1 /* $NetBSD: expand.c,v 1.52 2001/09/19 06:38:19 itojun 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 1.52 2001/09/19 06:38:19 itojun 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 extern int oexitstatus; 119 120 /* 121 * Expand shell variables and backquotes inside a here document. 122 */ 123 124 void 125 expandhere(arg, fd) 126 union node *arg; /* the document */ 127 int fd; /* where to write the expanded version */ 128 { 129 herefd = fd; 130 expandarg(arg, (struct arglist *)NULL, 0); 131 xwrite(fd, stackblock(), expdest - stackblock()); 132 } 133 134 135 /* 136 * Perform variable substitution and command substitution on an argument, 137 * placing the resulting list of arguments in arglist. If EXP_FULL is true, 138 * perform splitting and file name expansion. When arglist is NULL, perform 139 * here document expansion. 140 */ 141 142 void 143 expandarg(arg, arglist, flag) 144 union node *arg; 145 struct arglist *arglist; 146 int flag; 147 { 148 struct strlist *sp; 149 char *p; 150 151 argbackq = arg->narg.backquote; 152 STARTSTACKSTR(expdest); 153 ifsfirst.next = NULL; 154 ifslastp = NULL; 155 argstr(arg->narg.text, flag); 156 if (arglist == NULL) { 157 return; /* here document expanded */ 158 } 159 STPUTC('\0', expdest); 160 p = grabstackstr(expdest); 161 exparg.lastp = &exparg.list; 162 /* 163 * TODO - EXP_REDIR 164 */ 165 if (flag & EXP_FULL) { 166 ifsbreakup(p, &exparg); 167 *exparg.lastp = NULL; 168 exparg.lastp = &exparg.list; 169 expandmeta(exparg.list, flag); 170 } else { 171 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */ 172 rmescapes(p); 173 sp = (struct strlist *)stalloc(sizeof (struct strlist)); 174 sp->text = p; 175 *exparg.lastp = sp; 176 exparg.lastp = &sp->next; 177 } 178 ifsfree(); 179 *exparg.lastp = NULL; 180 if (exparg.list) { 181 *arglist->lastp = exparg.list; 182 arglist->lastp = exparg.lastp; 183 } 184 } 185 186 187 188 /* 189 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC 190 * characters to allow for further processing. Otherwise treat 191 * $@ like $* since no splitting will be performed. 192 */ 193 194 STATIC void 195 argstr(p, flag) 196 char *p; 197 int flag; 198 { 199 char c; 200 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */ 201 int firsteq = 1; 202 203 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE))) 204 p = exptilde(p, flag); 205 for (;;) { 206 switch (c = *p++) { 207 case '\0': 208 case CTLENDVAR: /* ??? */ 209 goto breakloop; 210 case CTLQUOTEMARK: 211 /* "$@" syntax adherence hack */ 212 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=') 213 break; 214 if ((flag & EXP_FULL) != 0) 215 STPUTC(c, expdest); 216 break; 217 case CTLESC: 218 if (quotes) 219 STPUTC(c, expdest); 220 c = *p++; 221 STPUTC(c, expdest); 222 break; 223 case CTLVAR: 224 p = evalvar(p, flag); 225 break; 226 case CTLBACKQ: 227 case CTLBACKQ|CTLQUOTE: 228 expbackq(argbackq->n, c & CTLQUOTE, flag); 229 argbackq = argbackq->next; 230 break; 231 case CTLENDARI: 232 expari(flag); 233 break; 234 case ':': 235 case '=': 236 /* 237 * sort of a hack - expand tildes in variable 238 * assignments (after the first '=' and after ':'s). 