1 /* $NetBSD: expand.c,v 1.49 2000/03/13 22:47:19 soren Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95"; 43 #else 44 __RCSID("$NetBSD: expand.c,v 1.49 2000/03/13 22:47:19 soren Exp $"); 45 #endif 46 #endif /* not lint */ 47 48 #include <sys/types.h> 49 #include <sys/time.h> 50 #include <sys/stat.h> 51 #include <errno.h> 52 #include <dirent.h> 53 #include <unistd.h> 54 #include <pwd.h> 55 #include <stdlib.h> 56 #include <stdio.h> 57 58 /* 59 * Routines to expand arguments to commands. We have to deal with 60 * backquotes, shell variables, and file metacharacters. 61 */ 62 63 #include "shell.h" 64 #include "main.h" 65 #include "nodes.h" 66 #include "eval.h" 67 #include "expand.h" 68 #include "syntax.h" 69 #include "parser.h" 70 #include "jobs.h" 71 #include "options.h" 72 #include "var.h" 73 #include "input.h" 74 #include "output.h" 75 #include "memalloc.h" 76 #include "error.h" 77 #include "mystring.h" 78 #include "show.h" 79 80 /* 81 * Structure specifying which parts of the string should be searched 82 * for IFS characters. 83 */ 84 85 struct ifsregion { 86 struct ifsregion *next; /* next region in list */ 87 int begoff; /* offset of start of region */ 88 int endoff; /* offset of end of region */ 89 int nulonly; /* search for nul bytes only */ 90 }; 91 92 93 char *expdest; /* output of current string */ 94 struct nodelist *argbackq; /* list of back quote expressions */ 95 struct ifsregion ifsfirst; /* first struct in list of ifs regions */ 96 struct ifsregion *ifslastp; /* last struct in list */ 97 struct arglist exparg; /* holds expanded arg list */ 98 99 STATIC void argstr __P((char *, int)); 100 STATIC char *exptilde __P((char *, int)); 101 STATIC void expbackq __P((union node *, int, int)); 102 STATIC int subevalvar __P((char *, char *, int, int, int, int)); 103 STATIC char *evalvar __P((char *, int)); 104 STATIC int varisset __P((char *, int)); 105 STATIC void varvalue __P((char *, int, int)); 106 STATIC void recordregion __P((int, int, int)); 107 STATIC void removerecordregions __P((int)); 108 STATIC void ifsbreakup __P((char *, struct arglist *)); 109 STATIC void ifsfree __P((void)); 110 STATIC void expandmeta __P((struct strlist *, int)); 111 STATIC void expmeta __P((char *, char *)); 112 STATIC void addfname __P((char *)); 113 STATIC struct strlist *expsort __P((struct strlist *)); 114 STATIC struct strlist *msort __P((struct strlist *, int)); 115 STATIC int pmatch __P((char *, char *, int)); 116 STATIC char *cvtnum __P((int, char *)); 117 118 /* 119 * Expand shell variables and backquotes inside a here document. 120 */ 121 122 void 123 expandhere(arg, fd) 124 union node *arg; /* the document */ 125 int fd; /* where to write the expanded version */ 126 { 127 herefd = fd; 128 expandarg(arg, (struct arglist *)NULL, 0); 129 xwrite(fd, stackblock(), expdest - stackblock()); 130 } 131 132 133 /* 134 * Perform variable substitution and command substitution on an argument, 135 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 136 * perform splitting and file name expansion. When arglist is NULL, perform 137 * here document expansion. 138 */ 139 140 void 141 expandarg(arg, arglist, flag) 142 union node *arg; 143 struct arglist *arglist; 144 int flag; 145 { 146 struct strlist *sp; 147 char *p; 148 149 argbackq = arg->narg.backquote; 150 STARTSTACKSTR(expdest); 151 ifsfirst.next = NULL; 152 ifslastp = NULL; 153 argstr(arg->narg.text, flag); 154 if (arglist == NULL) { 155 return; /* here document expanded */ 156 } 157 STPUTC('\0', expdest); 158 p = grabstackstr(expdest); 159 exparg.lastp = &exparg.list; 160 /* 161 * TODO - EXP_REDIR 162 */ 163 if (flag & EXP_FULL) { 164 ifsbreakup(p, &exparg); 165 *exparg.lastp = NULL; 166 exparg.lastp = &exparg.list; 167 expandmeta(exparg.list, flag); 168 } else { 169 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 170 rmescapes(p); 171 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 172 sp->text = p; 173 *exparg.lastp = sp; 174 exparg.lastp = &sp->next; 175 } 176 ifsfree(); 177 *exparg.lastp = NULL; 178 if (exparg.list) { 179 *arglist->lastp = exparg.list; 180 arglist->lastp = exparg.lastp; 181 } 182 } 183 184 185 186 /* 187 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC 188 * characters to allow for further processing. Otherwise treat 189 * $@ like $* since no splitting will be performed. 