1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * Copyright (c) 1997-2005 5 * Herbert Xu <herbert@gondor.apana.org.au>. 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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifndef lint 36 #if 0 37 static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95"; 38 #endif 39 #endif /* not lint */ 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include <sys/types.h> 44 #include <sys/time.h> 45 #include <sys/stat.h> 46 #include <dirent.h> 47 #include <errno.h> 48 #include <inttypes.h> 49 #include <limits.h> 50 #include <pwd.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.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 84 struct ifsregion { 85 struct ifsregion *next; /* next region in list */ 86 int begoff; /* offset of start of region */ 87 int endoff; /* offset of end of region */ 88 int inquotes; /* search for nul bytes only */ 89 }; 90 91 92 static char *expdest; /* output of current string */ 93 static struct nodelist *argbackq; /* list of back quote expressions */ 94 static struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 95 static struct ifsregion *ifslastp; /* last struct in list */ 96 static struct arglist exparg; /* holds expanded arg list */ 97 98 static void argstr(char *, int); 99 static char *exptilde(char *, int); 100 static void expbackq(union node *, int, int); 101 static int subevalvar(char *, char *, int, int, int, int, int); 102 static char *evalvar(char *, int); 103 static int varisset(char *, int); 104 static void varvalue(char *, int, int, int); 105 static void recordregion(int, int, int); 106 static void removerecordregions(int); 107 static void ifsbreakup(char *, struct arglist *); 108 static void expandmeta(struct strlist *, int); 109 static void expmeta(char *, char *); 110 static void addfname(char *); 111 static struct strlist *expsort(struct strlist *); 112 static struct strlist *msort(struct strlist *, int); 113 static char *cvtnum(int, char *); 114 static int collate_range_cmp(int, int); 115 116 static int 117 collate_range_cmp(int c1, int c2) 118 { 119 static char s1[2], s2[2]; 120 121 s1[0] = c1; 122 s2[0] = c2; 123 return (strcoll(s1, s2)); 124 } 125 126 /* 127 * Expand shell variables and backquotes inside a here document. 128 * union node *arg the document 129 * int fd; where to write the expanded version 130 */ 131 132 void 133 expandhere(union node *arg, int fd) 134 { 135 expandarg(arg, (struct arglist *)NULL, 0); 136 xwrite(fd, stackblock(), expdest - stackblock()); 137 } 138 139 static char * 140 stputs_quotes(const char *data, const char *syntax, char *p) 141 { 142 while (*data) { 143 CHECKSTRSPACE(2, p); 144 if (syntax[(int)*data] == CCTL) 145 USTPUTC(CTLESC, p); 146 USTPUTC(*data++, p); 147 } 148 return (p); 149 } 150 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p) 151 152 /* 153 * Perform expansions on an argument, placing the resulting list of arguments 154 * in arglist. Parameter expansion, command substitution and arithmetic 155 * expansion are always performed; additional expansions can be requested 156 * via flag (EXP_*). 157 * The result is left in the stack string. 158 * When arglist is NULL, perform here document expansion. A partial result 159 * may be written to herefd, which is then not included in the stack string. 160 * 161 * Caution: this function uses global state and is not reentrant. 162 * However, a new invocation after an interrupted invocation is safe 163 * and will reset the global state for the new call. 164 */ 165 void 166 expandarg(union node *arg, struct arglist *arglist, int flag) 167 { 168 struct strlist *sp; 169 char *p; 170 171 argbackq = arg->narg.backquote; 172 STARTSTACKSTR(expdest); 173 ifsfirst.next = NULL; 174 ifslastp = NULL; 175 argstr(arg->narg.text, flag); 176 if (arglist == NULL) { 177 return; /* here document expanded */ 178 } 179 STPUTC('\0', expdest); 180 p = grabstackstr(expdest); 181 exparg.lastp = &exparg.list; 182 /* 183 * TODO - EXP_REDIR 184 */ 185 if (flag & EXP_FULL) { 186 ifsbreakup(p, &exparg); 187 *exparg.lastp = NULL; 188 exparg.lastp = &exparg.list; 189 expandmeta(exparg.list, flag); 190 } else { 191 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 192 rmescapes(p); 193 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 194 sp->text = p; 195 *exparg.lastp = sp; 196 exparg.lastp = &sp->next; 197 } 198 while (ifsfirst.next != NULL) { 199 struct ifsregion *ifsp; 200 INTOFF; 201 ifsp = ifsfirst.next->next; 202 ckfree(ifsfirst.next); 203 ifsfirst.next = ifsp; 204 INTON; 205 } 206 *exparg.lastp = NULL; 207 if (exparg.list) { 208 *arglist->lastp = exparg.list; 209 arglist->lastp = exparg.lastp; 210 } 211 } 212 213 214 215 /* 216 * Perform parameter expansion, command substitution and arithmetic 217 * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE. 218 * Processing ends at a CTLENDVAR character as well as '\0'. 