLENGTH) {
 699                                 for (;*val; val++)
 700                                         varlen++;
 701                         } else {
 702                                 while (*val) {
 703                                         if (quotes && syntax[(int)*val] == CCTL)
 704                                                 STPUTC(CTLESC, expdest);
 705                                         STPUTC(*val++, expdest);
 706                                 }
 707
 708                         }
 709                 }
 710         }
 711
 712
 713         if (flag & EXP_IN_QUOTES)
 714                 apply_ifs = 0;
 715         else if (varflags & VSQUOTE) {
 716                 if  (*var == '@' && shellparam.nparam != 1)
 717                     apply_ifs = 1;
 718                 else {
 719                     /*
 720                      * Mark so that we don't apply IFS if we recurse through
 721                      * here expanding $bar from "${foo-$bar}".
 722                      */
 723                     flag |= EXP_IN_QUOTES;
 724                     apply_ifs = 0;
 725                 }
 726         } else
 727                 apply_ifs = 1;
 728
 729         switch (subtype) {
 730         case VSLENGTH:
 731                 expdest = cvtnum(varlen, expdest);
 732                 break;
 733
 734         case VSNORMAL:
 735                 break;
 736
 737         case VSPLUS:
 738                 set = !set;
 739                 /* FALLTHROUGH */
 740         case VSMINUS:
 741                 if (!set) {
 742                         argstr(p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0));
 743                         /*
 744                          * ${x-a b c} doesn't get split, but removing the
 745                          * 'apply_ifs = 0' apparently breaks ${1+"$@"}..
 746                          * ${x-'a b' c} should generate 2 args.
 747                          */
 748                         /* We should have marked stuff already */
 749                         apply_ifs = 0;
 750                 }
 751                 break;
 752
 753         case VSTRIMLEFT:
 754         case VSTRIMLEFTMAX:
 755         case VSTRIMRIGHT:
 756         case VSTRIMRIGHTMAX:
 757                 if (!set)
 758                         break;
 759                 /*
 760                  * Terminate the string and start recording the pattern
 761                  * right after it
 762                  */
 763                 STPUTC('\0', expdest);
 764                 patloc = expdest - stackblock();
 765                 if (subevalvar(p, NULL, patloc, subtype,
 766                                startloc, varflags, quotes) == 0) {
 767                         int amount = (expdest - stackblock() - patloc) + 1;
 768                         STADJUST(-amount, expdest);
 769                 }
 770                 /* Remove any recorded regions beyond start of variable */
 771                 removerecordregions(startloc);
 772                 apply_ifs = 1;
 773                 break;
 774
 775         case VSASSIGN:
 776         case VSQUESTION:
 777                 if (set)
 778                         break;
 779                 if (subevalvar(p, var, 0, subtype, startloc, varflags, quotes)) {
 780                         varflags &= ~VSNUL;
 781                         /*
 782                          * Remove any recorded regions beyond
 783                          * start of variable
 784                          */
 785                         removerecordregions(startloc);
 786                         goto again;
 787                 }
 788                 apply_ifs = 0;
 789                 break;
 790
 791         default:
 792                 abort();
 793         }
 794         p[-1] = '=';    /* recover overwritten '=' */
 795
 796         if (apply_ifs)
 797                 recordregion(startloc, expdest - stackblock(),
 798                              varflags & VSQUOTE);
 799
 800         if (subtype != VSNORMAL) {      /* skip to end of alternative */
 801                 int nesting = 1;
 802                 for (;;) {
 803                         if ((c = *p++) == CTLESC)
 804                                 p++;
 805                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
 806                                 if (set)
 807                                         argbackq = argbackq->next;
 808                         } else if (c == CTLVAR) {
 809                                 if ((*p++ & VSTYPE) != VSNORMAL)
 810                                         nesting++;
 811                         } else if (c == CTLENDVAR) {
 812                                 if (--nesting == 0)
 813                                         break;
 814                         }
 815                 }
 816         }
 817         return p;
 818 }
 819
 820
 821
 822 /*
 823  * Test whether a specialized variable is set.
