expand.c revision 200988
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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#ifndef lint 34#if 0 35static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95"; 36#endif 37#endif /* not lint */ 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: head/bin/sh/expand.c 200988 2009-12-25 15:29:18Z jilles $"); 40 41#include <sys/types.h> 42#include <sys/time.h> 43#include <sys/stat.h> 44#include <errno.h> 45#include <dirent.h> 46#include <unistd.h> 47#include <pwd.h> 48#include <stdlib.h> 49#include <limits.h> 50#include <stdio.h> 51#include <string.h> 52 53/* 54 * Routines to expand arguments to commands. We have to deal with 55 * backquotes, shell variables, and file metacharacters. 56 */ 57 58#include "shell.h" 59#include "main.h" 60#include "nodes.h" 61#include "eval.h" 62#include "expand.h" 63#include "syntax.h" 64#include "parser.h" 65#include "jobs.h" 66#include "options.h" 67#include "var.h" 68#include "input.h" 69#include "output.h" 70#include "memalloc.h" 71#include "error.h" 72#include "mystring.h" 73#include "arith.h" 74#include "show.h" 75 76/* 77 * Structure specifying which parts of the string should be searched 78 * for IFS characters. 79 */ 80 81struct ifsregion { 82 struct ifsregion *next; /* next region in list */ 83 int begoff; /* offset of start of region */ 84 int endoff; /* offset of end of region */ 85 int inquotes; /* search for nul bytes only */ 86}; 87 88 89STATIC char *expdest; /* output of current string */ 90STATIC struct nodelist *argbackq; /* list of back quote expressions */ 91STATIC struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 92STATIC struct ifsregion *ifslastp; /* last struct in list */ 93STATIC struct arglist exparg; /* holds expanded arg list */ 94 95STATIC void argstr(char *, int); 96STATIC char *exptilde(char *, int); 97STATIC void expbackq(union node *, int, int); 98STATIC int subevalvar(char *, char *, int, int, int, int); 99STATIC char *evalvar(char *, int); 100STATIC int varisset(char *, int); 101STATIC void varvalue(char *, int, int, int); 102STATIC void recordregion(int, int, int); 103STATIC void removerecordregions(int); 104STATIC void ifsbreakup(char *, struct arglist *); 105STATIC void expandmeta(struct strlist *, int); 106STATIC void expmeta(char *, char *); 107STATIC void addfname(char *); 108STATIC struct strlist *expsort(struct strlist *); 109STATIC struct strlist *msort(struct strlist *, int); 110STATIC int pmatch(const char *, const char *, int); 111STATIC char *cvtnum(int, char *); 112STATIC int collate_range_cmp(int, int); 113 114STATIC int 115collate_range_cmp(int c1, int c2) 116{ 117 static char s1[2], s2[2]; 118 119 s1[0] = c1; 120 s2[0] = c2; 121 return (strcoll(s1, s2)); 122} 123 124/* 125 * Expand shell variables and backquotes inside a here document. 126 * union node *arg the document 127 * int fd; where to write the expanded version 128 */ 129 130void 131expandhere(union node *arg, int fd) 132{ 133 herefd = fd; 134 expandarg(arg, (struct arglist *)NULL, 0); 135 xwrite(fd, stackblock(), expdest - stackblock()); 136} 137 138 139/* 140 * Perform variable substitution and command substitution on an argument, 141 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 142 * perform splitting and file name expansion. When arglist is NULL, perform 143 * here document expansion. 144 */ 145 146void 147expandarg(union node *arg, struct arglist *arglist, int flag) 148{ 149 struct strlist *sp; 150 char *p; 151 152 argbackq = arg->narg.backquote; 153 STARTSTACKSTR(expdest); 154 ifsfirst.next = NULL; 155 ifslastp = NULL; 156 argstr(arg->narg.text, flag); 157 if (arglist == NULL) { 158 return; /* here document expanded */ 159 } 160 STPUTC('\0', expdest); 161 p = grabstackstr(expdest); 162 exparg.lastp = &exparg.list; 163 /* 164 * TODO - EXP_REDIR 165 */ 166 if (flag & EXP_FULL) { 167 ifsbreakup(p, &exparg); 168 *exparg.lastp = NULL; 169 exparg.lastp = &exparg.list; 170 expandmeta(exparg.list, flag); 171 } else { 172 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 173 rmescapes(p); 174 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 175 sp->text = p; 176 *exparg.lastp = sp; 177 exparg.lastp = &sp->next; 178 } 179 while (ifsfirst.next != NULL) { 180 struct ifsregion *ifsp; 181 INTOFF; 182 ifsp = ifsfirst.next->next; 183 ckfree(ifsfirst.next); 184 ifsfirst.next = ifsp; 185 INTON; 186 } 187 *exparg.lastp = NULL; 188 if (exparg.list) { 189 *arglist->lastp = exparg.list; 190 arglist->lastp = exparg.lastp; 191 } 192} 193 194 195 196/* 197 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC 198 * characters to allow for further processing. Otherwise treat 199 * $@ like $* since no splitting will be performed. 