239 */ 240 STPUTC(c, expdest); 241 if (flag & EXP_VARTILDE && *p == '~') { 242 if (c == '=') { 243 if (firsteq) 244 firsteq = 0; 245 else 246 break; 247 } 248 p = exptilde(p, flag); 249 } 250 break; 251 default: 252 STPUTC(c, expdest); 253 } 254 } 255 breakloop:; 256 return; 257 } 258 259 STATIC char * 260 exptilde(p, flag) 261 char *p; 262 int flag; 263 { 264 char c, *startp = p; 265 struct passwd *pw; 266 const char *home; 267 int quotes = flag & (EXP_FULL | EXP_CASE); 268 269 while ((c = *p) != '\0') { 270 switch(c) { 271 case CTLESC: 272 return (startp); 273 case CTLQUOTEMARK: 274 return (startp); 275 case ':': 276 if (flag & EXP_VARTILDE) 277 goto done; 278 break; 279 case '/': 280 goto done; 281 } 282 p++; 283 } 284 done: 285 *p = '\0'; 286 if (*(startp+1) == '\0') { 287 if ((home = lookupvar("HOME")) == NULL) 288 goto lose; 289 } else { 290 if ((pw = getpwnam(startp+1)) == NULL) 291 goto lose; 292 home = pw->pw_dir; 293 } 294 if (*home == '\0') 295 goto lose; 296 *p = c; 297 while ((c = *home++) != '\0') { 298 if (quotes && SQSYNTAX[(int)c] == CCTL) 299 STPUTC(CTLESC, expdest); 300 STPUTC(c, expdest); 301 } 302 return (p); 303 lose: 304 *p = c; 305 return (startp); 306 } 307 308 309 STATIC void 310 removerecordregions(endoff) 311 int endoff; 312 { 313 if (ifslastp == NULL) 314 return; 315 316 if (ifsfirst.endoff > endoff) { 317 while (ifsfirst.next != NULL) { 318 struct ifsregion *ifsp; 319 INTOFF; 320 ifsp = ifsfirst.next->next; 321 ckfree(ifsfirst.next); 322 ifsfirst.next = ifsp; 323 INTON; 324 } 325 if (ifsfirst.begoff > endoff) 326 ifslastp = NULL; 327 else { 328 ifslastp = &ifsfirst; 329 ifsfirst.endoff = endoff; 330 } 331 return; 332 } 333 334 ifslastp = &ifsfirst; 335 while (ifslastp->next && ifslastp->next->begoff < endoff) 336 ifslastp=ifslastp->next; 337 while (ifslastp->next != NULL) { 338 struct ifsregion *ifsp; 339 INTOFF; 340 ifsp = ifslastp->next->next; 341 ckfree(ifslastp->next); 342 ifslastp->next = ifsp; 343 INTON; 344 } 345 if (ifslastp->endoff > endoff) 346 ifslastp->endoff = endoff; 347 } 348 349 350 /* 351 * Expand arithmetic expression. Backup to start of expression, 352 * evaluate, place result in (backed up) result, adjust string position. 353 */ 354 void 355 expari(flag) 356 int flag; 357 { 358 char *p, *start; 359 int result; 360 int begoff; 361 int quotes = flag & (EXP_FULL | EXP_CASE); 362 int quoted; 363 364 /* ifsfree(); */ 365 366 /* 367 * This routine is slightly over-complicated for 368 * efficiency. First we make sure there is 369 * enough space for the result, which may be bigger 370 * than the expression if we add exponentation. Next we 371 * scan backwards looking for the start of arithmetic. If the 372 * next previous character is a CTLESC character, then we 373 * have to rescan starting from the beginning since CTLESC 374 * characters have to be processed left to right. 375 */ 376 #if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10 377 #error "integers with more than 10 digits are not supported" 378 #endif 379 CHECKSTRSPACE(12 - 2, expdest); 380 USTPUTC('\0', expdest); 381 start = stackblock(); 382 p = expdest - 1; 383 while (*p != CTLARI && p >= start) 384 --p; 385 if (*p != CTLARI) 386 error("missing CTLARI (shouldn't happen)"); 387 if (p > start && *(p-1) == CTLESC) 388 for (p = start; *p != CTLARI; p++) 389 if (*p == CTLESC) 390 p++; 391 392 if (p[1] == '"') 393 quoted=1; 394 else 395 quoted=0; 396 begoff = p - start; 397 removerecordregions(begoff); 398 if (quotes) 399 rmescapes(p+2); 400 result = arith(p+2); 401 fmtstr(p, 12, "%d", result); 402 403 while (*p++) 404 ; 405 406 if (quoted == 0) 407 recordregion(begoff, p - 1 - start, 0); 408 result = expdest - p + 1; 409 STADJUST(-result, expdest); 410 } 411 412 413 /* 414 * Expand stuff in backwards quotes. 