190 */ 191 192 STATIC void 193 argstr(p, flag) 194 char *p; 195 int flag; 196 { 197 char c; 198 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */ 199 int firsteq = 1; 200 201 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 202 p = exptilde(p, flag); 203 for (;;) { 204 switch (c = *p++) { 205 case '\0': 206 case CTLENDVAR: /* ??? */ 207 goto breakloop; 208 case CTLQUOTEMARK: 209 /* "$@" syntax adherence hack */ 210 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 211 break; 212 if ((flag & EXP_FULL) != 0) 213 STPUTC(c, expdest); 214 break; 215 case CTLESC: 216 if (quotes) 217 STPUTC(c, expdest); 218 c = *p++; 219 STPUTC(c, expdest); 220 break; 221 case CTLVAR: 222 p = evalvar(p, flag); 223 break; 224 case CTLBACKQ: 225 case CTLBACKQ|CTLQUOTE: 226 expbackq(argbackq->n, c & CTLQUOTE, flag); 227 argbackq = argbackq->next; 228 break; 229 case CTLENDARI: 230 expari(flag); 231 break; 232 case ':': 233 case '=': 234 /* 235 * sort of a hack - expand tildes in variable 236 * assignments (after the first '=' and after ':'s). 237 */ 238 STPUTC(c, expdest); 239 if (flag & EXP_VARTILDE && *p == '~') { 240 if (c == '=') { 241 if (firsteq) 242 firsteq = 0; 243 else 244 break; 245 } 246 p = exptilde(p, flag); 247 } 248 break; 249 default: 250 STPUTC(c, expdest); 251 } 252 } 253 breakloop:; 254 return; 255 } 256 257 STATIC char * 258 exptilde(p, flag) 259 char *p; 260 int flag; 261 { 262 char c, *startp = p; 263 struct passwd *pw; 264 const char *home; 265 int quotes = flag & (EXP_FULL | EXP_CASE); 266 267 while ((c = *p) != '\0') { 268 switch(c) { 269 case CTLESC: 270 return (startp); 271 case CTLQUOTEMARK: 272 return (startp); 273 case ':': 274 if (flag & EXP_VARTILDE) 275 goto done; 276 break; 277 case '/': 278 goto done; 279 } 280 p++; 281 } 282 done: 283 *p = '\0'; 284 if (*(startp+1) == '\0') { 285 if ((home = lookupvar("HOME")) == NULL) 286 goto lose; 287 } else { 288 if ((pw = getpwnam(startp+1)) == NULL) 289 goto lose; 290 home = pw->pw_dir; 291 } 292 if (*home == '\0') 293 goto lose; 294 *p = c; 295 while ((c = *home++) != '\0') { 296 if (quotes && SQSYNTAX[(int)c] == CCTL) 297 STPUTC(CTLESC, expdest); 298 STPUTC(c, expdest); 299 } 300 return (p); 301 lose: 302 *p = c; 303 return (startp); 304 } 305 306 307 STATIC void 308 removerecordregions(endoff) 309 int endoff; 310 { 311 if (ifslastp == NULL) 312 return; 313 314 if (ifsfirst.endoff > endoff) { 315 while (ifsfirst.next != NULL) { 316 struct ifsregion *ifsp; 317 INTOFF; 318 ifsp = ifsfirst.next->next; 319 ckfree(ifsfirst.next); 320 ifsfirst.next = ifsp; 321 INTON; 322 } 323 if (ifsfirst.begoff > endoff) 324 ifslastp = NULL; 325 else { 326 ifslastp = &ifsfirst; 327 ifsfirst.endoff = endoff; 328 } 329 return; 330 } 331 332 ifslastp = &ifsfirst; 333 while (ifslastp->next && ifslastp->next->begoff < endoff) 334 ifslastp=ifslastp->next; 335 while (ifslastp->next != NULL) { 336 struct ifsregion *ifsp; 337 INTOFF; 338 ifsp = ifslastp->next->next; 339 ckfree(ifslastp->next); 340 ifslastp->next = ifsp; 341 INTON; 342 } 343 if (ifslastp->endoff > endoff) 344 ifslastp->endoff = endoff; 345 } 346 347 348 /* 349 * Expand arithmetic expression. Backup to start of expression, 350 * evaluate, place result in (backed up) result, adjust string position. 351 */ 352 void 353 expari(flag) 354 int flag; 355 { 356 char *p, *start; 357 int result; 358 int begoff; 359 int quotes = flag & (EXP_FULL | EXP_CASE); 360 int quoted; 361 362 /* ifsfree(); */ 363 364 /* 365 * This routine is slightly over-complicated for 366 * efficiency. First we make sure there is 367 * enough space for the result, which may be bigger 368 * than the expression if we add exponentation. Next we 369 * scan backwards looking for the start of arithmetic. If the 370 * next previous character is a CTLESC character, then we 371 * have to rescan starting from the beginning since CTLESC 372 * characters have to be processed left to right. 