1 /* $NetBSD: expand.c,v 1.56 2002/11/24 22:35:39 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 1.56 2002/11/24 22:35:39 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(char *, int); 100 STATIC char *exptilde(char *, int); 101 STATIC void expbackq(union node *, int, int); 102 STATIC int subevalvar(char *, char *, int, int, int, int); 103 STATIC char *evalvar(char *, int); 104 STATIC int varisset(char *, int); 105 STATIC void varvalue(char *, int, int); 106 STATIC void recordregion(int, int, int); 107 STATIC void removerecordregions(int); 108 STATIC void ifsbreakup(char *, struct arglist *); 109 STATIC void ifsfree(void); 110 STATIC void expandmeta(struct strlist *, int); 111 STATIC void expmeta(char *, char *); 112 STATIC void addfname(char *); 113 STATIC struct strlist *expsort(struct strlist *); 114 STATIC struct strlist *msort(struct strlist *, int); 115 STATIC int pmatch(char *, char *, int); 116 STATIC char *cvtnum(int, char *); 117 118 /* 119 * Expand shell variables and backquotes inside a here document. 120 */ 121 122 void 123 expandhere(union node *arg, int fd) 124 { 125 herefd = fd; 126 expandarg(arg, (struct arglist *)NULL, 0); 127 xwrite(fd, stackblock(), expdest - stackblock()); 128 } 129 130 131 /* 132 * Perform variable substitution and command substitution on an argument, 133 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 134 * perform splitting and file name expansion. When arglist is NULL, perform 135 * here document expansion. 136 */ 137 138 void 139 expandarg(union node *arg, struct arglist *arglist, int flag) 140 { 141 struct strlist *sp; 142 char *p; 143 144 argbackq = arg->narg.backquote; 145 STARTSTACKSTR(expdest); 146 ifsfirst.next = NULL; 147 ifslastp = NULL; 148 argstr(arg->narg.text, flag); 149 if (arglist == NULL) { 150 return; /* here document expanded */ 151 } 152 STPUTC('\0', expdest); 153 p = grabstackstr(expdest); 154 exparg.lastp = &exparg.list; 155 /* 156 * TODO - EXP_REDIR 157 */ 158 if (flag & EXP_FULL) { 159 ifsbreakup(p, &exparg); 160 *exparg.lastp = NULL; 161 exparg.lastp = &exparg.list; 162 expandmeta(exparg.list, flag); 163 } else { 164 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 165 rmescapes(p); 166 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 167 sp->text = p; 168 *exparg.lastp = sp; 169 exparg.lastp = &sp->next; 170 } 171 ifsfree(); 172 *exparg.lastp = NULL; 173 if (exparg.list) { 174 *arglist->lastp = exparg.list; 175 arglist->lastp = exparg.lastp; 176 } 177 } 178 179 180 181 /* 182 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC 183 * characters to allow for further processing. Otherwise treat 184 * $@ like $* since no splitting will be performed. 185 */ 186 187 STATIC void 188 argstr(char *p, int flag) 189 { 190 char c; 191 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */ 192 int firsteq = 1; 193 194 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 195 p = exptilde(p, flag); 196 for (;;) { 197 switch (c = *p++) { 198 case '\0': 199 case CTLENDVAR: /* ??? */ 200 goto breakloop; 201 case CTLQUOTEMARK: 202 /* "$@" syntax adherence hack */ 203 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 204 break; 205 if ((flag & EXP_FULL) != 0) 206 STPUTC(c, expdest); 207 break; 208 case CTLESC: 209 if (quotes) 210 STPUTC(c, expdest); 211 c = *p++; 212 STPUTC(c, expdest); 213 break; 214 case CTLVAR: 215 p = evalvar(p, flag); 216 break; 217 case CTLBACKQ: 218 case CTLBACKQ|CTLQUOTE: 219 expbackq(argbackq->n, c & CTLQUOTE, flag); 220 argbackq = argbackq->next; 221 break; 222 case CTLENDARI: 223 expari(flag); 224 break; 225 case ':': 226 case '=': 227 /* 228 * sort of a hack - expand tildes in variable 229 * assignments (after the first '=' and after ':'s). 