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; 434 435 for (sp = cmdenviron ; sp ; sp = sp->next) { 436 if (varequal(sp->text, name)) 437 return strchr(sp->text, '=') + 1; 438 } 439 for (v = *hashvar(name) ; v ; v = v->next) { 440 if (varequal(v->text, name)) { 441 if ((v->flags & VUNSET) 442 || (!doall && (v->flags & VEXPORT) == 0)) 443 return NULL; 444 return strchr(v->text, '=') + 1; 445 } 446 } 447 return NULL; 448 } 449 450 451 /* 452 * Set up locale for a builtin (LANG/LC_* assignments). 453 */ 454 void 455 bltinsetlocale(void) 456 { 457 struct strlist *lp; 458 int act = 0; 459 char *loc, *locdef; 460 int i; 461 462 for (lp = cmdenviron ; lp ; lp = lp->next) { 463 if (localevar(lp->text)) { 464 act = 1; 465 break; 466 } 467 } 468 if (!act) 469 return; 470 loc = bltinlookup("LC_ALL", 0); 471 INTOFF; 472 if (loc != NULL) { 473 setlocale(LC_ALL, loc); 474 INTON; 475 return; 476 } 477 locdef = bltinlookup("LANG", 0); 478 for (i = 0; locale_names[i] != NULL; i++) { 479 loc = bltinlookup(locale_names[i], 0); 480 if (loc == NULL) 481 loc = locdef; 482 if (loc != NULL) 483 setlocale(locale_categories[i], loc); 484 } 485 INTON; 486 } 487 488 /* 489 * Undo the effect of bltinlocaleset(). 490 */ 491 void 492 bltinunsetlocale(void) 493 { 494 struct strlist *lp; 495 496 INTOFF; 497 for (lp = cmdenviron ; lp ; lp = lp->next) { 498 if (localevar(lp->text)) { 499 setlocale(LC_ALL, ""); 500 return; 501 } 502 } 503 INTON; 504 } 505 506 507 /* 508 * Generate a list of exported variables. This routine is used to construct 509 * the third argument to execve when executing a program. 510 */ 511 512 char ** 513 environment(void) 514 { 515 int nenv; 516 struct var **vpp; 517 struct var *vp; 518 char **env, **ep; 519 520 nenv = 0; 521 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 522 for (vp = *vpp ; vp ; vp = vp->next) 523 if (vp->flags & VEXPORT) 524 nenv++; 525 } 526 ep = env = stalloc((nenv + 1) * sizeof *env); 527 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 528 for (vp = *vpp ; vp ; vp = vp->next) 529 if (vp->flags & VEXPORT) 530 *ep++ = vp->text; 531 } 532 *ep = NULL; 533 return env; 534 } 535 536 537 /* 538 * Called when a shell procedure is invoked to clear out nonexported 539 * variables. It is also necessary to reallocate variables of with 540 * VSTACK set since these are currently allocated on the stack. 541 */ 542 543 MKINIT void shprocvar(void); 544 545 #ifdef mkinit 546 SHELLPROC { 547 shprocvar(); 548 } 549 #endif 550 551 void 552 shprocvar(void) 553 { 554 struct var **vpp; 555 struct var *vp, **prev; 556 557 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 558 for (prev = vpp ; (vp = *prev) != NULL ; ) { 559 if ((vp->flags & VEXPORT) == 0) { 560 *prev = vp->next; 561 if ((vp->flags & VTEXTFIXED) == 0) 562 ckfree(vp->text); 563 if ((vp->flags & VSTRFIXED) == 0) 564 ckfree(vp); 565 } else { 566 if (vp->flags & VSTACK) { 567 vp->text = savestr(vp->text); 568 vp->flags &=~ VSTACK; 569 } 570 prev = &vp->next; 571 } 572 } 573 } 574 initvar(); 575 } 576 577 578 static int 579 var_compare(const void *a, const void *b) 580 { 581 const char *const *sa, *const *sb; 582 583 sa = a; 584 sb = b; 585 /* 586 * This compares two var=value strings which creates a different 587 * order from what you would probably expect. POSIX is somewhat 588 * ambiguous on what should be sorted exactly. 589 */ 590 return strcoll(*sa, *sb); 591 } 592 593 594 /* 595 * Command to list all variables which are set. Currently this command 596 * is invoked from the set command when the set command is called without 597 * any variables. 