1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <unistd.h> 42 #include <stdlib.h> 43 #include <paths.h> 44 45 /* 46 * Shell variables. 47 */ 48 49 #include <locale.h> 50 51 #include "shell.h" 52 #include "output.h" 53 #include "expand.h" 54 #include "nodes.h" /* for other headers */ 55 #include "eval.h" /* defines cmdenviron */ 56 #include "exec.h" 57 #include "syntax.h" 58 #include "options.h" 59 #include "mail.h" 60 #include "var.h" 61 #include "memalloc.h" 62 #include "error.h" 63 #include "mystring.h" 64 #include "parser.h" 65 #ifndef NO_HISTORY 66 #include "myhistedit.h" 67 #endif 68 69 70 #define VTABSIZE 39 71 72 73 struct varinit { 74 struct var *var; 75 int flags; 76 const char *text; 77 void (*func)(const char *); 78 }; 79 80 81 #ifndef NO_HISTORY 82 struct var vhistsize; 83 struct var vterm; 84 #endif 85 struct var vifs; 86 struct var vmail; 87 struct var vmpath; 88 struct var vpath; 89 struct var vppid; 90 struct var vps1; 91 struct var vps2; 92 struct var vps4; 93 struct var vvers; 94 static struct var voptind; 95 96 static const struct varinit varinit[] = { 97 #ifndef NO_HISTORY 98 { &vhistsize, VUNSET, "HISTSIZE=", 99 sethistsize }, 100 #endif 101 { &vifs, 0, "IFS= \t\n", 102 NULL }, 103 { &vmail, VUNSET, "MAIL=", 104 NULL }, 105 { &vmpath, VUNSET, "MAILPATH=", 106 NULL }, 107 { &vpath, 0, "PATH=" _PATH_DEFPATH, 108 changepath }, 109 { &vppid, VUNSET, "PPID=", 110 NULL }, 111 /* 112 * vps1 depends on uid 113 */ 114 { &vps2, 0, "PS2=> ", 115 NULL }, 116 { &vps4, 0, "PS4=+ ", 117 NULL }, 118 #ifndef NO_HISTORY 119 { &vterm, VUNSET, "TERM=", 120 setterm }, 121 #endif 122 { &voptind, 0, "OPTIND=1", 123 getoptsreset }, 124 { NULL, 0, NULL, 125 NULL } 126 }; 127 128 static struct var *vartab[VTABSIZE]; 129 130 static const char *const locale_names[7] = { 131 "LC_COLLATE", "LC_CTYPE", "LC_MONETARY", 132 "LC_NUMERIC", "LC_TIME", "LC_MESSAGES", NULL 133 }; 134 static const int locale_categories[7] = { 135 LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME, LC_MESSAGES, 0 136 }; 137 138 static struct var **hashvar(const char *); 139 static int varequal(const char *, const char *); 140 static int localevar(const char *); 141 142 /* 143 * Initialize the variable symbol tables and import the environment. 144 */ 145 146 #ifdef mkinit 147 INCLUDE "var.h" 148 MKINIT char **environ; 149 INIT { 150 char **envp; 151 152 initvar(); 153 for (envp = environ ; *envp ; envp++) { 154 if (strchr(*envp, '=')) { 155 setvareq(*envp, VEXPORT|VTEXTFIXED); 156 } 157 } 158 } 159 #endif 160 161 162 /* 163 * This routine initializes the builtin variables. It is called when the 164 * shell is initialized and again when a shell procedure is spawned. 165 */ 166 167 void 168 initvar(void) 169 { 170 char ppid[20]; 171 const struct varinit *ip; 172 struct var *vp; 173 struct var **vpp; 174 175 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { 176 if ((vp->flags & VEXPORT) == 0) { 177 vpp = hashvar(ip->text); 178 vp->next = *vpp; 179 *vpp = vp; 180 vp->text = __DECONST(char *, ip->text); 181 vp->flags = ip->flags | VSTRFIXED | VTEXTFIXED; 182 vp->func = ip->func; 183 } 184 } 185 /* 186 * PS1 depends on uid 187 */ 188 if ((vps1.flags & VEXPORT) == 0) { 189 vpp = hashvar("PS1="); 190 vps1.next = *vpp; 191 *vpp = &vps1; 192 vps1.text = __DECONST(char *, geteuid() ? "PS1=$ " : "PS1=# "); 193 vps1.flags = VSTRFIXED|VTEXTFIXED; 194 } 195 if ((vppid.flags & VEXPORT) == 0) { 196 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid()); 197 setvarsafe("PPID", ppid, 0); 198 } 199 } 200 201 /* 202 * Safe version of setvar, returns 1 on success 0 on failure. 