230 */ 231 STPUTC(c, expdest); 232 if (flag & EXP_VARTILDE && *p == '~') { 233 if (c == '=') { 234 if (firsteq) 235 firsteq = 0; 236 else 237 break; 238 } 239 p = exptilde(p, flag); 240 } 241 break; 242 default: 243 STPUTC(c, expdest); 244 } 245 } 246 breakloop:; 247 return; 248 } 249 250 STATIC char * 251 exptilde(char *p, int flag) 252 { 253 char c, *startp = p; 254 struct passwd *pw; 255 const char *home; 256 int quotes = flag & (EXP_FULL | EXP_CASE); 257 258 while ((c = *p) != '\0') { 259 switch(c) { 260 case CTLESC: 261 return (startp); 262 case CTLQUOTEMARK: 263 return (startp); 264 case ':': 265 if (flag & EXP_VARTILDE) 266 goto done; 267 break; 268 case '/': 269 goto done; 270 } 271 p++; 272 } 273 done: 274 *p = '\0'; 275 if (*(startp+1) == '\0') { 276 if ((home = lookupvar("HOME")) == NULL) 277 goto lose; 278 } else { 279 if ((pw = getpwnam(startp+1)) == NULL) 280 goto lose; 281 home = pw->pw_dir; 282 } 283 if (*home == '\0') 284 goto lose; 285 *p = c; 286 while ((c = *home++) != '\0') { 287 if (quotes && SQSYNTAX[(int)c] == CCTL) 288 STPUTC(CTLESC, expdest); 289 STPUTC(c, expdest); 290 } 291 return (p); 292 lose: 293 *p = c; 294 return (startp); 295 } 296 297 298 STATIC void 299 removerecordregions(int endoff) 300 { 301 if (ifslastp == NULL) 302 return; 303 304 if (ifsfirst.endoff > endoff) { 305 while (ifsfirst.next != NULL) { 306 struct ifsregion *ifsp; 307 INTOFF; 308 ifsp = ifsfirst.next->next; 309 ckfree(ifsfirst.next); 310 ifsfirst.next = ifsp; 311 INTON; 312 } 313 if (ifsfirst.begoff > endoff) 314 ifslastp = NULL; 315 else { 316 ifslastp = &ifsfirst; 317 ifsfirst.endoff = endoff; 318 } 319 return; 320 } 321 322 ifslastp = &ifsfirst; 323 while (ifslastp->next && ifslastp->next->begoff < endoff) 324 ifslastp=ifslastp->next; 325 while (ifslastp->next != NULL) { 326 struct ifsregion *ifsp; 327 INTOFF; 328 ifsp = ifslastp->next->next; 329 ckfree(ifslastp->next); 330 ifslastp->next = ifsp; 331 INTON; 332 } 333 if (ifslastp->endoff > endoff) 334 ifslastp->endoff = endoff; 335 } 336 337 338 /* 339 * Expand arithmetic expression. Backup to start of expression, 340 * evaluate, place result in (backed up) result, adjust string position. 341 */ 342 void 343 expari(int flag) 344 { 345 char *p, *start; 346 int result; 347 int begoff; 348 int quotes = flag & (EXP_FULL | EXP_CASE); 349 int quoted; 350 351 /* ifsfree(); */ 352 353 /* 354 * This routine is slightly over-complicated for 355 * efficiency. First we make sure there is 356 * enough space for the result, which may be bigger 357 * than the expression if we add exponentation. Next we 358 * scan backwards looking for the start of arithmetic. If the 359 * next previous character is a CTLESC character, then we 360 * have to rescan starting from the beginning since CTLESC 361 * characters have to be processed left to right. 362 */ 363 #if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10 364 #error "integers with more than 10 digits are not supported" 365 #endif 366 CHECKSTRSPACE(12 - 2, expdest); 367 USTPUTC('\0', expdest); 368 start = stackblock(); 369 p = expdest - 1; 370 while (*p != CTLARI && p >= start) 371 --p; 372 if (*p != CTLARI) 373 error("missing CTLARI (shouldn't happen)"); 374 if (p > start && *(p-1) == CTLESC) 375 for (p = start; *p != CTLARI; p++) 376 if (*p == CTLESC) 377 p++; 378 379 if (p[1] == '"') 380 quoted=1; 381 else 382 quoted=0; 383 begoff = p - start; 384 removerecordregions(begoff); 385 if (quotes) 386 rmescapes(p+2); 387 result = arith(p+2); 388 fmtstr(p, 12, "%d", result); 389 390 while (*p++) 391 ; 392 393 if (quoted == 0) 394 recordregion(begoff, p - 1 - start, 0); 395 result = expdest - p + 1; 396 STADJUST(-result, expdest); 397 } 398 399 400 /* 401 * Expand stuff in backwards quotes. 