415 */ 416 417 STATIC void 418 expbackq(cmd, quoted, flag) 419 union node *cmd; 420 int quoted; 421 int flag; 422 { 423 struct backcmd in; 424 int i; 425 char buf[128]; 426 char *p; 427 char *dest = expdest; 428 struct ifsregion saveifs, *savelastp; 429 struct nodelist *saveargbackq; 430 char lastc; 431 int startloc = dest - stackblock(); 432 char const *syntax = quoted? DQSYNTAX : BASESYNTAX; 433 int saveherefd; 434 int quotes = flag & (EXP_FULL | EXP_CASE); 435 436 INTOFF; 437 saveifs = ifsfirst; 438 savelastp = ifslastp; 439 saveargbackq = argbackq; 440 saveherefd = herefd; 441 herefd = -1; 442 p = grabstackstr(dest); 443 evalbackcmd(cmd, &in); 444 ungrabstackstr(p, dest); 445 ifsfirst = saveifs; 446 ifslastp = savelastp; 447 argbackq = saveargbackq; 448 herefd = saveherefd; 449 450 p = in.buf; 451 lastc = '\0'; 452 for (;;) { 453 if (--in.nleft < 0) { 454 if (in.fd < 0) 455 break; 456 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR); 457 TRACE(("expbackq: read returns %d\n", i)); 458 if (i <= 0) 459 break; 460 p = buf; 461 in.nleft = i - 1; 462 } 463 lastc = *p++; 464 if (lastc != '\0') { 465 if (quotes && syntax[(int)lastc] == CCTL) 466 STPUTC(CTLESC, dest); 467 STPUTC(lastc, dest); 468 } 469 } 470 471 /* Eat all trailing newlines */ 472 for (p--; lastc == '\n'; lastc = *--p) 473 STUNPUTC(dest); 474 475 if (in.fd >= 0) 476 close(in.fd); 477 if (in.buf) 478 ckfree(in.buf); 479 if (in.jp) 480 exitstatus = waitforjob(in.jp); 481 if (quoted == 0) 482 recordregion(startloc, dest - stackblock(), 0); 483 TRACE(("evalbackq: size=%d: \"%.*s\"\n", 484 (dest - stackblock()) - startloc, 485 (dest - stackblock()) - startloc, 486 stackblock() + startloc)); 487 expdest = dest; 488 INTON; 489 } 490 491 492 493 STATIC int 494 subevalvar(p, str, strloc, subtype, startloc, varflags) 495 char *p; 496 char *str; 497 int strloc; 498 int subtype; 499 int startloc; 500 int varflags; 501 { 502 char *startp; 503 char *loc = NULL; 504 char *q; 505 int c = 0; 506 int saveherefd = herefd; 507 struct nodelist *saveargbackq = argbackq; 508 int amount; 509 510 herefd = -1; 511 argstr(p, 0); 512 STACKSTRNUL(expdest); 513 herefd = saveherefd; 514 argbackq = saveargbackq; 515 startp = stackblock() + startloc; 516 if (str == NULL) 517 str = stackblock() + strloc; 518 519 switch (subtype) { 520 case VSASSIGN: 521 setvar(str, startp, 0); 522 amount = startp - expdest; 523 STADJUST(amount, expdest); 524 varflags &= ~VSNUL; 525 if (c != 0) 526 *loc = c; 527 return 1; 528 529 case VSQUESTION: 530 if (*p != CTLENDVAR) { 531 outfmt(&errout, "%s\n", startp); 532 error((char *)NULL); 533 } 534 error("%.*s: parameter %snot set", p - str - 1, 535 str, (varflags & VSNUL) ? "null or " 536 : nullstr); 537 /* NOTREACHED */ 538 539 case VSTRIMLEFT: 540 for (loc = startp; loc < str; loc++) { 541 c = *loc; 542 *loc = '\0'; 543 if (patmatch(str, startp, varflags & VSQUOTE)) 544 goto recordleft; 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 goto recordleft; 557 *loc = c; 558 loc--; 559 if ((varflags & VSQUOTE) && loc > startp && 560 *(loc - 1) == CTLESC) { 561 for (q = startp; q < loc; q++) 562 if (*q == CTLESC) 563 q++; 564 if (q > loc) 565 loc--; 566 } 567 } 568 return 0; 569 570 case VSTRIMRIGHT: 571 for (loc = str - 1; loc >= startp;) { 572 if (patmatch(str, loc, varflags & VSQUOTE)) 573 goto recordright; 574 loc--; 575 if ((varflags & VSQUOTE) && loc > startp && 576 *(loc - 1) == CTLESC) { 577 for (q = startp; q < loc; q++) 578 if (*q == CTLESC) 579 q++; 580 if (q > loc) 581 loc--; 582 } 583 } 584 return 0; 585 586 case VSTRIMRIGHTMAX: 587 for (loc = startp; loc < str - 1; loc++) { 588 if (patmatch(str, loc, varflags & VSQUOTE)) 589 goto recordright; 590 if ((varflags & VSQUOTE) && *loc == CTLESC) 591 loc++; 592 } 593 return 0; 594 595 default: 596 abort(); 597 } 598 599 recordleft: 600 *loc = c; 601 amount = ((str - 1) - (loc - startp)) - expdest; 602 STADJUST(amount, expdest); 603 while (loc != str - 1) 604 *startp++ = *loc++; 605 return 1; 606 607 recordright: 608 amount = loc - expdest; 609 STADJUST(amount, expdest); 610 STPUTC('\0', expdest); 611 STADJUST(-1, expdest); 612 return 1; 613 } 614 615 616 /* 617 * Expand a variable, and return a pointer to the next character in the 618 * input string. 