598 */ 599 600 int 601 showvarscmd(int argc __unused, char **argv __unused) 602 { 603 struct var **vpp; 604 struct var *vp; 605 const char *s; 606 const char **vars; 607 int i, n; 608 609 /* 610 * POSIX requires us to sort the variables. 611 */ 612 n = 0; 613 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 614 for (vp = *vpp; vp; vp = vp->next) { 615 if (!(vp->flags & VUNSET)) 616 n++; 617 } 618 } 619 620 INTON; 621 vars = ckmalloc(n * sizeof(*vars)); 622 i = 0; 623 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 624 for (vp = *vpp; vp; vp = vp->next) { 625 if (!(vp->flags & VUNSET)) 626 vars[i++] = vp->text; 627 } 628 } 629 630 qsort(vars, n, sizeof(*vars), var_compare); 631 for (i = 0; i < n; i++) { 632 for (s = vars[i]; *s != '='; s++) 633 out1c(*s); 634 out1c('='); 635 out1qstr(s + 1); 636 out1c('\n'); 637 } 638 ckfree(vars); 639 INTOFF; 640 641 return 0; 642 } 643 644 645 646 /* 647 * The export and readonly commands. 648 */ 649 650 int 651 exportcmd(int argc, char **argv) 652 { 653 struct var **vpp; 654 struct var *vp; 655 char *name; 656 char *p; 657 char *cmdname; 658 int ch, values; 659 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 660 661 cmdname = argv[0]; 662 optreset = optind = 1; 663 opterr = 0; 664 values = 0; 665 while ((ch = getopt(argc, argv, "p")) != -1) { 666 switch (ch) { 667 case 'p': 668 values = 1; 669 break; 670 case '?': 671 default: 672 error("unknown option: -%c", optopt); 673 } 674 } 675 argc -= optind; 676 argv += optind; 677 678 if (values && argc != 0) 679 error("-p requires no arguments"); 680 if (argc != 0) { 681 while ((name = *argv++) != NULL) { 682 if ((p = strchr(name, '=')) != NULL) { 683 p++; 684 } else { 685 vpp = hashvar(name); 686 for (vp = *vpp ; vp ; vp = vp->next) { 687 if (varequal(vp->text, name)) { 688 689 vp->flags |= flag; 690 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 691 change_env(vp->text, 1); 692 (void) setlocale(LC_ALL, ""); 693 } 694 goto found; 695 } 696 } 697 } 698 setvar(name, p, flag); 699 found:; 700 } 701 } else { 702 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 703 for (vp = *vpp ; vp ; vp = vp->next) { 704 if (vp->flags & flag) { 705 if (values) { 706 out1str(cmdname); 707 out1c(' '); 708 } 709 for (p = vp->text ; *p != '=' ; p++) 710 out1c(*p); 711 if (values && !(vp->flags & VUNSET)) { 712 out1c('='); 713 out1qstr(p + 1); 714 } 715 out1c('\n'); 716 } 717 } 718 } 719 } 720 return 0; 721 } 722 723 724 /* 725 * The "local" command. 726 */ 727 728 int 729 localcmd(int argc __unused, char **argv __unused) 730 { 731 char *name; 732 733 if (! in_function()) 734 error("Not in a function"); 735 while ((name = *argptr++) != NULL) { 736 mklocal(name); 737 } 738 return 0; 739 } 740 741 742 /* 743 * Make a variable a local variable. When a variable is made local, it's 744 * value and flags are saved in a localvar structure. The saved values 745 * will be restored when the shell function returns. We handle the name 746 * "-" as a special case. 747 */ 748 749 void 750 mklocal(char *name) 751 { 752 struct localvar *lvp; 753 struct var **vpp; 754 struct var *vp; 755 756 INTOFF; 757 lvp = ckmalloc(sizeof (struct localvar)); 758 if (name[0] == '-' && name[1] == '\0') { 759 lvp->text = ckmalloc(sizeof optlist); 760 memcpy(lvp->text, optlist, sizeof optlist); 761 vp = NULL; 762 } else { 763 vpp = hashvar(name); 764 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); 765 if (vp == NULL) { 766 if (strchr(name, '=')) 767 setvareq(savestr(name), VSTRFIXED); 768 else 769 setvar(name, NULL, VSTRFIXED); 770 vp = *vpp; /* the new variable */ 771 lvp->text = NULL; 772 lvp->flags = VUNSET; 773 } else { 774 lvp->text = vp->text; 775 lvp->flags = vp->flags; 776 vp->flags |= VSTRFIXED|VTEXTFIXED; 777 if (strchr(name, '=')) 778 setvareq(savestr(name), 0); 779 } 780 } 781 lvp->vp = vp; 782 lvp->next = localvars; 783 localvars = lvp; 784 INTON; 785 } 786 787 788 /* 789 * Called after a function returns. 