expand.c revision 54631
1/*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37#ifndef lint 38#if 0 39static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95"; 40#endif 41static const char rcsid[] = 42 "$FreeBSD: head/bin/sh/expand.c 54631 1999-12-15 11:46:32Z cracauer $"; 43#endif /* not lint */ 44 45#include <sys/types.h> 46#include <sys/time.h> 47#include <sys/stat.h> 48#include <errno.h> 49#include <dirent.h> 50#include <unistd.h> 51#include <pwd.h> 52#include <stdlib.h> 53#include <limits.h> 54#include <stdio.h> 55 56/* 57 * Routines to expand arguments to commands. We have to deal with 58 * backquotes, shell variables, and file metacharacters. 59 */ 60 61#include "shell.h" 62#include "main.h" 63#include "nodes.h" 64#include "eval.h" 65#include "expand.h" 66#include "syntax.h" 67#include "parser.h" 68#include "jobs.h" 69#include "options.h" 70#include "var.h" 71#include "input.h" 72#include "output.h" 73#include "memalloc.h" 74#include "error.h" 75#include "mystring.h" 76#include "arith.h" 77#include "show.h" 78 79/* 80 * Structure specifying which parts of the string should be searched 81 * for IFS characters. 82 */ 83 84struct 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 nulonly; /* search for nul bytes only */ 89}; 90 91 92char *expdest; /* output of current string */ 93struct nodelist *argbackq; /* list of back quote expressions */ 94struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 95struct ifsregion *ifslastp; /* last struct in list */ 96struct arglist exparg; /* holds expanded arg list */ 97 98STATIC void argstr __P((char *, int)); 99STATIC char *exptilde __P((char *, int)); 100STATIC void expbackq __P((union node *, int, int)); 101STATIC int subevalvar __P((char *, char *, int, int, int, int)); 102STATIC char *evalvar __P((char *, int)); 103STATIC int varisset __P((char *, int)); 104STATIC void varvalue __P((char *, int, int)); 105STATIC void recordregion __P((int, int, int)); 106STATIC void removerecordregions __P((int)); 107STATIC void ifsbreakup __P((char *, struct arglist *)); 108STATIC void expandmeta __P((struct strlist *, int)); 109STATIC void expmeta __P((char *, char *)); 110STATIC void addfname __P((char *)); 111STATIC struct strlist *expsort __P((struct strlist *)); 112STATIC struct strlist *msort __P((struct strlist *, int)); 113STATIC int pmatch __P((char *, char *, int)); 114STATIC char *cvtnum __P((int, char *)); 115STATIC int collate_range_cmp __P((int, int)); 116 117STATIC int collate_range_cmp (c1, c2) 118 int c1, c2; 119{ 120 static char s1[2], s2[2]; 121 int ret; 122 123 c1 &= UCHAR_MAX; 124 c2 &= UCHAR_MAX; 125 if (c1 == c2) 126 return (0); 127 s1[0] = c1; 128 s2[0] = c2; 129 if ((ret = strcoll(s1, s2)) != 0) 130 return (ret); 131 return (c1 - c2); 132} 133 134/* 135 * Expand shell variables and backquotes inside a here document. 136 */ 137 138void 139expandhere(arg, fd) 140 union node *arg; /* the document */ 141 int fd; /* where to write the expanded version */ 142 { 143 herefd = fd; 144 expandarg(arg, (struct arglist *)NULL, 0); 145 xwrite(fd, stackblock(), expdest - stackblock()); 146} 147 148 149/* 150 * Perform variable substitution and command substitution on an argument, 151 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 152 * perform splitting and file name expansion. When arglist is NULL, perform 153 * here document expansion. 154 */ 155 156void 157expandarg(arg, arglist, flag) 158 union node *arg; 159 struct arglist *arglist; 160 int flag; 161{ 162 struct strlist *sp; 163 char *p; 164 165 argbackq = arg->narg.backquote; 166 STARTSTACKSTR(expdest); 167 ifsfirst.next = NULL; 168 ifslastp = NULL; 169 argstr(arg->narg.text, flag); 170 if (arglist == NULL) { 171 return; /* here document expanded */ 172 } 173 STPUTC('\0', expdest); 174 p = grabstackstr(expdest); 175 exparg.lastp = &exparg.list; 176 /* 177 * TODO - EXP_REDIR 178 */ 179 if (flag & EXP_FULL) { 180 ifsbreakup(p, &exparg); 181 *exparg.lastp = NULL; 182 exparg.lastp = &exparg.list; 183 expandmeta(exparg.list, flag); 