 824  */
 825
 826 STATIC int
 827 varisset(char *name, int nulok)
 828 {
 829         if (*name == '!')
 830                 return backgndpid != -1;
 831         else if (*name == '@' || *name == '*') {
 832                 if (*shellparam.p == NULL)
 833                         return 0;
 834
 835                 if (nulok) {
 836                         char **av;
 837
 838                         for (av = shellparam.p; *av; av++)
 839                                 if (**av != '\0')
 840                                         return 1;
 841                         return 0;
 842                 }
 843         } else if (is_digit(*name)) {
 844                 char *ap;
 845                 int num = atoi(name);
 846
 847                 if (num > shellparam.nparam)
 848                         return 0;
 849
 850                 if (num == 0)
 851                         ap = arg0;
 852                 else
 853                         ap = shellparam.p[num - 1];
 854
 855                 if (nulok && (ap == NULL || *ap == '\0'))
 856                         return 0;
 857         }
 858         return 1;
 859 }
 860
 861
 862
 863 /*
 864  * Add the value of a specialized variable to the stack string.
 865  */
 866
 867 STATIC void
 868 varvalue(char *name, int quoted, int subtype, int flag)
 869 {
 870         int num;
 871         char *p;
 872         int i;
 873         char sep;
 874         char **ap;
 875         char const *syntax;
 876
 877 #define STRTODEST(p) \
 878         do {\
 879         if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
 880                 syntax = quoted? DQSYNTAX : BASESYNTAX; \
 881                 while (*p) { \
 882                         if (syntax[(int)*p] == CCTL) \
 883                                 STPUTC(CTLESC, expdest); \
 884                         STPUTC(*p++, expdest); \
 885                 } \
 886         } else \
 887                 while (*p) \
 888                         STPUTC(*p++, expdest); \
 889         } while (0)
 890
 891
 892         switch (*name) {
 893         case '$':
 894                 num = rootpid;
 895                 goto numvar;
 896         case '?':
 897                 num = exitstatus;
 898                 goto numvar;
 899         case '#':
 900                 num = shellparam.nparam;
 901                 goto numvar;
 902         case '!':
 903                 num = backgndpid;
 904 numvar:
 905                 expdest = cvtnum(num, expdest);
 906                 break;
 907         case '-':
 908                 for (i = 0; optlist[i].name; i++) {
 909                         if (optlist[i].val && optlist[i].letter)
 910                                 STPUTC(optlist[i].letter, expdest);
 911                 }
 912                 break;
 913         case '@':
 914                 if (flag & EXP_FULL && quoted) {
 915                         for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 916                                 STRTODEST(p);
 917                                 if (*ap)
 918                                         /* A NUL separates args inside "" */
 919                                         STPUTC('\0', expdest);
 920                         }
 921                         break;
 922                 }
 923                 /* fall through */
 924         case '*':
 925                 if (ifsset() != 0)
 926                         sep = ifsval()[0];
 927                 else
 928                         sep = ' ';
 929                 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
 930                         STRTODEST(p);
 931                         if (*ap && sep)
 932                                 STPUTC(sep, expdest);
 933                 }
 934                 break;
 935         case '0':
 936                 p = arg0;
 937                 STRTODEST(p);
 938                 break;
 939         default:
 940                 if (is_digit(*name)) {
 941                         num = atoi(name);
 942                         if (num > 0 && num <= shellparam.nparam) {
 943                                 p = shellparam.p[num - 1];
 944                                 STRTODEST(p);
 945                         }
 946                 }
 947                 break;
 948         }
 949 }
 950
 951
 952
 953 /*
 954  * Record the fact that we have to scan this region of the
 955  * string for IFS characters.