619 */ 620 621 STATIC char * 622 evalvar(p, flag) 623 char *p; 624 int flag; 625 { 626 int subtype; 627 int varflags; 628 char *var; 629 char *val; 630 int patloc; 631 int c; 632 int set; 633 int special; 634 int startloc; 635 int varlen; 636 int easy; 637 int quotes = flag & (EXP_FULL | EXP_CASE); 638 639 varflags = *p++; 640 subtype = varflags & VSTYPE; 641 var = p; 642 special = 0; 643 if (! is_name(*p)) 644 special = 1; 645 p = strchr(p, '=') + 1; 646 again: /* jump here after setting a variable with ${var=text} */ 647 if (special) { 648 set = varisset(var, varflags & VSNUL); 649 val = NULL; 650 } else { 651 val = lookupvar(var); 652 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) { 653 val = NULL; 654 set = 0; 655 } else 656 set = 1; 657 } 658 varlen = 0; 659 startloc = expdest - stackblock(); 660 if (set && subtype != VSPLUS) { 661 /* insert the value of the variable */ 662 if (special) { 663 varvalue(var, varflags & VSQUOTE, flag & EXP_FULL); 664 if (subtype == VSLENGTH) { 665 varlen = expdest - stackblock() - startloc; 666 STADJUST(-varlen, expdest); 667 } 668 } else { 669 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX 670 : BASESYNTAX; 671 672 if (subtype == VSLENGTH) { 673 for (;*val; val++) 674 varlen++; 675 } 676 else { 677 while (*val) { 678 if (quotes && syntax[(int)*val] == CCTL) 679 STPUTC(CTLESC, expdest); 680 STPUTC(*val++, expdest); 681 } 682 683 } 684 } 685 } 686 687 if (subtype == VSPLUS) 688 set = ! set; 689 690 easy = ((varflags & VSQUOTE) == 0 || 691 (*var == '@' && shellparam.nparam != 1)); 692 693 694 switch (subtype) { 695 case VSLENGTH: 696 expdest = cvtnum(varlen, expdest); 697 goto record; 698 699 case VSNORMAL: 700 if (!easy) 701 break; 702 record: 703 recordregion(startloc, expdest - stackblock(), 704 varflags & VSQUOTE); 705 break; 706 707 case VSPLUS: 708 case VSMINUS: 709 if (!set) { 710 argstr(p, flag); 711 break; 712 } 713 if (easy) 714 goto record; 715 break; 716 717 case VSTRIMLEFT: 718 case VSTRIMLEFTMAX: 719 case VSTRIMRIGHT: 720 case VSTRIMRIGHTMAX: 721 if (!set) 722 break; 723 /* 724 * Terminate the string and start recording the pattern 725 * right after it 726 */ 727 STPUTC('\0', expdest); 728 patloc = expdest - stackblock(); 729 if (subevalvar(p, NULL, patloc, subtype, 730 startloc, varflags) == 0) { 731 int amount = (expdest - stackblock() - patloc) + 1; 732 STADJUST(-amount, expdest); 733 } 734 /* Remove any recorded regions beyond start of variable */ 735 removerecordregions(startloc); 736 goto record; 737 738 case VSASSIGN: 739 case VSQUESTION: 740 if (!set) { 741 if (subevalvar(p, var, 0, subtype, startloc, 742 varflags)) { 743 varflags &= ~VSNUL; 744 /* 745 * Remove any recorded regions beyond 746 * start of variable 747 */ 748 removerecordregions(startloc); 749 goto again; 750 } 751 break; 752 } 753 if (easy) 754 goto record; 755 break; 756 757 default: 758 abort(); 759 } 760 761 if (subtype != VSNORMAL) { /* skip to end of alternative */ 762 int nesting = 1; 763 for (;;) { 764 if ((c = *p++) == CTLESC) 765 p++; 766 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) { 767 if (set) 768 argbackq = argbackq->next; 769 } else if (c == CTLVAR) { 770 if ((*p++ & VSTYPE) != VSNORMAL) 771 nesting++; 772 } else if (c == CTLENDVAR) { 773 if (--nesting == 0) 774 break; 775 } 776 } 777 } 778 return p; 779 } 780 781 782 783 /* 784 * Test whether a specialized variable is set. 785 */ 786 787 STATIC int 788 varisset(name, nulok) 789 char *name; 790 int nulok; 791 { 792 if (*name == '!') 