184 } else { 185 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 186 rmescapes(p); 187 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 188 sp->text = p; 189 *exparg.lastp = sp; 190 exparg.lastp = &sp->next; 191 } 192 while (ifsfirst.next != NULL) { 193 struct ifsregion *ifsp; 194 INTOFF; 195 ifsp = ifsfirst.next->next; 196 ckfree(ifsfirst.next); 197 ifsfirst.next = ifsp; 198 INTON; 199 } 200 *exparg.lastp = NULL; 201 if (exparg.list) { 202 *arglist->lastp = exparg.list; 203 arglist->lastp = exparg.lastp; 204 } 205} 206 207 208 209/* 210 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC 211 * characters to allow for further processing. Otherwise treat 212 * $@ like $* since no splitting will be performed. 213 */ 214 215STATIC void 216argstr(p, flag) 217 char *p; 218 int flag; 219{ 220 char c; 221 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */ 222 int firsteq = 1; 223 224 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 225 p = exptilde(p, flag); 226 for (;;) { 227 switch (c = *p++) { 228 case '\0': 229 case CTLENDVAR: /* ??? */ 230 goto breakloop; 231 case CTLQUOTEMARK: 232 /* "$@" syntax adherence hack */ 233 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 234 break; 235 if ((flag & EXP_FULL) != 0) 236 STPUTC(c, expdest); 237 break; 238 case CTLESC: 239 if (quotes) 240 STPUTC(c, expdest); 241 c = *p++; 242 STPUTC(c, expdest); 243 break; 244 case CTLVAR: 245 p = evalvar(p, flag); 246 break; 247 case CTLBACKQ: 248 case CTLBACKQ|CTLQUOTE: 249 expbackq(argbackq->n, c & CTLQUOTE, flag); 250 argbackq = argbackq->next; 251 break; 252 case CTLENDARI: 253 expari(flag); 254 break; 255 case ':': 256 case '=': 257 /* 258 * sort of a hack - expand tildes in variable 259 * assignments (after the first '=' and after ':'s). 260 */ 261 STPUTC(c, expdest); 262 if (flag & EXP_VARTILDE && *p == '~') { 263 if (c == '=') { 264 if (firsteq) 265 firsteq = 0; 266 else 267 break; 268 } 269 p = exptilde(p, flag); 270 } 271 break; 272 default: 273 STPUTC(c, expdest); 274 } 275 } 276breakloop:; 277} 278 279STATIC char * 280exptilde(p, flag) 281 char *p; 282 int flag; 283{ 284 char c, *startp = p; 285 struct passwd *pw; 286 char *home; 287 int quotes = flag & (EXP_FULL | EXP_CASE); 288 289 while ((c = *p) != '\0') { 290 switch(c) { 291 case CTLESC: 292 return (startp); 293 case CTLQUOTEMARK: 294 return (startp); 295 case ':': 296 if (flag & EXP_VARTILDE) 297 goto done; 298 break; 299 case '/': 300 goto done; 301 } 302 p++; 303 } 304done: 305 *p = '\0'; 306 if (*(startp+1) == '\0') { 307 if ((home = lookupvar("HOME")) == NULL) 308 goto lose; 309 } else { 310 if ((pw = getpwnam(startp+1)) == NULL) 311 goto lose; 312 home = pw->pw_dir; 313 } 314 if (*home == '\0') 315 goto lose; 316 *p = c; 317 while ((c = *home++) != '\0') { 318 if (quotes && c >= 0 && SQSYNTAX[(int)c] == CCTL) 319 STPUTC(CTLESC, expdest); 320 STPUTC(c, expdest); 321 } 322 return (p); 323lose: 324 *p = c; 325 return (startp); 326} 327 328 329STATIC void 330removerecordregions(endoff) 331 int endoff; 332{ 333 if (ifslastp == NULL) 334 return; 335 336 if (ifsfirst.endoff > endoff) { 337 while (ifsfirst.next != NULL) { 338 struct ifsregion *ifsp; 339 INTOFF; 340 ifsp = ifsfirst.next->next; 341 ckfree(ifsfirst.next); 342 ifsfirst.next = ifsp; 343 INTON; 344 } 345 if (ifsfirst.begoff > endoff) 346 ifslastp = NULL; 347 else { 348 ifslastp = &ifsfirst; 349 ifsfirst.endoff = endoff; 350 } 351 return; 352 } 353 354 ifslastp = &ifsfirst; 355 while (ifslastp->next && ifslastp->next->begoff < endoff) 356 ifslastp=ifslastp->next; 357 while (ifslastp->next != NULL) { 358 struct ifsregion *ifsp; 359 INTOFF; 360 ifsp = ifslastp->next->next; 361 ckfree(ifslastp->next); 362 ifslastp->next = ifsp; 363 INTON; 364 } 365 if (ifslastp->endoff > endoff) 366 ifslastp->endoff = endoff; 367} 368 369/* 370 * Expand arithmetic expression. Backup to start of expression, 371 * evaluate, place result in (backed up) result, adjust string position. 