1 /* $NetBSD: expand.c,v 1.53 2002/05/15 14:59:21 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95"; 43 #else 44 __RCSID("$NetBSD: expand.c,v 1.53 2002/05/15 14:59:21 christos Exp $"); 45 #endif 46 #endif /* not lint */ 47 48 #include <sys/types.h> 49 #include <sys/time.h> 50 #include <sys/stat.h> 51 #include <errno.h> 52 #include <dirent.h> 53 #include <unistd.h> 54 #include <pwd.h> 55 #include <stdlib.h> 56 #include <stdio.h> 57 58 /* 59 * Routines to expand arguments to commands. We have to deal with 60 * backquotes, shell variables, and file metacharacters. 61 */ 62 63 #include "shell.h" 64 #include "main.h" 65 #include "nodes.h" 66 #include "eval.h" 67 #include "expand.h" 68 #include "syntax.h" 69 #include "parser.h" 70 #include "jobs.h" 71 #include "options.h" 72 #include "var.h" 73 #include "input.h" 74 #include "output.h" 75 #include "memalloc.h" 76 #include "error.h" 77 #include "mystring.h" 78 #include "show.h" 79 80 /* 81 * Structure specifying which parts of the string should be searched 82 * for IFS characters. 83 */ 84 85 struct ifsregion { 86 struct ifsregion *next; /* next region in list */ 87 int begoff; /* offset of start of region */ 88 int endoff; /* offset of end of region */ 89 int nulonly; /* search for nul bytes only */ 90 }; 91 92 93 char *expdest; /* output of current string */ 94 struct nodelist *argbackq; /* list of back quote expressions */ 95 struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 96 struct ifsregion *ifslastp; /* last struct in list */ 97 struct arglist exparg; /* holds expanded arg list */ 98 99 STATIC void argstr __P((char *, int)); 100 STATIC char *exptilde __P((char *, int)); 101 STATIC void expbackq __P((union node *, int, int)); 102 STATIC int subevalvar __P((char *, char *, int, int, int, int)); 103 STATIC char *evalvar __P((char *, int)); 104 STATIC int varisset __P((char *, int)); 105 STATIC void varvalue __P((char *, int, int)); 106 STATIC void recordregion __P((int, int, int)); 107 STATIC void removerecordregions __P((int)); 108 STATIC void ifsbreakup __P((char *, struct arglist *)); 109 STATIC void ifsfree __P((void)); 110 STATIC void expandmeta __P((struct strlist *, int)); 111 STATIC void expmeta __P((char *, char *)); 112 STATIC void addfname __P((char *)); 113 STATIC struct strlist *expsort __P((struct strlist *)); 114 STATIC struct strlist *msort __P((struct strlist *, int)); 115 STATIC int pmatch __P((char *, char *, int)); 116 STATIC char *cvtnum __P((int, char *)); 117 118 extern int oexitstatus; 119 120 /* 121 * Expand shell variables and backquotes inside a here document. 122 */ 123 124 void 125 expandhere(arg, fd) 126 union node *arg; /* the document */ 127 int fd; /* where to write the expanded version */ 128 { 129 herefd = fd; 130 expandarg(arg, (struct arglist *)NULL, 0); 131 xwrite(fd, stackblock(), expdest - stackblock()); 132 } 133 134 135 /* 136 * Perform variable substitution and command substitution on an argument, 137 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 138 * perform splitting and file name expansion. When arglist is NULL, perform 139 * here document expansion. 140 */ 141 142 void 143 expandarg(arg, arglist, flag) 144 union node *arg; 145 struct arglist *arglist; 146 int flag; 147 { 148 struct strlist *sp; 149 char *p; 150 151 argbackq = arg->narg.backquote; 152 STARTSTACKSTR(expdest); 153 ifsfirst.next = NULL; 154 ifslastp = NULL; 155 argstr(arg->narg.text, flag); 156 if (arglist == NULL) { 157 return; /* here document expanded */ 158 } 159 STPUTC('\0', expdest); 160 p = grabstackstr(expdest); 161 exparg.lastp = &exparg.list; 162 /* 163 * TODO - EXP_REDIR 164 */ 165 if (flag & EXP_FULL) { 166 ifsbreakup(p, &exparg); 167 *exparg.lastp = NULL; 168 exparg.lastp = &exparg.list; 169 expandmeta(exparg.list, flag); 170 } else { 171 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 172 rmescapes(p); 173 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 174 sp->text = p; 175 *exparg.lastp = sp; 176 exparg.lastp = &sp->next; 177 } 178 ifsfree(); 179 *exparg.lastp = NULL; 180 if (exparg.list) { 181 *arglist->lastp = exparg.list; 182 arglist->lastp = exparg.lastp; 183 } 184 } 185 186 187 188 /* 189 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC 190 * characters to allow for further processing. Otherwise treat 191 * $@ like $* since no splitting will be performed. 