1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#ifndef lint 36#if 0 37static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95"; 38#endif 39#endif /* not lint */ 40#include <sys/cdefs.h> 41__FBSDID("$FreeBSD$"); 42 43#include <unistd.h> 44#include <stdlib.h> 45#include <paths.h> 46 47/* 48 * Shell variables. 49 */ 50 51#include <locale.h> 52#include <langinfo.h> 53 54#include "shell.h" 55#include "output.h" 56#include "expand.h" 57#include "nodes.h" /* for other headers */ 58#include "eval.h" /* defines cmdenviron */ 59#include "exec.h" 60#include "syntax.h" 61#include "options.h" 62#include "mail.h" 63#include "var.h" 64#include "memalloc.h" 65#include "error.h" 66#include "mystring.h" 67#include "parser.h" 68#include "builtins.h" 69#ifndef NO_HISTORY 70#include "myhistedit.h" 71#endif 72 73 74#ifndef VTABSIZE 75#define VTABSIZE 39 76#endif 77 78 79struct varinit { 80 struct var *var; 81 int flags; 82 const char *text; 83 void (*func)(const char *); 84}; 85 86 87#ifndef NO_HISTORY 88struct var vhistsize; 89struct var vterm; 90#endif 91struct var vifs; 92struct var vmail; 93struct var vmpath; 94struct var vpath; 95struct var vps1; 96struct var vps2; 97struct var vps4; 98static struct var voptind; 99struct var vdisvfork; 100 101struct localvar *localvars; 102int forcelocal; 103 104static const struct varinit varinit[] = { 105#ifndef NO_HISTORY 106 { &vhistsize, VUNSET, "HISTSIZE=", 107 sethistsize }, 108#endif 109 { &vifs, 0, "IFS= \t\n", 110 NULL }, 111 { &vmail, VUNSET, "MAIL=", 112 NULL }, 113 { &vmpath, VUNSET, "MAILPATH=", 114 NULL }, 115 { &vpath, 0, "PATH=" _PATH_DEFPATH, 116 changepath }, 117 /* 118 * vps1 depends on uid 119 */ 120 { &vps2, 0, "PS2=> ", 121 NULL }, 122 { &vps4, 0, "PS4=+ ", 123 NULL }, 124#ifndef NO_HISTORY 125 { &vterm, VUNSET, "TERM=", 126 setterm }, 127#endif 128 { &voptind, 0, "OPTIND=1", 129 getoptsreset }, 130 { &vdisvfork, VUNSET, "SH_DISABLE_VFORK=", 131 NULL }, 132 { NULL, 0, NULL, 133 NULL } 134}; 135 136static struct var *vartab[VTABSIZE]; 137 138static const char *const locale_names[7] = { 139 "LC_COLLATE", "LC_CTYPE", "LC_MONETARY", 140 "LC_NUMERIC", "LC_TIME", "LC_MESSAGES", NULL 141}; 142static const int locale_categories[7] = { 143 LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME, LC_MESSAGES, 0 144}; 145 146static int varequal(const char *, const char *); 147static struct var *find_var(const char *, struct var ***, int *); 148static int localevar(const char *); 149static void setvareq_const(const char *s, int flags); 150 151extern char **environ; 152 153/* 154 * This routine initializes the builtin variables and imports the environment. 155 * It is called when the shell is initialized. 156 */ 157 158void 159initvar(void) 160{ 161 char ppid[20]; 162 const struct varinit *ip; 163 struct var *vp; 164 struct var **vpp; 165 char **envp; 166 167 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { 168 if (find_var(ip->text, &vpp, &vp->name_len) != NULL) 169 continue; 170 vp->next = *vpp; 171 *vpp = vp; 172 vp->text = __DECONST(char *, ip->text); 173 vp->flags = ip->flags | VSTRFIXED | VTEXTFIXED; 174 vp->func = ip->func; 175 } 176 /* 177 * PS1 depends on uid 178 */ 179 