372 */ 373void 374expari(flag) 375 int flag; 376{ 377 char *p, *start; 378 int result; 379 int begoff; 380 int quotes = flag & (EXP_FULL | EXP_CASE); 381 int quoted; 382 383 384 /* 385 * This routine is slightly over-complicated for 386 * efficiency. First we make sure there is 387 * enough space for the result, which may be bigger 388 * than the expression if we add exponentiation. Next we 389 * scan backwards looking for the start of arithmetic. If the 390 * next previous character is a CTLESC character, then we 391 * have to rescan starting from the beginning since CTLESC 392 * characters have to be processed left to right. 393 */ 394#if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10 395#error "integers with more than 10 digits are not supported" 396#endif 397 CHECKSTRSPACE(12 - 2, expdest); 398 USTPUTC('\0', expdest); 399 start = stackblock(); 400 p = expdest; 401 while (*p != CTLARI && p >= start) 402 --p; 403 if (*p != CTLARI) 404 error("missing CTLARI (shouldn't happen)"); 405 if (p > start && *(p-1) == CTLESC) 406 for (p = start; *p != CTLARI; p++) 407 if (*p == CTLESC) 408 p++; 409 410 if (p[1] == '"') 411 quoted=1; 412 else 413 quoted=0; 414 begoff = p - start; 415 removerecordregions(begoff); 416 if (quotes) 417 rmescapes(p+2); 418 result = arith(p+2); 419 fmtstr(p, 12, "%d", result); 420 while (*p++) 421 ; 422 if (quoted == 0) 423 recordregion(begoff, p - 1 - start, 0); 424 result = expdest - p + 1; 425 STADJUST(-result, expdest); 426} 427 428 429/* 430 * Expand stuff in backwards quotes. 431 */ 432 433STATIC void 434expbackq(cmd, quoted, flag) 435 union node *cmd; 436 int quoted; 437 int flag; 438{ 439 struct backcmd in; 440 int i; 441 char buf[128]; 442 char *p; 443 char *dest = expdest; 444 struct ifsregion saveifs, *savelastp; 445 struct nodelist *saveargbackq; 446 char lastc; 447 int startloc = dest - stackblock(); 448 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 449 int saveherefd; 450 int quotes = flag & (EXP_FULL | EXP_CASE); 451 452 INTOFF; 453 saveifs = ifsfirst; 454 savelastp = ifslastp; 455 saveargbackq = argbackq; 456 saveherefd = herefd; 457 herefd = -1; 458 p = grabstackstr(dest); 459 evalbackcmd(cmd, &in); 460 ungrabstackstr(p, dest); 461 ifsfirst = saveifs; 462 ifslastp = savelastp; 463 argbackq = saveargbackq; 464 herefd = saveherefd; 465 466 p = in.buf; 467 lastc = '\0'; 468 for (;;) { 469 if (--in.nleft < 0) { 470 if (in.fd < 0) 471 break; 472 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 473 TRACE(("expbackq: read returns %d\n", i)); 474 if (i <= 0) 475 break; 476 p = buf; 477 in.nleft = i - 1; 478 } 479 lastc = *p++; 480 if (lastc != '\0') { 481 if (quotes && lastc >= 0 && syntax[(int)lastc] == CCTL) 482 STPUTC(CTLESC, dest); 483 STPUTC(lastc, dest); 484 } 485 } 486 487 /* Eat all trailing newlines */ 488 for (p--; lastc == '\n'; lastc = *--p) 489 STUNPUTC(dest); 490 491 if (in.fd >= 0) 492 close(in.fd); 493 if (in.buf) 494 ckfree(in.buf); 495 if (in.jp) 496 exitstatus = waitforjob(in.jp, (int *)NULL); 497 if (quoted == 0) 498 recordregion(startloc, dest - stackblock(), 0); 499 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 500 (dest - stackblock()) - startloc, 501 (dest - stackblock()) - startloc, 502 stackblock() + startloc)); 503 expdest = dest; 504 INTON; 505} 506 507 508 509STATIC int 510subevalvar(p, str, strloc, subtype, startloc, varflags) 511 char *p; 512 char *str; 513 int strloc; 514 int subtype; 515 int startloc; 516 int varflags; 517{ 518 char *startp; 519 char *loc = NULL; 520 char *q; 521 int c = 0; 522 int saveherefd = herefd; 523 struct nodelist *saveargbackq = argbackq; 524 int amount; 525 526 herefd = -1; 527 argstr(p, 0); 528 STACKSTRNUL(expdest); 529 herefd = saveherefd; 530 argbackq = saveargbackq; 531 startp = stackblock() + startloc; 532 if (str == NULL) 533 str = stackblock() + strloc; 534 535 switch (subtype) { 536 case VSASSIGN: 537 setvar(str, startp, 0); 538 amount = startp - expdest; 539 STADJUST(amount, expdest); 540 varflags &= ~VSNUL; 541 if (c != 0) 542 *loc = c; 543 return 1; 544 545 case VSQUESTION: 546 if (*p != CTLENDVAR) { 547 outfmt(&errout, "%s\n", startp); 548 error((char *)NULL); 549 } 550 error("%.