373 */ 374 CHECKSTRSPACE(8, expdest); 375 USTPUTC('\0', expdest); 376 start = stackblock(); 377 p = expdest - 1; 378 while (*p != CTLARI && p >= start) 379 --p; 380 if (*p != CTLARI) 381 error("missing CTLARI (shouldn't happen)"); 382 if (p > start && *(p-1) == CTLESC) 383 for (p = start; *p != CTLARI; p++) 384 if (*p == CTLESC) 385 p++; 386 387 if (p[1] == '"') 388 quoted=1; 389 else 390 quoted=0; 391 begoff = p - start; 392 removerecordregions(begoff); 393 if (quotes) 394 rmescapes(p+2); 395 result = arith(p+2); 396 fmtstr(p, 10, "%d", result); 397 398 while (*p++) 399 ; 400 401 if (quoted == 0) 402 recordregion(begoff, p - 1 - start, 0); 403 result = expdest - p + 1; 404 STADJUST(-result, expdest); 405 } 406 407 408 /* 409 * Expand stuff in backwards quotes. 410 */ 411 412 STATIC void 413 expbackq(cmd, quoted, flag) 414 union node *cmd; 415 int quoted; 416 int flag; 417 { 418 struct backcmd in; 419 int i; 420 char buf[128]; 421 char *p; 422 char *dest = expdest; 423 struct ifsregion saveifs, *savelastp; 424 struct nodelist *saveargbackq; 425 char lastc; 426 int startloc = dest - stackblock(); 427 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 428 int saveherefd; 429 int quotes = flag & (EXP_FULL | EXP_CASE); 430 431 INTOFF; 432 saveifs = ifsfirst; 433 savelastp = ifslastp; 434 saveargbackq = argbackq; 435 saveherefd = herefd; 436 herefd = -1; 437 p = grabstackstr(dest); 438 evalbackcmd(cmd, &in); 439 ungrabstackstr(p, dest); 440 ifsfirst = saveifs; 441 ifslastp = savelastp; 442 argbackq = saveargbackq; 443 herefd = saveherefd; 444 445 p = in.buf; 446 lastc = '\0'; 447 for (;;) { 448 if (--in.nleft < 0) { 449 if (in.fd < 0) 450 break; 451 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 452 TRACE(("expbackq: read returns %d\n", i)); 453 if (i <= 0) 454 break; 455 p = buf; 456 in.nleft = i - 1; 457 } 458 lastc = *p++; 459 if (lastc != '\0') { 460 if (quotes && syntax[(int)lastc] == CCTL) 461 STPUTC(CTLESC, dest); 462 STPUTC(lastc, dest); 463 } 464 } 465 466 /* Eat all trailing newlines */ 467 for (p--; lastc == '\n'; lastc = *--p) 468 STUNPUTC(dest); 469 470 if (in.fd >= 0) 471 close(in.fd); 472 if (in.buf) 473 ckfree(in.buf); 474 if (in.jp) 475 exitstatus = waitforjob(in.jp); 476 if (quoted == 0) 477 recordregion(startloc, dest - stackblock(), 0); 478 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 479 (dest - stackblock()) - startloc, 480 (dest - stackblock()) - startloc, 481 stackblock() + startloc)); 482 expdest = dest; 483 INTON; 484 } 485 486 487 488 STATIC int 489 subevalvar(p, str, strloc, subtype, startloc, varflags) 490 char *p; 491 char *str; 492 int strloc; 493 int subtype; 494 int startloc; 495 int varflags; 496 { 497 char *startp; 498 char *loc = NULL; 499 char *q; 500 int c = 0; 501 int saveherefd = herefd; 502 struct nodelist *saveargbackq = argbackq; 503 int amount; 504 505 herefd = -1; 506 argstr(p, 0); 507 STACKSTRNUL(expdest); 508 herefd = saveherefd; 509 argbackq = saveargbackq; 510 startp = stackblock() + startloc; 511 if (str == NULL) 512 str = stackblock() + strloc; 513 514 switch (subtype) { 515 case VSASSIGN: 516 setvar(str, startp, 0); 517 amount = startp - expdest; 518 STADJUST(amount, expdest); 519 varflags &= ~VSNUL; 520 if (c != 0) 521 *loc = c; 522 return 1; 523 524 case VSQUESTION: 525 if (*p != CTLENDVAR) { 526 outfmt(&errout, "%s\n", startp); 527 error((char *)NULL); 528 } 529 error("%.