219 * This is used to expand word in ${var+word} etc. 220 * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC 221 * characters to allow for further processing. 222 * If EXP_FULL is set, also preserve CTLQUOTEMARK characters. 223 */ 224 static void 225 argstr(char *p, int flag) 226 { 227 char c; 228 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */ 229 int firsteq = 1; 230 int split_lit; 231 int lit_quoted; 232 233 split_lit = flag & EXP_SPLIT_LIT; 234 lit_quoted = flag & EXP_LIT_QUOTED; 235 flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED); 236 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 237 p = exptilde(p, flag); 238 for (;;) { 239 CHECKSTRSPACE(2, expdest); 240 switch (c = *p++) { 241 case '\0': 242 case CTLENDVAR: 243 goto breakloop; 244 case CTLQUOTEMARK: 245 lit_quoted = 1; 246 /* "$@" syntax adherence hack */ 247 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 248 break; 249 if ((flag & EXP_FULL) != 0) 250 USTPUTC(c, expdest); 251 break; 252 case CTLQUOTEEND: 253 lit_quoted = 0; 254 break; 255 case CTLESC: 256 if (quotes) 257 USTPUTC(c, expdest); 258 c = *p++; 259 USTPUTC(c, expdest); 260 if (split_lit && !lit_quoted) 261 recordregion(expdest - stackblock() - 262 (quotes ? 2 : 1), 263 expdest - stackblock(), 0); 264 break; 265 case CTLVAR: 266 p = evalvar(p, flag); 267 break; 268 case CTLBACKQ: 269 case CTLBACKQ|CTLQUOTE: 270 expbackq(argbackq->n, c & CTLQUOTE, flag); 271 argbackq = argbackq->next; 272 break; 273 case CTLENDARI: 274 expari(flag); 275 break; 276 case ':': 277 case '=': 278 /* 279 * sort of a hack - expand tildes in variable 280 * assignments (after the first '=' and after ':'s). 281 */ 282 USTPUTC(c, expdest); 283 if (split_lit && !lit_quoted) 284 recordregion(expdest - stackblock() - 1, 285 expdest - stackblock(), 0); 286 if (flag & EXP_VARTILDE && *p == '~' && 287 (c != '=' || firsteq)) { 288 if (c == '=') 289 firsteq = 0; 290 p = exptilde(p, flag); 291 } 292 break; 293 default: 294 USTPUTC(c, expdest); 295 if (split_lit && !lit_quoted) 296 recordregion(expdest - stackblock() - 1, 297 expdest - stackblock(), 0); 298 } 299 } 300 breakloop:; 301 } 302 303 /* 304 * Perform tilde expansion, placing the result in the stack string and 305 * returning the next position in the input string to process. 306 */ 307 static char * 308 exptilde(char *p, int flag) 309 { 310 char c, *startp = p; 311 struct passwd *pw; 312 char *home; 313 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 314 315 while ((c = *p) != '\0') { 316 switch(c) { 317 case CTLESC: /* This means CTL* are always considered quoted. */ 318 case CTLVAR: 319 case CTLBACKQ: 320 case CTLBACKQ | CTLQUOTE: 321 case CTLARI: 322 case CTLENDARI: 323 case CTLQUOTEMARK: 324 return (startp); 325 case ':': 326 if (flag & EXP_VARTILDE) 327 goto done; 328 break; 329 case '/': 330 case CTLENDVAR: 331 goto done; 332 } 333 p++; 334 } 335 done: 336 *p = '\0'; 337 if (*(startp+1) == '\0') { 338 if ((home = lookupvar("HOME")) == NULL) 339 goto lose; 340 } else { 341 if ((pw = getpwnam(startp+1)) == NULL) 342 goto lose; 343 home = pw->pw_dir; 344 } 345 if (*home == '\0') 346 goto lose; 347 *p = c; 348 if (quotes) 349 STPUTS_QUOTES(home, SQSYNTAX, expdest); 350 else 351 STPUTS(home, expdest); 352 return (p); 353 lose: 354 *p = c; 355 return (startp); 356 } 357 358 359 static void 360 removerecordregions(int endoff) 361 { 362 if (ifslastp == NULL) 363 return; 364 365 if (ifsfirst.endoff > endoff) { 366 while (ifsfirst.next != NULL) { 367 struct ifsregion *ifsp; 368 INTOFF; 369 ifsp = ifsfirst.next->next; 370 ckfree(ifsfirst.next); 371 ifsfirst.next = ifsp; 372 INTON; 373 } 374 if (ifsfirst.begoff > endoff) 375 ifslastp = NULL; 376 else { 377 ifslastp = &ifsfirst; 378 ifsfirst.endoff = endoff; 379 } 380 return; 381 } 382 383 ifslastp = &ifsfirst; 384 while (ifslastp->next && ifslastp->next->begoff < endoff) 385 ifslastp=ifslastp->next; 386 while (ifslastp->next != NULL) { 387 struct ifsregion *ifsp; 388 INTOFF; 389 ifsp = ifslastp->next->next; 390 ckfree(ifslastp->next); 391 ifslastp->next = ifsp; 392 INTON; 393 } 394 if (ifslastp->endoff > endoff) 395 ifslastp->endoff = endoff; 396 } 397 398 /* 399 * Expand arithmetic expression. Backup to start of expression, 400 * evaluate, place result in (backed up) result, adjust string position. 