 956  */
 957
 958 STATIC void
 959 recordregion(int start, int end, int inquotes)
 960 {
 961         struct ifsregion *ifsp;
 962
 963         if (ifslastp == NULL) {
 964                 ifsp = &ifsfirst;
 965         } else {
 966                 if (ifslastp->endoff == start
 967                     && ifslastp->inquotes == inquotes) {
 968                         /* extend previous area */
 969                         ifslastp->endoff = end;
 970                         return;
 971                 }
 972                 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
 973                 ifslastp->next = ifsp;
 974         }
 975         ifslastp = ifsp;
 976         ifslastp->next = NULL;
 977         ifslastp->begoff = start;
 978         ifslastp->endoff = end;
 979         ifslastp->inquotes = inquotes;
 980 }
 981
 982
 983
 984 /*
 985  * Break the argument string into pieces based upon IFS and add the
 986  * strings to the argument list.  The regions of the string to be
 987  * searched for IFS characters have been stored by recordregion.
 988  */
 989 STATIC void
 990 ifsbreakup(char *string, struct arglist *arglist)
 991 {
 992         struct ifsregion *ifsp;
 993         struct strlist *sp;
 994         char *start;
 995         char *p;
 996         char *q;
 997         const char *ifs;
 998         const char *ifsspc;
 999         int had_param_ch = 0;
1000
1001         start = string;
1002
1003         if (ifslastp == NULL) {
1004                 /* Return entire argument, IFS doesn't apply to any of it */
1005                 sp = (struct strlist *)stalloc(sizeof *sp);
1006                 sp->text = start;
1007                 *arglist->lastp = sp;
1008                 arglist->lastp = &sp->next;
1009                 return;
1010         }
1011
1012         ifs = ifsset() ? ifsval() : " \t\n";
1013
1014         for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
1015                 p = string + ifsp->begoff;
1016                 while (p < string + ifsp->endoff) {
1017                         had_param_ch = 1;
1018                         q = p;
1019                         if (*p == CTLESC)
1020                                 p++;
1021                         if (ifsp->inquotes) {
1022                                 /* Only NULs (should be from "$@") end args */
1023                                 if (*p != 0) {
1024                                         p++;
1025                                         continue;
1026                                 }
1027                                 ifsspc = NULL;
1028                         } else {
1029                                 if (!strchr(ifs, *p)) {
1030                                         p++;
1031                                         continue;
1032                                 }
1033                                 had_param_ch = 0;
1034                                 ifsspc = strchr(" \t\n", *p);
1035
1036                                 /* Ignore IFS whitespace at start */
1037                                 if (q == start && ifsspc != NULL) {
1038                                         p++;
1039                                         start = p;
1040                                         continue;
1041                                 }
1042                         }
1043
1044                         /* Save this argument... */
1045                         *q = '\0';
1046                         sp = (struct strlist *)stalloc(sizeof *sp);
1047                         sp->text = start;
1048                         *arglist->lastp = sp;
1049                         arglist->lastp = &sp->next;
1050                         p++;
1051
1052                         if (ifsspc != NULL) {
1053                                 /* Ignore further trailing IFS whitespace */
1054                                 for (; p < string + ifsp->endoff; p++) {
1055                                         q = p;
1056                                         if (*p == CTLESC)
1057                                                 p++;
1058                                         if (strchr(ifs, *p) == NULL) {
1059                                                 p = q;
1060                                                 break;
1061                                         }
1062                                         if (strchr(" \t\n", *p) == NULL) {
1063                                                 p++;
1064                                                 break;
1065                                         }
1066                                 }
1067                         }
1068                         start = p;
1069                 }
1070         }
1071
1072         /*
1073          * Save anything left as an argument.
1074          * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1075          * generating 2 arguments, the second of which is empty.
1076          * Some recent clarification of the Posix spec say that it
1077          * should only generate one....