402 */ 403 404 STATIC void 405 expbackq(union node *cmd, int quoted, int flag) 406 { 407 struct backcmd in; 408 int i; 409 char buf[128]; 410 char *p; 411 char *dest = expdest; 412 struct ifsregion saveifs, *savelastp; 413 struct nodelist *saveargbackq; 414 char lastc; 415 int startloc = dest - stackblock(); 416 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 417 int saveherefd; 418 int quotes = flag & (EXP_FULL | EXP_CASE); 419 420 INTOFF; 421 saveifs = ifsfirst; 422 savelastp = ifslastp; 423 saveargbackq = argbackq; 424 saveherefd = herefd; 425 herefd = -1; 426 p = grabstackstr(dest); 427 evalbackcmd(cmd, &in); 428 ungrabstackstr(p, dest); 429 ifsfirst = saveifs; 430 ifslastp = savelastp; 431 argbackq = saveargbackq; 432 herefd = saveherefd; 433 434 p = in.buf; 435 lastc = '\0'; 436 for (;;) { 437 if (--in.nleft < 0) { 438 if (in.fd < 0) 439 break; 440 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 441 TRACE(("expbackq: read returns %d\n", i)); 442 if (i <= 0) 443 break; 444 p = buf; 445 in.nleft = i - 1; 446 } 447 lastc = *p++; 448 if (lastc != '\0') { 449 if (quotes && syntax[(int)lastc] == CCTL) 450 STPUTC(CTLESC, dest); 451 STPUTC(lastc, dest); 452 } 453 } 454 455 /* Eat all trailing newlines */ 456 for (p--; lastc == '\n'; lastc = *--p) 457 STUNPUTC(dest); 458 459 if (in.fd >= 0) 460 close(in.fd); 461 if (in.buf) 462 ckfree(in.buf); 463 if (in.jp) 464 back_exitstatus = waitforjob(in.jp); 465 if (quoted == 0) 466 recordregion(startloc, dest - stackblock(), 0); 467 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 468 (dest - stackblock()) - startloc, 469 (dest - stackblock()) - startloc, 470 stackblock() + startloc)); 471 expdest = dest; 472 INTON; 473 } 474 475 476 477 STATIC int 478 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags) 479 { 480 char *startp; 481 char *loc = NULL; 482 char *q; 483 int c = 0; 484 int saveherefd = herefd; 485 struct nodelist *saveargbackq = argbackq; 486 int amount; 487 488 herefd = -1; 489 argstr(p, 0); 490 STACKSTRNUL(expdest); 491 herefd = saveherefd; 492 argbackq = saveargbackq; 493 startp = stackblock() + startloc; 494 if (str == NULL) 495 str = stackblock() + strloc; 496 497 switch (subtype) { 498 case VSASSIGN: 499 setvar(str, startp, 0); 500 amount = startp - expdest; 501 STADJUST(amount, expdest); 502 varflags &= ~VSNUL; 503 if (c != 0) 504 *loc = c; 505 return 1; 506 507 case VSQUESTION: 508 if (*p != CTLENDVAR) { 509 outfmt(&errout, "%s\n", startp); 510 error((char *)NULL); 511 } 512 error("%.*s: parameter %snot set", p - str - 1, 513 str, (varflags & VSNUL) ? "null or " 514 : nullstr); 515 /* NOTREACHED */ 516 517 case VSTRIMLEFT: 518 for (loc = startp; loc < str; loc++) { 519 c = *loc; 520 *loc = '\0'; 521 if (patmatch(str, startp, varflags & VSQUOTE)) 522 goto recordleft; 523 *loc = c; 524 if ((varflags & VSQUOTE) && *loc == CTLESC) 525 loc++; 526 } 527 return 0; 528 529 case VSTRIMLEFTMAX: 530 for (loc = str - 1; loc >= startp;) { 531 c = *loc; 532 *loc = '\0'; 533 if (patmatch(str, startp, varflags & VSQUOTE)) 534 goto recordleft; 535 *loc = c; 536 loc--; 537 if ((varflags & VSQUOTE) && loc > startp && 538 *(loc - 1) == CTLESC) { 539 for (q = startp; q < loc; q++) 540 if (*q == CTLESC) 541 q++; 542 if (q > loc) 543 loc--; 544 } 545 } 546 return 0; 547 548 case VSTRIMRIGHT: 549 for (loc = str - 1; loc >= startp;) { 550 if (patmatch(str, loc, varflags & VSQUOTE)) 551 goto recordright; 552 loc--; 553 if ((varflags & VSQUOTE) && loc > startp && 554 *(loc - 1) == CTLESC) { 555 for (q = startp; q < loc; q++) 556 if (*q == CTLESC) 557 q++; 558 if (q > loc) 559 loc--; 560 } 561 } 562 return 0; 563 564 case VSTRIMRIGHTMAX: 565 for (loc = startp; loc < str - 1; loc++) { 566 if (patmatch(str, loc, varflags & VSQUOTE)) 567 goto