203 */ 204 205 int 206 setvarsafe(const char *name, const char *val, int flags) 207 { 208 struct jmploc jmploc; 209 struct jmploc *const savehandler = handler; 210 int err = 0; 211 int inton; 212 213 inton = is_int_on(); 214 if (setjmp(jmploc.loc)) 215 err = 1; 216 else { 217 handler = &jmploc; 218 setvar(name, val, flags); 219 } 220 handler = savehandler; 221 SETINTON(inton); 222 return err; 223 } 224 225 /* 226 * Set the value of a variable. The flags argument is stored with the 227 * flags of the variable. If val is NULL, the variable is unset. 228 */ 229 230 void 231 setvar(const char *name, const char *val, int flags) 232 { 233 const char *p; 234 int len; 235 int namelen; 236 char *nameeq; 237 int isbad; 238 239 isbad = 0; 240 p = name; 241 if (! is_name(*p)) 242 isbad = 1; 243 p++; 244 for (;;) { 245 if (! is_in_name(*p)) { 246 if (*p == '\0' || *p == '=') 247 break; 248 isbad = 1; 249 } 250 p++; 251 } 252 namelen = p - name; 253 if (isbad) 254 error("%.*s: bad variable name", namelen, name); 255 len = namelen + 2; /* 2 is space for '=' and '\0' */ 256 if (val == NULL) { 257 flags |= VUNSET; 258 } else { 259 len += strlen(val); 260 } 261 nameeq = ckmalloc(len); 262 memcpy(nameeq, name, namelen); 263 nameeq[namelen] = '='; 264 if (val) 265 scopy(val, nameeq + namelen + 1); 266 else 267 nameeq[namelen + 1] = '\0'; 268 setvareq(nameeq, flags); 269 } 270 271 static int 272 localevar(const char *s) 273 { 274 const char *const *ss; 275 276 if (*s != 'L') 277 return 0; 278 if (varequal(s + 1, "ANG")) 279 return 1; 280 if (strncmp(s + 1, "C_", 2) != 0) 281 return 0; 282 if (varequal(s + 3, "ALL")) 283 return 1; 284 for (ss = locale_names; *ss ; ss++) 285 if (varequal(s + 3, *ss + 3)) 286 return 1; 287 return 0; 288 } 289 290 291 /* 292 * Sets/unsets an environment variable from a pointer that may actually be a 293 * pointer into environ where the string should not be manipulated. 294 */ 295 static void 296 change_env(const char *s, int set) 297 { 298 char *eqp; 299 char *ss; 300 301 ss = savestr(s); 302 if ((eqp = strchr(ss, '=')) != NULL) 303 *eqp = '\0'; 304 if (set && eqp != NULL) 305 (void) setenv(ss, eqp + 1, 1); 306 else 307 (void) unsetenv(ss); 308 ckfree(ss); 309 310 return; 311 } 312 313 314 /* 315 * Same as setvar except that the variable and value are passed in 316 * the first argument as name=value. Since the first argument will 317 * be actually stored in the table, it should not be a string that 318 * will go away. 319 */ 320 321 void 322 setvareq(char *s, int flags) 323 { 324 struct var *vp, **vpp; 325 int len; 326 327 if (aflag) 328 flags |= VEXPORT; 329 vpp = hashvar(s); 330 for (vp = *vpp ; vp ; vp = vp->next) { 331 if (varequal(s, vp->text)) { 332 if (vp->flags & VREADONLY) { 333 len = strchr(s, '=') - s; 334 error("%.