793 return backgndpid != -1; 794 else if (*name == '@' || *name == '*') { 795 if (*shellparam.p == NULL) 796 return 0; 797 798 if (nulok) { 799 char **av; 800 801 for (av = shellparam.p; *av; av++) 802 if (**av != '\0') 803 return 1; 804 return 0; 805 } 806 } else if (is_digit(*name)) { 807 char *ap; 808 int num = atoi(name); 809 810 if (num > shellparam.nparam) 811 return 0; 812 813 if (num == 0) 814 ap = arg0; 815 else 816 ap = shellparam.p[num - 1]; 817 818 if (nulok && (ap == NULL || *ap == '\0')) 819 return 0; 820 } 821 return 1; 822 } 823 824 825 826 /* 827 * Add the value of a specialized variable to the stack string. 828 */ 829 830 STATIC void 831 varvalue(name, quoted, allow_split) 832 char *name; 833 int quoted; 834 int allow_split; 835 { 836 int num; 837 char *p; 838 int i; 839 char sep; 840 char **ap; 841 char const *syntax; 842 843 #define STRTODEST(p) \ 844 do {\ 845 if (allow_split) { \ 846 syntax = quoted? DQSYNTAX : BASESYNTAX; \ 847 while (*p) { \ 848 if (syntax[(int)*p] == CCTL) \ 849 STPUTC(CTLESC, expdest); \ 850 STPUTC(*p++, expdest); \ 851 } \ 852 } else \ 853 while (*p) \ 854 STPUTC(*p++, expdest); \ 855 } while (0) 856 857 858 switch (*name) { 859 case '$': 860 num = rootpid; 861 goto numvar; 862 case '?': 863 num = oexitstatus; 864 goto numvar; 865 case '#': 866 num = shellparam.nparam; 867 goto numvar; 868 case '!': 869 num = backgndpid; 870 numvar: 871 expdest = cvtnum(num, expdest); 872 break; 873 case '-': 874 for (i = 0 ; i < NOPTS ; i++) { 875 if (optlist[i].val) 876 STPUTC(optlist[i].letter, expdest); 877 } 878 break; 879 case '@': 880 if (allow_split && quoted) { 881 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 882 STRTODEST(p); 883 if (*ap) 884 STPUTC('\0', expdest); 885 } 886 break; 887 } 888 /* fall through */ 889 case '*': 890 if (ifsset() != 0) 891 sep = ifsval()[0]; 892 else 893 sep = ' '; 894 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) { 895 STRTODEST(p); 896 if (*ap && sep) 897 STPUTC(sep, expdest); 898 } 899 break; 900 case '0': 901 p = arg0; 902 STRTODEST(p); 903 break; 904 default: 905 if (is_digit(*name)) { 906 num = atoi(name); 907 if (num > 0 && num <= shellparam.nparam) { 908 p = shellparam.p[num - 1]; 909 STRTODEST(p); 910 } 911 } 912 break; 913 } 914 } 915 916 917 918 /* 919 * Record the fact that we have to scan this region of the 920 * string for IFS characters. 921 */ 922 923 STATIC void 924 recordregion(start, end, nulonly) 925 int start; 926 int end; 927 int nulonly; 928 { 929 struct ifsregion *ifsp; 930 931 if (ifslastp == NULL) { 932 ifsp = &ifsfirst; 933 } else { 934 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion)); 935 ifslastp->next = ifsp; 936 } 937 ifslastp = ifsp; 938 ifslastp->next = NULL; 939 ifslastp->begoff = start; 940 ifslastp->endoff = end; 941 ifslastp->nulonly = nulonly; 942 } 943 944 945 946 /* 947 * Break the argument string into pieces based upon IFS and add the 948 * strings to the argument list. The regions of the string to be 949 * searched for IFS characters have been stored by recordregion. 950 */ 951 STATIC void 952 ifsbreakup(string, arglist) 953 char *string; 954 struct arglist *arglist; 955 { 956 struct ifsregion *ifsp; 957 struct strlist *sp; 958 char *start; 959 char *p; 960 char *q; 961 const char *ifs; 962 int ifsspc; 963 int nulonly; 964 965 966 start = string; 967 ifsspc = 0; 968 nulonly = 0; 969 if (ifslastp != NULL) { 970 ifsp = &ifsfirst; 971 do { 972 p = string + ifsp->begoff; 973 nulonly = ifsp->nulonly; 974 ifs = nulonly ? nullstr : 975 ( ifsset() ? ifsval() : " \t\n" ); 976 ifsspc = 0; 977 while (p < string + ifsp->endoff) { 978 q = p; 979 if (*p == CTLESC) 980 p++; 981 if (strchr(ifs, *p)) { 982 if (!nulonly) 983 ifsspc = (strchr(" \t\n", *p) != NULL); 