1078          */
1079         if (had_param_ch || *start != 0) {
1080                 sp = (struct strlist *)stalloc(sizeof *sp);
1081                 sp->text = start;
1082                 *arglist->lastp = sp;
1083                 arglist->lastp = &sp->next;
1084         }
1085 }
1086
1087 STATIC void
1088 ifsfree(void)
1089 {
1090         while (ifsfirst.next != NULL) {
1091                 struct ifsregion *ifsp;
1092                 INTOFF;
1093                 ifsp = ifsfirst.next->next;
1094                 ckfree(ifsfirst.next);
1095                 ifsfirst.next = ifsp;
1096                 INTON;
1097         }
1098         ifslastp = NULL;
1099         ifsfirst.next = NULL;
1100 }
1101
1102
1103
1104 /*
1105  * Expand shell metacharacters.  At this point, the only control characters
1106  * should be escapes.  The results are stored in the list exparg.
1107  */
1108
1109 char *expdir;
1110
1111
1112 STATIC void
1113 expandmeta(struct strlist *str, int flag)
1114 {
1115         char *p;
1116         struct strlist **savelastp;
1117         struct strlist *sp;
1118         char c;
1119         /* TODO - EXP_REDIR */
1120
1121         while (str) {
1122                 if (fflag)
1123                         goto nometa;
1124                 p = str->text;
1125                 for (;;) {                      /* fast check for meta chars */
1126                         if ((c = *p++) == '\0')
1127                                 goto nometa;
1128                         if (c == '*' || c == '?' || c == '[' || c == '!')
1129                                 break;
1130                 }
1131                 savelastp = exparg.lastp;
1132                 INTOFF;
1133                 if (expdir == NULL) {
1134                         int i = strlen(str->text);
1135                         expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
1136                 }
1137
1138                 expmeta(expdir, str->text);
1139                 ckfree(expdir);
1140                 expdir = NULL;
1141                 INTON;
1142                 if (exparg.lastp == savelastp) {
1143                         /*
1144                          * no matches
1145                          */
1146 nometa:
1147                         *exparg.lastp = str;
1148                         rmescapes(str->text);
1149                         exparg.lastp = &str->next;
1150                 } else {
1151                         *exparg.lastp = NULL;
1152                         *savelastp = sp = expsort(*savelastp);
1153                         while (sp->next != NULL)
1154                                 sp = sp->next;
1155                         exparg.lastp = &sp->next;
1156                 }
1157                 str = str->next;
1158         }
1159 }
1160
1161
1162 /*
1163  * Do metacharacter (i.e. *, ?, [...]) expansion.
1164  */
1165
1166 STATIC void
1167 expmeta(char *enddir, char *name)
1168 {
1169         char *p;
1170         const char *cp;
1171         char *q;
1172         char *start;
1173         char *endname;
1174         int metaflag;
1175         struct stat statb;
1176         DIR *dirp;
1177         struct dirent *dp;
1178         int atend;
1179         int matchdot;
1180
1181         metaflag = 0;
1182         start = name;
1183         for (p = name ; ; p++) {
1184                 if (*p == '*' || *p == '?')
1185                         metaflag = 1;
1186                 else if (*p == '[') {
1187                         q = p + 1;
1188                         if (*q == '!')