*s: parameter %snot set", p - str - 1, 530 str, (varflags & VSNUL) ? "null or " 531 : nullstr); 532 /* NOTREACHED */ 533 534 case VSTRIMLEFT: 535 for (loc = startp; loc < str; loc++) { 536 c = *loc; 537 *loc = '\0'; 538 if (patmatch(str, startp, varflags & VSQUOTE)) 539 goto recordleft; 540 *loc = c; 541 if ((varflags & VSQUOTE) && *loc == CTLESC) 542 loc++; 543 } 544 return 0; 545 546 case VSTRIMLEFTMAX: 547 for (loc = str - 1; loc >= startp;) { 548 c = *loc; 549 *loc = '\0'; 550 if (patmatch(str, startp, varflags & VSQUOTE)) 551 goto recordleft; 552 *loc = c; 553 loc--; 554 if ((varflags & VSQUOTE) && loc > startp && 555 *(loc - 1) == CTLESC) { 556 for (q = startp; q < loc; q++) 557 if (*q == CTLESC) 558 q++; 559 if (q > loc) 560 loc--; 561 } 562 } 563 return 0; 564 565 case VSTRIMRIGHT: 566 for (loc = str - 1; loc >= startp;) { 567 if (patmatch(str, loc, varflags & VSQUOTE)) 568 goto recordright; 569 loc--; 570 if ((varflags & VSQUOTE) && loc > startp && 571 *(loc - 1) == CTLESC) { 572 for (q = startp; q < loc; q++) 573 if (*q == CTLESC) 574 q++; 575 if (q > loc) 576 loc--; 577 } 578 } 579 return 0; 580 581 case VSTRIMRIGHTMAX: 582 for (loc = startp; loc < str - 1; loc++) { 583 if (patmatch(str, loc, varflags & VSQUOTE)) 584 goto recordright; 585 if ((varflags & VSQUOTE) && *loc == CTLESC) 586 loc++; 587 } 588 return 0; 589 590 default: 591 abort(); 592 } 593 594 recordleft: 595 *loc = c; 596 amount = ((str - 1) - (loc - startp)) - expdest; 597 STADJUST(amount, expdest); 598 while (loc != str - 1) 599 *startp++ = *loc++; 600 return 1; 601 602 recordright: 603 amount = loc - expdest; 604 STADJUST(amount, expdest); 605 STPUTC('\0', expdest); 606 STADJUST(-1, expdest); 607 return 1; 608 } 609 610 611 /* 612 * Expand a variable, and return a pointer to the next character in the 613 * input string. 614 */ 615 616 STATIC char * 617 evalvar(p, flag) 618 char *p; 619 int flag; 620 { 621 int subtype; 622 int varflags; 623 char *var; 624 char *val; 625 int patloc; 626 int c; 627 int set; 628 int special; 629 int startloc; 630 int varlen; 631 int easy; 632 int quotes = flag & (EXP_FULL | EXP_CASE); 633 634 varflags = *p++; 635 subtype = varflags & VSTYPE; 636 var = p; 637 special = 0; 638 if (! is_name(*p)) 639 special = 1; 640 p = strchr(p, '=') + 1; 641 again: /* jump here after setting a variable with ${var=text} */ 642 if (special) { 643 set = varisset(var, varflags & VSNUL); 644 val = NULL; 645 } else { 646 val = lookupvar(var); 647 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 648 val = NULL; 649 set = 0; 650 } else 651 set = 1; 652 } 653 varlen = 0; 654 startloc = expdest - stackblock(); 655 if (set && subtype != VSPLUS) { 656 /* insert the value of the variable */ 657 if (special) { 658 varvalue(var, varflags & VSQUOTE, flag & EXP_FULL); 659 if (subtype == VSLENGTH) { 660 varlen = expdest - stackblock() - startloc; 661 STADJUST(-varlen, expdest); 662 } 663 } else { 664 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 665 : BASESYNTAX; 666 667 if (subtype == VSLENGTH) { 668 for (;*val; val++) 669 varlen++; 670 } 671 else { 672 while (*val) { 673 if (quotes && syntax[(int)*val] == CCTL) 674 STPUTC(CTLESC, expdest); 675 STPUTC(*val++, expdest); 676 } 677 678 } 679 } 680 } 681 682 if (subtype == VSPLUS) 683 set = ! set; 684 685 easy = ((varflags & VSQUOTE) == 0 || 686 (*var == '@' && shellparam.nparam != 1)); 687 688 689 switch (subtype) { 690 case VSLENGTH: 691 expdest = cvtnum(varlen, expdest); 692 goto record; 693 694 case VSNORMAL: 695 if (!easy) 696 break; 697 record: 698 recordregion(startloc, expdest - stackblock(), 699 varflags & VSQUOTE); 700 break; 701 702 case VSPLUS: 703 case VSMINUS: 704 if (!set) { 705 argstr(p, flag); 706 break; 707 } 708 if (easy) 709 goto record; 710 break; 711 712 case VSTRIMLEFT: 713 case VSTRIMLEFTMAX: 714 case VSTRIMRIGHT: 715 case VSTRIMRIGHTMAX: 716 if (!set) 717 break; 718 /* 719 * Terminate the string and start recording the pattern 720 * right after it 721 */ 722 STPUTC('\0', expdest); 723 patloc = expdest - stackblock(); 724 if (subevalvar(p, NULL, patloc, subtype, 725 startloc, varflags) == 0) { 726 int amount = (expdest - stackblock() - patloc) + 1; 727 STADJUST(-amount, expdest); 728 } 729 /* Remove any