192 */ 193 194 STATIC void 195 argstr(p, flag) 196 char *p; 197 int flag; 198 { 199 char c; 200 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */ 201 int firsteq = 1; 202 203 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 204 p = exptilde(p, flag); 205 for (;;) { 206 switch (c = *p++) { 207 case '\0': 208 case CTLENDVAR: /* ??? */ 209 goto breakloop; 210 case CTLQUOTEMARK: 211 /* "$@" syntax adherence hack */ 212 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 213 break; 214 if ((flag & EXP_FULL) != 0) 215 STPUTC(c, expdest); 216 break; 217 case CTLESC: 218 if (quotes) 219 STPUTC(c, expdest); 220 c = *p++; 221 STPUTC(c, expdest); 222 break; 223 case CTLVAR: 224 p = evalvar(p, flag); 225 break; 226 case CTLBACKQ: 227 case CTLBACKQ|CTLQUOTE: 228 expbackq(argbackq->n, c & CTLQUOTE, flag); 229 argbackq = argbackq->next; 230 break; 231 case CTLENDARI: 232 expari(flag); 233 break; 234 case ':': 235 case '=': 236 /* 237 * sort of a hack - expand tildes in variable 238 * assignments (after the first '=' and after ':'s). 239 */ 240 STPUTC(c, expdest); 241 if (flag & EXP_VARTILDE && *p == '~') { 242 if (c == '=') { 243 if (firsteq) 244 firsteq = 0; 245 else 246 break; 247 } 248 p = exptilde(p, flag); 249 } 250 break; 251 default: 252 STPUTC(c, expdest); 253 } 254 } 255 breakloop:; 256 return; 257 } 258 259 STATIC char * 260 exptilde(p, flag) 261 char *p; 262 int flag; 263 { 264 char c, *startp = p; 265 struct passwd *pw; 266 const char *home; 267 int quotes = flag & (EXP_FULL | EXP_CASE); 268 269 while ((c = *p) != '\0') { 270 switch(c) { 271 case CTLESC: 272 return (startp); 273 case CTLQUOTEMARK: 274 return (startp); 275 case ':': 276 if (flag & EXP_VARTILDE) 277 goto done; 278 break; 279 case '/': 280 goto done; 281 } 282 p++; 283 } 284 done: 285 *p = '\0'; 286 if (*(startp+1) == '\0') { 287 if ((home = lookupvar("HOME")) == NULL) 288 goto lose; 289 } else { 290 if ((pw = getpwnam(startp+1)) == NULL) 291 goto lose; 292 home = pw->pw_dir; 293 } 294 if (*home == '\0') 295 goto lose; 296 *p = c; 297 while ((c = *home++) != '\0') { 298 if (quotes && SQSYNTAX[(int)c] == CCTL) 299 STPUTC(CTLESC, expdest); 300 STPUTC(c, expdest); 301 } 302 return (p); 303 lose: 304 *p = c; 305 return (startp); 306 } 307 308 309 STATIC void 310 removerecordregions(endoff) 311 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(flag) 356 int flag; 357 { 358 char *p, *start; 359 int result; 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 #if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10 377 #error "integers with more than 10 digits are not supported" 378 #endif 379 CHECKSTRSPACE(12 - 2, expdest); 380 USTPUTC('\0', expdest); 381 start = stackblock(); 382 p = expdest - 1; 383 while (*p != CTLARI && p >= start) 384 --p; 385 if (*p != CTLARI) 386 error("missing CTLARI (shouldn't happen)"); 387 if (p > start && *(p-1) == CTLESC) 388 for (p = start; *p != CTLARI; p++) 389 if (*p == CTLESC) 390 p++; 391 392 if (p[1] == '"') 393 quoted=1; 394 else 395 quoted=0; 396 begoff = p - start; 397 removerecordregions(begoff); 398 if (quotes) 399 rmescapes(p+2); 400 result = arith(p+2); 401 fmtstr(p, 12, "%d", result); 402 403 while (*p++) 404 ; 405 406 if (quoted == 0) 407 recordregion(begoff, p - 1 - start, 0); 408 result = expdest - p + 1; 409 STADJUST(-result, expdest); 410 } 411 412 413 /* 414 * Expand stuff in backwards quotes. 