*s: parameter %snot set", p - str - 1, 551 str, (varflags & VSNUL) ? "null or " 552 : nullstr); 553 return 0; 554 555 case VSTRIMLEFT: 556 for (loc = startp; loc < str; loc++) { 557 c = *loc; 558 *loc = '\0'; 559 if (patmatch(str, startp, varflags & VSQUOTE)) { 560 *loc = c; 561 goto recordleft; 562 } 563 *loc = c; 564 if ((varflags & VSQUOTE) && *loc == CTLESC) 565 loc++; 566 } 567 return 0; 568 569 case VSTRIMLEFTMAX: 570 for (loc = str - 1; loc >= startp;) { 571 c = *loc; 572 *loc = '\0'; 573 if (patmatch(str, startp, varflags & VSQUOTE)) { 574 *loc = c; 575 goto recordleft; 576 } 577 *loc = c; 578 loc--; 579 if ((varflags & VSQUOTE) && loc > startp && 580 *(loc - 1) == CTLESC) { 581 for (q = startp; q < loc; q++) 582 if (*q == CTLESC) 583 q++; 584 if (q > loc) 585 loc--; 586 } 587 } 588 return 0; 589 590 case VSTRIMRIGHT: 591 for (loc = str - 1; loc >= startp;) { 592 if (patmatch(str, loc, varflags & VSQUOTE)) { 593 amount = loc - expdest; 594 STADJUST(amount, expdest); 595 return 1; 596 } 597 loc--; 598 if ((varflags & VSQUOTE) && loc > startp && 599 *(loc - 1) == CTLESC) { 600 for (q = startp; q < loc; q++) 601 if (*q == CTLESC) 602 q++; 603 if (q > loc) 604 loc--; 605 } 606 } 607 return 0; 608 609 case VSTRIMRIGHTMAX: 610 for (loc = startp; loc < str - 1; loc++) { 611 if (patmatch(str, loc, varflags & VSQUOTE)) { 612 amount = loc - expdest; 613 STADJUST(amount, expdest); 614 return 1; 615 } 616 if ((varflags & VSQUOTE) && *loc == CTLESC) 617 loc++; 618 } 619 return 0; 620 621 622 default: 623 abort(); 624 } 625 626recordleft: 627 amount = ((str - 1) - (loc - startp)) - expdest; 628 STADJUST(amount, expdest); 629 while (loc != str - 1) 630 *startp++ = *loc++; 631 return 1; 632} 633 634 635/* 636 * Expand a variable, and return a pointer to the next character in the 637 * input string. 638 */ 639 640STATIC char * 641evalvar(p, flag) 642 char *p; 643 int flag; 644{ 645 int subtype; 646 int varflags; 647 char *var; 648 char *val; 649 int patloc; 650 int c; 651 int set; 652 int special; 653 int startloc; 654 int varlen; 655 int easy; 656 int quotes = flag & (EXP_FULL | EXP_CASE); 657 658 varflags = *p++; 659 subtype = varflags & VSTYPE; 660 var = p; 661 special = 0; 662 if (! is_name(*p)) 663 special = 1; 664 p = strchr(p, '=') + 1; 665again: /* jump here after setting a variable with ${var=text} */ 666 if (special) { 667 set = varisset(var, varflags & VSNUL); 668 val = NULL; 669 } else { 670 val = lookupvar(var); 671 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 672 val = NULL; 673 set = 0; 674 } else 675 set = 1; 676 } 677 varlen = 0; 678 startloc = expdest - stackblock(); 679 if (set && subtype != VSPLUS) { 680 /* insert the value of the variable */ 681 if (special) { 682 varvalue(var, varflags & VSQUOTE, flag & EXP_FULL); 683 if (subtype == VSLENGTH) { 684 varlen = expdest - stackblock() - startloc; 685 STADJUST(-varlen, expdest); 686 } 687 } else { 688 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 689 : BASESYNTAX; 690 691 if (subtype == VSLENGTH) { 692 for (;*val; val++) 693 varlen++; 694 } 695 else { 696 while (*val) { 697 if (quotes && *val >= 0 && 698 syntax[(int)*val] == CCTL) 699 STPUTC(CTLESC, expdest); 700 STPUTC(*val++, expdest); 701 } 702 703 } 704 } 705 } 706 707 if (subtype == VSPLUS) 708 set = ! set; 709 710 easy = ((varflags & VSQUOTE) == 0 || 711 (*var == '@' && shellparam.nparam != 1)); 712 713 714 switch (subtype) { 715 case VSLENGTH: 716 expdest = cvtnum(varlen, expdest); 717 goto record; 718 719 case VSNORMAL: 720 if (!easy) 721 break; 722record: 723 recordregion(startloc, expdest - stackblock(), 724 varflags & VSQUOTE); 725 break; 726 727 case VSPLUS: 728 case VSMINUS: 729 if (!set) { 730 argstr(p, flag); 731 break; 732 } 733 if (easy) 734 goto record; 735 break; 736 737 case VSTRIMLEFT: 738 case VSTRIMLEFTMAX: 739 case VSTRIMRIGHT: 740 case VSTRIMRIGHTMAX: 