200 */ 201 202STATIC void 203argstr(char *p, int flag) 204{ 205 char c; 206 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */ 207 int firsteq = 1; 208 209 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 210 p = exptilde(p, flag); 211 for (;;) { 212 switch (c = *p++) { 213 case '\0': 214 case CTLENDVAR: /* ??? */ 215 goto breakloop; 216 case CTLQUOTEMARK: 217 /* "$@" syntax adherence hack */ 218 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 219 break; 220 if ((flag & EXP_FULL) != 0) 221 STPUTC(c, expdest); 222 break; 223 case CTLESC: 224 if (quotes) 225 STPUTC(c, expdest); 226 c = *p++; 227 STPUTC(c, expdest); 228 break; 229 case CTLVAR: 230 p = evalvar(p, flag); 231 break; 232 case CTLBACKQ: 233 case CTLBACKQ|CTLQUOTE: 234 expbackq(argbackq->n, c & CTLQUOTE, flag); 235 argbackq = argbackq->next; 236 break; 237 case CTLENDARI: 238 expari(flag); 239 break; 240 case ':': 241 case '=': 242 /* 243 * sort of a hack - expand tildes in variable 244 * assignments (after the first '=' and after ':'s). 245 */ 246 STPUTC(c, expdest); 247 if (flag & EXP_VARTILDE && *p == '~') { 248 if (c == '=') { 249 if (firsteq) 250 firsteq = 0; 251 else 252 break; 253 } 254 p = exptilde(p, flag); 255 } 256 break; 257 default: 258 STPUTC(c, expdest); 259 } 260 } 261breakloop:; 262} 263 264STATIC char * 265exptilde(char *p, int flag) 266{ 267 char c, *startp = p; 268 struct passwd *pw; 269 char *home; 270 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 271 272 while ((c = *p) != '\0') { 273 switch(c) { 274 case CTLESC: /* This means CTL* are always considered quoted. */ 275 case CTLVAR: 276 case CTLENDVAR: 277 case CTLBACKQ: 278 case CTLBACKQ | CTLQUOTE: 279 case CTLARI: 280 case CTLENDARI: 281 case CTLQUOTEMARK: 282 return (startp); 283 case ':': 284 if (flag & EXP_VARTILDE) 285 goto done; 286 break; 287 case '/': 288 goto done; 289 } 290 p++; 291 } 292done: 293 *p = '\0'; 294 if (*(startp+1) == '\0') { 295 if ((home = lookupvar("HOME")) == NULL) 296 goto lose; 297 } else { 298 if ((pw = getpwnam(startp+1)) == NULL) 299 goto lose; 300 home = pw->pw_dir; 301 } 302 if (*home == '\0') 303 goto lose; 304 *p = c; 305 while ((c = *home++) != '\0') { 306 if (quotes && SQSYNTAX[(int)c] == CCTL) 307 STPUTC(CTLESC, expdest); 308 STPUTC(c, expdest); 309 } 310 return (p); 311lose: 312 *p = c; 313 return (startp); 314} 315 316 317STATIC void 318removerecordregions(int endoff) 319{ 320 if (ifslastp == NULL) 321 return; 322 323 if (ifsfirst.endoff > endoff) { 324 while (ifsfirst.next != NULL) { 325 struct ifsregion *ifsp; 326 INTOFF; 327 ifsp = ifsfirst.next->next; 328 ckfree(ifsfirst.next); 329 ifsfirst.next = ifsp; 330 INTON; 331 } 332 if (ifsfirst.begoff > endoff) 333 ifslastp = NULL; 334 else { 335 ifslastp = &ifsfirst; 336 ifsfirst.endoff = endoff; 337 } 338 return; 339 } 340 341 ifslastp = &ifsfirst; 342 while (ifslastp->next && ifslastp->next->begoff < endoff) 343 ifslastp=ifslastp->next; 344 while (ifslastp->next != NULL) { 345 struct ifsregion *ifsp; 346 INTOFF; 347 ifsp = ifslastp->next->next; 348 ckfree(ifslastp->next); 349 ifslastp->next = ifsp; 350 INTON; 351 } 352 if (ifslastp->endoff > endoff) 353 ifslastp->endoff = endoff; 354} 355 356/* 357 * Expand arithmetic expression. Backup to start of expression, 358 * evaluate, place result in (backed up) result, adjust string position. 