401 */ 402 void 403 expari(int flag) 404 { 405 char *p, *q, *start; 406 arith_t result; 407 int begoff; 408 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 409 int quoted; 410 411 /* 412 * This routine is slightly over-complicated for 413 * efficiency. First we make sure there is 414 * enough space for the result, which may be bigger 415 * than the expression. Next we 416 * scan backwards looking for the start of arithmetic. If the 417 * next previous character is a CTLESC character, then we 418 * have to rescan starting from the beginning since CTLESC 419 * characters have to be processed left to right. 420 */ 421 CHECKSTRSPACE(DIGITS(result) - 2, expdest); 422 USTPUTC('\0', expdest); 423 start = stackblock(); 424 p = expdest - 2; 425 while (p >= start && *p != CTLARI) 426 --p; 427 if (p < start || *p != CTLARI) 428 error("missing CTLARI (shouldn't happen)"); 429 if (p > start && *(p - 1) == CTLESC) 430 for (p = start; *p != CTLARI; p++) 431 if (*p == CTLESC) 432 p++; 433 434 if (p[1] == '"') 435 quoted=1; 436 else 437 quoted=0; 438 begoff = p - start; 439 removerecordregions(begoff); 440 if (quotes) 441 rmescapes(p+2); 442 q = grabstackstr(expdest); 443 result = arith(p+2); 444 ungrabstackstr(q, expdest); 445 fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result); 446 while (*p++) 447 ; 448 if (quoted == 0) 449 recordregion(begoff, p - 1 - start, 0); 450 result = expdest - p + 1; 451 STADJUST(-result, expdest); 452 } 453 454 455 /* 456 * Perform command substitution. 457 */ 458 static void 459 expbackq(union node *cmd, int quoted, int flag) 460 { 461 struct backcmd in; 462 int i; 463 char buf[128]; 464 char *p; 465 char *dest = expdest; 466 struct ifsregion saveifs, *savelastp; 467 struct nodelist *saveargbackq; 468 char lastc; 469 int startloc = dest - stackblock(); 470 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 471 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 472 int nnl; 473 474 INTOFF; 475 saveifs = ifsfirst; 476 savelastp = ifslastp; 477 saveargbackq = argbackq; 478 p = grabstackstr(dest); 479 evalbackcmd(cmd, &in); 480 ungrabstackstr(p, dest); 481 ifsfirst = saveifs; 482 ifslastp = savelastp; 483 argbackq = saveargbackq; 484 485 p = in.buf; 486 lastc = '\0'; 487 nnl = 0; 488 /* Don't copy trailing newlines */ 489 for (;;) { 490 if (--in.nleft < 0) { 491 if (in.fd < 0) 492 break; 493 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 494 TRACE(("expbackq: read returns %d\n", i)); 495 if (i <= 0) 496 break; 497 p = buf; 498 in.nleft = i - 1; 499 } 500 lastc = *p++; 501 if (lastc != '\0') { 502 if (lastc == '\n') { 503 nnl++; 504 } else { 505 CHECKSTRSPACE(nnl + 2, dest); 506 while (nnl > 0) { 507 nnl--; 508 USTPUTC('\n', dest); 509 } 510 if (quotes && syntax[(int)lastc] == CCTL) 511 USTPUTC(CTLESC, dest); 512 USTPUTC(lastc, dest); 513 } 514 } 515 } 516 517 if (in.fd >= 0) 518 close(in.fd); 519 if (in.buf) 520 ckfree(in.buf); 521 if (in.jp) 522 exitstatus = waitforjob(in.jp, (int *)NULL); 523 if (quoted == 0) 524 recordregion(startloc, dest - stackblock(), 0); 525 TRACE(("expbackq: size=%td: \"%.*s\"\n", 526 ((dest - stackblock()) - startloc), 527 (int)((dest - stackblock()) - startloc), 528 stackblock() + startloc)); 529 expdest = dest; 530 INTON; 531 } 532 533 534 535 static int 536 subevalvar(char *p, char *str, int strloc, int subtype, int startloc, 537 int varflags, int quotes) 538 { 539 char *startp; 540 char *loc = NULL; 541 char *q; 542 int c = 0; 543 struct nodelist *saveargbackq = argbackq; 544 int amount; 545 546 argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX || 547 subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ? 548 EXP_CASE : 0) | EXP_TILDE); 549 STACKSTRNUL(expdest); 550 argbackq = saveargbackq; 551 startp = stackblock() + startloc; 552 if (str == NULL) 553 str = stackblock() + strloc; 554 555 switch (subtype) { 556 case VSASSIGN: 557 setvar(str, startp, 0); 558 amount = startp - expdest; 559 STADJUST(amount, expdest); 560 varflags &= ~VSNUL; 561 return 1; 562 563 case VSQUESTION: 564 if (*p != CTLENDVAR) { 565 outfmt(out2, "%s\n", startp); 566 error((char *)NULL); 567 } 568 error("%.