741 if (!set) 742 break; 743 /* 744 * Terminate the string and start recording the pattern 745 * right after it 746 */ 747 STPUTC('\0', expdest); 748 patloc = expdest - stackblock(); 749 if (subevalvar(p, NULL, patloc, subtype, 750 startloc, varflags) == 0) { 751 int amount = (expdest - stackblock() - patloc) + 1; 752 STADJUST(-amount, expdest); 753 } 754 /* Remove any recorded regions beyond start of variable */ 755 removerecordregions(startloc); 756 goto record; 757 758 case VSASSIGN: 759 case VSQUESTION: 760 if (!set) { 761 if (subevalvar(p, var, 0, subtype, startloc, varflags)) { 762 varflags &= ~VSNUL; 763 /* 764 * Remove any recorded regions beyond 765 * start of variable 766 */ 767 removerecordregions(startloc); 768 goto again; 769 } 770 break; 771 } 772 if (easy) 773 goto record; 774 break; 775 776 default: 777 abort(); 778 } 779 780 if (subtype != VSNORMAL) { /* skip to end of alternative */ 781 int nesting = 1; 782 for (;;) { 783 if ((c = *p++) == CTLESC) 784 p++; 785 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 786 if (set) 787 argbackq = argbackq->next; 788 } else if (c == CTLVAR) { 789 if ((*p++ & VSTYPE) != VSNORMAL) 790 nesting++; 791 } else if (c == CTLENDVAR) { 792 if (--nesting == 0) 793 break; 794 } 795 } 796 } 797 return p; 798} 799 800 801 802/* 803 * Test whether a specialized variable is set. 804 */ 805 806STATIC int 807varisset(name, nulok) 808 char *name; 809 int nulok; 810{ 811 812 if (*name == '!') 813 return backgndpid != -1; 814 else if (*name == '@' || *name == '*') { 815 if (*shellparam.p == NULL) 816 return 0; 817 818 if (nulok) { 819 char **av; 820 821 for (av = shellparam.p; *av; av++) 822 if (**av != '\0') 823 return 1; 824 return 0; 825 } 826 } else if (is_digit(*name)) { 827 char *ap; 828 int num = atoi(name); 829 830 if (num > shellparam.nparam) 831 return 0; 832 833 if (num == 0) 834 ap = arg0; 835 else 836 ap = shellparam.p[num - 1]; 837 838 if (nulok && (ap == NULL || *ap == '\0')) 839 return 0; 840 } 841 return 1; 842} 843 844 845 846/* 847 * Add the value of a specialized variable to the stack string. 848 */ 849 850STATIC void 851varvalue(name, quoted, allow_split) 852 char *name; 853 int quoted; 854 int allow_split; 855{ 856 int num; 857 char *p; 858 int i; 859 extern int oexitstatus; 860 char sep; 861 char **ap; 862 char const *syntax; 863 864#define STRTODEST(p) \ 865 do {\ 866 if (allow_split) { \ 867 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 868 while (*p) { \ 869 if (*p >= 0 && syntax[(int)*p] == CCTL) \ 870 STPUTC(CTLESC, expdest); \ 871 STPUTC(*p++, expdest); \ 872 } \ 873 } else \ 874 while (*p) \ 875 STPUTC(*p++, expdest); \ 876 } while (0) 877 878 879 switch (*name) { 880 case '$': 881 num = rootpid; 882 goto numvar; 883 case '?': 884 num = oexitstatus; 885 goto numvar; 886 case '#': 887 num = shellparam.nparam; 888 goto numvar; 889 case '!': 890 num = backgndpid; 891numvar: 892 expdest = cvtnum(num, expdest); 893 break; 894 case '-': 895 for (i = 0 ; i < NOPTS ; i++) { 896 if (optlist[i].val) 897 STPUTC(optlist[i].letter, expdest); 898 } 899 break; 900 case '@': 901 if (allow_split && quoted) { 902 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 903 STRTODEST(p); 904 if (*ap) 905 STPUTC('\0', expdest); 906 } 907 break; 908 } 909 /* fall through */ 910 case '*': 911 if (ifsset() != 0) 912 sep = ifsval()[0]; 913 else 914 sep = ' '; 915 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 916 STRTODEST(p); 917 if (*ap && sep) 918 STPUTC(sep, expdest); 919 } 920 break; 921 case '0': 922 p = arg0; 923 STRTODEST(p); 924 break; 925 default: 926 if (is_digit(*name)) { 927 num = atoi(name); 928 if (num > 0 && num <= shellparam.nparam) { 929 p = shellparam.p[num - 1]; 930 STRTODEST(p); 931 } 932 } 933 break; 934 } 935} 936 937 938 939/* 940 * Record the the fact that we have to scan this region of the 941 * string for IFS characters. 