recordright; 568 if ((varflags & VSQUOTE) && *loc == CTLESC) 569 loc++; 570 } 571 return 0; 572 573 default: 574 abort(); 575 } 576 577 recordleft: 578 *loc = c; 579 amount = ((str - 1) - (loc - startp)) - expdest; 580 STADJUST(amount, expdest); 581 while (loc != str - 1) 582 *startp++ = *loc++; 583 return 1; 584 585 recordright: 586 amount = loc - expdest; 587 STADJUST(amount, expdest); 588 STPUTC('\0', expdest); 589 STADJUST(-1, expdest); 590 return 1; 591 } 592 593 594 /* 595 * Expand a variable, and return a pointer to the next character in the 596 * input string. 597 */ 598 599 STATIC char * 600 evalvar(char *p, int flag) 601 { 602 int subtype; 603 int varflags; 604 char *var; 605 char *val; 606 int patloc; 607 int c; 608 int set; 609 int special; 610 int startloc; 611 int varlen; 612 int easy; 613 int quotes = flag & (EXP_FULL | EXP_CASE); 614 615 varflags = *p++; 616 subtype = varflags & VSTYPE; 617 var = p; 618 special = 0; 619 if (! is_name(*p)) 620 special = 1; 621 p = strchr(p, '=') + 1; 622 again: /* jump here after setting a variable with ${var=text} */ 623 if (special) { 624 set = varisset(var, varflags & VSNUL); 625 val = NULL; 626 } else { 627 val = lookupvar(var); 628 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 629 val = NULL; 630 set = 0; 631 } else 632 set = 1; 633 } 634 varlen = 0; 635 startloc = expdest - stackblock(); 636 if (!set && uflag) 637 switch (subtype) { 638 case VSNORMAL: 639 case VSTRIMLEFT: 640 case VSTRIMLEFTMAX: 641 case VSTRIMRIGHT: 642 case VSTRIMRIGHTMAX: 643 case VSLENGTH: 644 error("%.*s: parameter not set", p - var - 1, var); 645 /* NOTREACHED */ 646 } 647 if (set && subtype != VSPLUS) { 648 /* insert the value of the variable */ 649 if (special) { 650 varvalue(var, varflags & VSQUOTE, flag & EXP_FULL); 651 if (subtype == VSLENGTH) { 652 varlen = expdest - stackblock() - startloc; 653 STADJUST(-varlen, expdest); 654 } 655 } else { 656 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 657 : BASESYNTAX; 658 659 if (subtype == VSLENGTH) { 660 for (;*val; val++) 661 varlen++; 662 } 663 else { 664 while (*val) { 665 if (quotes && syntax[(int)*val] == CCTL) 666 STPUTC(CTLESC, expdest); 667 STPUTC(*val++, expdest); 668 } 669 670 } 671 } 672 } 673 674 if (subtype == VSPLUS) 675 set = ! set; 676 677 easy = ((varflags & VSQUOTE) == 0 || 678 (*var == '@' && shellparam.nparam != 1)); 679 680 681 switch (subtype) { 682 case VSLENGTH: 683 expdest = cvtnum(varlen, expdest); 684 goto record; 685 686 case VSNORMAL: 687 if (!easy) 688 break; 689 record: 690 recordregion(startloc, expdest - stackblock(), 691 varflags & VSQUOTE); 692 break; 693 694 case VSPLUS: 695 case VSMINUS: 696 if (!set) { 697 argstr(p, flag); 698 break; 699 } 700 if (easy) 701 goto record; 702 break; 703 704 case VSTRIMLEFT: 705 case VSTRIMLEFTMAX: 706 case VSTRIMRIGHT: 707 case VSTRIMRIGHTMAX: 708 if (!set) 709 break; 710 /* 711 * Terminate the string and start recording the pattern 712 * right after it 713 */ 714 STPUTC('\0', expdest); 715 patloc = expdest - stackblock(); 716 if (subevalvar(p, NULL, patloc, subtype, 717 startloc, varflags) == 0) { 718 int amount = (expdest - stackblock() - patloc) + 1; 719 STADJUST(-amount, expdest); 720 } 721 /* Remove any recorded regions beyond start of variable */ 722 removerecordregions(startloc); 723 goto record; 724 725 case VSASSIGN: 726 case VSQUESTION: 727 if (!set) { 728 if (subevalvar(p, var, 0, subtype, startloc, 729 varflags)) { 730 varflags &= ~VSNUL; 731 /* 732 * Remove any recorded regions beyond 733 * start of variable 734 */ 735 removerecordregions(startloc); 736 goto again; 737 } 738 break; 739 } 740 if (easy) 741 goto record; 742 break; 743 744 default: 745 abort(); 746 } 747 748 if (subtype != VSNORMAL) { /* skip to end of alternative */ 749 int nesting = 1; 750 for (;;) { 751 if ((c = *p++) == CTLESC) 752 p++; 753 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 754 if (set) 755 argbackq = argbackq->next; 756 } else if (c == CTLVAR) { 757 if ((*p++ & VSTYPE) != VSNORMAL) 758 nesting++; 759 } else if (c == CTLENDVAR) { 760 if (--nesting == 0) 761 break; 762 } 763 } 764 } 765 return p; 766 } 767 768 769 770 /* 771 * Test whether a specialized variable is set. 772 */ 773 774 STATIC int 775 varisset(char *name, int nulok) 776 { 777 if (*name == '!') 