recorded regions beyond start of variable */ 730 removerecordregions(startloc); 731 goto record; 732 733 case VSASSIGN: 734 case VSQUESTION: 735 if (!set) { 736 if (subevalvar(p, var, 0, subtype, startloc, 737 varflags)) { 738 varflags &= ~VSNUL; 739 /* 740 * Remove any recorded regions beyond 741 * start of variable 742 */ 743 removerecordregions(startloc); 744 goto again; 745 } 746 break; 747 } 748 if (easy) 749 goto record; 750 break; 751 752 default: 753 abort(); 754 } 755 756 if (subtype != VSNORMAL) { /* skip to end of alternative */ 757 int nesting = 1; 758 for (;;) { 759 if ((c = *p++) == CTLESC) 760 p++; 761 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 762 if (set) 763 argbackq = argbackq->next; 764 } else if (c == CTLVAR) { 765 if ((*p++ & VSTYPE) != VSNORMAL) 766 nesting++; 767 } else if (c == CTLENDVAR) { 768 if (--nesting == 0) 769 break; 770 } 771 } 772 } 773 return p; 774 } 775 776 777 778 /* 779 * Test whether a specialized variable is set. 780 */ 781 782 STATIC int 783 varisset(name, nulok) 784 char *name; 785 int nulok; 786 { 787 if (*name == '!') 788 return backgndpid != -1; 789 else if (*name == '@' || *name == '*') { 790 if (*shellparam.p == NULL) 791 return 0; 792 793 if (nulok) { 794 char **av; 795 796 for (av = shellparam.p; *av; av++) 797 if (**av != '\0') 798 return 1; 799 return 0; 800 } 801 } else if (is_digit(*name)) { 802 char *ap; 803 int num = atoi(name); 804 805 if (num > shellparam.nparam) 806 return 0; 807 808 if (num == 0) 809 ap = arg0; 810 else 811 ap = shellparam.p[num - 1]; 812 813 if (nulok && (ap == NULL || *ap == '\0')) 814 return 0; 815 } 816 return 1; 817 } 818 819 820 821 /* 822 * Add the value of a specialized variable to the stack string. 823 */ 824 825 STATIC void 826 varvalue(name, quoted, allow_split) 827 char *name; 828 int quoted; 829 int allow_split; 830 { 831 int num; 832 char *p; 833 int i; 834 extern int oexitstatus; 835 char sep; 836 char **ap; 837 char const *syntax; 838 839 #define STRTODEST(p) \ 840 do {\ 841 if (allow_split) { \ 842 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 843 while (*p) { \ 844 if (syntax[(int)*p] == CCTL) \ 845 STPUTC(CTLESC, expdest); \ 846 STPUTC(*p++, expdest); \ 847 } \ 848 } else \ 849 while (*p) \ 850 STPUTC(*p++, expdest); \ 851 } while (0) 852 853 854 switch (*name) { 855 case '$': 856 num = rootpid; 857 goto numvar; 858 case '?': 859 num = oexitstatus; 860 goto numvar; 861 case '#': 862 num = shellparam.nparam; 863 goto numvar; 864 case '!': 865 num = backgndpid; 866 numvar: 867 expdest = cvtnum(num, expdest); 868 break; 869 case '-': 870 for (i = 0 ; i < NOPTS ; i++) { 871 if (optlist[i].val) 872 STPUTC(optlist[i].letter, expdest); 873 } 874 break; 875 case '@': 876 if (allow_split && quoted) { 877 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 878 STRTODEST(p); 879 if (*ap) 880 STPUTC('\0', expdest); 881 } 882 break; 883 } 884 /* fall through */ 885 case '*': 886 if (ifsset() != 0) 887 sep = ifsval()[0]; 888 else 889 sep = ' '; 890 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 891 STRTODEST(p); 892 if (*ap && sep) 893 STPUTC(sep, expdest); 894 } 895 break; 896 case '0': 897 p = arg0; 898 STRTODEST(p); 899 break; 900 default: 901 if (is_digit(*name)) { 902 num = atoi(name); 903 if (num > 0 && num <= shellparam.nparam) { 904 p = shellparam.p[num - 1]; 905 STRTODEST(p); 906 } 907 } 908 break; 909 } 910 } 911 912 913 914 /* 915 * Record the fact that we have to scan this region of the 916 * string for IFS characters. 917 */ 918 919 STATIC void 920 recordregion(start, end, nulonly) 921 int start; 922 int end; 923 int nulonly; 924 { 925 struct ifsregion *ifsp; 926 927 if (ifslastp == NULL) { 928 ifsp = &ifsfirst; 929 } else { 930 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 931 ifslastp->next = ifsp; 932 } 933 ifslastp = ifsp; 934 ifslastp->next = NULL; 935 ifslastp->begoff = start; 936 ifslastp->endoff = end; 937 ifslastp->nulonly = nulonly; 938 } 939 940 941 942 /* 943 * Break the argument string into pieces based upon IFS and add the 944 * strings to the argument list. The regions of the string to be 945 * searched for IFS characters have been stored by recordregion. 