415 */ 416 417 STATIC void 418 expbackq(cmd, quoted, flag) 419 union node *cmd; 420 int quoted; 421 int flag; 422 { 423 struct backcmd in; 424 int i; 425 char buf[128]; 426 char *p; 427 char *dest = expdest; 428 struct ifsregion saveifs, *savelastp; 429 struct nodelist *saveargbackq; 430 char lastc; 431 int startloc = dest - stackblock(); 432 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 433 int saveherefd; 434 int quotes = flag & (EXP_FULL | EXP_CASE); 435 436 INTOFF; 437 saveifs = ifsfirst; 438 savelastp = ifslastp; 439 saveargbackq = argbackq; 440 saveherefd = herefd; 441 herefd = -1; 442 p = grabstackstr(dest); 443 evalbackcmd(cmd, &in); 444 ungrabstackstr(p, dest); 445 ifsfirst = saveifs; 446 ifslastp = savelastp; 447 argbackq = saveargbackq; 448 herefd = saveherefd; 449 450 p = in.buf; 451 lastc = '\0'; 452 for (;;) { 453 if (--in.nleft < 0) { 454 if (in.fd < 0) 455 break; 456 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 457 TRACE(("expbackq: read returns %d\n", i)); 458 if (i <= 0) 459 break; 460 p = buf; 461 in.nleft = i - 1; 462 } 463 lastc = *p++; 464 if (lastc != '\0') { 465 if (quotes && syntax[(int)lastc] == CCTL) 466 STPUTC(CTLESC, dest); 467 STPUTC(lastc, dest); 468 } 469 } 470 471 /* Eat all trailing newlines */ 472 for (p--; lastc == '\n'; lastc = *--p) 473 STUNPUTC(dest); 474 475 if (in.fd >= 0) 476 close(in.fd); 477 if (in.buf) 478 ckfree(in.buf); 479 if (in.jp) 480 exitstatus = waitforjob(in.jp); 481 if (quoted == 0) 482 recordregion(startloc, dest - stackblock(), 0); 483 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 484 (dest - stackblock()) - startloc, 485 (dest - stackblock()) - startloc, 486 stackblock() + startloc)); 487 expdest = dest; 488 INTON; 489 } 490 491 492 493 STATIC int 494 subevalvar(p, str, strloc, subtype, startloc, varflags) 495 char *p; 496 char *str; 497 int strloc; 498 int subtype; 499 int startloc; 500 int varflags; 501 { 502 char *startp; 503 char *loc = NULL; 504 char *q; 505 int c = 0; 506 int saveherefd = herefd; 507 struct nodelist *saveargbackq = argbackq; 508 int amount; 509 510 herefd = -1; 511 argstr(p, 0); 512 STACKSTRNUL(expdest); 513 herefd = saveherefd; 514 argbackq = saveargbackq; 515 startp = stackblock() + startloc; 516 if (str == NULL) 517 str = stackblock() + strloc; 518 519 switch (subtype) { 520 case VSASSIGN: 521 setvar(str, startp, 0); 522 amount = startp - expdest; 523 STADJUST(amount, expdest); 524 varflags &= ~VSNUL; 525 if (c != 0) 526 *loc = c; 527 return 1; 528 529 case VSQUESTION: 530 if (*p != CTLENDVAR) { 531 outfmt(&errout, "%s\n", startp); 532 error((char *)NULL); 533 } 534 error("%.*s: parameter %snot set", p - str - 1, 535 str, (varflags & VSNUL) ? "null or " 536 : nullstr); 537 /* NOTREACHED */ 538 539 case VSTRIMLEFT: 540 for (loc = startp; loc < str; loc++) { 541 c = *loc; 542 *loc = '\0'; 543 if (patmatch(str, startp, varflags & VSQUOTE)) 544 goto recordleft; 545 *loc = c; 546 if ((varflags & VSQUOTE) && *loc == CTLESC) 547 loc++; 548 } 549 return 0; 550 551 case VSTRIMLEFTMAX: 552 for (loc = str - 1; loc >= startp;) { 553 c = *loc; 554 *loc = '\0'; 555 if (patmatch(str, startp, varflags & VSQUOTE)) 556 goto recordleft; 557 *loc = c; 558 loc--; 559 if ((varflags & VSQUOTE) && loc > startp && 560 *(loc - 1) == CTLESC) { 561 for (q = startp; q < loc; q++) 562 if (*q == CTLESC) 563 q++; 564 if (q > loc) 565 loc--; 566 } 567 } 568 return 0; 569 570 case VSTRIMRIGHT: 571 for (loc = str - 1; loc >= startp;) { 572 if (patmatch(str, loc, varflags & VSQUOTE)) 573 goto recordright; 574 loc--; 575 if ((varflags & VSQUOTE) && loc > startp && 576 *(loc - 1) == CTLESC) { 577 for (q = startp; q < loc; q++) 578 if (*q == CTLESC) 579 q++; 580 if (q > loc) 581 loc--; 582 } 583 } 584 return 0; 585 586 case VSTRIMRIGHTMAX: 587 for (loc = startp; loc < str - 1; loc++) { 588 if (patmatch(str, loc, varflags & VSQUOTE)) 589 goto recordright; 590 if ((varflags & VSQUOTE) && *loc == CTLESC) 591 loc++; 592 } 593 return 0; 594 595 default: 596 abort(); 597 } 598 599 recordleft: 600 *loc = c; 601 amount = ((str - 1) - (loc - startp)) - expdest; 602 STADJUST(amount, expdest); 603 while (loc != str - 1) 604 *startp++ = *loc++; 605 return 1; 606 607 recordright: 608 amount = loc - expdest; 609 STADJUST(amount, expdest); 610 STPUTC('\0', expdest); 611 STADJUST(-1, expdest); 612 return 1; 613 } 614 615 616 /* 617 * Expand a variable, and return a pointer to the next character in the 618 * input string. 619 */ 620 621 STATIC char * 622 evalvar(p, flag) 623 char *p; 624 int flag; 625 { 626 int subtype; 627 int varflags; 628 char *var; 629 char *val; 630 int patloc; 631 int c; 632 int set; 633 int special; 634 int startloc; 635 int varlen; 636 int easy; 637 int quotes = flag & (EXP_FULL | EXP_CASE); 638 639 varflags = *p++; 640 subtype = varflags & VSTYPE; 641 var = p; 642 special = 0; 643 if (! is_name(*p)) 644 special = 1; 645 p = strchr(p, '=') + 1; 646 again: /* jump here after setting a variable with ${var=text} */ 647 if (special) { 648 set = varisset(var, varflags & VSNUL); 649 val = NULL; 650 } else { 651 val = lookupvar(var); 652 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 653 val = NULL; 654 set = 0; 655 } else 656 set = 1; 657 } 658 varlen = 0; 659 startloc = expdest - stackblock(); 660 if (!set && uflag) 661 switch (subtype) { 662 case VSNORMAL: 663 case VSTRIMLEFT: 664 case VSTRIMLEFTMAX: 665 case VSTRIMRIGHT: 666 case VSTRIMRIGHTMAX: 667 case VSLENGTH: 668 error("%.*s: parameter not set", p - var - 1, var); 669 /* NOTREACHED */ 670 } 671 if (set && subtype != VSPLUS) { 672 /* insert the value of the variable */ 673 if (special) { 674 varvalue(var, varflags & VSQUOTE, flag & EXP_FULL); 675 if (subtype == VSLENGTH) { 676 varlen = expdest - stackblock() - startloc; 677 STADJUST(-varlen, expdest); 678 } 679 } else { 680 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 681 : BASESYNTAX; 682 683 if (subtype == VSLENGTH) { 684 for (;*val; val++) 685 varlen++; 686 } 687 else { 688 while (*val) { 689 if (quotes && syntax[(int)*val] == CCTL) 690 STPUTC(CTLESC, expdest); 691 STPUTC(*val++, expdest); 692 } 693 694 } 695 } 696 } 697 698 if (subtype == VSPLUS) 699 set = ! set; 700 701 easy = ((varflags & VSQUOTE) == 0 || 702 (*var == '@' && shellparam.nparam != 1)); 703 704 705 switch (subtype) { 706 case VSLENGTH: 707 expdest = cvtnum(varlen, expdest); 708 goto record; 709 710 case VSNORMAL: 711 if (!easy) 712 break; 713 record: 714 recordregion(startloc, expdest - stackblock(), 715 varflags & VSQUOTE); 716 break; 717 718 case VSPLUS: 719 case VSMINUS: 720 if (!set) { 721 argstr(p, flag); 722 break; 723 } 724 if (easy) 725 goto record; 726 break; 727 728 case VSTRIMLEFT: 729 case VSTRIMLEFTMAX: 730 case VSTRIMRIGHT: 731 case VSTRIMRIGHTMAX: 732 if (!set) 733 break; 734 /* 735 * Terminate the string and start recording the pattern 736 * right after it 737 */ 738 STPUTC('\0', expdest); 739 patloc = expdest - stackblock(); 740 if (subevalvar(p, NULL, patloc, subtype, 741 startloc, varflags) == 0) { 742 int amount = (expdest - stackblock() - patloc) + 1; 743 STADJUST(-amount, expdest); 744 } 745 /* Remove any recorded regions beyond start of variable */ 746 removerecordregions(startloc); 747 goto record; 748 749 case VSASSIGN: 750 case VSQUESTION: 751 if (!set) { 752 if (subevalvar(p, var, 0, subtype, startloc, 753 varflags)) { 754 varflags &= ~VSNUL; 755 /* 756 * Remove any recorded regions beyond 757 * start of variable 758 */ 759 removerecordregions(startloc); 760 goto again; 761 } 762 break; 763 } 764 if (easy) 765 goto record; 766 break; 767 768 default: 769 abort(); 770 } 771 772 if (subtype != VSNORMAL) { /* skip