1189                                 q++;
1190                         for (;;) {
1191                                 while (*q == CTLQUOTEMARK)
1192                                         q++;
1193                                 if (*q == CTLESC)
1194                                         q++;
1195                                 if (*q == '/' || *q == '\0')
1196                                         break;
1197                                 if (*++q == ']') {
1198                                         metaflag = 1;
1199                                         break;
1200                                 }
1201                         }
1202                 } else if (*p == '!' && p[1] == '!'     && (p == name || p[-1] == '/')) {
1203                         metaflag = 1;
1204                 } else if (*p == '\0')
1205                         break;
1206                 else if (*p == CTLQUOTEMARK)
1207                         continue;
1208                 else if (*p == CTLESC)
1209                         p++;
1210                 if (*p == '/') {
1211                         if (metaflag)
1212                                 break;
1213                         start = p + 1;
1214                 }
1215         }
1216         if (metaflag == 0) {    /* we've reached the end of the file name */
1217                 if (enddir != expdir)
1218                         metaflag++;
1219                 for (p = name ; ; p++) {
1220                         if (*p == CTLQUOTEMARK)
1221                                 continue;
1222                         if (*p == CTLESC)
1223                                 p++;
1224                         *enddir++ = *p;
1225                         if (*p == '\0')
1226                                 break;
1227                 }
1228                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1229                         addfname(expdir);
1230                 return;
1231         }
1232         endname = p;
1233         if (start != name) {
1234                 p = name;
1235                 while (p < start) {
1236                         while (*p == CTLQUOTEMARK)
1237                                 p++;
1238                         if (*p == CTLESC)
1239                                 p++;
1240                         *enddir++ = *p++;
1241                 }
1242         }
1243         if (enddir == expdir) {
1244                 cp = ".";
1245         } else if (enddir == expdir + 1 && *expdir == '/') {
1246                 cp = "/";
1247         } else {
1248                 cp = expdir;
1249                 enddir[-1] = '\0';
1250         }
1251         if ((dirp = opendir(cp)) == NULL)
1252                 return;
1253         if (enddir != expdir)
1254                 enddir[-1] = '/';
1255         if (*endname == 0) {
1256                 atend = 1;
1257         } else {
1258                 atend = 0;
1259                 *endname++ = '\0';
1260         }
1261         matchdot = 0;
1262         p = start;
1263         while (*p == CTLQUOTEMARK)
1264                 p++;
1265         if (*p == CTLESC)
1266                 p++;
1267         if (*p == '.')
1268                 matchdot++;
1269         while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1270                 if (dp->d_name[0] == '.' && ! matchdot)
1271                         continue;
1272                 if (patmatch(start, dp->d_name, 0)) {
1273                         if (atend) {
1274                                 scopy(dp->d_name, enddir);
1275                                 addfname(expdir);
1276                         } else {
1277                                 for (p = enddir, cp = dp->d_name;
1278                                      (*p++ = *cp++) != '\0';)
1279                                         continue;
1280                                 p[-1] = '/';
1281                                 expmeta(p, endname);
1282                         }
1283                 }
1284         }
1285         closedir(dirp);
1286         if (! atend)
1287                 endname[-1] = '/';
1288 }
1289
1290
1291 /*
1292  * Add a file name to the list.
1293  */
1294
1295 STATIC void
1296 addfname(char *name)
1297 {
1298         char *p;
1299         struct strlist *sp;
1300
1301         p = stalloc(strlen(name) + 1);
1302         scopy(name, p);
1303         sp = (struct strlist *)stalloc(sizeof *sp);
1304         sp->text = p;
1305         *exparg.lastp = sp;
1306         exparg.lastp = &sp->next;
1307 }
1308
1309
1310 /*
1311  * Sort the results of file name expansion.  It calculates the number of
1312  * strings to sort and then calls msort (short for merge sort) to do the
1313  * work.
1314  */
1315
1316 STATIC struct strlist *
1317 expsort(struct strlist *str)
1318 {
1319         int len;
1320         struct strlist *sp;
1321
1322         len = 0;
1323         for (sp = str ; sp ; sp = sp->next)
1324                 len++;
1325         return msort(str, len);
1326 }
1327
1328
1329 STATIC struct strlist *
1330 msort(struct strlist *list, int len)
1331 {
1332         struct strlist *p, *q = NULL;
1333         struct strlist **lpp;
1334         int half;
1335         int n;
1336
1337         if (len <= 1)
1338                 return list;
1339         half = len >> 1;
1340         p = list;
1341         for (n = half ; --n >= 0 ; ) {
1342                 q = p;
1343                 p = p->next;
1344         }
1345         q->next = NULL;                 /* terminate first half of list */
1346         q = msort(list, half);          /* sort first half of list */
1347         p = msort(p, len - half);               /* sort second half */
1348         lpp = &list;
1349         for (;;) {
1350                 if (strcmp(p->text, q->text) < 0) {
1351                         *lpp = p;
1352                         lpp = &p->next;
1353                         if ((p = *lpp) == NULL) {
1354                                 *lpp = q;
1355                                 break;
1356                         }
1357                 } else {
1358                         *lpp = q;
1359                         lpp = &q->next;
1360                         if ((q = *lpp) == NULL) {
1361                                 *lpp = p;
1362                                 break;
1363                         }
1364                 }
1365         }
1366         return list;
1367 }
1368
1369
1370 /*
1371  * See if a character matches a character class, starting at the first colon
1372  * of "[:class:]".