984 /* Ignore IFS whitespace at start */ 985 if (q == start && ifsspc) { 986 p++; 987 start = p; 988 continue; 989 } 990 *q = '\0'; 991 sp = (struct strlist *)stalloc(sizeof *sp); 992 sp->text = start; 993 *arglist->lastp = sp; 994 arglist->lastp = &sp->next; 995 p++; 996 if (!nulonly) { 997 for (;;) { 998 if (p >= string + ifsp->endoff) { 999 break; 1000 } 1001 q = p; 1002 if (*p == CTLESC) 1003 p++; 1004 if (strchr(ifs, *p) == NULL ) { 1005 p = q; 1006 break; 1007 } else if (strchr(" \t\n",*p) == NULL) { 1008 if (ifsspc) { 1009 p++; 1010 ifsspc = 0; 1011 } else { 1012 p = q; 1013 break; 1014 } 1015 } else 1016 p++; 1017 } 1018 } 1019 start = p; 1020 } else 1021 p++; 1022 } 1023 } while ((ifsp = ifsp->next) != NULL); 1024 if (*start || (!ifsspc && start > string && 1025 (nulonly || 1))) { 1026 sp = (struct strlist *)stalloc(sizeof *sp); 1027 sp->text = start; 1028 *arglist->lastp = sp; 1029 arglist->lastp = &sp->next; 1030 } 1031 } else { 1032 sp = (struct strlist *)stalloc(sizeof *sp); 1033 sp->text = start; 1034 *arglist->lastp = sp; 1035 arglist->lastp = &sp->next; 1036 } 1037 } 1038 1039 STATIC void 1040 ifsfree() 1041 { 1042 while (ifsfirst.next != NULL) { 1043 struct ifsregion *ifsp; 1044 INTOFF; 1045 ifsp = ifsfirst.next->next; 1046 ckfree(ifsfirst.next); 1047 ifsfirst.next = ifsp; 1048 INTON; 1049 } 1050 ifslastp = NULL; 1051 ifsfirst.next = NULL; 1052 } 1053 1054 1055 1056 /* 1057 * Expand shell metacharacters. At this point, the only control characters 1058 * should be escapes. The results are stored in the list exparg. 1059 */ 1060 1061 char *expdir; 1062 1063 1064 STATIC void 1065 expandmeta(str, flag) 1066 struct strlist *str; 1067 int flag; 1068 { 1069 char *p; 1070 struct strlist **savelastp; 1071 struct strlist *sp; 1072 char c; 1073 /* TODO - EXP_REDIR */ 1074 1075 while (str) { 1076 if (fflag) 1077 goto nometa; 1078 p = str->text; 1079 for (;;) { /* fast check for meta chars */ 1080 if ((c = *p++) == '\0') 1081 goto nometa; 1082 if (c == '*' || c == '?' || c == '[' || c == '!') 1083 break; 1084 } 1085 savelastp = exparg.lastp; 1086 INTOFF; 1087 if (expdir == NULL) { 1088 int i = strlen(str->text); 1089 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */ 1090 } 1091 1092 expmeta(expdir, str->text); 1093 ckfree(expdir); 1094 expdir = NULL; 1095 INTON; 1096 if (exparg.lastp == savelastp) { 1097 /* 1098 * no matches 1099 */ 1100 nometa: 1101 *exparg.lastp = str; 1102 rmescapes(str->text); 1103 exparg.lastp = &str->next; 1104 } else { 1105 *exparg.lastp = NULL; 1106 *savelastp = sp = expsort(*savelastp); 1107 while (sp->next != NULL) 1108 sp = sp->next; 1109 exparg.lastp = &sp->next; 1110 } 1111 str = str->next; 1112 } 1113 } 1114 1115 1116 /* 1117 * Do metacharacter (i.e. *, ?, [...]) expansion. 1118 */ 1119 1120 STATIC void 1121 expmeta(enddir, name) 1122 char *enddir; 1123 char *name; 1124 { 1125 char *p; 1126 const char *cp; 1127 char *q; 1128 char *start; 1129 char *endname; 1130 int metaflag; 1131 struct stat statb; 1132 DIR *dirp; 1133 struct dirent *dp; 1134 int atend; 1135 int matchdot; 1136 1137 metaflag = 0; 1138 start = name; 1139 for (p = name ; ; p++) { 1140 if (*p == '*' || *p == '?') 1141 metaflag = 1; 1142 else if (*p == '[') { 1143 q = p + 1; 1144 if (*q == '!') 