946 */ 947 STATIC void 948 ifsbreakup(string, arglist) 949 char *string; 950 struct arglist *arglist; 951 { 952 struct ifsregion *ifsp; 953 struct strlist *sp; 954 char *start; 955 char *p; 956 char *q; 957 const char *ifs; 958 int ifsspc; 959 int nulonly; 960 961 962 start = string; 963 ifsspc = 0; 964 nulonly = 0; 965 if (ifslastp != NULL) { 966 ifsp = &ifsfirst; 967 do { 968 p = string + ifsp->begoff; 969 nulonly = ifsp->nulonly; 970 ifs = nulonly ? nullstr : 971 ( ifsset() ? ifsval() : " \t\n" ); 972 ifsspc = 0; 973 while (p < string + ifsp->endoff) { 974 q = p; 975 if (*p == CTLESC) 976 p++; 977 if (strchr(ifs, *p)) { 978 if (!nulonly) 979 ifsspc = (strchr(" \t\n", *p) != NULL); 980 /* Ignore IFS whitespace at start */ 981 if (q == start && ifsspc) { 982 p++; 983 start = p; 984 continue; 985 } 986 *q = '\0'; 987 sp = (struct strlist *)stalloc(sizeof *sp); 988 sp->text = start; 989 *arglist->lastp = sp; 990 arglist->lastp = &sp->next; 991 p++; 992 if (!nulonly) { 993 for (;;) { 994 if (p >= string + ifsp->endoff) { 995 break; 996 } 997 q = p; 998 if (*p == CTLESC) 999 p++; 1000 if (strchr(ifs, *p) == NULL ) { 1001 p = q; 1002 break; 1003 } else if (strchr(" \t\n",*p) == NULL) { 1004 if (ifsspc) { 1005 p++; 1006 ifsspc = 0; 1007 } else { 1008 p = q; 1009 break; 1010 } 1011 } else 1012 p++; 1013 } 1014 } 1015 start = p; 1016 } else 1017 p++; 1018 } 1019 } while ((ifsp = ifsp->next) != NULL); 1020 if (*start || (!ifsspc && start > string && 1021 (nulonly || 1))) { 1022 sp = (struct strlist *)stalloc(sizeof *sp); 1023 sp->text = start; 1024 *arglist->lastp = sp; 1025 arglist->lastp = &sp->next; 1026 } 1027 } else { 1028 sp = (struct strlist *)stalloc(sizeof *sp); 1029 sp->text = start; 1030 *arglist->lastp = sp; 1031 arglist->lastp = &sp->next; 1032 } 1033 } 1034 1035 STATIC void 1036 ifsfree() 1037 { 1038 while (ifsfirst.next != NULL) { 1039 struct ifsregion *ifsp; 1040 INTOFF; 1041 ifsp = ifsfirst.next->next; 1042 ckfree(ifsfirst.next); 1043 ifsfirst.next = ifsp; 1044 INTON; 1045 } 1046 ifslastp = NULL; 1047 ifsfirst.next = NULL; 1048 } 1049 1050 1051 1052 /* 1053 * Expand shell metacharacters. At this point, the only control characters 1054 * should be escapes. The results are stored in the list exparg. 1055 */ 1056 1057 char *expdir; 1058 1059 1060 STATIC void 1061 expandmeta(str, flag) 1062 struct strlist *str; 1063 int flag; 1064 { 1065 char *p; 1066 struct strlist **savelastp; 1067 struct strlist *sp; 1068 char c; 1069 /* TODO - EXP_REDIR */ 1070 1071 while (str) { 1072 if (fflag) 1073 goto nometa; 1074 p = str->text; 1075 for (;;) { /* fast check for meta chars */ 1076 if ((c = *p++) == '\0') 1077 goto nometa; 1078 if (c == '*' || c == '?' || c == '[' || c == '!') 1079 break; 1080 } 1081 savelastp = exparg.lastp; 1082 INTOFF; 1083 if (expdir == NULL) { 1084 int i = strlen(str->text); 1085 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1086 } 1087 1088 expmeta(expdir, str->text); 1089 ckfree(expdir); 1090 expdir = NULL; 1091 INTON; 1092 if (exparg.lastp == savelastp) { 1093 /* 1094 * no matches 1095 */ 1096 nometa: 1097 *exparg.lastp = str; 1098 rmescapes(str->text); 1099 exparg.lastp = &str->next; 1100 } else { 1101 *exparg.lastp = NULL; 1102 *savelastp = sp = expsort(*savelastp); 1103 while (sp->next != NULL) 1104 sp = sp->next; 1105 exparg.lastp = &sp->next; 1106 } 1107 str = str->next; 1108 } 1109 } 1110 1111 1112 /* 1113 * Do metacharacter (i.e. *, ?, [...]) expansion. 1114 */ 1115 1116 STATIC void 1117 expmeta(enddir, name) 1118 char *enddir; 1119 char *name; 1120 { 1121 char *p; 1122 const char *cp; 1123 char *q; 1124 char *start; 1125 char *endname; 1126 int metaflag; 1127 struct stat statb; 1128 DIR *dirp; 1129 struct dirent *dp; 1130 int atend; 1131 int matchdot; 1132 1133 metaflag = 0; 1134 start = name; 1135 for (p = name ; ; p++) { 1136 if (*p == '*' || *p == '?') 