*s: parameter %snot set", (int)(p - str - 1), 569 str, (varflags & VSNUL) ? "null or " 570 : nullstr); 571 return 0; 572 573 case VSTRIMLEFT: 574 for (loc = startp; loc < str; loc++) { 575 c = *loc; 576 *loc = '\0'; 577 if (patmatch(str, startp, quotes)) { 578 *loc = c; 579 goto recordleft; 580 } 581 *loc = c; 582 if (quotes && *loc == CTLESC) 583 loc++; 584 } 585 return 0; 586 587 case VSTRIMLEFTMAX: 588 for (loc = str - 1; loc >= startp;) { 589 c = *loc; 590 *loc = '\0'; 591 if (patmatch(str, startp, quotes)) { 592 *loc = c; 593 goto recordleft; 594 } 595 *loc = c; 596 loc--; 597 if (quotes && loc > startp && *(loc - 1) == CTLESC) { 598 for (q = startp; q < loc; q++) 599 if (*q == CTLESC) 600 q++; 601 if (q > loc) 602 loc--; 603 } 604 } 605 return 0; 606 607 case VSTRIMRIGHT: 608 for (loc = str - 1; loc >= startp;) { 609 if (patmatch(str, loc, quotes)) { 610 amount = loc - expdest; 611 STADJUST(amount, expdest); 612 return 1; 613 } 614 loc--; 615 if (quotes && loc > startp && *(loc - 1) == CTLESC) { 616 for (q = startp; q < loc; q++) 617 if (*q == CTLESC) 618 q++; 619 if (q > loc) 620 loc--; 621 } 622 } 623 return 0; 624 625 case VSTRIMRIGHTMAX: 626 for (loc = startp; loc < str - 1; loc++) { 627 if (patmatch(str, loc, quotes)) { 628 amount = loc - expdest; 629 STADJUST(amount, expdest); 630 return 1; 631 } 632 if (quotes && *loc == CTLESC) 633 loc++; 634 } 635 return 0; 636 637 638 default: 639 abort(); 640 } 641 642 recordleft: 643 amount = ((str - 1) - (loc - startp)) - expdest; 644 STADJUST(amount, expdest); 645 while (loc != str - 1) 646 *startp++ = *loc++; 647 return 1; 648 } 649 650 651 /* 652 * Expand a variable, and return a pointer to the next character in the 653 * input string. 654 */ 655 656 static char * 657 evalvar(char *p, int flag) 658 { 659 int subtype; 660 int varflags; 661 char *var; 662 char *val; 663 int patloc; 664 int c; 665 int set; 666 int special; 667 int startloc; 668 int varlen; 669 int easy; 670 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); 671 672 varflags = (unsigned char)*p++; 673 subtype = varflags & VSTYPE; 674 var = p; 675 special = 0; 676 if (! is_name(*p)) 677 special = 1; 678 p = strchr(p, '=') + 1; 679 again: /* jump here after setting a variable with ${var=text} */ 680 if (varflags & VSLINENO) { 681 set = 1; 682 special = 0; 683 val = var; 684 p[-1] = '\0'; /* temporarily overwrite '=' to have \0 685 terminated string */ 686 } else if (special) { 687 set = varisset(var, varflags & VSNUL); 688 val = NULL; 689 } else { 690 val = bltinlookup(var, 1); 691 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 692 val = NULL; 693 set = 0; 694 } else 695 set = 1; 696 } 697 varlen = 0; 698 startloc = expdest - stackblock(); 699 if (!set && uflag && *var != '@' && *var != '*') { 700 switch (subtype) { 701 case VSNORMAL: 702 case VSTRIMLEFT: 703 case VSTRIMLEFTMAX: 704 case VSTRIMRIGHT: 705 case VSTRIMRIGHTMAX: 706 case VSLENGTH: 707 error("%.*s: parameter not set", (int)(p - var - 1), 708 var); 709 } 710 } 711 if (set && subtype != VSPLUS) { 712 /* insert the value of the variable */ 713 if (special) { 714 varvalue(var, varflags & VSQUOTE, subtype, flag); 715 if (subtype == VSLENGTH) { 716 varlen = expdest - stackblock() - startloc; 717 STADJUST(-varlen, expdest); 718 } 719 } else { 720 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 721 : BASESYNTAX; 722 723 if (subtype == VSLENGTH) { 724 for (;*val; val++) 725 varlen++; 726 } 727 else { 728 if (quotes) 729 STPUTS_QUOTES(val, syntax, expdest); 730 else 731 STPUTS(val, expdest); 732 733 } 734 } 735 } 736 737 if (subtype == VSPLUS) 738 set = ! set; 739 740 easy = ((varflags & VSQUOTE) == 0 || 741 (*var == '@' && shellparam.nparam != 1)); 742 743 744 switch (subtype) { 745 case VSLENGTH: 746 expdest = cvtnum(varlen, expdest); 747 goto record; 748 749 case VSNORMAL: 750 if (!easy) 751 break; 752 record: 753 recordregion(startloc, expdest - stackblock(), 754 varflags & VSQUOTE); 755 break; 756 757 case VSPLUS: 758 case VSMINUS: 759 if (!set) { 760 argstr(p, flag | (flag & EXP_FULL ? EXP_SPLIT_LIT : 0) | 761 (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0)); 762 break; 763 } 764 if (easy) 765 goto record; 766 break; 767 768 case VSTRIMLEFT: 769 case VSTRIMLEFTMAX: 770 case VSTRIMRIGHT: 771 case VSTRIMRIGHTMAX: 772 if (!set) 773 break; 774 /* 775 * Terminate the string and start recording the pattern 776 * right after it 777 */ 778 STPUTC('\0', expdest); 779 patloc = expdest - stackblock(); 780 if (subevalvar(p, NULL, patloc, subtype, 781 startloc, varflags, quotes) == 0) { 782 int amount = (expdest - stackblock() - patloc) + 1; 783 STADJUST(-amount, expdest); 784 } 785 /* Remove any recorded regions beyond start of variable */ 786 removerecordregions(startloc); 787 goto record; 788 789 case VSASSIGN: 790 case VSQUESTION: 791 if (!set) { 792 if (subevalvar(p, var, 0, subtype, startloc, varflags, 793 quotes)) { 794 varflags &= ~VSNUL; 795 /* 796 * Remove any recorded regions beyond 797 * start of variable 798 */ 799 removerecordregions(startloc); 800 goto again; 801 } 802 break; 803 } 804 if (easy) 805 goto record; 806 break; 807 808 case VSERROR: 809 c = p - var - 1; 810 error("${%.