942 */ 943 944STATIC void 945recordregion(start, end, nulonly) 946 int start; 947 int end; 948 int nulonly; 949{ 950 struct ifsregion *ifsp; 951 952 if (ifslastp == NULL) { 953 ifsp = &ifsfirst; 954 } else { 955 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 956 ifslastp->next = ifsp; 957 } 958 ifslastp = ifsp; 959 ifslastp->next = NULL; 960 ifslastp->begoff = start; 961 ifslastp->endoff = end; 962 ifslastp->nulonly = nulonly; 963} 964 965 966 967/* 968 * Break the argument string into pieces based upon IFS and add the 969 * strings to the argument list. The regions of the string to be 970 * searched for IFS characters have been stored by recordregion. 971 */ 972STATIC void 973ifsbreakup(string, arglist) 974 char *string; 975 struct arglist *arglist; 976 { 977 struct ifsregion *ifsp; 978 struct strlist *sp; 979 char *start; 980 char *p; 981 char *q; 982 char *ifs; 983 int ifsspc; 984 int nulonly; 985 986 987 start = string; 988 ifsspc = 0; 989 nulonly = 0; 990 if (ifslastp != NULL) { 991 ifsp = &ifsfirst; 992 do { 993 p = string + ifsp->begoff; 994 nulonly = ifsp->nulonly; 995 ifs = nulonly ? nullstr : 996 ( ifsset() ? ifsval() : " \t\n" ); 997 ifsspc = 0; 998 while (p < string + ifsp->endoff) { 999 q = p; 1000 if (*p == CTLESC) 1001 p++; 1002 if (strchr(ifs, *p)) { 1003 if (!nulonly) 1004 ifsspc = (strchr(" \t\n", *p) != NULL); 1005 /* Ignore IFS whitespace at start */ 1006 if (q == start && ifsspc) { 1007 p++; 1008 start = p; 1009 continue; 1010 } 1011 *q = '\0'; 1012 sp = (struct strlist *)stalloc(sizeof *sp); 1013 sp->text = start; 1014 *arglist->lastp = sp; 1015 arglist->lastp = &sp->next; 1016 p++; 1017 if (!nulonly) { 1018 for (;;) { 1019 if (p >= string + ifsp->endoff) { 1020 break; 1021 } 1022 q = p; 1023 if (*p == CTLESC) 1024 p++; 1025 if (strchr(ifs, *p) == NULL ) { 1026 p = q; 1027 break; 1028 } else if (strchr(" \t\n",*p) == NULL) { 1029 if (ifsspc) { 1030 p++; 1031 ifsspc = 0; 1032 } else { 1033 p = q; 1034 break; 1035 } 1036 } else 1037 p++; 1038 } 1039 } 1040 start = p; 1041 } else 1042 p++; 1043 } 1044 } while ((ifsp = ifsp->next) != NULL); 1045 if (*start || (!ifsspc && start > string && 1046 (nulonly || 1))) { 1047 sp = (struct strlist *)stalloc(sizeof *sp); 1048 sp->text = start; 1049 *arglist->lastp = sp; 1050 arglist->lastp = &sp->next; 1051 } 1052 } else { 1053 sp = (struct strlist *)stalloc(sizeof *sp); 1054 sp->text = start; 1055 *arglist->lastp = sp; 1056 arglist->lastp = &sp->next; 1057 } 1058} 1059 1060 1061 1062/* 1063 * Expand shell metacharacters. At this point, the only control characters 1064 * should be escapes. The results are stored in the list exparg. 1065 */ 1066 1067char *expdir; 1068 1069 1070STATIC void 1071expandmeta(str, flag) 1072 struct strlist *str; 1073 int flag __unused; 1074{ 1075 char *p; 1076 struct strlist **savelastp; 1077 struct strlist *sp; 1078 char c; 1079 /* TODO - EXP_REDIR */ 1080 1081 while (str) { 1082 if (fflag) 1083 goto nometa; 1084 p = str->text; 1085 for (;;) { /* fast check for meta chars */ 1086 if ((c = *p++) == '\0') 1087 goto nometa; 1088 if (c == '*' || c == '?' || c == '[' || c == '!') 1089 break; 1090 } 1091 savelastp = exparg.lastp; 1092 INTOFF; 1093 if (expdir == NULL) { 1094 int i = strlen(str->text); 1095 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1096 } 1097 1098 expmeta(expdir, str->text); 1099 ckfree(expdir); 1100 expdir = NULL; 1101 INTON; 1102 if (exparg.lastp == savelastp) { 1103 /* 1104 * no matches 1105 */ 1106nometa: 1107 *exparg.lastp = str; 1108 rmescapes(str->text); 1109 exparg.lastp = &str->next; 1110 } else { 1111 *exparg.lastp = NULL; 1112 *savelastp = sp = expsort(*savelastp); 1113 while (sp->next != NULL) 1114 sp = sp->next; 1115 exparg.lastp = &sp->next; 1116 } 1117 str = str->next; 1118 } 1119} 1120 1121 1122/* 1123 * Do metacharacter (i.e. *, ?, [...]) expansion. 1124 */ 1125 1126STATIC void 1127expmeta(enddir, name) 1128 char *enddir; 1129 char *name; 1130 { 1131 char *p; 1132 char *q; 1133 char *start; 1134 char *endname; 1135 int metaflag; 1136 struct stat statb; 1137 DIR *dirp; 1138 struct dirent *dp; 1139 int atend; 1140 int matchdot; 1141 1142 metaflag = 0; 1143 start = name; 1144 for (p = name ; ; p++) { 1145 if (*p == '*' || *p == '?') 