*s: is read only", len, s); 335 } 336 INTOFF; 337 338 if (vp->func && (flags & VNOFUNC) == 0) 339 (*vp->func)(strchr(s, '=') + 1); 340 341 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) 342 ckfree(vp->text); 343 344 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET); 345 vp->flags |= flags; 346 vp->text = s; 347 348 /* 349 * We could roll this to a function, to handle it as 350 * a regular variable function callback, but why bother? 351 * 352 * Note: this assumes iflag is not set to 1 initially. 353 * As part of init(), this is called before arguments 354 * are looked at. 355 */ 356 if ((vp == &vmpath || (vp == &vmail && ! mpathset())) && 357 iflag == 1) 358 chkmail(1); 359 if ((vp->flags & VEXPORT) && localevar(s)) { 360 change_env(s, 1); 361 (void) setlocale(LC_ALL, ""); 362 } 363 INTON; 364 return; 365 } 366 } 367 /* not found */ 368 vp = ckmalloc(sizeof (*vp)); 369 vp->flags = flags; 370 vp->text = s; 371 vp->next = *vpp; 372 vp->func = NULL; 373 INTOFF; 374 *vpp = vp; 375 if ((vp->flags & VEXPORT) && localevar(s)) { 376 change_env(s, 1); 377 (void) setlocale(LC_ALL, ""); 378 } 379 INTON; 380 } 381 382 383 384 /* 385 * Process a linked list of variable assignments. 386 */ 387 388 void 389 listsetvar(struct strlist *list) 390 { 391 struct strlist *lp; 392 393 INTOFF; 394 for (lp = list ; lp ; lp = lp->next) { 395 setvareq(savestr(lp->text), 0); 396 } 397 INTON; 398 } 399 400 401 402 /* 403 * Find the value of a variable. Returns NULL if not set. 404 */ 405 406 char * 407 lookupvar(const char *name) 408 { 409 struct var *v; 410 411 for (v = *hashvar(name) ; v ; v = v->next) { 412 if (varequal(v->text, name)) { 413 if (v->flags & VUNSET) 414 return NULL; 415 return strchr(v->text, '=') + 1; 416 } 417 } 418 return NULL; 419 } 420 421 422 423 /* 424 * Search the environment of a builtin command. If the second argument 425 * is nonzero, return the value of a variable even if it hasn't been 426 * exported. 427 */ 428 429 char * 430 bltinlookup(const char *name, int doall) 431 { 432 struct strlist *sp; 433 struct var *v; 434 char *result; 435 436 result = NULL; 437 for (sp = cmdenviron ; sp ; sp = sp->next) { 438 if (varequal(sp->text, name)) 439 result = strchr(sp->text, '=') + 1; 440 } 441 if (result != NULL) 442 return result; 443 for (v = *hashvar(name) ; v ; v = v->next) { 444 if (varequal(v->text, name)) { 445 if ((v->flags & VUNSET) 446 || (!doall && (v->flags & VEXPORT) == 0)) 447 return NULL; 448 return strchr(v->text, '=') + 1; 449 } 450 } 451 return NULL; 452 } 453 454 455 /* 456 * Set up locale for a builtin (LANG/LC_* assignments). 457 */ 458 void 459 bltinsetlocale(void) 460 { 461 struct strlist *lp; 462 int act = 0; 463 char *loc, *locdef; 464 int i; 465 466 for (lp = cmdenviron ; lp ; lp = lp->next) { 467 if (localevar(lp->text)) { 468 act = 1; 469 break; 470 } 471 } 472 if (!act) 473 return; 474 loc = bltinlookup("LC_ALL", 0); 475 INTOFF; 476 if (loc != NULL) { 477 setlocale(LC_ALL, loc); 478 INTON; 479 return; 480 } 481 locdef = bltinlookup("LANG", 0); 482 for (i = 0; locale_names[i] != NULL; i++) { 483 loc = bltinlookup(locale_names[i], 0); 484 if (loc == NULL) 485 loc = locdef; 486 if (loc != NULL) 487 setlocale(locale_categories[i], loc); 488 } 489 INTON; 490 } 491 492 /* 493 * Undo the effect of bltinlocaleset(). 