*s%s}: Bad substitution", c, var, 811 (c > 0 && *p != CTLENDVAR) ? "..." : ""); 812 813 default: 814 abort(); 815 } 816 p[-1] = '='; /* recover overwritten '=' */ 817 818 if (subtype != VSNORMAL) { /* skip to end of alternative */ 819 int nesting = 1; 820 for (;;) { 821 if ((c = *p++) == CTLESC) 822 p++; 823 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 824 if (set) 825 argbackq = argbackq->next; 826 } else if (c == CTLVAR) { 827 if ((*p++ & VSTYPE) != VSNORMAL) 828 nesting++; 829 } else if (c == CTLENDVAR) { 830 if (--nesting == 0) 831 break; 832 } 833 } 834 } 835 return p; 836 } 837 838 839 840 /* 841 * Test whether a specialized variable is set. 842 */ 843 844 static int 845 varisset(char *name, int nulok) 846 { 847 848 if (*name == '!') 849 return backgndpidset(); 850 else if (*name == '@' || *name == '*') { 851 if (*shellparam.p == NULL) 852 return 0; 853 854 if (nulok) { 855 char **av; 856 857 for (av = shellparam.p; *av; av++) 858 if (**av != '\0') 859 return 1; 860 return 0; 861 } 862 } else if (is_digit(*name)) { 863 char *ap; 864 int num = atoi(name); 865 866 if (num > shellparam.nparam) 867 return 0; 868 869 if (num == 0) 870 ap = arg0; 871 else 872 ap = shellparam.p[num - 1]; 873 874 if (nulok && (ap == NULL || *ap == '\0')) 875 return 0; 876 } 877 return 1; 878 } 879 880 static void 881 strtodest(const char *p, int flag, int subtype, int quoted) 882 { 883 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) 884 STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest); 885 else 886 STPUTS(p, expdest); 887 } 888 889 /* 890 * Add the value of a specialized variable to the stack string. 891 */ 892 893 static void 894 varvalue(char *name, int quoted, int subtype, int flag) 895 { 896 int num; 897 char *p; 898 int i; 899 char sep; 900 char **ap; 901 902 switch (*name) { 903 case '$': 904 num = rootpid; 905 goto numvar; 906 case '?': 907 num = oexitstatus; 908 goto numvar; 909 case '#': 910 num = shellparam.nparam; 911 goto numvar; 912 case '!': 913 num = backgndpidval(); 914 numvar: 915 expdest = cvtnum(num, expdest); 916 break; 917 case '-': 918 for (i = 0 ; i < NOPTS ; i++) { 919 if (optlist[i].val) 920 STPUTC(optlist[i].letter, expdest); 921 } 922 break; 923 case '@': 924 if (flag & EXP_FULL && quoted) { 925 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 926 strtodest(p, flag, subtype, quoted); 927 if (*ap) 928 STPUTC('\0', expdest); 929 } 930 break; 931 } 932 /* FALLTHROUGH */ 933 case '*': 934 if (ifsset()) 935 sep = ifsval()[0]; 936 else 937 sep = ' '; 938 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 939 strtodest(p, flag, subtype, quoted); 940 if (*ap && sep) 941 STPUTC(sep, expdest); 942 } 943 break; 944 case '0': 945 p = arg0; 946 strtodest(p, flag, subtype, quoted); 947 break; 948 default: 949 if (is_digit(*name)) { 950 num = atoi(name); 951 if (num > 0 && num <= shellparam.nparam) { 952 p = shellparam.p[num - 1]; 953 strtodest(p, flag, subtype, quoted); 954 } 955 } 956 break; 957 } 958 } 959 960 961 962 /* 963 * Record the the fact that we have to scan this region of the 964 * string for IFS characters. 965 */ 966 967 static void 968 recordregion(int start, int end, int inquotes) 969 { 970 struct ifsregion *ifsp; 971 972 if (ifslastp == NULL) { 973 ifsp = &ifsfirst; 974 } else { 975 if (ifslastp->endoff == start 976 && ifslastp->inquotes == inquotes) { 977 /* extend previous area */ 978 ifslastp->endoff = end; 979 return; 980 } 981 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 982 ifslastp->next = ifsp; 983 } 984 ifslastp = ifsp; 985 ifslastp->next = NULL; 986 ifslastp->begoff = start; 987 ifslastp->endoff = end; 988 ifslastp->inquotes = inquotes; 989 } 990 991 992 993 /* 994 * Break the argument string into pieces based upon IFS and add the 995 * strings to the argument list. The regions of the string to be 996 * searched for IFS characters have been stored by recordregion. 997 * CTLESC characters are preserved but have little effect in this pass 998 * other than escaping CTL* characters. In particular, they do not escape 999 * IFS characters: that should be done with the ifsregion mechanism. 1000 * CTLQUOTEMARK characters are used to preserve empty quoted strings. 