1145 q++; 1146 for (;;) { 1147 while (*q == CTLQUOTEMARK) 1148 q++; 1149 if (*q == CTLESC) 1150 q++; 1151 if (*q == '/' || *q == '\0') 1152 break; 1153 if (*++q == ']') { 1154 metaflag = 1; 1155 break; 1156 } 1157 } 1158 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) { 1159 metaflag = 1; 1160 } else if (*p == '\0') 1161 break; 1162 else if (*p == CTLQUOTEMARK) 1163 continue; 1164 else if (*p == CTLESC) 1165 p++; 1166 if (*p == '/') { 1167 if (metaflag) 1168 break; 1169 start = p + 1; 1170 } 1171 } 1172 if (metaflag == 0) { /* we've reached the end of the file name */ 1173 if (enddir != expdir) 1174 metaflag++; 1175 for (p = name ; ; p++) { 1176 if (*p == CTLQUOTEMARK) 1177 continue; 1178 if (*p == CTLESC) 1179 p++; 1180 *enddir++ = *p; 1181 if (*p == '\0') 1182 break; 1183 } 1184 if (metaflag == 0 || lstat(expdir, &statb) >= 0) 1185 addfname(expdir); 1186 return; 1187 } 1188 endname = p; 1189 if (start != name) { 1190 p = name; 1191 while (p < start) { 1192 while (*p == CTLQUOTEMARK) 1193 p++; 1194 if (*p == CTLESC) 1195 p++; 1196 *enddir++ = *p++; 1197 } 1198 } 1199 if (enddir == expdir) { 1200 cp = "."; 1201 } else if (enddir == expdir + 1 && *expdir == '/') { 1202 cp = "/"; 1203 } else { 1204 cp = expdir; 1205 enddir[-1] = '\0'; 1206 } 1207 if ((dirp = opendir(cp)) == NULL) 1208 return; 1209 if (enddir != expdir) 1210 enddir[-1] = '/'; 1211 if (*endname == 0) { 1212 atend = 1; 1213 } else { 1214 atend = 0; 1215 *endname++ = '\0'; 1216 } 1217 matchdot = 0; 1218 p = start; 1219 while (*p == CTLQUOTEMARK) 1220 p++; 1221 if (*p == CTLESC) 1222 p++; 1223 if (*p == '.') 1224 matchdot++; 1225 while (! int_pending() && (dp = readdir(dirp)) != NULL) { 1226 if (dp->d_name[0] == '.' && ! matchdot) 1227 continue; 1228 if (patmatch(start, dp->d_name, 0)) { 1229 if (atend) { 1230 scopy(dp->d_name, enddir); 1231 addfname(expdir); 1232 } else { 1233 for (p = enddir, cp = dp->d_name; 1234 (*p++ = *cp++) != '\0';) 1235 continue; 1236 p[-1] = '/'; 1237 expmeta(p, endname); 1238 } 1239 } 1240 } 1241 closedir(dirp); 1242 if (! atend) 1243 endname[-1] = '/'; 1244 } 1245 1246 1247 /* 1248 * Add a file name to the list. 1249 */ 1250 1251 STATIC void 1252 addfname(name) 1253 char *name; 1254 { 1255 char *p; 1256 struct strlist *sp; 1257 1258 p = stalloc(strlen(name) + 1); 1259 scopy(name, p); 1260 sp = (struct strlist *)stalloc(sizeof *sp); 1261 sp->text = p; 1262 *exparg.lastp = sp; 1263 exparg.lastp = &sp->next; 1264 } 1265 1266 1267 /* 1268 * Sort the results of file name expansion. It calculates the number of 1269 * strings to sort and then calls msort (short for merge sort) to do the 1270 * work. 1271 */ 1272 1273 STATIC struct strlist * 1274 expsort(str) 1275 struct strlist *str; 1276 { 1277 int len; 1278 struct strlist *sp; 1279 1280 len = 0; 1281 for (sp = str ; sp ; sp = sp->next) 1282 len++; 1283 return msort(str, len); 1284 } 1285 1286 1287 STATIC struct strlist * 1288 msort(list, len) 1289 struct strlist *list; 1290 int len; 1291 { 1292 struct strlist *p, *q = NULL; 1293 struct strlist **lpp; 1294 int half; 1295 int n; 1296 1297 if (len <= 1) 1298 return list; 1299 half = len >> 1; 1300 p = list; 1301 for (n = half ; --n >= 0 ; ) { 1302 q = p; 1303 p = p->next; 1304 } 1305 q->next = NULL; /* terminate first half of list */ 1306 q = msort(list, half); /* sort first half of list */ 1307 p = msort(p, len - half); /* sort second half */ 1308 lpp = &list; 1309 for (;;) { 1310 if (strcmp(p->text, q->text) < 0) { 1311 *lpp = p; 1312 lpp = &p->next; 1313 if ((p = *lpp) == NULL) { 1314 *lpp = q; 1315 break; 1316 } 1317 } else { 1318 *lpp = q; 1319 lpp = &q->next; 1320 if ((q = *lpp) == NULL) { 1321 *lpp = p; 1322 break; 1323 } 1324 } 1325 } 1326 return list; 1327 } 1328 1329 1330 1331 /* 1332 * Returns true if the pattern matches the string. 1333 */ 1334 1335 int 1336 patmatch(pattern, string, squoted) 1337 char *pattern; 1338 char *string; 1339 int squoted; /* string might have quote chars */ 1340 { 1341 #ifdef notdef 1342 if (pattern[0] == '!' && pattern[1] == '!') 