494 */ 495 void 496 bltinunsetlocale(void) 497 { 498 struct strlist *lp; 499 500 INTOFF; 501 for (lp = cmdenviron ; lp ; lp = lp->next) { 502 if (localevar(lp->text)) { 503 setlocale(LC_ALL, ""); 504 return; 505 } 506 } 507 INTON; 508 } 509 510 511 /* 512 * Generate a list of exported variables. This routine is used to construct 513 * the third argument to execve when executing a program. 514 */ 515 516 char ** 517 environment(void) 518 { 519 int nenv; 520 struct var **vpp; 521 struct var *vp; 522 char **env, **ep; 523 524 nenv = 0; 525 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 526 for (vp = *vpp ; vp ; vp = vp->next) 527 if (vp->flags & VEXPORT) 528 nenv++; 529 } 530 ep = env = stalloc((nenv + 1) * sizeof *env); 531 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 532 for (vp = *vpp ; vp ; vp = vp->next) 533 if (vp->flags & VEXPORT) 534 *ep++ = vp->text; 535 } 536 *ep = NULL; 537 return env; 538 } 539 540 541 /* 542 * Called when a shell procedure is invoked to clear out nonexported 543 * variables. It is also necessary to reallocate variables of with 544 * VSTACK set since these are currently allocated on the stack. 545 */ 546 547 MKINIT void shprocvar(void); 548 549 #ifdef mkinit 550 SHELLPROC { 551 shprocvar(); 552 } 553 #endif 554 555 void 556 shprocvar(void) 557 { 558 struct var **vpp; 559 struct var *vp, **prev; 560 561 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 562 for (prev = vpp ; (vp = *prev) != NULL ; ) { 563 if ((vp->flags & VEXPORT) == 0) { 564 *prev = vp->next; 565 if ((vp->flags & VTEXTFIXED) == 0) 566 ckfree(vp->text); 567 if ((vp->flags & VSTRFIXED) == 0) 568 ckfree(vp); 569 } else { 570 if (vp->flags & VSTACK) { 571 vp->text = savestr(vp->text); 572 vp->flags &=~ VSTACK; 573 } 574 prev = &vp->next; 575 } 576 } 577 } 578 initvar(); 579 } 580 581 582 static int 583 var_compare(const void *a, const void *b) 584 { 585 const char *const *sa, *const *sb; 586 587 sa = a; 588 sb = b; 589 /* 590 * This compares two var=value strings which creates a different 591 * order from what you would probably expect. POSIX is somewhat 592 * ambiguous on what should be sorted exactly. 593 */ 594 return strcoll(*sa, *sb); 595 } 596 597 598 /* 599 * Command to list all variables which are set. Currently this command 600 * is invoked from the set command when the set command is called without 601 * any variables. 602 */ 603 604 int 605 showvarscmd(int argc __unused, char **argv __unused) 606 { 607 struct var **vpp; 608 struct var *vp; 609 const char *s; 610 const char **vars; 611 int i, n; 612 613 /* 614 * POSIX requires us to sort the variables. 615 */ 616 n = 0; 617 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 618 for (vp = *vpp; vp; vp = vp->next) { 619 if (!(vp->flags & VUNSET)) 620 n++; 621 } 622 } 623 624 INTON; 625 vars = ckmalloc(n * sizeof(*vars)); 626 i = 0; 627 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 628 for (vp = *vpp; vp; vp = vp->next) { 629 if (!