1137 metaflag = 1; 1138 else if (*p == '[') { 1139 q = p + 1; 1140 if (*q == '!') 1141 q++; 1142 for (;;) { 1143 while (*q == CTLQUOTEMARK) 1144 q++; 1145 if (*q == CTLESC) 1146 q++; 1147 if (*q == '/' || *q == '\0') 1148 break; 1149 if (*++q == ']') { 1150 metaflag = 1; 1151 break; 1152 } 1153 } 1154 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1155 metaflag = 1; 1156 } else if (*p == '\0') 1157 break; 1158 else if (*p == CTLQUOTEMARK) 1159 continue; 1160 else if (*p == CTLESC) 1161 p++; 1162 if (*p == '/') { 1163 if (metaflag) 1164 break; 1165 start = p + 1; 1166 } 1167 } 1168 if (metaflag == 0) { /* we've reached the end of the file name */ 1169 if (enddir != expdir) 1170 metaflag++; 1171 for (p = name ; ; p++) { 1172 if (*p == CTLQUOTEMARK) 1173 continue; 1174 if (*p == CTLESC) 1175 p++; 1176 *enddir++ = *p; 1177 if (*p == '\0') 1178 break; 1179 } 1180 if (metaflag == 0 || stat(expdir, &statb) >= 0) 1181 addfname(expdir); 1182 return; 1183 } 1184 endname = p; 1185 if (start != name) { 1186 p = name; 1187 while (p < start) { 1188 while (*p == CTLQUOTEMARK) 1189 p++; 1190 if (*p == CTLESC) 1191 p++; 1192 *enddir++ = *p++; 1193 } 1194 } 1195 if (enddir == expdir) { 1196 cp = "."; 1197 } else if (enddir == expdir + 1 && *expdir == '/') { 1198 cp = "/"; 1199 } else { 1200 cp = expdir; 1201 enddir[-1] = '\0'; 1202 } 1203 if ((dirp = opendir(cp)) == NULL) 1204 return; 1205 if (enddir != expdir) 1206 enddir[-1] = '/'; 1207 if (*endname == 0) { 1208 atend = 1; 1209 } else { 1210 atend = 0; 1211 *endname++ = '\0'; 1212 } 1213 matchdot = 0; 1214 p = start; 1215 while (*p == CTLQUOTEMARK) 1216 p++; 1217 if (*p == CTLESC) 1218 p++; 1219 if (*p == '.') 1220 matchdot++; 1221 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1222 if (dp->d_name[0] == '.' && ! matchdot) 1223 continue; 1224 if (patmatch(start, dp->d_name, 0)) { 1225 if (atend) { 1226 scopy(dp->d_name, enddir); 1227 addfname(expdir); 1228 } else { 1229 for (p = enddir, cp = dp->d_name; 1230 (*p++ = *cp++) != '\0';) 1231 continue; 1232 p[-1] = '/'; 1233 expmeta(p, endname); 1234 } 1235 } 1236 } 1237 closedir(dirp); 1238 if (! atend) 1239 endname[-1] = '/'; 1240 } 1241 1242 1243 /* 1244 * Add a file name to the list. 1245 */ 1246 1247 STATIC void 1248 addfname(name) 1249 char *name; 1250 { 1251 char *p; 1252 struct strlist *sp; 1253 1254 p = stalloc(strlen(name) + 1); 1255 scopy(name, p); 1256 sp = (struct strlist *)stalloc(sizeof *sp); 1257 sp->text = p; 1258 *exparg.lastp = sp; 1259 exparg.lastp = &sp->next; 1260 } 1261 1262 1263 /* 1264 * Sort the results of file name expansion. It calculates the number of 1265 * strings to sort and then calls msort (short for merge sort) to do the 1266 * work. 1267 */ 1268 1269 STATIC struct strlist * 1270 expsort(str) 1271 struct strlist *str; 1272 { 1273 int len; 1274 struct strlist *sp; 1275 1276 len = 0; 1277 for (sp = str ; sp ; sp = sp->next) 1278 len++; 1279 return msort(str, len); 1280 } 1281 1282 1283 STATIC struct strlist * 1284 msort(list, len) 1285 struct strlist *list; 1286 int len; 1287 { 1288 struct strlist *p, *q = NULL; 1289 struct strlist **lpp; 1290 int half; 1291 int n; 1292 1293 if (len <= 1) 1294 return list; 1295 half = len >> 1; 1296 p = list; 1297 for (n = half ; --n >= 0 ; ) { 1298 q = p; 1299 p = p->next; 1300 } 1301 q->next = NULL; /* terminate first half of list */ 1302 q = msort(list, half); /* sort first half of list */ 1303 p = msort(p, len - half); /* sort second half */ 1304 lpp = &list; 1305 for (;;) { 1306 if (strcmp(p->text, q->text) < 0) { 1307 *lpp = p; 1308 lpp = &p->next; 1309 if ((p = *lpp) == NULL) { 1310 *lpp = q; 1311 break; 1312 } 1313 } else { 1314 *lpp = q; 1315 lpp = &q->next; 1316 if ((q = *lpp) == NULL) { 1317 *lpp = p; 1318 break; 1319 } 1320 } 1321 } 1322 return list; 1323 } 1324 1325 1326 1327 /* 1328 * Returns true if the pattern matches the string. 