to end of alternative */ 773 int nesting = 1; 774 for (;;) { 775 if ((c = *p++) == CTLESC) 776 p++; 777 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 778 if (set) 779 argbackq = argbackq->next; 780 } else if (c == CTLVAR) { 781 if ((*p++ & VSTYPE) != VSNORMAL) 782 nesting++; 783 } else if (c == CTLENDVAR) { 784 if (--nesting == 0) 785 break; 786 } 787 } 788 } 789 return p; 790 } 791 792 793 794 /* 795 * Test whether a specialized variable is set. 796 */ 797 798 STATIC int 799 varisset(name, nulok) 800 char *name; 801 int nulok; 802 { 803 if (*name == '!') 804 return backgndpid != -1; 805 else if (*name == '@' || *name == '*') { 806 if (*shellparam.p == NULL) 807 return 0; 808 809 if (nulok) { 810 char **av; 811 812 for (av = shellparam.p; *av; av++) 813 if (**av != '\0') 814 return 1; 815 return 0; 816 } 817 } else if (is_digit(*name)) { 818 char *ap; 819 int num = atoi(name); 820 821 if (num > shellparam.nparam) 822 return 0; 823 824 if (num == 0) 825 ap = arg0; 826 else 827 ap = shellparam.p[num - 1]; 828 829 if (nulok && (ap == NULL || *ap == '\0')) 830 return 0; 831 } 832 return 1; 833 } 834 835 836 837 /* 838 * Add the value of a specialized variable to the stack string. 839 */ 840 841 STATIC void 842 varvalue(name, quoted, allow_split) 843 char *name; 844 int quoted; 845 int allow_split; 846 { 847 int num; 848 char *p; 849 int i; 850 char sep; 851 char **ap; 852 char const *syntax; 853 854 #define STRTODEST(p) \ 855 do {\ 856 if (allow_split) { \ 857 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 858 while (*p) { \ 859 if (syntax[(int)*p] == CCTL) \ 860 STPUTC(CTLESC, expdest); \ 861 STPUTC(*p++, expdest); \ 862 } \ 863 } else \ 864 while (*p) \ 865 STPUTC(*p++, expdest); \ 866 } while (0) 867 868 869 switch (*name) { 870 case '$': 871 num = rootpid; 872 goto numvar; 873 case '?': 874 num = oexitstatus; 875 goto numvar; 876 case '#': 877 num = shellparam.nparam; 878 goto numvar; 879 case '!': 880 num = backgndpid; 881 numvar: 882 expdest = cvtnum(num, expdest); 883 break; 884 case '-': 885 for (i = 0 ; i < NOPTS ; i++) { 886 if (optlist[i].val) 887 STPUTC(optlist[i].letter, expdest); 888 } 889 break; 890 case '@': 891 if (allow_split && quoted) { 892 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 893 STRTODEST(p); 894 if (*ap) 895 STPUTC('\0', expdest); 896 } 897 break; 898 } 899 /* fall through */ 900 case '*': 901 if (ifsset() != 0) 902 sep = ifsval()[0]; 903 else 904 sep = ' '; 905 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 906 STRTODEST(p); 907 if (*ap && sep) 908 STPUTC(sep, expdest); 909 } 910 break; 911 case '0': 912 p = arg0; 913 STRTODEST(p); 914 break; 915 default: 916 if (is_digit(*name)) { 917 num = atoi(name); 918 if (num > 0 && num <= shellparam.nparam) { 919 p = shellparam.p[num - 1]; 920 STRTODEST(p); 921 } 922 } 923 break; 924 } 925 } 926 927 928 929 /* 930 * Record the fact that we have to scan this region of the 931 * string for IFS characters. 932 */ 933 934 STATIC void 935 recordregion(start, end, nulonly) 936 int start; 937 int end; 938 int nulonly; 939 { 940 struct ifsregion *ifsp; 941 942 if (ifslastp == NULL) { 943 ifsp = &ifsfirst; 944 } else { 945 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 946 ifslastp->next = ifsp; 947 } 948 ifslastp = ifsp; 949 ifslastp->next = NULL; 950 ifslastp->begoff = start; 951 ifslastp->endoff = end; 952 ifslastp->nulonly = nulonly; 953 } 954 955 956 957 /* 958 * Break the argument string into pieces based upon IFS and add the 959 * strings to the argument list. The regions of the string to be 960 * searched for IFS characters have been stored by recordregion. 