778 return backgndpid != -1; 779 else if (*name == '@' || *name == '*') { 780 if (*shellparam.p == NULL) 781 return 0; 782 783 if (nulok) { 784 char **av; 785 786 for (av = shellparam.p; *av; av++) 787 if (**av != '\0') 788 return 1; 789 return 0; 790 } 791 } else if (is_digit(*name)) { 792 char *ap; 793 int num = atoi(name); 794 795 if (num > shellparam.nparam) 796 return 0; 797 798 if (num == 0) 799 ap = arg0; 800 else 801 ap = shellparam.p[num - 1]; 802 803 if (nulok && (ap == NULL || *ap == '\0')) 804 return 0; 805 } 806 return 1; 807 } 808 809 810 811 /* 812 * Add the value of a specialized variable to the stack string. 813 */ 814 815 STATIC void 816 varvalue(char *name, int quoted, int allow_split) 817 { 818 int num; 819 char *p; 820 int i; 821 char sep; 822 char **ap; 823 char const *syntax; 824 825 #define STRTODEST(p) \ 826 do {\ 827 if (allow_split) { \ 828 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 829 while (*p) { \ 830 if (syntax[(int)*p] == CCTL) \ 831 STPUTC(CTLESC, expdest); \ 832 STPUTC(*p++, expdest); \ 833 } \ 834 } else \ 835 while (*p) \ 836 STPUTC(*p++, expdest); \ 837 } while (0) 838 839 840 switch (*name) { 841 case '$': 842 num = rootpid; 843 goto numvar; 844 case '?': 845 num = exitstatus; 846 goto numvar; 847 case '#': 848 num = shellparam.nparam; 849 goto numvar; 850 case '!': 851 num = backgndpid; 852 numvar: 853 expdest = cvtnum(num, expdest); 854 break; 855 case '-': 856 for (i = 0; optlist[i].name; i++) { 857 if (optlist[i].val) 858 STPUTC(optlist[i].letter, expdest); 859 } 860 break; 861 case '@': 862 if (allow_split && quoted) { 863 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 864 STRTODEST(p); 865 if (*ap) 866 STPUTC('\0', expdest); 867 } 868 break; 869 } 870 /* fall through */ 871 case '*': 872 if (ifsset() != 0) 873 sep = ifsval()[0]; 874 else 875 sep = ' '; 876 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 877 STRTODEST(p); 878 if (*ap && sep) 879 STPUTC(sep, expdest); 880 } 881 break; 882 case '0': 883 p = arg0; 884 STRTODEST(p); 885 break; 886 default: 887 if (is_digit(*name)) { 888 num = atoi(name); 889 if (num > 0 && num <= shellparam.nparam) { 890 p = shellparam.p[num - 1]; 891 STRTODEST(p); 892 } 893 } 894 break; 895 } 896 } 897 898 899 900 /* 901 * Record the fact that we have to scan this region of the 902 * string for IFS characters. 903 */ 904 905 STATIC void 906 recordregion(int start, int end, int nulonly) 907 { 908 struct ifsregion *ifsp; 909 910 if (ifslastp == NULL) { 911 ifsp = &ifsfirst; 912 } else { 913 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 914 ifslastp->next = ifsp; 915 } 916 ifslastp = ifsp; 917 ifslastp->next = NULL; 918 ifslastp->begoff = start; 919 ifslastp->endoff = end; 920 ifslastp->nulonly = nulonly; 921 } 922 923 924 925 /* 926 * Break the argument string into pieces based upon IFS and add the 927 * strings to the argument list. The regions of the string to be 928 * searched for IFS characters have been stored by recordregion. 