1373  * If a valid character class is recognized, a pointer to the next character
1374  * after the final closing bracket is stored into *end, otherwise a null
1375  * pointer is stored into *end.
1376  */
1377 static int
1378 match_charclass(char *p, wchar_t chr, char **end)
1379 {
1380         char name[20];
1381         char *nameend;
1382         wctype_t cclass;
1383
1384         *end = NULL;
1385         p++;
1386         nameend = strstr(p, ":]");
1387         if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1388             nameend == p)
1389                 return 0;
1390         memcpy(name, p, nameend - p);
1391         name[nameend - p] = '\0';
1392         *end = nameend + 2;
1393         cclass = wctype(name);
1394         /* An unknown class matches nothing but is valid nevertheless. */
1395         if (cclass == 0)
1396                 return 0;
1397         return iswctype(chr, cclass);
1398 }
1399
1400
1401
1402 /*
1403  * Returns true if the pattern matches the string.
1404  */
1405
1406 int
1407 patmatch(char *pattern, char *string, int squoted)
1408 {
1409 #ifdef notdef
1410         if (pattern[0] == '!' && pattern[1] == '!')
1411                 return 1 - pmatch(pattern + 2, string);
1412         else
1413 #endif
1414                 return pmatch(pattern, string, squoted);
1415 }
1416
1417
1418 STATIC int
1419 pmatch(char *pattern, char *string, int squoted)
1420 {
1421         char *p, *q, *end;
1422         char c;
1423
1424         p = pattern;
1425         q = string;
1426         for (;;) {
1427                 switch (c = *p++) {
1428                 case '\0':
1429                         goto breakloop;
1430                 case CTLESC:
1431                         if (squoted && *q == CTLESC)
1432                                 q++;
1433                         if (*q++ != *p++)
1434                                 return 0;
1435                         break;
1436                 case CTLQUOTEMARK:
1437                         continue;
1438                 case '?':
1439                         if (squoted && *q == CTLESC)
1440                                 q++;
1441                         if (*q++ == '\0')
1442                                 return 0;
1443                         break;
1444                 case '*':
1445                         c = *p;
1446                         while (c == CTLQUOTEMARK || c == '*')
1447                                 c = *++p;
1448                         if (c != CTLESC &&  c != CTLQUOTEMARK &&
1449                             c != '?' && c != '*' && c != '[') {
1450                                 while (*q != c) {
1451                                         if (squoted && *q == CTLESC &&
1452                                             q[1] == c)
1453                                                 break;
1454                                         if (*q == '\0')
1455                                                 return 0;
1456                                         if (squoted && *q == CTLESC)
1457                                                 q++;
1458                                         q++;
1459                                 }
1460                         }
1461                         do {
1462                                 if (pmatch(p, q, squoted))
1463                                         return 1;
1464                                 if (squoted && *q == CTLESC)
1465                                         q++;
1466                         } while (*q++ != '\0');
1467                         return 0;
1468                 case '[': {
1469                         char *endp;
1470                         int invert, found;
1471                         char chr;
1472
1473                         endp = p;
1474                         if (*endp == '!')