1146 metaflag = 1; 1147 else if (*p == '[') { 1148 q = p + 1; 1149 if (*q == '!' || *q == '^') 1150 q++; 1151 for (;;) { 1152 while (*q == CTLQUOTEMARK) 1153 q++; 1154 if (*q == CTLESC) 1155 q++; 1156 if (*q == '/' || *q == '\0') 1157 break; 1158 if (*++q == ']') { 1159 metaflag = 1; 1160 break; 1161 } 1162 } 1163 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1164 metaflag = 1; 1165 } else if (*p == '\0') 1166 break; 1167 else if (*p == CTLQUOTEMARK) 1168 continue; 1169 else if (*p == CTLESC) 1170 p++; 1171 if (*p == '/') { 1172 if (metaflag) 1173 break; 1174 start = p + 1; 1175 } 1176 } 1177 if (metaflag == 0) { /* we've reached the end of the file name */ 1178 if (enddir != expdir) 1179 metaflag++; 1180 for (p = name ; ; p++) { 1181 if (*p == CTLQUOTEMARK) 1182 continue; 1183 if (*p == CTLESC) 1184 p++; 1185 *enddir++ = *p; 1186 if (*p == '\0') 1187 break; 1188 } 1189 if (metaflag == 0 || stat(expdir, &statb) >= 0) 1190 addfname(expdir); 1191 return; 1192 } 1193 endname = p; 1194 if (start != name) { 1195 p = name; 1196 while (p < start) { 1197 while (*p == CTLQUOTEMARK) 1198 p++; 1199 if (*p == CTLESC) 1200 p++; 1201 *enddir++ = *p++; 1202 } 1203 } 1204 if (enddir == expdir) { 1205 p = "."; 1206 } else if (enddir == expdir + 1 && *expdir == '/') { 1207 p = "/"; 1208 } else { 1209 p = expdir; 1210 enddir[-1] = '\0'; 1211 } 1212 if ((dirp = opendir(p)) == NULL) 1213 return; 1214 if (enddir != expdir) 1215 enddir[-1] = '/'; 1216 if (*endname == 0) { 1217 atend = 1; 1218 } else { 1219 atend = 0; 1220 *endname++ = '\0'; 1221 } 1222 matchdot = 0; 1223 p = start; 1224 while (*p == CTLQUOTEMARK) 1225 p++; 1226 if (*p == CTLESC) 1227 p++; 1228 if (*p == '.') 1229 matchdot++; 1230 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1231 if (dp->d_name[0] == '.' && ! matchdot) 1232 continue; 1233 if (patmatch(start, dp->d_name, 0)) { 1234 if (atend) { 1235 scopy(dp->d_name, enddir); 1236 addfname(expdir); 1237 } else { 1238 char *q; 1239 for (p = enddir, q = dp->d_name; 1240 (*p++ = *q++) != '\0';) 1241 continue; 1242 p[-1] = '/'; 1243 expmeta(p, endname); 1244 } 1245 } 1246 } 1247 closedir(dirp); 1248 if (! atend) 1249 endname[-1] = '/'; 1250} 1251 1252 1253/* 1254 * Add a file name to the list. 1255 */ 1256 1257STATIC void 1258addfname(name) 1259 char *name; 1260 { 1261 char *p; 1262 struct strlist *sp; 1263 1264 p = stalloc(strlen(name) + 1); 1265 scopy(name, p); 1266 sp = (struct strlist *)stalloc(sizeof *sp); 1267 sp->text = p; 1268 *exparg.lastp = sp; 1269 exparg.lastp = &sp->next; 1270} 1271 1272 1273/* 1274 * Sort the results of file name expansion. It calculates the number of 1275 * strings to sort and then calls msort (short for merge sort) to do the 1276 * work. 1277 */ 1278 1279STATIC struct strlist * 1280expsort(str) 1281 struct strlist *str; 1282 { 1283 int len; 1284 struct strlist *sp; 1285 1286 len = 0; 1287 for (sp = str ; sp ; sp = sp->next) 1288 len++; 1289 return msort(str, len); 1290} 1291 1292 1293STATIC struct strlist * 1294msort(list, len) 1295 struct strlist *list; 1296 int len; 1297{ 1298 struct strlist *p, *q = NULL; 1299 struct strlist **lpp; 1300 int half; 1301 int n; 1302 1303 if (len <= 1) 1304 return list; 1305 half = len >> 1; 1306 p = list; 1307 for (n = half ; --n >= 0 ; ) { 1308 q = p; 1309 p = p->next; 1310 } 1311 q->next = NULL; /* terminate first half of list */ 1312 q = msort(list, half); /* sort first half of list */ 1313 p = msort(p, len - half); /* sort second half */ 1314 lpp = &list; 1315 for (;;) { 1316 if (strcmp(p->text, q->text) < 0) { 1317 *lpp = p; 1318 lpp = &p->next; 1319 if ((p = *lpp) == NULL) { 1320 *lpp = q; 1321 break; 1322 } 1323 } else { 1324 *lpp = q; 1325 lpp = &q->next; 1326 if ((q = *lpp) == NULL) { 1327 *lpp = p; 1328 break; 1329 } 1330 } 1331 } 1332 return list; 1333} 1334 1335 1336 1337/* 1338 * Returns true if the pattern matches the string. 