929 */ 930 STATIC void 931 ifsbreakup(char *string, struct arglist *arglist) 932 { 933 struct ifsregion *ifsp; 934 struct strlist *sp; 935 char *start; 936 char *p; 937 char *q; 938 const char *ifs; 939 int ifsspc; 940 int nulonly; 941 942 943 start = string; 944 ifsspc = 0; 945 nulonly = 0; 946 if (ifslastp != NULL) { 947 ifsp = &ifsfirst; 948 do { 949 p = string + ifsp->begoff; 950 nulonly = ifsp->nulonly; 951 ifs = nulonly ? nullstr : 952 ( ifsset() ? ifsval() : " \t\n" ); 953 ifsspc = 0; 954 while (p < string + ifsp->endoff) { 955 q = p; 956 if (*p == CTLESC) 957 p++; 958 if (strchr(ifs, *p)) { 959 if (!nulonly) 960 ifsspc = (strchr(" \t\n", *p) != NULL); 961 /* Ignore IFS whitespace at start */ 962 if (q == start && ifsspc) { 963 p++; 964 start = p; 965 continue; 966 } 967 *q = '\0'; 968 sp = (struct strlist *)stalloc(sizeof *sp); 969 sp->text = start; 970 *arglist->lastp = sp; 971 arglist->lastp = &sp->next; 972 p++; 973 if (!nulonly) { 974 for (;;) { 975 if (p >= string + ifsp->endoff) { 976 break; 977 } 978 q = p; 979 if (*p == CTLESC) 980 p++; 981 if (strchr(ifs, *p) == NULL ) { 982 p = q; 983 break; 984 } else if (strchr(" \t\n",*p) == NULL) { 985 if (ifsspc) { 986 p++; 987 ifsspc = 0; 988 } else { 989 p = q; 990 break; 991 } 992 } else 993 p++; 994 } 995 } 996 start = p; 997 } else 998 p++; 999 } 1000 } while ((ifsp = ifsp->next) != NULL); 1001 if (*start || (!ifsspc && start > string && 1002 (nulonly || 1))) { 1003 sp = (struct strlist *)stalloc(sizeof *sp); 1004 sp->text = start; 1005 *arglist->lastp = sp; 1006 arglist->lastp = &sp->next; 1007 } 1008 } else { 1009 sp = (struct strlist *)stalloc(sizeof *sp); 1010 sp->text = start; 1011 *arglist->lastp = sp; 1012 arglist->lastp = &sp->next; 1013 } 1014 } 1015 1016 STATIC void 1017 ifsfree(void) 1018 { 1019 while (ifsfirst.next != NULL) { 1020 struct ifsregion *ifsp; 1021 INTOFF; 1022 ifsp = ifsfirst.next->next; 1023 ckfree(ifsfirst.next); 1024 ifsfirst.next = ifsp; 1025 INTON; 1026 } 1027 ifslastp = NULL; 1028 ifsfirst.next = NULL; 1029 } 1030 1031 1032 1033 /* 1034 * Expand shell metacharacters. At this point, the only control characters 1035 * should be escapes. The results are stored in the list exparg. 1036 */ 1037 1038 char *expdir; 1039 1040 1041 STATIC void 1042 expandmeta(struct strlist *str, int flag) 1043 { 1044 char *p; 1045 struct strlist **savelastp; 1046 struct strlist *sp; 1047 char c; 1048 /* TODO - EXP_REDIR */ 1049 1050 while (str) { 1051 if (fflag) 1052 goto nometa; 1053 p = str->text; 1054 for (;;) { /* fast check for meta chars */ 1055 if ((c = *p++) == '\0') 1056 goto nometa; 1057 if (c == '*' || c == '?' || c == '[' || c == '!') 1058 break; 1059 } 1060 savelastp = exparg.lastp; 1061 INTOFF; 1062 if (expdir == NULL) { 1063 int i = strlen(str->text); 1064 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1065 } 1066 1067 expmeta(expdir, str->text); 1068 ckfree(expdir); 1069 expdir = NULL; 1070 INTON; 1071 if (exparg.lastp == savelastp) { 1072 /* 1073 * no matches 1074 */ 1075 nometa: 1076 *exparg.lastp = str; 1077 rmescapes(str->text); 1078 exparg.lastp = &str->next; 1079 } else { 1080 *exparg.lastp = NULL; 1081 *savelastp = sp = expsort(*savelastp); 1082 while (sp->next != NULL) 1083 sp = sp->next; 1084 exparg.lastp = &sp->next; 1085 } 1086 str = str->next; 1087 } 1088 } 1089 1090 1091 /* 1092 * Do metacharacter (i.e. *, ?, [...]) expansion. 1093 */ 1094 1095 STATIC void 1096 expmeta(char *enddir, char *name) 1097 { 1098 char *p; 1099 const char *cp; 1100 char *q; 1101 char *start; 1102 char *endname; 1103 int metaflag; 1104 struct stat statb; 1105 DIR *dirp; 1106 struct dirent *dp; 1107 int atend; 1108 int matchdot; 1109 1110 metaflag = 0; 1111 start = name; 1112 for (p = name ; ; p++) { 1113 if (*p == '*' || *p == '?') 1114 metaflag = 1; 1115 else if (*p == '[') { 1116 q = p + 1; 1117 if (*q == '!') 