359 */ 360void 361expari(int flag) 362{ 363 char *p, *start; 364 arith_t result; 365 int begoff; 366 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 367 int quoted; 368 369 370 /* 371 * This routine is slightly over-complicated for 372 * efficiency. First we make sure there is 373 * enough space for the result, which may be bigger 374 * than the expression if we add exponentiation. Next we 375 * scan backwards looking for the start of arithmetic. If the 376 * next previous character is a CTLESC character, then we 377 * have to rescan starting from the beginning since CTLESC 378 * characters have to be processed left to right. 379 */ 380 CHECKSTRSPACE(DIGITS(result) - 2, expdest); 381 USTPUTC('\0', expdest); 382 start = stackblock(); 383 p = expdest - 2; 384 while (p >= start && *p != CTLARI) 385 --p; 386 if (p < start || *p != CTLARI) 387 error("missing CTLARI (shouldn't happen)"); 388 if (p > start && *(p - 1) == CTLESC) 389 for (p = start; *p != CTLARI; p++) 390 if (*p == CTLESC) 391 p++; 392 393 if (p[1] == '"') 394 quoted=1; 395 else 396 quoted=0; 397 begoff = p - start; 398 removerecordregions(begoff); 399 if (quotes) 400 rmescapes(p+2); 401 result = arith(p+2); 402 fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result); 403 while (*p++) 404 ; 405 if (quoted == 0) 406 recordregion(begoff, p - 1 - start, 0); 407 result = expdest - p + 1; 408 STADJUST(-result, expdest); 409} 410 411 412/* 413 * Expand stuff in backwards quotes. 414 */ 415 416STATIC void 417expbackq(union node *cmd, int quoted, int flag) 418{ 419 struct backcmd in; 420 int i; 421 char buf[128]; 422 char *p; 423 char *dest = expdest; 424 struct ifsregion saveifs, *savelastp; 425 struct nodelist *saveargbackq; 426 char lastc; 427 int startloc = dest - stackblock(); 428 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 429 int saveherefd; 430 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 431 int nnl; 432 433 INTOFF; 434 saveifs = ifsfirst; 435 savelastp = ifslastp; 436 saveargbackq = argbackq; 437 saveherefd = herefd; 438 herefd = -1; 439 p = grabstackstr(dest); 440 evalbackcmd(cmd, &in); 441 ungrabstackstr(p, dest); 442 ifsfirst = saveifs; 443 ifslastp = savelastp; 444 argbackq = saveargbackq; 445 herefd = saveherefd; 446 447 p = in.buf; 448 lastc = '\0'; 449 nnl = 0; 450 /* Don't copy trailing newlines */ 451 for (;;) { 452 if (--in.nleft < 0) { 453 if (in.fd < 0) 454 break; 455 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 456 TRACE(("expbackq: read returns %d\n", i)); 457 if (i <= 0) 458 break; 459 p = buf; 460 in.nleft = i - 1; 461 } 462 lastc = *p++; 463 if (lastc != '\0') { 464 if (quotes && syntax[(int)lastc] == CCTL) 465 STPUTC(CTLESC, dest); 466 if (lastc == '\n') { 467 nnl++; 468 } else { 469 while (nnl > 0) { 470 nnl--; 471 STPUTC('\n', dest); 472 } 473 STPUTC(lastc, dest); 474 } 475 } 476 } 477 478 if (in.fd >= 0) 479 close(in.fd); 480 if (in.buf) 481 ckfree(in.buf); 482 if (in.jp) 483 exitstatus = waitforjob(in.jp, (int *)NULL); 484 if (quoted == 0) 485 recordregion(startloc, dest - stackblock(), 0); 486 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 487 (dest - stackblock()) - startloc, 488 (dest - stackblock()) - startloc, 489 stackblock() + startloc)); 490 expdest = dest; 491 INTON; 492} 493 494 495 496STATIC int 497subevalvar(char *p, char *str, int strloc, int subtype, int startloc, 498 int varflags) 499{ 500 char *startp; 501 char *loc = NULL; 502 char *q; 503 int c = 0; 504 int saveherefd = herefd; 505 struct nodelist *saveargbackq = argbackq; 506 int amount; 507 508 herefd = -1; 509 argstr(p, 0); 510 STACKSTRNUL(expdest); 511 herefd = saveherefd; 512 argbackq = saveargbackq; 513 startp = stackblock() + startloc; 514 if (str == NULL) 515 str = stackblock() + strloc; 516 517 switch (subtype) { 518 case VSASSIGN: 519 setvar(str, startp, 0); 520 amount = startp - expdest; 521 STADJUST(amount, expdest); 522 varflags &= ~VSNUL; 523 if (c != 0) 524 *loc = c; 525 return 1; 526 527 case VSQUESTION: 528 if (*p != CTLENDVAR) { 529 outfmt(&errout, "%s\n", startp); 530 error((char *)NULL); 531 } 532 error("%.