1339 */ 1340 1341int 1342patmatch(pattern, string, squoted) 1343 char *pattern; 1344 char *string; 1345 int squoted; /* string might have quote chars */ 1346 { 1347#ifdef notdef 1348 if (pattern[0] == '!' && pattern[1] == '!') 1349 return 1 - pmatch(pattern + 2, string); 1350 else 1351#endif 1352 return pmatch(pattern, string, squoted); 1353} 1354 1355 1356STATIC int 1357pmatch(pattern, string, squoted) 1358 char *pattern; 1359 char *string; 1360 int squoted; 1361 { 1362 char *p, *q; 1363 char c; 1364 1365 p = pattern; 1366 q = string; 1367 for (;;) { 1368 switch (c = *p++) { 1369 case '\0': 1370 goto breakloop; 1371 case CTLESC: 1372 if (squoted && *q == CTLESC) 1373 q++; 1374 if (*q++ != *p++) 1375 return 0; 1376 break; 1377 case CTLQUOTEMARK: 1378 continue; 1379 case '?': 1380 if (squoted && *q == CTLESC) 1381 q++; 1382 if (*q++ == '\0') 1383 return 0; 1384 break; 1385 case '*': 1386 c = *p; 1387 while (c == CTLQUOTEMARK || c == '*') 1388 c = *++p; 1389 if (c != CTLESC && c != CTLQUOTEMARK && 1390 c != '?' && c != '*' && c != '[') { 1391 while (*q != c) { 1392 if (squoted && *q == CTLESC && 1393 q[1] == c) 1394 break; 1395 if (*q == '\0') 1396 return 0; 1397 if (squoted && *q == CTLESC) 1398 q++; 1399 q++; 1400 } 1401 } 1402 do { 1403 if (pmatch(p, q, squoted)) 1404 return 1; 1405 if (squoted && *q == CTLESC) 1406 q++; 1407 } while (*q++ != '\0'); 1408 return 0; 1409 case '[': { 1410 char *endp; 1411 int invert, found; 1412 char chr; 1413 1414 endp = p; 1415 if (*endp == '!' || *endp == '^') 1416 endp++; 1417 for (;;) { 1418 while (*endp == CTLQUOTEMARK) 1419 endp++; 1420 if (*endp == '\0') 1421 goto dft; /* no matching ] */ 1422 if (*endp == CTLESC) 1423 endp++; 1424 if (*++endp == ']') 1425 break; 1426 } 1427 invert = 0; 1428 if (*p == '!' || *p == '^') { 1429 invert++; 1430 p++; 1431 } 1432 found = 0; 1433 chr = *q++; 1434 if (squoted && chr == CTLESC) 1435 chr = *q++; 1436 if (chr == '\0') 1437 return 0; 1438 c = *p++; 1439 do { 1440 if (c == CTLQUOTEMARK) 1441 continue; 1442 if (c == CTLESC) 1443 c = *p++; 1444 if (*p == '-' && p[1] != ']') { 1445 p++; 1446 while (*p == CTLQUOTEMARK) 1447 p++; 1448 if (*p == CTLESC) 1449 p++; 1450 if ( collate_range_cmp(chr, c) >= 0 1451 && collate_range_cmp(chr, *p) <= 0 1452 ) 1453 found = 1; 1454 p++; 1455 } else { 1456 if (chr == c) 1457 found = 1; 1458 } 1459 } while ((c = *p++) != ']'); 1460 if (found == invert) 1461 return 0; 1462 break; 1463 } 1464dft: default: 1465 if (squoted && *q == CTLESC) 1466 q++; 1467 if (*q++ != c) 1468 return 0; 1469 break; 1470 } 1471 } 1472breakloop: 1473 if (*q != '\0') 1474 return 0; 1475 return 1; 1476} 1477 1478 1479 1480/* 1481 * Remove any CTLESC characters from a string. 1482 */ 1483 1484void 1485rmescapes(str) 1486 char *str; 1487{ 1488 char *p, *q; 1489 1490 p = str; 1491 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1492 if (*p++ == '\0') 1493 return; 1494 } 1495 q = p; 1496 while (*p) { 1497 if (*p == CTLQUOTEMARK) { 1498 p++; 1499 continue; 1500 } 1501 if (*p == CTLESC) 1502 p++; 1503 *q++ = *p++; 1504 } 1505 *q = '\0'; 1506} 1507 1508 1509 1510/* 1511 * See if a pattern matches in a case statement. 1512 */ 1513 1514int 1515casematch(pattern, val) 1516 union node *pattern; 1517 char *val; 1518 { 1519 struct stackmark smark; 1520 int result; 1521 char *p; 1522 1523 setstackmark(&smark); 1524 argbackq = pattern->narg.backquote; 1525 STARTSTACKSTR(expdest); 1526 ifslastp = NULL; 1527 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1528 STPUTC('\0', expdest); 1529 p = grabstackstr(expdest); 1530 result = patmatch(p, val, 0); 1531 popstackmark(&smark); 1532 return result; 1533} 1534 1535/* 1536 * Our own itoa(). 1537 */ 1538 1539STATIC char * 1540cvtnum(num, buf) 1541 int num; 1542 char *buf; 1543 { 1544 char temp[32]; 1545 int neg = num < 0; 1546 char *p = temp + 31; 1547 1548 temp[31] = '\0'; 1549 1550 do { 1551 *--p = num % 10 + '0'; 1552 } while ((num /= 10) != 0); 1553 1554 if (neg) 1555 *--p = '-'; 1556 1557 while (*p) 1558 STPUTC(*p++, buf); 1559 return buf; 1560} 1561