1475                                 endp++;
1476                         for (;;) {
1477                                 while (*endp == CTLQUOTEMARK)
1478                                         endp++;
1479                                 if (*endp == '\0')
1480                                         goto dft;               /* no matching ] */
1481                                 if (*endp == CTLESC)
1482                                         endp++;
1483                                 if (*++endp == ']')
1484                                         break;
1485                         }
1486                         invert = 0;
1487                         if (*p == '!') {
1488                                 invert++;
1489                                 p++;
1490                         }
1491                         found = 0;
1492                         chr = *q++;
1493                         if (squoted && chr == CTLESC)
1494                                 chr = *q++;
1495                         if (chr == '\0')
1496                                 return 0;
1497                         c = *p++;
1498                         do {
1499                                 if (c == CTLQUOTEMARK)
1500                                         continue;
1501                                 if (c == '[' && *p == ':') {
1502                                         found |= match_charclass(p, chr, &end);
1503                                         if (end != NULL)
1504                                                 p = end;
1505                                 }
1506                                 if (c == CTLESC)
1507                                         c = *p++;
1508                                 if (*p == '-' && p[1] != ']') {
1509                                         p++;
1510                                         while (*p == CTLQUOTEMARK)
1511                                                 p++;
1512                                         if (*p == CTLESC)
1513                                                 p++;
1514                                         if (chr >= c && chr <= *p)
1515                                                 found = 1;
1516                                         p++;
1517                                 } else {
1518                                         if (chr == c)
1519                                                 found = 1;
1520                                 }
1521                         } while ((c = *p++) != ']');
1522                         if (found == invert)
1523                                 return 0;
1524                         break;
1525                 }
1526 dft:            default:
1527                         if (squoted && *q == CTLESC)
1528                                 q++;
1529                         if (*q++ != c)
1530                                 return 0;
1531                         break;
1532                 }
1533         }
1534 breakloop:
1535         if (*q != '\0')
1536                 return 0;
1537         return 1;
1538 }
1539
1540
1541
1542 /*
1543  * Remove any CTLESC characters from a string.
1544  */
1545
1546 void
1547 rmescapes(char *str)
1548 {
1549         char *p, *q;
1550
1551         p = str;
1552         while (*p != CTLESC && *p != CTLQUOTEMARK) {
1553                 if (*p++ == '\0')
1554                         return;
1555         }
1556         q = p;
1557         while (*p) {
1558                 if (*p == CTLQUOTEMARK) {
1559                         p++;
1560                         continue;
1561                 }
1562                 if (*p == CTLESC)
1563                         p++;
1564                 *q++ = *p++;
1565         }
1566         *q = '\0';
1567 }
1568
1569
1570
1571 /*
1572  * See if a pattern matches in a case statement.
1573  */
1574
1575 int
1576 casematch(union node *pattern, char *val)
1577 {
1578         struct stackmark smark;
1579         int result;
1580         char *p;
1581
1582         setstackmark(&smark);
1583         argbackq = pattern->narg.backquote;
1584         STARTSTACKSTR(expdest);
1585         ifslastp = NULL;
1586         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1587         STPUTC('\0', expdest);
1588         p = grabstackstr(expdest);
1589         result = patmatch(p, val, 0);
1590         popstackmark(&smark);
1591         return result;
1592 }
1593
1594 /*
1595  * Our own itoa().
1596  */
1597
1598 STATIC char *
1599 cvtnum(int num, char *buf)
1600 {
1601         char temp[32];
1602         int neg = num < 0;
1603         char *p = temp + 31;
1604
1605         temp[31] = '\0';
1606
1607         do {
1608                 *--p = num % 10 + '0';
1609         } while ((num /= 10) != 0);
1610
1611         if (neg)
1612                 *--p = '-';
1613
1614         while (*p)
1615                 STPUTC(*p++, buf);
1616         return buf;
1617 }
1618
1619 /*
1620  * Do most of the work for wordexp(3).
1621  */
1622
1623 int
1624 wordexpcmd(int argc, char **argv)
1625 {
1626         size_t len;
1627         int i;
1628
1629         out1fmt("%d", argc - 1);
1630         out1c('\0');
1631         for (i = 1, len = 0; i < argc; i++)
1632                 len += strlen(argv[i]);
1633         out1fmt("%zu", len);
1634         out1c('\0');
1635         for (i = 1; i < argc; i++) {
1636                 out1str(argv[i]);
1637                 out1c('\0');
1638         }
1639         return (0);
1640 }