*s: parameter %snot set", (int)(p - str - 1), 533 str, (varflags & VSNUL) ? "null or " 534 : nullstr); 535 return 0; 536 537 case VSTRIMLEFT: 538 for (loc = startp; loc < str; loc++) { 539 c = *loc; 540 *loc = '\0'; 541 if (patmatch(str, startp, varflags & VSQUOTE)) { 542 *loc = c; 543 goto recordleft; 544 } 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 *loc = c; 557 goto recordleft; 558 } 559 *loc = c; 560 loc--; 561 if ((varflags & VSQUOTE) && loc > startp && 562 *(loc - 1) == CTLESC) { 563 for (q = startp; q < loc; q++) 564 if (*q == CTLESC) 565 q++; 566 if (q > loc) 567 loc--; 568 } 569 } 570 return 0; 571 572 case VSTRIMRIGHT: 573 for (loc = str - 1; loc >= startp;) { 574 if (patmatch(str, loc, varflags & VSQUOTE)) { 575 amount = loc - expdest; 576 STADJUST(amount, expdest); 577 return 1; 578 } 579 loc--; 580 if ((varflags & VSQUOTE) && loc > startp && 581 *(loc - 1) == CTLESC) { 582 for (q = startp; q < loc; q++) 583 if (*q == CTLESC) 584 q++; 585 if (q > loc) 586 loc--; 587 } 588 } 589 return 0; 590 591 case VSTRIMRIGHTMAX: 592 for (loc = startp; loc < str - 1; loc++) { 593 if (patmatch(str, loc, varflags & VSQUOTE)) { 594 amount = loc - expdest; 595 STADJUST(amount, expdest); 596 return 1; 597 } 598 if ((varflags & VSQUOTE) && *loc == CTLESC) 599 loc++; 600 } 601 return 0; 602 603 604 default: 605 abort(); 606 } 607 608recordleft: 609 amount = ((str - 1) - (loc - startp)) - expdest; 610 STADJUST(amount, expdest); 611 while (loc != str - 1) 612 *startp++ = *loc++; 613 return 1; 614} 615 616 617/* 618 * Expand a variable, and return a pointer to the next character in the 619 * input string. 620 */ 621 622STATIC char * 623evalvar(char *p, int flag) 624{ 625 int subtype; 626 int varflags; 627 char *var; 628 char *val; 629 int patloc; 630 int c; 631 int set; 632 int special; 633 int startloc; 634 int varlen; 635 int easy; 636 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 637 638 varflags = (unsigned char)*p++; 639 subtype = varflags & VSTYPE; 640 var = p; 641 special = 0; 642 if (! is_name(*p)) 643 special = 1; 644 p = strchr(p, '=') + 1; 645again: /* jump here after setting a variable with ${var=text} */ 646 if (varflags & VSLINENO) { 647 set = 1; 648 special = 0; 649 val = var; 650 p[-1] = '\0'; /* temporarily overwrite '=' to have \0 651 terminated string */ 652 } else if (special) { 653 set = varisset(var, varflags & VSNUL); 654 val = NULL; 655 } else { 656 val = bltinlookup(var, 1); 657 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 658 val = NULL; 659 set = 0; 660 } else 661 set = 1; 662 } 663 varlen = 0; 664 startloc = expdest - stackblock(); 665 if (!set && uflag && *var != '@' && *var != '*') { 666 switch (subtype) { 667 case VSNORMAL: 668 case VSTRIMLEFT: 669 case VSTRIMLEFTMAX: 670 case VSTRIMRIGHT: 671 case VSTRIMRIGHTMAX: 672 case VSLENGTH: 673 error("%.*s: parameter not set", (int)(p - var - 1), 674 var); 675 } 676 } 677 if (set && subtype != VSPLUS) { 678 /* insert the value of the variable */ 679 if (special) { 680 varvalue(var, varflags & VSQUOTE, subtype, flag); 681 if (subtype == VSLENGTH) { 682 varlen = expdest - stackblock() - startloc; 683 STADJUST(-varlen, expdest); 684 } 685 } else { 686 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 687 : BASESYNTAX; 688 689 if (subtype == VSLENGTH) { 690 for (;*val; val++) 691 varlen++; 692 } 693 else { 694 while (*val) { 695 if (quotes && 696 syntax[(int)*val] == CCTL) 697 STPUTC(CTLESC, expdest); 698 STPUTC(*val++, expdest); 699 } 700 701 } 702 } 703 } 704 705 if (subtype == VSPLUS) 706 set = ! set; 707 708 easy = ((varflags & VSQUOTE) == 0 || 709 (*var == '@' && shellparam.nparam != 1)); 710 711 712 switch (subtype) { 713 case VSLENGTH: 714 expdest = cvtnum(varlen, expdest); 715 goto record; 716 717 case VSNORMAL: 718 if (!easy) 719 break; 720record: 721 recordregion(startloc, expdest - stackblock(), 722 varflags & VSQUOTE); 723 break; 724 725 case VSPLUS: 726 case VSMINUS: 727 if (!set) { 728 argstr(p, flag); 729 break; 730 } 731 if (easy) 732 goto record; 733 break; 734 735 case VSTRIMLEFT: 736 case VSTRIMLEFTMAX: 737 case VSTRIMRIGHT: 738 case VSTRIMRIGHTMAX: 739 if (!set) 740 break; 741 /* 742 * Terminate the string and start recording the pattern 743 * right after it 744 */ 745 STPUTC('\0', expdest); 746 patloc = expdest - stackblock(); 747 if (subevalvar(p, NULL, patloc, subtype, 748 startloc, varflags) == 0) { 749 int amount = (expdest - stackblock() - patloc) + 1; 750 STADJUST(-amount, expdest); 751 } 752 /* Remove any recorded regions beyond start of variable */ 753 removerecordregions(startloc); 754 goto record; 755 756 case VSASSIGN: 757 case VSQUESTION: 758 if (!set) { 759 if (subevalvar(p, var, 0, subtype, startloc, varflags)) { 760 varflags &= ~VSNUL; 761 /* 762 * Remove any recorded regions beyond 763 * start of variable 764 */ 765 removerecordregions(startloc); 766 goto again; 767 } 768 break; 769 } 770 if (easy) 771 goto record; 772 break; 773 774 case VSERROR: 775 c = p - var - 1; 776 error("${%.