1001 * This pass treats them as a regular character, making the string non-empty. 1002 * Later, they are removed along with the other CTL* characters. 1003 */ 1004 static void 1005 ifsbreakup(char *string, struct arglist *arglist) 1006 { 1007 struct ifsregion *ifsp; 1008 struct strlist *sp; 1009 char *start; 1010 char *p; 1011 char *q; 1012 const char *ifs; 1013 const char *ifsspc; 1014 int had_param_ch = 0; 1015 1016 start = string; 1017 1018 if (ifslastp == NULL) { 1019 /* Return entire argument, IFS doesn't apply to any of it */ 1020 sp = (struct strlist *)stalloc(sizeof *sp); 1021 sp->text = start; 1022 *arglist->lastp = sp; 1023 arglist->lastp = &sp->next; 1024 return; 1025 } 1026 1027 ifs = ifsset() ? ifsval() : " \t\n"; 1028 1029 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) { 1030 p = string + ifsp->begoff; 1031 while (p < string + ifsp->endoff) { 1032 q = p; 1033 if (*p == CTLESC) 1034 p++; 1035 if (ifsp->inquotes) { 1036 /* Only NULs (should be from "$@") end args */ 1037 had_param_ch = 1; 1038 if (*p != 0) { 1039 p++; 1040 continue; 1041 } 1042 ifsspc = NULL; 1043 } else { 1044 if (!strchr(ifs, *p)) { 1045 had_param_ch = 1; 1046 p++; 1047 continue; 1048 } 1049 ifsspc = strchr(" \t\n", *p); 1050 1051 /* Ignore IFS whitespace at start */ 1052 if (q == start && ifsspc != NULL) { 1053 p++; 1054 start = p; 1055 continue; 1056 } 1057 had_param_ch = 0; 1058 } 1059 1060 /* Save this argument... */ 1061 *q = '\0'; 1062 sp = (struct strlist *)stalloc(sizeof *sp); 1063 sp->text = start; 1064 *arglist->lastp = sp; 1065 arglist->lastp = &sp->next; 1066 p++; 1067 1068 if (ifsspc != NULL) { 1069 /* Ignore further trailing IFS whitespace */ 1070 for (; p < string + ifsp->endoff; p++) { 1071 q = p; 1072 if (*p == CTLESC) 1073 p++; 1074 if (strchr(ifs, *p) == NULL) { 1075 p = q; 1076 break; 1077 } 1078 if (strchr(" \t\n", *p) == NULL) { 1079 p++; 1080 break; 1081 } 1082 } 1083 } 1084 start = p; 1085 } 1086 } 1087 1088 /* 1089 * Save anything left as an argument. 1090 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as 1091 * generating 2 arguments, the second of which is empty. 1092 * Some recent clarification of the Posix spec say that it 1093 * should only generate one.... 1094 */ 1095 if (had_param_ch || *start != 0) { 1096 sp = (struct strlist *)stalloc(sizeof *sp); 1097 sp->text = start; 1098 *arglist->lastp = sp; 1099 arglist->lastp = &sp->next; 1100 } 1101 } 1102 1103 1104 static char expdir[PATH_MAX]; 1105 #define expdir_end (expdir + sizeof(expdir)) 1106 1107 /* 1108 * Perform pathname generation and remove control characters. 1109 * At this point, the only control characters should be CTLESC and CTLQUOTEMARK. 1110 * The results are stored in the list exparg. 1111 */ 1112 static void 1113 expandmeta(struct strlist *str, int flag __unused) 1114 { 1115 char *p; 1116 struct strlist **savelastp; 1117 struct strlist *sp; 1118 char c; 1119 /* TODO - EXP_REDIR */ 1120 1121 while (str) { 1122 if (fflag) 1123 goto nometa; 1124 p = str->text; 1125 for (;;) { /* fast check for meta chars */ 1126 if ((c = *p++) == '\0') 1127 goto nometa; 1128 if (c == '*' || c == '?' || c == '[') 1129 break; 1130 } 1131 savelastp = exparg.lastp; 1132 INTOFF; 1133 expmeta(expdir, str->text); 1134 INTON; 1135 if (exparg.lastp == savelastp) { 1136 /* 1137 * no matches 1138 */ 1139 nometa: 1140 *exparg.lastp = str; 1141 rmescapes(str->text); 1142 exparg.lastp = &str->next; 1143 } else { 1144 *exparg.lastp = NULL; 1145 *savelastp = sp = expsort(*savelastp); 1146 while (sp->next != NULL) 1147 sp = sp->next; 1148 exparg.lastp = &sp->next; 1149 } 1150 str = str->next; 1151 } 1152 } 1153 1154 1155 /* 1156 * Do metacharacter (i.e. *, ?, [...]) expansion. 1157 */ 1158 1159 static void 1160 expmeta(char *enddir, char *name) 1161 { 1162 char *p; 1163 char *q; 1164 char *start; 1165 char *endname; 1166 int metaflag; 1167 struct stat statb; 1168 DIR *dirp; 1169 struct dirent *dp; 1170 int atend; 1171 int matchdot; 1172 int esc; 1173 1174 metaflag = 0; 1175 start = name; 1176 for (p = name; esc = 0, *p; p += esc + 1) { 1177 if (*p == '*' || *p == '?') 