1118 q++; 1119 for (;;) { 1120 while (*q == CTLQUOTEMARK) 1121 q++; 1122 if (*q == CTLESC) 1123 q++; 1124 if (*q == '/' || *q == '\0') 1125 break; 1126 if (*++q == ']') { 1127 metaflag = 1; 1128 break; 1129 } 1130 } 1131 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1132 metaflag = 1; 1133 } else if (*p == '\0') 1134 break; 1135 else if (*p == CTLQUOTEMARK) 1136 continue; 1137 else if (*p == CTLESC) 1138 p++; 1139 if (*p == '/') { 1140 if (metaflag) 1141 break; 1142 start = p + 1; 1143 } 1144 } 1145 if (metaflag == 0) { /* we've reached the end of the file name */ 1146 if (enddir != expdir) 1147 metaflag++; 1148 for (p = name ; ; p++) { 1149 if (*p == CTLQUOTEMARK) 1150 continue; 1151 if (*p == CTLESC) 1152 p++; 1153 *enddir++ = *p; 1154 if (*p == '\0') 1155 break; 1156 } 1157 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1158 addfname(expdir); 1159 return; 1160 } 1161 endname = p; 1162 if (start != name) { 1163 p = name; 1164 while (p < start) { 1165 while (*p == CTLQUOTEMARK) 1166 p++; 1167 if (*p == CTLESC) 1168 p++; 1169 *enddir++ = *p++; 1170 } 1171 } 1172 if (enddir == expdir) { 1173 cp = "."; 1174 } else if (enddir == expdir + 1 && *expdir == '/') { 1175 cp = "/"; 1176 } else { 1177 cp = expdir; 1178 enddir[-1] = '\0'; 1179 } 1180 if ((dirp = opendir(cp)) == NULL) 1181 return; 1182 if (enddir != expdir) 1183 enddir[-1] = '/'; 1184 if (*endname == 0) { 1185 atend = 1; 1186 } else { 1187 atend = 0; 1188 *endname++ = '\0'; 1189 } 1190 matchdot = 0; 1191 p = start; 1192 while (*p == CTLQUOTEMARK) 1193 p++; 1194 if (*p == CTLESC) 1195 p++; 1196 if (*p == '.') 1197 matchdot++; 1198 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1199 if (dp->d_name[0] == '.' && ! matchdot) 1200 continue; 1201 if (patmatch(start, dp->d_name, 0)) { 1202 if (atend) { 1203 scopy(dp->d_name, enddir); 1204 addfname(expdir); 1205 } else { 1206 for (p = enddir, cp = dp->d_name; 1207 (*p++ = *cp++) != '\0';) 1208 continue; 1209 p[-1] = '/'; 1210 expmeta(p, endname); 1211 } 1212 } 1213 } 1214 closedir(dirp); 1215 if (! atend) 1216 endname[-1] = '/'; 1217 } 1218 1219 1220 /* 1221 * Add a file name to the list. 1222 */ 1223 1224 STATIC void 1225 addfname(char *name) 1226 { 1227 char *p; 1228 struct strlist *sp; 1229 1230 p = stalloc(strlen(name) + 1); 1231 scopy(name, p); 1232 sp = (struct strlist *)stalloc(sizeof *sp); 1233 sp->text = p; 1234 *exparg.lastp = sp; 1235 exparg.lastp = &sp->next; 1236 } 1237 1238 1239 /* 1240 * Sort the results of file name expansion. It calculates the number of 1241 * strings to sort and then calls msort (short for merge sort) to do the 1242 * work. 1243 */ 1244 1245 STATIC struct strlist * 1246 expsort(struct strlist *str) 1247 { 1248 int len; 1249 struct strlist *sp; 1250 1251 len = 0; 1252 for (sp = str ; sp ; sp = sp->next) 1253 len++; 1254 return msort(str, len); 1255 } 1256 1257 1258 STATIC struct strlist * 1259 msort(struct strlist *list, int len) 1260 { 1261 struct strlist *p, *q = NULL; 1262 struct strlist **lpp; 1263 int half; 1264 int n; 1265 1266 if (len <= 1) 1267 return list; 1268 half = len >> 1; 1269 p = list; 1270 for (n = half ; --n >= 0 ; ) { 1271 q = p; 1272 p = p->next; 1273 } 1274 q->next = NULL; /* terminate first half of list */ 1275 q = msort(list, half); /* sort first half of list */ 1276 p = msort(p, len - half); /* sort second half */ 1277 lpp = &list; 1278 for (;;) { 1279 if (strcmp(p->text, q->text) < 0) { 1280 *lpp = p; 1281 lpp = &p->next; 1282 if ((p = *lpp) == NULL) { 1283 *lpp = q; 1284 break; 1285 } 1286 } else { 1287 *lpp = q; 1288 lpp = &q->next; 1289 if ((q = *lpp) == NULL) { 1290 *lpp = p; 1291 break; 1292 } 1293 } 1294 } 1295 return list; 1296 } 1297 1298 1299 1300 /* 1301 * Returns true if the pattern matches the string. 