*s%s}: Bad substitution", c, var, 777 (c > 0 && *p != CTLENDVAR) ? "..." : ""); 778 779 default: 780 abort(); 781 } 782 p[-1] = '='; /* recover overwritten '=' */ 783 784 if (subtype != VSNORMAL) { /* skip to end of alternative */ 785 int nesting = 1; 786 for (;;) { 787 if ((c = *p++) == CTLESC) 788 p++; 789 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 790 if (set) 791 argbackq = argbackq->next; 792 } else if (c == CTLVAR) { 793 if ((*p++ & VSTYPE) != VSNORMAL) 794 nesting++; 795 } else if (c == CTLENDVAR) { 796 if (--nesting == 0) 797 break; 798 } 799 } 800 } 801 return p; 802} 803 804 805 806/* 807 * Test whether a specialized variable is set. 808 */ 809 810STATIC int 811varisset(char *name, int nulok) 812{ 813 814 if (*name == '!') 815 return backgndpid != -1; 816 else if (*name == '@' || *name == '*') { 817 if (*shellparam.p == NULL) 818 return 0; 819 820 if (nulok) { 821 char **av; 822 823 for (av = shellparam.p; *av; av++) 824 if (**av != '\0') 825 return 1; 826 return 0; 827 } 828 } else if (is_digit(*name)) { 829 char *ap; 830 int num = atoi(name); 831 832 if (num > shellparam.nparam) 833 return 0; 834 835 if (num == 0) 836 ap = arg0; 837 else 838 ap = shellparam.p[num - 1]; 839 840 if (nulok && (ap == NULL || *ap == '\0')) 841 return 0; 842 } 843 return 1; 844} 845 846 847 848/* 849 * Add the value of a specialized variable to the stack string. 850 */ 851 852STATIC void 853varvalue(char *name, int quoted, int subtype, int flag) 854{ 855 int num; 856 char *p; 857 int i; 858 extern int oexitstatus; 859 char sep; 860 char **ap; 861 char const *syntax; 862 863#define STRTODEST(p) \ 864 do {\ 865 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \ 866 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 867 while (*p) { \ 868 if (syntax[(int)*p] == CCTL) \ 869 STPUTC(CTLESC, expdest); \ 870 STPUTC(*p++, expdest); \ 871 } \ 872 } else \ 873 while (*p) \ 874 STPUTC(*p++, expdest); \ 875 } while (0) 876 877 878 switch (*name) { 879 case '$': 880 num = rootpid; 881 goto numvar; 882 case '?': 883 num = oexitstatus; 884 goto numvar; 885 case '#': 886 num = shellparam.nparam; 887 goto numvar; 888 case '!': 889 num = backgndpid; 890numvar: 891 expdest = cvtnum(num, expdest); 892 break; 893 case '-': 894 for (i = 0 ; i < NOPTS ; i++) { 895 if (optlist[i].val) 896 STPUTC(optlist[i].letter, expdest); 897 } 898 break; 899 case '@': 900 if (flag & EXP_FULL && quoted) { 901 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 902 STRTODEST(p); 903 if (*ap) 904 STPUTC('\0', expdest); 905 } 906 break; 907 } 908 /* FALLTHROUGH */ 909 case '*': 910 if (ifsset()) 911 sep = ifsval()[0]; 912 else 913 sep = ' '; 914 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 915 STRTODEST(p); 916 if (*ap && sep) 917 STPUTC(sep, expdest); 918 } 919 break; 920 case '0': 921 p = arg0; 922 STRTODEST(p); 923 break; 924 default: 925 if (is_digit(*name)) { 926 num = atoi(name); 927 if (num > 0 && num <= shellparam.nparam) { 928 p = shellparam.p[num - 1]; 929 STRTODEST(p); 930 } 931 } 932 break; 933 } 934} 935 936 937 938/* 939 * Record the the fact that we have to scan this region of the 940 * string for IFS characters. 