1178 metaflag = 1; 1179 else if (*p == '[') { 1180 q = p + 1; 1181 if (*q == '!' || *q == '^') 1182 q++; 1183 for (;;) { 1184 while (*q == CTLQUOTEMARK) 1185 q++; 1186 if (*q == CTLESC) 1187 q++; 1188 if (*q == '/' || *q == '\0') 1189 break; 1190 if (*++q == ']') { 1191 metaflag = 1; 1192 break; 1193 } 1194 } 1195 } else if (*p == '\0') 1196 break; 1197 else if (*p == CTLQUOTEMARK) 1198 continue; 1199 else { 1200 if (*p == CTLESC) 1201 esc++; 1202 if (p[esc] == '/') { 1203 if (metaflag) 1204 break; 1205 start = p + esc + 1; 1206 } 1207 } 1208 } 1209 if (metaflag == 0) { /* we've reached the end of the file name */ 1210 if (enddir != expdir) 1211 metaflag++; 1212 for (p = name ; ; p++) { 1213 if (*p == CTLQUOTEMARK) 1214 continue; 1215 if (*p == CTLESC) 1216 p++; 1217 *enddir++ = *p; 1218 if (*p == '\0') 1219 break; 1220 if (enddir == expdir_end) 1221 return; 1222 } 1223 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1224 addfname(expdir); 1225 return; 1226 } 1227 endname = p; 1228 if (start != name) { 1229 p = name; 1230 while (p < start) { 1231 while (*p == CTLQUOTEMARK) 1232 p++; 1233 if (*p == CTLESC) 1234 p++; 1235 *enddir++ = *p++; 1236 if (enddir == expdir_end) 1237 return; 1238 } 1239 } 1240 if (enddir == expdir) { 1241 p = "."; 1242 } else if (enddir == expdir + 1 && *expdir == '/') { 1243 p = "/"; 1244 } else { 1245 p = expdir; 1246 enddir[-1] = '\0'; 1247 } 1248 if ((dirp = opendir(p)) == NULL) 1249 return; 1250 if (enddir != expdir) 1251 enddir[-1] = '/'; 1252 if (*endname == 0) { 1253 atend = 1; 1254 } else { 1255 atend = 0; 1256 *endname = '\0'; 1257 endname += esc + 1; 1258 } 1259 matchdot = 0; 1260 p = start; 1261 while (*p == CTLQUOTEMARK) 1262 p++; 1263 if (*p == CTLESC) 1264 p++; 1265 if (*p == '.') 1266 matchdot++; 1267 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1268 if (dp->d_name[0] == '.' && ! matchdot) 1269 continue; 1270 if (patmatch(start, dp->d_name, 0)) { 1271 if (enddir + dp->d_namlen + 1 > expdir_end) 1272 continue; 1273 memcpy(enddir, dp->d_name, dp->d_namlen + 1); 1274 if (atend) 1275 addfname(expdir); 1276 else { 1277 if (enddir + dp->d_namlen + 2 > expdir_end) 1278 continue; 1279 enddir[dp->d_namlen] = '/'; 1280 enddir[dp->d_namlen + 1] = '\0'; 1281 expmeta(enddir + dp->d_namlen + 1, endname); 1282 } 1283 } 1284 } 1285 closedir(dirp); 1286 if (! atend) 1287 endname[-esc - 1] = esc ? CTLESC : '/'; 1288 } 1289 1290 1291 /* 1292 * Add a file name to the list. 1293 */ 1294 1295 static void 1296 addfname(char *name) 1297 { 1298 char *p; 1299 struct strlist *sp; 1300 1301 p = stalloc(strlen(name) + 1); 1302 scopy(name, p); 1303 sp = (struct strlist *)stalloc(sizeof *sp); 1304 sp->text = p; 1305 *exparg.lastp = sp; 1306 exparg.lastp = &sp->next; 1307 } 1308 1309 1310 /* 1311 * Sort the results of file name expansion. It calculates the number of 1312 * strings to sort and then calls msort (short for merge sort) to do the 1313 * work. 1314 */ 1315 1316 static struct strlist * 1317 expsort(struct strlist *str) 1318 { 1319 int len; 1320 struct strlist *sp; 1321 1322 len = 0; 1323 for (sp = str ; sp ; sp = sp->next) 1324 len++; 1325 return msort(str, len); 1326 } 1327 1328 1329 static struct strlist * 1330 msort(struct strlist *list, int len) 1331 { 1332 struct strlist *p, *q = NULL; 1333 struct strlist **lpp; 1334 int half; 1335 int n; 1336 1337 if (len <= 1) 1338 return list; 1339 half = len >> 1; 1340 p = list; 1341 for (n = half ; --n >= 0 ; ) { 1342 q = p; 1343 p = p->next; 1344 } 1345 q->next = NULL; /* terminate first half of list */ 1346 q = msort(list, half); /* sort first half of list */ 1347 p = msort(p, len - half); /* sort second half */ 1348 lpp = &list; 1349 for (;;) { 1350 if (strcmp(p->text, q->text) < 0) { 1351 *lpp = p; 1352 lpp = &p->next; 1353 if ((p = *lpp) == NULL) { 1354 *lpp = q; 1355 break; 1356 } 1357 } else { 1358 *lpp = q; 1359 lpp = &q->next; 1360 if ((q = *lpp) == NULL) { 1361 *lpp = p; 1362 break; 1363 } 1364 } 1365 } 1366 return list; 1367 } 1368 1369 1370 1371 /* 1372 * Returns true if the pattern matches the string. 1373 */ 1374 1375 int 1376 patmatch(const char *pattern, const char *string, int squoted) 1377 { 1378 const char *p, *q; 1379 char c; 1380 1381 p = pattern; 1382 q = string; 1383 for (;;) { 1384 switch (c = *p++) { 1385 case '\0': 1386 goto breakloop; 1387 case CTLESC: 1388 if (squoted && *q == CTLESC) 1389 q++; 1390 if (*q++ != *p++) 1391 return 0; 1392 break; 1393 case CTLQUOTEMARK: 1394 continue; 1395 case '?': 1396 if (squoted && *q == CTLESC) 1397 q++; 1398 if (*q++ == '\0') 1399 return 0; 1400 break; 1401 case '*': 1402 c = *p; 1403 while (c == CTLQUOTEMARK || c == '*') 1404 c = *++p; 1405 if (c != CTLESC && c != CTLQUOTEMARK && 1406 c != '?' && c != '*' && c != '[') { 1407 while (*q != c) { 1408 if (squoted && *q == CTLESC && 1409 q[1] == c) 1410 break; 1411 if (*q == '\0') 1412 return 0; 1413 if (squoted && *q == CTLESC) 1414 q++; 1415 q++; 1416 } 1417 } 1418 do { 1419 if (patmatch(p, q, squoted)) 1420 return 1; 1421 if (squoted && *q == CTLESC) 1422 