1343 return 1 - pmatch(pattern + 2, string); 1344 else 1345 #endif 1346 return pmatch(pattern, string, squoted); 1347 } 1348 1349 1350 STATIC int 1351 pmatch(pattern, string, squoted) 1352 char *pattern; 1353 char *string; 1354 int squoted; 1355 { 1356 char *p, *q; 1357 char c; 1358 1359 p = pattern; 1360 q = string; 1361 for (;;) { 1362 switch (c = *p++) { 1363 case '\0': 1364 goto breakloop; 1365 case CTLESC: 1366 if (squoted && *q == CTLESC) 1367 q++; 1368 if (*q++ != *p++) 1369 return 0; 1370 break; 1371 case CTLQUOTEMARK: 1372 continue; 1373 case '?': 1374 if (squoted && *q == CTLESC) 1375 q++; 1376 if (*q++ == '\0') 1377 return 0; 1378 break; 1379 case '*': 1380 c = *p; 1381 while (c == CTLQUOTEMARK || c == '*') 1382 c = *++p; 1383 if (c != CTLESC && c != CTLQUOTEMARK && 1384 c != '?' && c != '*' && c != '[') { 1385 while (*q != c) { 1386 if (squoted && *q == CTLESC && 1387 q[1] == c) 1388 break; 1389 if (*q == '\0') 1390 return 0; 1391 if (squoted && *q == CTLESC) 1392 q++; 1393 q++; 1394 } 1395 } 1396 do { 1397 if (pmatch(p, q, squoted)) 1398 return 1; 1399 if (squoted && *q == CTLESC) 1400 q++; 1401 } while (*q++ != '\0'); 1402 return 0; 1403 case '[': { 1404 char *endp; 1405 int invert, found; 1406 char chr; 1407 1408 endp = p; 1409 if (*endp == '!') 1410 endp++; 1411 for (;;) { 1412 while (*endp == CTLQUOTEMARK) 1413 endp++; 1414 if (*endp == '\0') 1415 goto dft; /* no matching ] */ 1416 if (*endp == CTLESC) 1417 endp++; 1418 if (*++endp == ']') 1419 break; 1420 } 1421 invert = 0; 1422 if (*p == '!') { 1423 invert++; 1424 p++; 1425 } 1426 found = 0; 1427 chr = *q++; 1428 if (squoted && chr == CTLESC) 1429 chr = *q++; 1430 if (chr == '\0') 1431 return 0; 1432 c = *p++; 1433 do { 1434 if (c == CTLQUOTEMARK) 1435 continue; 1436 if (c == CTLESC) 1437 c = *p++; 1438 if (*p == '-' && p[1] != ']') { 1439 p++; 1440 while (*p == CTLQUOTEMARK) 1441 p++; 1442 if (*p == CTLESC) 1443 p++; 1444 if (chr >= c && chr <= *p) 1445 found = 1; 1446 p++; 1447 } else { 1448 if (chr == c) 1449 found = 1; 1450 } 1451 } while ((c = *p++) != ']'); 1452 if (found == invert) 1453 return 0; 1454 break; 1455 } 1456 dft: default: 1457 if (squoted && *q == CTLESC) 1458 q++; 1459 if (*q++ != c) 1460 return 0; 1461 break; 1462 } 1463 } 1464 breakloop: 1465 if (*q != '\0') 1466 return 0; 1467 return 1; 1468 } 1469 1470 1471 1472 /* 1473 * Remove any CTLESC characters from a string. 1474 */ 1475 1476 void 1477 rmescapes(str) 1478 char *str; 1479 { 1480 char *p, *q; 1481 1482 p = str; 1483 while (*p != CTLESC && *p != CTLQUOTEMARK) { 1484 if (*p++ == '\0') 1485 return; 1486 } 1487 q = p; 1488 while (*p) { 1489 if (*p == CTLQUOTEMARK) { 1490 p++; 1491 continue; 1492 } 1493 if (*p == CTLESC) 1494 p++; 1495 *q++ = *p++; 1496 } 1497 *q = '\0'; 1498 } 1499 1500 1501 1502 /* 1503 * See if a pattern matches in a case statement. 1504 */ 1505 1506 int 1507 casematch(pattern, val) 1508 union node *pattern; 1509 char *val; 1510 { 1511 struct stackmark smark; 1512 int result; 1513 char *p; 1514 1515 setstackmark(&smark); 1516 argbackq = pattern->narg.backquote; 1517 STARTSTACKSTR(expdest); 1518 ifslastp = NULL; 1519 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE); 1520 STPUTC('\0', expdest); 1521 p = grabstackstr(expdest); 1522 result = patmatch(p, val, 0); 1523 popstackmark(&smark); 1524 return result; 1525 } 1526 1527 /* 1528 * Our own itoa(). 1529 */ 1530 1531 STATIC char * 1532 cvtnum(num, buf) 1533 int num; 1534 char *buf; 1535 { 1536 char temp[32]; 1537 int neg = num < 0; 1538 char *p = temp + 31; 1539 1540 temp[31] = '\0'; 1541 1542 do { 1543 *--p = num % 10 + '0'; 1544 } while ((num /= 10) != 0); 1545 1546 if (neg) 1547 *--p = '-'; 1548 1549 while (*p) 1550 STPUTC(*p++, buf); 1551 return buf; 1552 } 1553