1302 */ 1303 1304 int 1305 patmatch(char *pattern, char *string, int squoted) 1306 { 1307 #ifdef notdef 1308 if (pattern[0] == '!' && pattern[1] == '!') 1309 return 1 - pmatch(pattern + 2, string); 1310 else 1311 #endif 1312 return pmatch(pattern, string, squoted); 1313 } 1314 1315 1316 STATIC int 1317 pmatch(char *pattern, char *string, int squoted) 1318 { 1319 char *p, *q; 1320 char c; 1321 1322 p = pattern; 1323 q = string; 1324 for (;;) { 1325 switch (c = *p++) { 1326 case '\0': 1327 goto breakloop; 1328 case CTLESC: 1329 if (squoted && *q == CTLESC) 1330 q++; 1331 if (*q++ != *p++) 1332 return 0; 1333 break; 1334 case CTLQUOTEMARK: 1335 continue; 1336 case '?': 1337 if (squoted && *q == CTLESC) 1338 q++; 1339 if (*q++ == '\0') 1340 return 0; 1341 break; 1342 case '*': 1343 c = *p; 1344 while (c == CTLQUOTEMARK || c == '*') 1345 c = *++p; 1346 if (c != CTLESC && c != CTLQUOTEMARK && 1347 c != '?' && c != '*' && c != '[') { 1348 while (*q != c) { 1349 if (squoted && *q == CTLESC && 1350 q[1] == c) 1351 break; 1352 if (*q == '\0') 1353 return 0; 1354 if (squoted && *q == CTLESC) 1355 q++; 1356 q++; 1357 } 1358 } 1359 do { 1360 if (pmatch(p, q, squoted)) 1361 return 1; 1362 if (squoted && *q == CTLESC) 1363 q++; 1364 } while (*q++ != '\0'); 1365 return 0; 1366 case '[': { 1367 char *endp; 1368 int invert, found; 1369 char chr; 1370 1371 endp = p; 1372 if (*endp == '!') 1373 endp++; 1374 for (;;) { 1375 while (*endp == CTLQUOTEMARK) 1376 endp++; 1377 if (*endp == '\0') 1378 goto dft; /* no matching ] */ 1379 if (*endp == CTLESC) 1380 endp++; 1381 if (*++endp == ']') 1382 break; 1383 } 1384 invert = 0; 1385 if (*p == '!') { 1386 invert++; 1387 p++; 1388 } 1389 found = 0; 1390 chr = *q++; 1391 if (squoted && chr == CTLESC) 1392 chr = *q++; 1393 if (chr == '\0') 1394 return 0; 1395 c = *p++; 1396 do { 1397 if (c == CTLQUOTEMARK) 1398 continue; 1399 if (c == CTLESC) 1400 c = *p++; 1401 if (*p == '-' && p[1] != ']') { 1402 p++; 1403 while (*p == CTLQUOTEMARK) 1404 p++; 1405 if (*p == CTLESC) 1406 p++; 1407 if (chr >= c && chr <= *p) 1408 found = 1; 1409 p++; 1410 } else { 1411 if (chr == c) 1412 found = 1; 1413 } 1414 } while ((c = *p++) != ']'); 1415 if (found == invert) 1416 return 0; 1417 break; 1418 } 1419 dft: default: 1420 if (squoted && *q == CTLESC) 1421 q++; 1422 if (*q++ != c) 1423 return 0; 1424 break; 1425 } 1426 } 1427 breakloop: 1428 if (*q != '\0') 1429 return 0; 1430 return 1; 1431 } 1432 1433 1434 1435 /* 1436 * Remove any CTLESC characters from a string. 1437 */ 1438 1439 void 1440 rmescapes(char *str) 1441 { 1442 char *p, *q; 1443 1444 p = str; 1445 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1446 if (*p++ == '\0') 1447 return; 1448 } 1449 q = p; 1450 while (*p) { 1451 if (*p == CTLQUOTEMARK) { 1452 p++; 1453 continue; 1454 } 1455 if (*p == CTLESC) 1456 p++; 1457 *q++ = *p++; 1458 } 1459 *q = '\0'; 1460 } 1461 1462 1463 1464 /* 1465 * See if a pattern matches in a case statement. 1466 */ 1467 1468 int 1469 casematch(union node *pattern, char *val) 1470 { 1471 struct stackmark smark; 1472 int result; 1473 char *p; 1474 1475 setstackmark(&smark); 1476 argbackq = pattern->narg.backquote; 1477 STARTSTACKSTR(expdest); 1478 ifslastp = NULL; 1479 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1480 STPUTC('\0', expdest); 1481 p = grabstackstr(expdest); 1482 result = patmatch(p, val, 0); 1483 popstackmark(&smark); 1484 return result; 1485 } 1486 1487 /* 1488 * Our own itoa(). 1489 */ 1490 1491 STATIC char * 1492 cvtnum(int num, char *buf) 1493 { 1494 char temp[32]; 1495 int neg = num < 0; 1496 char *p = temp + 31; 1497 1498 temp[31] = '\0'; 1499 1500 do { 1501 *--p = num % 10 + '0'; 1502 } while ((num /= 10) != 0); 1503 1504 if (neg) 1505 *--p = '-'; 1506 1507 while (*p) 1508 STPUTC(*p++, buf); 1509 return buf; 1510 } 1511