q++; 1423 } while (*q++ != '\0'); 1424 return 0; 1425 case '[': { 1426 const char *endp; 1427 int invert, found; 1428 char chr; 1429 1430 endp = p; 1431 if (*endp == '!' || *endp == '^') 1432 endp++; 1433 for (;;) { 1434 while (*endp == CTLQUOTEMARK) 1435 endp++; 1436 if (*endp == '\0') 1437 goto dft; /* no matching ] */ 1438 if (*endp == CTLESC) 1439 endp++; 1440 if (*++endp == ']') 1441 break; 1442 } 1443 invert = 0; 1444 if (*p == '!' || *p == '^') { 1445 invert++; 1446 p++; 1447 } 1448 found = 0; 1449 chr = *q++; 1450 if (squoted && chr == CTLESC) 1451 chr = *q++; 1452 if (chr == '\0') 1453 return 0; 1454 c = *p++; 1455 do { 1456 if (c == CTLQUOTEMARK) 1457 continue; 1458 if (c == CTLESC) 1459 c = *p++; 1460 if (*p == '-' && p[1] != ']') { 1461 p++; 1462 while (*p == CTLQUOTEMARK) 1463 p++; 1464 if (*p == CTLESC) 1465 p++; 1466 if ( collate_range_cmp(chr, c) >= 0 1467 && collate_range_cmp(chr, *p) <= 0 1468 ) 1469 found = 1; 1470 p++; 1471 } else { 1472 if (chr == c) 1473 found = 1; 1474 } 1475 } while ((c = *p++) != ']'); 1476 if (found == invert) 1477 return 0; 1478 break; 1479 } 1480 dft: default: 1481 if (squoted && *q == CTLESC) 1482 q++; 1483 if (*q++ != c) 1484 return 0; 1485 break; 1486 } 1487 } 1488 breakloop: 1489 if (*q != '\0') 1490 return 0; 1491 return 1; 1492 } 1493 1494 1495 1496 /* 1497 * Remove any CTLESC and CTLQUOTEMARK characters from a string. 1498 */ 1499 1500 void 1501 rmescapes(char *str) 1502 { 1503 char *p, *q; 1504 1505 p = str; 1506 while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) { 1507 if (*p++ == '\0') 1508 return; 1509 } 1510 q = p; 1511 while (*p) { 1512 if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) { 1513 p++; 1514 continue; 1515 } 1516 if (*p == CTLESC) 1517 p++; 1518 *q++ = *p++; 1519 } 1520 *q = '\0'; 1521 } 1522 1523 1524 1525 /* 1526 * See if a pattern matches in a case statement. 1527 */ 1528 1529 int 1530 casematch(union node *pattern, const char *val) 1531 { 1532 struct stackmark smark; 1533 int result; 1534 char *p; 1535 1536 setstackmark(&smark); 1537 argbackq = pattern->narg.backquote; 1538 STARTSTACKSTR(expdest); 1539 ifslastp = NULL; 1540 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1541 STPUTC('\0', expdest); 1542 p = grabstackstr(expdest); 1543 result = patmatch(p, val, 0); 1544 popstackmark(&smark); 1545 return result; 1546 } 1547 1548 /* 1549 * Our own itoa(). 1550 */ 1551 1552 static char * 1553 cvtnum(int num, char *buf) 1554 { 1555 char temp[32]; 1556 int neg = num < 0; 1557 char *p = temp + 31; 1558 1559 temp[31] = '\0'; 1560 1561 do { 1562 *--p = num % 10 + '0'; 1563 } while ((num /= 10) != 0); 1564 1565 if (neg) 1566 *--p = '-'; 1567 1568 STPUTS(p, buf); 1569 return buf; 1570 } 1571 1572 /* 1573 * Check statically if expanding a string may have side effects. 1574 */ 1575 int 1576 expandhassideeffects(const char *p) 1577 { 1578 int c; 1579 int arinest; 1580 1581 arinest = 0; 1582 while ((c = *p++) != '\0') { 1583 switch (c) { 1584 case CTLESC: 1585 p++; 1586 break; 1587 case CTLVAR: 1588 c = *p++; 1589 /* Expanding $! sets the job to remembered. */ 1590 if (*p == '!') 1591 return 1; 1592 if ((c & VSTYPE) == VSASSIGN) 1593 return 1; 1594 /* 1595 * If we are in arithmetic, the parameter may contain 1596 * '=' which may cause side effects. Exceptions are 1597 * the length of a parameter and $$, $# and $? which 1598 * are always numeric. 1599 */ 1600 if ((c & VSTYPE) == VSLENGTH) { 1601 while (*p != '=') 1602 p++; 1603 p++; 1604 break; 1605 } 1606 if ((*p == '$' || *p == '#' || *p == '?') && 1607 p[1] == '=') { 1608 p += 2; 1609 break; 1610 } 1611 if (arinest > 0) 1612 return 1; 1613 break; 1614 case CTLBACKQ: 1615 case CTLBACKQ | CTLQUOTE: 1616 if (arinest > 0) 1617 return 1; 1618 break; 1619 case CTLARI: 1620 arinest++; 1621 break; 1622 case CTLENDARI: 1623 arinest--; 1624 break; 1625 case '=': 1626 if (*p == '=') { 1627 /* Allow '==' operator. */ 1628 p++; 1629 continue; 1630 } 1631 if (arinest > 0) 1632 return 1; 1633 break; 1634 case '!': case '<': case '>': 1635 /* Allow '!=', '<=', '>=' operators. */ 1636 if (*p == '=') 1637 p++; 1638 break; 1639 } 1640 } 1641 return 0; 1642 } 1643 1644 /* 1645 * Do most of the work for wordexp(3). 1646 */ 1647 1648 int 1649 wordexpcmd(int argc, char **argv) 1650 { 1651 size_t len; 1652 int i; 1653 1654 out1fmt("%08x", argc - 1); 1655 for (i = 1, len = 0; i < argc; i++) 1656 len += strlen(argv[i]); 1657 out1fmt("%08x", (int)len); 1658 for (i = 1; i < argc; i++) 1659 outbin(argv[i], strlen(argv[i]) + 1, out1); 1660 return (0); 1661 } 1662