961 */ 962 STATIC void 963 ifsbreakup(string, arglist) 964 char *string; 965 struct arglist *arglist; 966 { 967 struct ifsregion *ifsp; 968 struct strlist *sp; 969 char *start; 970 char *p; 971 char *q; 972 const char *ifs; 973 int ifsspc; 974 int nulonly; 975 976 977 start = string; 978 ifsspc = 0; 979 nulonly = 0; 980 if (ifslastp != NULL) { 981 ifsp = &ifsfirst; 982 do { 983 p = string + ifsp->begoff; 984 nulonly = ifsp->nulonly; 985 ifs = nulonly ? nullstr : 986 ( ifsset() ? ifsval() : " \t\n" ); 987 ifsspc = 0; 988 while (p < string + ifsp->endoff) { 989 q = p; 990 if (*p == CTLESC) 991 p++; 992 if (strchr(ifs, *p)) { 993 if (!nulonly) 994 ifsspc = (strchr(" \t\n", *p) != NULL); 995 /* Ignore IFS whitespace at start */ 996 if (q == start && ifsspc) { 997 p++; 998 start = p; 999 continue; 1000 } 1001 *q = '\0'; 1002 sp = (struct strlist *)stalloc(sizeof *sp); 1003 sp->text = start; 1004 *arglist->lastp = sp; 1005 arglist->lastp = &sp->next; 1006 p++; 1007 if (!nulonly) { 1008 for (;;) { 1009 if (p >= string + ifsp->endoff) { 1010 break; 1011 } 1012 q = p; 1013 if (*p == CTLESC) 1014 p++; 1015 if (strchr(ifs, *p) == NULL ) { 1016 p = q; 1017 break; 1018 } else if (strchr(" \t\n",*p) == NULL) { 1019 if (ifsspc) { 1020 p++; 1021 ifsspc = 0; 1022 } else { 1023 p = q; 1024 break; 1025 } 1026 } else 1027 p++; 1028 } 1029 } 1030 start = p; 1031 } else 1032 p++; 1033 } 1034 } while ((ifsp = ifsp->next) != NULL); 1035 if (*start || (!ifsspc && start > string && 1036 (nulonly || 1))) { 1037 sp = (struct strlist *)stalloc(sizeof *sp); 1038 sp->text = start; 1039 *arglist->lastp = sp; 1040 arglist->lastp = &sp->next; 1041 } 1042 } else { 1043 sp = (struct strlist *)stalloc(sizeof *sp); 1044 sp->text = start; 1045 *arglist->lastp = sp; 1046 arglist->lastp = &sp->next; 1047 } 1048 } 1049 1050 STATIC void 1051 ifsfree() 1052 { 1053 while (ifsfirst.next != NULL) { 1054 struct ifsregion *ifsp; 1055 INTOFF; 1056 ifsp = ifsfirst.next->next; 1057 ckfree(ifsfirst.next); 1058 ifsfirst.next = ifsp; 1059 INTON; 1060 } 1061 ifslastp = NULL; 1062 ifsfirst.next = NULL; 1063 } 1064 1065 1066 1067 /* 1068 * Expand shell metacharacters. At this point, the only control characters 1069 * should be escapes. The results are stored in the list exparg. 1070 */ 1071 1072 char *expdir; 1073 1074 1075 STATIC void 1076 expandmeta(str, flag) 1077 struct strlist *str; 1078 int flag; 1079 { 1080 char *p; 1081 struct strlist **savelastp; 1082 struct strlist *sp; 1083 char c; 1084 /* TODO - EXP_REDIR */ 1085 1086 while (str) { 1087 if (fflag) 1088 goto nometa; 1089 p = str->text; 1090 for (;;) { /* fast check for meta chars */ 1091 if ((c = *p++) == '\0') 1092 goto nometa; 1093 if (c == '*' || c == '?' || c == '[' || c == '!') 1094 break; 1095 } 1096 savelastp = exparg.lastp; 1097 INTOFF; 1098 if (expdir == NULL) { 1099 int i = strlen(str->text); 1100 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1101 } 1102 1103 expmeta(expdir, str->text); 1104 ckfree(expdir); 1105 expdir = NULL; 1106 INTON; 1107 if (exparg.lastp == savelastp) { 1108 /* 1109 * no matches 1110 */ 1111 nometa: 1112 *exparg.lastp = str; 1113 rmescapes(str->text); 1114 exparg.lastp = &str->next; 1115 } else { 1116 *exparg.lastp = NULL; 1117 *savelastp = sp = expsort(*savelastp); 1118 while (sp->next != NULL) 1119 sp = sp->next; 1120 exparg.lastp = &sp->next; 1121 } 1122 str = str->next; 1123 } 1124 } 1125 1126 1127 /* 1128 * Do metacharacter (i.e. *, ?, [...]) expansion. 1129 */ 1130 1131 STATIC void 1132 expmeta(enddir, name) 1133 char *enddir; 1134 char *name; 1135 { 1136 char *p; 1137 const char *cp; 1138 char *q; 1139 char *start; 1140 char *endname; 1141 int metaflag; 1142 struct stat statb; 1143 DIR *dirp; 1144 struct dirent *dp; 1145 int atend; 1146 int matchdot; 1147 1148 metaflag = 0; 1149 start = name; 1150 for (p = name ; ; p++) { 1151 if (*p == '*' || *p == '?') 1152 metaflag = 1; 1153 else if (*p == '[') { 1154 q = p + 1; 1155 if (*q == '!') 