941 */ 942 943STATIC void 944recordregion(int start, int end, int inquotes) 945{ 946 struct ifsregion *ifsp; 947 948 if (ifslastp == NULL) { 949 ifsp = &ifsfirst; 950 } else { 951 if (ifslastp->endoff == start 952 && ifslastp->inquotes == inquotes) { 953 /* extend previous area */ 954 ifslastp->endoff = end; 955 return; 956 } 957 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 958 ifslastp->next = ifsp; 959 } 960 ifslastp = ifsp; 961 ifslastp->next = NULL; 962 ifslastp->begoff = start; 963 ifslastp->endoff = end; 964 ifslastp->inquotes = inquotes; 965} 966 967 968 969/* 970 * Break the argument string into pieces based upon IFS and add the 971 * strings to the argument list. The regions of the string to be 972 * searched for IFS characters have been stored by recordregion. 973 */ 974STATIC void 975ifsbreakup(char *string, 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 const char *ifsspc; 984 int had_param_ch = 0; 985 986 start = string; 987 988 if (ifslastp == NULL) { 989 /* Return entire argument, IFS doesn't apply to any of it */ 990 sp = (struct strlist *)stalloc(sizeof *sp); 991 sp->text = start; 992 *arglist->lastp = sp; 993 arglist->lastp = &sp->next; 994 return; 995 } 996 997 ifs = ifsset() ? ifsval() : " \t\n"; 998 999 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) { 1000 p = string + ifsp->begoff; 1001 while (p < string + ifsp->endoff) { 1002 q = p; 1003 if (*p == CTLESC) 1004 p++; 1005 if (ifsp->inquotes) { 1006 /* Only NULs (should be from "$@") end args */ 1007 had_param_ch = 1; 1008 if (*p != 0) { 1009 p++; 1010 continue; 1011 } 1012 ifsspc = NULL; 1013 } else { 1014 if (!strchr(ifs, *p)) { 1015 had_param_ch = 1; 1016 p++; 1017 continue; 1018 } 1019 ifsspc = strchr(" \t\n", *p); 1020 1021 /* Ignore IFS whitespace at start */ 1022 if (q == start && ifsspc != NULL) { 1023 p++; 1024 start = p; 1025 continue; 1026 } 1027 had_param_ch = 0; 1028 } 1029 1030 /* Save this argument... */ 1031 *q = '\0'; 1032 sp = (struct strlist *)stalloc(sizeof *sp); 1033 sp->text = start; 1034 *arglist->lastp = sp; 1035 arglist->lastp = &sp->next; 1036 p++; 1037 1038 if (ifsspc != NULL) { 1039 /* Ignore further trailing IFS whitespace */ 1040 for (; p < string + ifsp->endoff; p++) { 1041 q = p; 1042 if (*p == CTLESC) 1043 p++; 1044 if (strchr(ifs, *p) == NULL) { 1045 p = q; 1046 break; 1047 } 1048 if (strchr(" \t\n", *p) == NULL) { 1049 p++; 1050 break; 1051 } 1052 } 1053 } 1054 start = p; 1055 } 1056 } 1057 1058 /* 1059 * Save anything left as an argument. 1060 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as 1061 * generating 2 arguments, the second of which is empty. 1062 * Some recent clarification of the Posix spec say that it 1063 * should only generate one.... 1064 */ 1065 if (had_param_ch || *start != 0) { 1066 sp = (struct strlist *)stalloc(sizeof *sp); 1067 sp->text = start; 1068 *arglist->lastp = sp; 1069 arglist->lastp = &sp->next; 1070 } 1071} 1072 1073 1074 1075/* 1076 * Expand shell metacharacters. At this point, the only control characters 1077 * should be escapes. The results are stored in the list exparg. 1078 */ 1079 1080STATIC char *expdir; 1081 1082 1083STATIC void 1084expandmeta(struct strlist *str, int flag __unused) 1085{ 1086 char *p; 1087 struct strlist **savelastp; 1088 struct strlist *sp; 1089 char c; 1090 /* TODO - EXP_REDIR */ 1091 1092 while (str) { 1093 if (fflag) 1094 goto nometa; 1095 p = str->text; 1096 for (;;) { /* fast check for meta chars */ 1097 if ((c = *p++) == '\0') 1098 goto nometa; 1099 if (c == '*' || c == '?' || c == '[' || c == '!') 1100 break; 1101 } 1102 savelastp = exparg.lastp; 1103 INTOFF; 1104 if (expdir == NULL) { 1105 int i = strlen(str->text); 1106 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1107 } 1108 1109 expmeta(expdir, str->text); 1110 ckfree(expdir); 1111 expdir = NULL; 1112 INTON; 1113 if (exparg.lastp == savelastp) { 1114 /* 1115 * no matches 1116 */ 1117nometa: 1118 *exparg.lastp = str; 1119 rmescapes(str->text); 1120 exparg.lastp = &str->next; 1121 } else { 1122 *exparg.lastp = NULL; 1123 *savelastp = sp = expsort(*savelastp); 1124 while (sp->next != NULL) 1125 sp = sp->next; 1126 exparg.lastp = &sp->next; 1127 } 1128 str = str->next; 1129 } 1130} 1131 1132 1133/* 1134 * Do metacharacter (i.e. *, ?, [...]) expansion. 1135 */ 1136 1137STATIC void 1138expmeta(char *enddir, char *name) 1139{ 1140 char *p; 1141 char *q; 1142 char *start; 1143 char *endname; 1144 int metaflag; 1145 struct stat statb; 1146 DIR *dirp; 1147 struct dirent *dp; 1148 int atend; 1149 int matchdot; 1150 1151 metaflag = 0; 1152 start = name; 1153 for (p = name ; ; p++) { 1154 if (*p == '*' || *p == '?') 