1329 */ 1330 1331 int 1332 patmatch(pattern, string, squoted) 1333 char *pattern; 1334 char *string; 1335 int squoted; /* string might have quote chars */ 1336 { 1337 #ifdef notdef 1338 if (pattern[0] == '!' && pattern[1] == '!') 1339 return 1 - pmatch(pattern + 2, string); 1340 else 1341 #endif 1342 return pmatch(pattern, string, squoted); 1343 } 1344 1345 1346 STATIC int 1347 pmatch(pattern, string, squoted) 1348 char *pattern; 1349 char *string; 1350 int squoted; 1351 { 1352 char *p, *q; 1353 char c; 1354 1355 p = pattern; 1356 q = string; 1357 for (;;) { 1358 switch (c = *p++) { 1359 case '\0': 1360 goto breakloop; 1361 case CTLESC: 1362 if (squoted && *q == CTLESC) 1363 q++; 1364 if (*q++ != *p++) 1365 return 0; 1366 break; 1367 case CTLQUOTEMARK: 1368 continue; 1369 case '?': 1370 if (squoted && *q == CTLESC) 1371 q++; 1372 if (*q++ == '\0') 1373 return 0; 1374 break; 1375 case '*': 1376 c = *p; 1377 while (c == CTLQUOTEMARK || c == '*') 1378 c = *++p; 1379 if (c != CTLESC && c != CTLQUOTEMARK && 1380 c != '?' && c != '*' && c != '[') { 1381 while (*q != c) { 1382 if (squoted && *q == CTLESC && 1383 q[1] == c) 1384 break; 1385 if (*q == '\0') 1386 return 0; 1387 if (squoted && *q == CTLESC) 1388 q++; 1389 q++; 1390 } 1391 } 1392 do { 1393 if (pmatch(p, q, squoted)) 1394 return 1; 1395 if (squoted && *q == CTLESC) 1396 q++; 1397 } while (*q++ != '\0'); 1398 return 0; 1399 case '[': { 1400 char *endp; 1401 int invert, found; 1402 char chr; 1403 1404 endp = p; 1405 if (*endp == '!') 1406 endp++; 1407 for (;;) { 1408 while (*endp == CTLQUOTEMARK) 1409 endp++; 1410 if (*endp == '\0') 1411 goto dft; /* no matching ] */ 1412 if (*endp == CTLESC) 1413 endp++; 1414 if (*++endp == ']') 1415 break; 1416 } 1417 invert = 0; 1418 if (*p == '!') { 1419 invert++; 1420 p++; 1421 } 1422 found = 0; 1423 chr = *q++; 1424 if (squoted && chr == CTLESC) 1425 chr = *q++; 1426 if (chr == '\0') 1427 return 0; 1428 c = *p++; 1429 do { 1430 if (c == CTLQUOTEMARK) 1431 continue; 1432 if (c == CTLESC) 1433 c = *p++; 1434 if (*p == '-' && p[1] != ']') { 1435 p++; 1436 while (*p == CTLQUOTEMARK) 1437 p++; 1438 if (*p == CTLESC) 1439 p++; 1440 if (chr >= c && chr <= *p) 1441 found = 1; 1442 p++; 1443 } else { 1444 if (chr == c) 1445 found = 1; 1446 } 1447 } while ((c = *p++) != ']'); 1448 if (found == invert) 1449 return 0; 1450 break; 1451 } 1452 dft: default: 1453 if (squoted && *q == CTLESC) 1454 q++; 1455 if (*q++ != c) 1456 return 0; 1457 break; 1458 } 1459 } 1460 breakloop: 1461 if (*q != '\0') 1462 return 0; 1463 return 1; 1464 } 1465 1466 1467 1468 /* 1469 * Remove any CTLESC characters from a string. 1470 */ 1471 1472 void 1473 rmescapes(str) 1474 char *str; 1475 { 1476 char *p, *q; 1477 1478 p = str; 1479 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1480 if (*p++ == '\0') 1481 return; 1482 } 1483 q = p; 1484 while (*p) { 1485 if (*p == CTLQUOTEMARK) { 1486 p++; 1487 continue; 1488 } 1489 if (*p == CTLESC) 1490 p++; 1491 *q++ = *p++; 1492 } 1493 *q = '\0'; 1494 } 1495 1496 1497 1498 /* 1499 * See if a pattern matches in a case statement. 1500 */ 1501 1502 int 1503 casematch(pattern, val) 1504 union node *pattern; 1505 char *val; 1506 { 1507 struct stackmark smark; 1508 int result; 1509 char *p; 1510 1511 setstackmark(&smark); 1512 argbackq = pattern->narg.backquote; 1513 STARTSTACKSTR(expdest); 1514 ifslastp = NULL; 1515 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1516 STPUTC('\0', expdest); 1517 p = grabstackstr(expdest); 1518 result = patmatch(p, val, 0); 1519 popstackmark(&smark); 1520 return result; 1521 } 1522 1523 /* 1524 * Our own itoa(). 1525 */ 1526 1527 STATIC char * 1528 cvtnum(num, buf) 1529 int num; 1530 char *buf; 1531 { 1532 char temp[32]; 1533 int neg = num < 0; 1534 char *p = temp + 31; 1535 1536 temp[31] = '\0'; 1537 1538 do { 1539 *--p = num % 10 + '0'; 1540 } while ((num /= 10) != 0); 1541 1542 if (neg) 1543 *--p = '-'; 1544 1545 while (*p) 1546 STPUTC(*p++, buf); 1547 return buf; 1548 } 1549