1156 q++; 1157 for (;;) { 1158 while (*q == CTLQUOTEMARK) 1159 q++; 1160 if (*q == CTLESC) 1161 q++; 1162 if (*q == '/' || *q == '\0') 1163 break; 1164 if (*++q == ']') { 1165 metaflag = 1; 1166 break; 1167 } 1168 } 1169 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1170 metaflag = 1; 1171 } else if (*p == '\0') 1172 break; 1173 else if (*p == CTLQUOTEMARK) 1174 continue; 1175 else if (*p == CTLESC) 1176 p++; 1177 if (*p == '/') { 1178 if (metaflag) 1179 break; 1180 start = p + 1; 1181 } 1182 } 1183 if (metaflag == 0) { /* we've reached the end of the file name */ 1184 if (enddir != expdir) 1185 metaflag++; 1186 for (p = name ; ; p++) { 1187 if (*p == CTLQUOTEMARK) 1188 continue; 1189 if (*p == CTLESC) 1190 p++; 1191 *enddir++ = *p; 1192 if (*p == '\0') 1193 break; 1194 } 1195 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1196 addfname(expdir); 1197 return; 1198 } 1199 endname = p; 1200 if (start != name) { 1201 p = name; 1202 while (p < start) { 1203 while (*p == CTLQUOTEMARK) 1204 p++; 1205 if (*p == CTLESC) 1206 p++; 1207 *enddir++ = *p++; 1208 } 1209 } 1210 if (enddir == expdir) { 1211 cp = "."; 1212 } else if (enddir == expdir + 1 && *expdir == '/') { 1213 cp = "/"; 1214 } else { 1215 cp = expdir; 1216 enddir[-1] = '\0'; 1217 } 1218 if ((dirp = opendir(cp)) == NULL) 1219 return; 1220 if (enddir != expdir) 1221 enddir[-1] = '/'; 1222 if (*endname == 0) { 1223 atend = 1; 1224 } else { 1225 atend = 0; 1226 *endname++ = '\0'; 1227 } 1228 matchdot = 0; 1229 p = start; 1230 while (*p == CTLQUOTEMARK) 1231 p++; 1232 if (*p == CTLESC) 1233 p++; 1234 if (*p == '.') 1235 matchdot++; 1236 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1237 if (dp->d_name[0] == '.' && ! matchdot) 1238 continue; 1239 if (patmatch(start, dp->d_name, 0)) { 1240 if (atend) { 1241 scopy(dp->d_name, enddir); 1242 addfname(expdir); 1243 } else { 1244 for (p = enddir, cp = dp->d_name; 1245 (*p++ = *cp++) != '\0';) 1246 continue; 1247 p[-1] = '/'; 1248 expmeta(p, endname); 1249 } 1250 } 1251 } 1252 closedir(dirp); 1253 if (! atend) 1254 endname[-1] = '/'; 1255 } 1256 1257 1258 /* 1259 * Add a file name to the list. 1260 */ 1261 1262 STATIC void 1263 addfname(name) 1264 char *name; 1265 { 1266 char *p; 1267 struct strlist *sp; 1268 1269 p = stalloc(strlen(name) + 1); 1270 scopy(name, p); 1271 sp = (struct strlist *)stalloc(sizeof *sp); 1272 sp->text = p; 1273 *exparg.lastp = sp; 1274 exparg.lastp = &sp->next; 1275 } 1276 1277 1278 /* 1279 * Sort the results of file name expansion. It calculates the number of 1280 * strings to sort and then calls msort (short for merge sort) to do the 1281 * work. 1282 */ 1283 1284 STATIC struct strlist * 1285 expsort(str) 1286 struct strlist *str; 1287 { 1288 int len; 1289 struct strlist *sp; 1290 1291 len = 0; 1292 for (sp = str ; sp ; sp = sp->next) 1293 len++; 1294 return msort(str, len); 1295 } 1296 1297 1298 STATIC struct strlist * 1299 msort(list, len) 1300 struct strlist *list; 1301 int len; 1302 { 1303 struct strlist *p, *q = NULL; 1304 struct strlist **lpp; 1305 int half; 1306 int n; 1307 1308 if (len <= 1) 1309 return list; 1310 half = len >> 1; 1311 p = list; 1312 for (n = half ; --n >= 0 ; ) { 1313 q = p; 1314 p = p->next; 1315 } 1316 q->next = NULL; /* terminate first half of list */ 1317 q = msort(list, half); /* sort first half of list */ 1318 p = msort(p, len - half); /* sort second half */ 1319 lpp = &list; 1320 for (;;) { 1321 if (strcmp(p->text, q->text) < 0) { 1322 *lpp = p; 1323 lpp = &p->next; 1324 if ((p = *lpp) == NULL) { 1325 *lpp = q; 1326 break; 1327 } 1328 } else { 1329 *lpp = q; 1330 lpp = &q->next; 1331 if ((q = *lpp) == NULL) { 1332 *lpp = p; 1333 break; 1334 } 1335 } 1336 } 1337 return list; 1338 } 1339 1340 1341 1342 /* 1343 * Returns true if the pattern matches the string. 1344 */ 1345 1346 int 1347 patmatch(pattern, string, squoted) 1348 char *pattern; 1349 char *string; 1350 int squoted; /* string might have quote chars */ 1351 { 1352 #ifdef notdef 1353 if (pattern[0] == '!' && pattern[1] == '!') 