1155 metaflag = 1; 1156 else if (*p == '[') { 1157 q = p + 1; 1158 if (*q == '!' || *q == '^') 1159 q++; 1160 for (;;) { 1161 while (*q == CTLQUOTEMARK) 1162 q++; 1163 if (*q == CTLESC) 1164 q++; 1165 if (*q == '/' || *q == '\0') 1166 break; 1167 if (*++q == ']') { 1168 metaflag = 1; 1169 break; 1170 } 1171 } 1172 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1173 metaflag = 1; 1174 } else if (*p == '\0') 1175 break; 1176 else if (*p == CTLQUOTEMARK) 1177 continue; 1178 else if (*p == CTLESC) 1179 p++; 1180 if (*p == '/') { 1181 if (metaflag) 1182 break; 1183 start = p + 1; 1184 } 1185 } 1186 if (metaflag == 0) { /* we've reached the end of the file name */ 1187 if (enddir != expdir) 1188 metaflag++; 1189 for (p = name ; ; p++) { 1190 if (*p == CTLQUOTEMARK) 1191 continue; 1192 if (*p == CTLESC) 1193 p++; 1194 *enddir++ = *p; 1195 if (*p == '\0') 1196 break; 1197 } 1198 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1199 addfname(expdir); 1200 return; 1201 } 1202 endname = p; 1203 if (start != name) { 1204 p = name; 1205 while (p < start) { 1206 while (*p == CTLQUOTEMARK) 1207 p++; 1208 if (*p == CTLESC) 1209 p++; 1210 *enddir++ = *p++; 1211 } 1212 } 1213 if (enddir == expdir) { 1214 p = "."; 1215 } else if (enddir == expdir + 1 && *expdir == '/') { 1216 p = "/"; 1217 } else { 1218 p = expdir; 1219 enddir[-1] = '\0'; 1220 } 1221 if ((dirp = opendir(p)) == NULL) 1222 return; 1223 if (enddir != expdir) 1224 enddir[-1] = '/'; 1225 if (*endname == 0) { 1226 atend = 1; 1227 } else { 1228 atend = 0; 1229 *endname++ = '\0'; 1230 } 1231 matchdot = 0; 1232 p = start; 1233 while (*p == CTLQUOTEMARK) 1234 p++; 1235 if (*p == CTLESC) 1236 p++; 1237 if (*p == '.') 1238 matchdot++; 1239 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1240 if (dp->d_name[0] == '.' && ! matchdot) 1241 continue; 1242 if (patmatch(start, dp->d_name, 0)) { 1243 if (atend) { 1244 scopy(dp->d_name, enddir); 1245 addfname(expdir); 1246 } else { 1247 for (p = enddir, q = dp->d_name; 1248 (*p++ = *q++) != '\0';) 1249 continue; 1250 p[-1] = '/'; 1251 expmeta(p, endname); 1252 } 1253 } 1254 } 1255 closedir(dirp); 1256 if (! atend) 1257 endname[-1] = '/'; 1258} 1259 1260 1261/* 1262 * Add a file name to the list. 1263 */ 1264 1265STATIC void 1266addfname(char *name) 1267{ 1268 char *p; 1269 struct strlist *sp; 1270 1271 p = stalloc(strlen(name) + 1); 1272 scopy(name, p); 1273 sp = (struct strlist *)stalloc(sizeof *sp); 1274 sp->text = p; 1275 *exparg.lastp = sp; 1276 exparg.lastp = &sp->next; 1277} 1278 1279 1280/* 1281 * Sort the results of file name expansion. It calculates the number of 1282 * strings to sort and then calls msort (short for merge sort) to do the 1283 * work. 1284 */ 1285 1286STATIC struct strlist * 1287expsort(struct strlist *str) 1288{ 1289 int len; 1290 struct strlist *sp; 1291 1292 len = 0; 1293 for (sp = str ; sp ; sp = sp->next) 1294 len++; 1295 return msort(str, len); 1296} 1297 1298 1299STATIC struct strlist * 1300msort(struct strlist *list, int len) 1301{ 1302 struct strlist *p, *q = NULL; 1303 struct strlist **lpp; 1304 int half; 1305 int n; 1306 1307 if (len <= 1) 1308 return list; 1309 half = len >> 1; 1310 p = list; 1311 for (n = half ; --n >= 0 ; ) { 1312 q = p; 1313 p = p->next; 1314 } 1315 q->next = NULL; /* terminate first half of list */ 1316 q = msort(list, half); /* sort first half of list */ 1317 p = msort(p, len - half); /* sort second half */ 1318 lpp = &list; 1319 for (;;) { 1320 if (strcmp(p->text, q->text) < 0) { 1321 *lpp = p; 1322 lpp = &p->next; 1323 if ((p = *lpp) == NULL) { 1324 *lpp = q; 1325 break; 1326 } 1327 } else { 1328 *lpp = q; 1329 lpp = &q->next; 1330 if ((q = *lpp) == NULL) { 1331 *lpp = p; 1332 break; 1333 } 1334 } 1335 } 1336 return list; 1337} 1338 1339 1340 1341/* 1342 * Returns true if the pattern matches the string. 1343 */ 1344 1345int 1346patmatch(const char *pattern, const char *string, int squoted) 1347{ 1348#ifdef notdef 1349 if (pattern[0] == '!' && pattern[1] == '!') 