(vp->flags & VUNSET)) 630 vars[i++] = vp->text; 631 } 632 } 633 634 qsort(vars, n, sizeof(*vars), var_compare); 635 for (i = 0; i < n; i++) { 636 for (s = vars[i]; *s != '='; s++) 637 out1c(*s); 638 out1c('='); 639 out1qstr(s + 1); 640 out1c('\n'); 641 } 642 ckfree(vars); 643 INTOFF; 644 645 return 0; 646 } 647 648 649 650 /* 651 * The export and readonly commands. 652 */ 653 654 int 655 exportcmd(int argc, char **argv) 656 { 657 struct var **vpp; 658 struct var *vp; 659 char *name; 660 char *p; 661 char *cmdname; 662 int ch, values; 663 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 664 665 cmdname = argv[0]; 666 optreset = optind = 1; 667 opterr = 0; 668 values = 0; 669 while ((ch = getopt(argc, argv, "p")) != -1) { 670 switch (ch) { 671 case 'p': 672 values = 1; 673 break; 674 case '?': 675 default: 676 error("unknown option: -%c", optopt); 677 } 678 } 679 argc -= optind; 680 argv += optind; 681 682 if (values && argc != 0) 683 error("-p requires no arguments"); 684 if (argc != 0) { 685 while ((name = *argv++) != NULL) { 686 if ((p = strchr(name, '=')) != NULL) { 687 p++; 688 } else { 689 vpp = hashvar(name); 690 for (vp = *vpp ; vp ; vp = vp->next) { 691 if (varequal(vp->text, name)) { 692 693 vp->flags |= flag; 694 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 695 change_env(vp->text, 1); 696 (void) setlocale(LC_ALL, ""); 697 } 698 goto found; 699 } 700 } 701 } 702 setvar(name, p, flag); 703 found:; 704 } 705 } else { 706 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 707 for (vp = *vpp ; vp ; vp = vp->next) { 708 if (vp->flags & flag) { 709 if (values) { 710 out1str(cmdname); 711 out1c(' '); 712 } 713 for (p = vp->text ; *p != '=' ; p++) 714 out1c(*p); 715 if (values && !(vp->flags & VUNSET)) { 716 out1c('='); 717 out1qstr(p + 1); 718 } 719 out1c('\n'); 720 } 721 } 722 } 723 } 724 return 0; 725 } 726 727 728 /* 729 * The "local" command. 730 */ 731 732 int 733 localcmd(int argc __unused, char **argv __unused) 734 { 735 char *name; 736 737 if (! in_function()) 738 error("Not in a function"); 739 while ((name = *argptr++) != NULL) { 740 mklocal(name); 741 } 742 return 0; 743 } 744 745 746 /* 747 * Make a variable a local variable. When a variable is made local, it's 748 * value and flags are saved in a localvar structure. The saved values 749 * will be restored when the shell function returns. We handle the name 750 * "-" as a special case. 751 */ 752 753 void 754 mklocal(char *name) 755 { 756 struct localvar *lvp; 757 struct var **vpp; 758 struct var *vp; 759 760 INTOFF; 761 lvp = ckmalloc(sizeof (struct localvar)); 762 if (name[0] == '-' && name[1] == '\0') { 763 lvp->text = ckmalloc(sizeof optlist); 764 memcpy(lvp->text, optlist, sizeof optlist); 765 vp = NULL; 766 } else { 767 vpp = hashvar(name); 768 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); 769 if (vp == NULL) { 770 if (strchr(name, '=')) 771 setvareq(savestr(name), VSTRFIXED); 772 else 773 setvar(name, NULL, VSTRFIXED); 774 vp = *vpp; /* the new variable */ 775 lvp->text = NULL; 776 lvp->flags = VUNSET; 777 } else { 778 lvp->text = vp->text; 779 lvp->flags = vp->flags; 780 vp->flags |= VSTRFIXED|VTEXTFIXED; 781 if (strchr(name, '=')) 782 setvareq(savestr(name), 0); 783 } 784 } 785 lvp->vp = vp; 786 lvp->next = localvars; 787 localvars = lvp; 788 INTON; 789 } 790 791 792 /* 793 * Called after a function returns. 