1354 return 1 - pmatch(pattern + 2, string); 1355 else 1356 #endif 1357 return pmatch(pattern, string, squoted); 1358 } 1359 1360 1361 STATIC int 1362 pmatch(pattern, string, squoted) 1363 char *pattern; 1364 char *string; 1365 int squoted; 1366 { 1367 char *p, *q; 1368 char c; 1369 1370 p = pattern; 1371 q = string; 1372 for (;;) { 1373 switch (c = *p++) { 1374 case '\0': 1375 goto breakloop; 1376 case CTLESC: 1377 if (squoted && *q == CTLESC) 1378 q++; 1379 if (*q++ != *p++) 1380 return 0; 1381 break; 1382 case CTLQUOTEMARK: 1383 continue; 1384 case '?': 1385 if (squoted && *q == CTLESC) 1386 q++; 1387 if (*q++ == '\0') 1388 return 0; 1389 break; 1390 case '*': 1391 c = *p; 1392 while (c == CTLQUOTEMARK || c == '*') 1393 c = *++p; 1394 if (c != CTLESC && c != CTLQUOTEMARK && 1395 c != '?' && c != '*' && c != '[') { 1396 while (*q != c) { 1397 if (squoted && *q == CTLESC && 1398 q[1] == c) 1399 break; 1400 if (*q == '\0') 1401 return 0; 1402 if (squoted && *q == CTLESC) 1403 q++; 1404 q++; 1405 } 1406 } 1407 do { 1408 if (pmatch(p, q, squoted)) 1409 return 1; 1410 if (squoted && *q == CTLESC) 1411 q++; 1412 } while (*q++ != '\0'); 1413 return 0; 1414 case '[': { 1415 char *endp; 1416 int invert, found; 1417 char chr; 1418 1419 endp = p; 1420 if (*endp == '!') 1421 endp++; 1422 for (;;) { 1423 while (*endp == CTLQUOTEMARK) 1424 endp++; 1425 if (*endp == '\0') 1426 goto dft; /* no matching ] */ 1427 if (*endp == CTLESC) 1428 endp++; 1429 if (*++endp == ']') 1430 break; 1431 } 1432 invert = 0; 1433 if (*p == '!') { 1434 invert++; 1435 p++; 1436 } 1437 found = 0; 1438 chr = *q++; 1439 if (squoted && chr == CTLESC) 1440 chr = *q++; 1441 if (chr == '\0') 1442 return 0; 1443 c = *p++; 1444 do { 1445 if (c == CTLQUOTEMARK) 1446 continue; 1447 if (c == CTLESC) 1448 c = *p++; 1449 if (*p == '-' && p[1] != ']') { 1450 p++; 1451 while (*p == CTLQUOTEMARK) 1452 p++; 1453 if (*p == CTLESC) 1454 p++; 1455 if (chr >= c && chr <= *p) 1456 found = 1; 1457 p++; 1458 } else { 1459 if (chr == c) 1460 found = 1; 1461 } 1462 } while ((c = *p++) != ']'); 1463 if (found == invert) 1464 return 0; 1465 break; 1466 } 1467 dft: default: 1468 if (squoted && *q == CTLESC) 1469 q++; 1470 if (*q++ != c) 1471 return 0; 1472 break; 1473 } 1474 } 1475 breakloop: 1476 if (*q != '\0') 1477 return 0; 1478 return 1; 1479 } 1480 1481 1482 1483 /* 1484 * Remove any CTLESC characters from a string. 1485 */ 1486 1487 void 1488 rmescapes(str) 1489 char *str; 1490 { 1491 char *p, *q; 1492 1493 p = str; 1494 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1495 if (*p++ == '\0') 1496 return; 1497 } 1498 q = p; 1499 while (*p) { 1500 if (*p == CTLQUOTEMARK) { 1501 p++; 1502 continue; 1503 } 1504 if (*p == CTLESC) 1505 p++; 1506 *q++ = *p++; 1507 } 1508 *q = '\0'; 1509 } 1510 1511 1512 1513 /* 1514 * See if a pattern matches in a case statement. 1515 */ 1516 1517 int 1518 casematch(pattern, val) 1519 union node *pattern; 1520 char *val; 1521 { 1522 struct stackmark smark; 1523 int result; 1524 char *p; 1525 1526 setstackmark(&smark); 1527 argbackq = pattern->narg.backquote; 1528 STARTSTACKSTR(expdest); 1529 ifslastp = NULL; 1530 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1531 STPUTC('\0', expdest); 1532 p = grabstackstr(expdest); 1533 result = patmatch(p, val, 0); 1534 popstackmark(&smark); 1535 return result; 1536 } 1537 1538 /* 1539 * Our own itoa(). 1540 */ 1541 1542 STATIC char * 1543 cvtnum(num, buf) 1544 int num; 1545 char *buf; 1546 { 1547 char temp[32]; 1548 int neg = num < 0; 1549 char *p = temp + 31; 1550 1551 temp[31] = '\0'; 1552 1553 do { 1554 *--p = num % 10 + '0'; 1555 } while ((num /= 10) != 0); 1556 1557 if (neg) 1558 *--p = '-'; 1559 1560 while (*p) 1561 STPUTC(*p++, buf); 1562 return buf; 1563 } 1564