790 */ 791 792 void 793 poplocalvars(void) 794 { 795 struct localvar *lvp; 796 struct var *vp; 797 798 while ((lvp = localvars) != NULL) { 799 localvars = lvp->next; 800 vp = lvp->vp; 801 if (vp == NULL) { /* $- saved */ 802 memcpy(optlist, lvp->text, sizeof optlist); 803 ckfree(lvp->text); 804 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 805 (void)unsetvar(vp->text); 806 } else { 807 if ((vp->flags & VTEXTFIXED) == 0) 808 ckfree(vp->text); 809 vp->flags = lvp->flags; 810 vp->text = lvp->text; 811 } 812 ckfree(lvp); 813 } 814 } 815 816 817 int 818 setvarcmd(int argc, char **argv) 819 { 820 if (argc <= 2) 821 return unsetcmd(argc, argv); 822 else if (argc == 3) 823 setvar(argv[1], argv[2], 0); 824 else 825 error("List assignment not implemented"); 826 return 0; 827 } 828 829 830 /* 831 * The unset builtin command. We unset the function before we unset the 832 * variable to allow a function to be unset when there is a readonly variable 833 * with the same name. 834 */ 835 836 int 837 unsetcmd(int argc __unused, char **argv __unused) 838 { 839 char **ap; 840 int i; 841 int flg_func = 0; 842 int flg_var = 0; 843 int ret = 0; 844 845 while ((i = nextopt("vf")) != '\0') { 846 if (i == 'f') 847 flg_func = 1; 848 else 849 flg_var = 1; 850 } 851 if (flg_func == 0 && flg_var == 0) 852 flg_var = 1; 853 854 for (ap = argptr; *ap ; ap++) { 855 if (flg_func) 856 ret |= unsetfunc(*ap); 857 if (flg_var) 858 ret |= unsetvar(*ap); 859 } 860 return ret; 861 } 862 863 864 /* 865 * Unset the specified variable. 866 */ 867 868 int 869 unsetvar(const char *s) 870 { 871 struct var **vpp; 872 struct var *vp; 873 874 vpp = hashvar(s); 875 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 876 if (varequal(vp->text, s)) { 877 if (vp->flags & VREADONLY) 878 return (1); 879 INTOFF; 880 if (*(strchr(vp->text, '=') + 1) != '\0') 881 setvar(s, nullstr, 0); 882 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 883 change_env(s, 0); 884 setlocale(LC_ALL, ""); 885 } 886 vp->flags &= ~VEXPORT; 887 vp->flags |= VUNSET; 888 if ((vp->flags & VSTRFIXED) == 0) { 889 if ((vp->flags & VTEXTFIXED) == 0) 890 ckfree(vp->text); 891 *vpp = vp->next; 892 ckfree(vp); 893 } 894 INTON; 895 return (0); 896 } 897 } 898 899 return (0); 900 } 901 902 903 904 /* 905 * Find the appropriate entry in the hash table from the name. 906 */ 907 908 STATIC struct var ** 909 hashvar(const char *p) 910 { 911 unsigned int hashval; 912 913 hashval = ((unsigned char) *p) << 4; 914 while (*p && *p != '=') 915 hashval += (unsigned char) *p++; 916 return &vartab[hashval % VTABSIZE]; 917 } 918 919 920 921 /* 922 * Returns true if the two strings specify the same varable. The first 923 * variable name is terminated by '='; the second may be terminated by 924 * either '=' or '\0'. 925 */ 926 927 STATIC int 928 varequal(const char *p, const char *q) 929 { 930 while (*p == *q++) { 931 if (*p++ == '=') 932 return 1; 933 } 934 if (*p == '=' && *(q - 1) == '\0') 935 return 1; 936 return 0; 937 } 938