794 */ 795 796 void 797 poplocalvars(void) 798 { 799 struct localvar *lvp; 800 struct var *vp; 801 802 while ((lvp = localvars) != NULL) { 803 localvars = lvp->next; 804 vp = lvp->vp; 805 if (vp == NULL) { /* $- saved */ 806 memcpy(optlist, lvp->text, sizeof optlist); 807 ckfree(lvp->text); 808 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 809 (void)unsetvar(vp->text); 810 } else { 811 if ((vp->flags & VTEXTFIXED) == 0) 812 ckfree(vp->text); 813 vp->flags = lvp->flags; 814 vp->text = lvp->text; 815 } 816 ckfree(lvp); 817 } 818 } 819 820 821 int 822 setvarcmd(int argc, char **argv) 823 { 824 if (argc <= 2) 825 return unsetcmd(argc, argv); 826 else if (argc == 3) 827 setvar(argv[1], argv[2], 0); 828 else 829 error("too many arguments"); 830 return 0; 831 } 832 833 834 /* 835 * The unset builtin command. We unset the function before we unset the 836 * variable to allow a function to be unset when there is a readonly variable 837 * with the same name. 838 */ 839 840 int 841 unsetcmd(int argc __unused, char **argv __unused) 842 { 843 char **ap; 844 int i; 845 int flg_func = 0; 846 int flg_var = 0; 847 int ret = 0; 848 849 while ((i = nextopt("vf")) != '\0') { 850 if (i == 'f') 851 flg_func = 1; 852 else 853 flg_var = 1; 854 } 855 if (flg_func == 0 && flg_var == 0) 856 flg_var = 1; 857 858 for (ap = argptr; *ap ; ap++) { 859 if (flg_func) 860 ret |= unsetfunc(*ap); 861 if (flg_var) 862 ret |= unsetvar(*ap); 863 } 864 return ret; 865 } 866 867 868 /* 869 * Unset the specified variable. 870 */ 871 872 int 873 unsetvar(const char *s) 874 { 875 struct var **vpp; 876 struct var *vp; 877 878 vpp = hashvar(s); 879 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 880 if (varequal(vp->text, s)) { 881 if (vp->flags & VREADONLY) 882 return (1); 883 INTOFF; 884 if (*(strchr(vp->text, '=') + 1) != '\0') 885 setvar(s, nullstr, 0); 886 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 887 change_env(s, 0); 888 setlocale(LC_ALL, ""); 889 } 890 vp->flags &= ~VEXPORT; 891 vp->flags |= VUNSET; 892 if ((vp->flags & VSTRFIXED) == 0) { 893 if ((vp->flags & VTEXTFIXED) == 0) 894 ckfree(vp->text); 895 *vpp = vp->next; 896 ckfree(vp); 897 } 898 INTON; 899 return (0); 900 } 901 } 902 903 return (0); 904 } 905 906 907 908 /* 909 * Find the appropriate entry in the hash table from the name. 910 */ 911 912 static struct var ** 913 hashvar(const char *p) 914 { 915 unsigned int hashval; 916 917 hashval = ((unsigned char) *p) << 4; 918 while (*p && *p != '=') 919 hashval += (unsigned char) *p++; 920 return &vartab[hashval % VTABSIZE]; 921 } 922 923 924 925 /* 926 * Returns true if the two strings specify the same varable. The first 927 * variable name is terminated by '='; the second may be terminated by 928 * either '=' or '\0'. 929 */ 930 931 static int 932 varequal(const char *p, const char *q) 933 { 934 while (*p == *q++) { 935 if (*p++ == '=') 936 return 1; 937 } 938 if (*p == '=' && *(q - 1) == '\0') 939 return 1; 940 return 0; 941 } 942