1350 return 1 - pmatch(pattern + 2, string); 1351 else 1352#endif 1353 return pmatch(pattern, string, squoted); 1354} 1355 1356 1357STATIC int 1358pmatch(const char *pattern, const char *string, int squoted) 1359{ 1360 const char *p, *q; 1361 char c; 1362 1363 p = pattern; 1364 q = string; 1365 for (;;) { 1366 switch (c = *p++) { 1367 case '\0': 1368 goto breakloop; 1369 case CTLESC: 1370 if (squoted && *q == CTLESC) 1371 q++; 1372 if (*q++ != *p++) 1373 return 0; 1374 break; 1375 case CTLQUOTEMARK: 1376 continue; 1377 case '?': 1378 if (squoted && *q == CTLESC) 1379 q++; 1380 if (*q++ == '\0') 1381 return 0; 1382 break; 1383 case '*': 1384 c = *p; 1385 while (c == CTLQUOTEMARK || c == '*') 1386 c = *++p; 1387 if (c != CTLESC && c != CTLQUOTEMARK && 1388 c != '?' && c != '*' && c != '[') { 1389 while (*q != c) { 1390 if (squoted && *q == CTLESC && 1391 q[1] == c) 1392 break; 1393 if (*q == '\0') 1394 return 0; 1395 if (squoted && *q == CTLESC) 1396 q++; 1397 q++; 1398 } 1399 } 1400 do { 1401 if (pmatch(p, q, squoted)) 1402 return 1; 1403 if (squoted && *q == CTLESC) 1404 q++; 1405 } while (*q++ != '\0'); 1406 return 0; 1407 case '[': { 1408 const char *endp; 1409 int invert, found; 1410 char chr; 1411 1412 endp = p; 1413 if (*endp == '!' || *endp == '^') 1414 endp++; 1415 for (;;) { 1416 while (*endp == CTLQUOTEMARK) 1417 endp++; 1418 if (*endp == '\0') 1419 goto dft; /* no matching ] */ 1420 if (*endp == CTLESC) 1421 endp++; 1422 if (*++endp == ']') 1423 break; 1424 } 1425 invert = 0; 1426 if (*p == '!' || *p == '^') { 1427 invert++; 1428 p++; 1429 } 1430 found = 0; 1431 chr = *q++; 1432 if (squoted && chr == CTLESC) 1433 chr = *q++; 1434 if (chr == '\0') 1435 return 0; 1436 c = *p++; 1437 do { 1438 if (c == CTLQUOTEMARK) 1439 continue; 1440 if (c == CTLESC) 1441 c = *p++; 1442 if (*p == '-' && p[1] != ']') { 1443 p++; 1444 while (*p == CTLQUOTEMARK) 1445 p++; 1446 if (*p == CTLESC) 1447 p++; 1448 if ( collate_range_cmp(chr, c) >= 0 1449 && collate_range_cmp(chr, *p) <= 0 1450 ) 1451 found = 1; 1452 p++; 1453 } else { 1454 if (chr == c) 1455 found = 1; 1456 } 1457 } while ((c = *p++) != ']'); 1458 if (found == invert) 1459 return 0; 1460 break; 1461 } 1462dft: default: 1463 if (squoted && *q == CTLESC) 1464 q++; 1465 if (*q++ != c) 1466 return 0; 1467 break; 1468 } 1469 } 1470breakloop: 1471 if (*q != '\0') 1472 return 0; 1473 return 1; 1474} 1475 1476 1477 1478/* 1479 * Remove any CTLESC characters from a string. 1480 */ 1481 1482void 1483rmescapes(char *str) 1484{ 1485 char *p, *q; 1486 1487 p = str; 1488 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1489 if (*p++ == '\0') 1490 return; 1491 } 1492 q = p; 1493 while (*p) { 1494 if (*p == CTLQUOTEMARK) { 1495 p++; 1496 continue; 1497 } 1498 if (*p == CTLESC) 1499 p++; 1500 *q++ = *p++; 1501 } 1502 *q = '\0'; 1503} 1504 1505 1506 1507/* 1508 * See if a pattern matches in a case statement. 1509 */ 1510 1511int 1512casematch(union node *pattern, const char *val) 1513{ 1514 struct stackmark smark; 1515 int result; 1516 char *p; 1517 1518 setstackmark(&smark); 1519 argbackq = pattern->narg.backquote; 1520 STARTSTACKSTR(expdest); 1521 ifslastp = NULL; 1522 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1523 STPUTC('\0', expdest); 1524 p = grabstackstr(expdest); 1525 result = patmatch(p, val, 0); 1526 popstackmark(&smark); 1527 return result; 1528} 1529 1530/* 1531 * Our own itoa(). 1532 */ 1533 1534STATIC char * 1535cvtnum(int num, char *buf) 1536{ 1537 char temp[32]; 1538 int neg = num < 0; 1539 char *p = temp + 31; 1540 1541 temp[31] = '\0'; 1542 1543 do { 1544 *--p = num % 10 + '0'; 1545 } while ((num /= 10) != 0); 1546 1547 if (neg) 1548 *--p = '-'; 1549 1550 while (*p) 1551 STPUTC(*p++, buf); 1552 return buf; 1553} 1554 1555/* 1556 * Do most of the work for wordexp(3). 1557 */ 1558 1559int 1560wordexpcmd(int argc, char **argv) 1561{ 1562 size_t len; 1563 int i; 1564 1565 out1fmt("%08x", argc - 1); 1566 for (i = 1, len = 0; i < argc; i++) 1567 len += strlen(argv[i]); 1568 out1fmt("%08x", (int)len); 1569 for (i = 1; i < argc; i++) { 1570 out1str(argv[i]); 1571 out1c('\0'); 1572 } 1573 return (0); 1574} 1575