if (find_var("PS1", &vpp, &vps1.name_len) == NULL) { 180 vps1.next = *vpp; 181 *vpp = &vps1; 182 vps1.text = __DECONST(char *, geteuid() ? "PS1=$ " : "PS1=# "); 183 vps1.flags = VSTRFIXED|VTEXTFIXED; 184 } 185 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid()); 186 setvarsafe("PPID", ppid, 0); 187 for (envp = environ ; *envp ; envp++) { 188 if (strchr(*envp, '=')) { 189 setvareq(*envp, VEXPORT|VTEXTFIXED); 190 } 191 } 192 setvareq_const("OPTIND=1", 0); 193 setvareq_const("IFS= \t\n", 0); 194} 195 196/* 197 * Safe version of setvar, returns 1 on success 0 on failure. 198 */ 199 200int 201setvarsafe(const char *name, const char *val, int flags) 202{ 203 struct jmploc jmploc; 204 struct jmploc *const savehandler = handler; 205 int err = 0; 206 int inton; 207 208 inton = is_int_on(); 209 if (setjmp(jmploc.loc)) 210 err = 1; 211 else { 212 handler = &jmploc; 213 setvar(name, val, flags); 214 } 215 handler = savehandler; 216 SETINTON(inton); 217 return err; 218} 219 220/* 221 * Set the value of a variable. The flags argument is stored with the 222 * flags of the variable. If val is NULL, the variable is unset. 223 */ 224 225void 226setvar(const char *name, const char *val, int flags) 227{ 228 const char *p; 229 size_t len; 230 size_t namelen; 231 size_t vallen; 232 char *nameeq; 233 int isbad; 234 235 isbad = 0; 236 p = name; 237 if (! is_name(*p)) 238 isbad = 1; 239 p++; 240 for (;;) { 241 if (! is_in_name(*p)) { 242 if (*p == '\0' || *p == '=') 243 break; 244 isbad = 1; 245 } 246 p++; 247 } 248 namelen = p - name; 249 if (isbad) 250 error("%.*s: bad variable name", (int)namelen, name); 251 len = namelen + 2; /* 2 is space for '=' and '\0' */ 252 if (val == NULL) { 253 flags |= VUNSET; 254 vallen = 0; 255 } else { 256 vallen = strlen(val); 257 len += vallen; 258 } 259 INTOFF; 260 nameeq = ckmalloc(len); 261 memcpy(nameeq, name, namelen); 262 nameeq[namelen] = '='; 263 if (val) 264 memcpy(nameeq + namelen + 1, val, vallen + 1); 265 else 266 nameeq[namelen + 1] = '\0'; 267 setvareq(nameeq, flags); 268 INTON; 269} 270 271static int 272localevar(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 */ 295static void 296change_env(const char *s, int set) 297{ 298 char *eqp; 299 char *ss; 300 301 INTOFF; 302 ss = savestr(s); 303 if ((eqp = strchr(ss, '=')) != NULL) 304 *eqp = '\0'; 305 if (set && eqp != NULL) 306 (void) setenv(ss, eqp + 1, 1); 307 else 308 (void) unsetenv(ss); 309 ckfree(ss); 310 INTON; 311 312 return; 313} 314 315 316/* 317 * Same as setvar except that the variable and value are passed in 318 * the first argument as name=value. Since the first argument will 319 * be actually stored in the table, it should not be a string that 320 * will go away. 321 */ 322 323void 324setvareq(char *s, int flags) 325{ 326 struct var *vp, **vpp; 327 int nlen; 328 329 if (aflag) 330 flags |= VEXPORT; 331 if (forcelocal && !(flags & (VNOSET | VNOLOCAL))) 332 mklocal(s); 333 vp = find_var(s, &vpp, &nlen); 334 if (vp != NULL) { 335 if (vp->flags & VREADONLY) { 336 if ((flags & (VTEXTFIXED|VSTACK)) == 0) 337 ckfree(s); 338 error("%.*s: is read only", vp->name_len, vp->text); 339 } 340 if (flags & VNOSET) { 341 if ((flags & (VTEXTFIXED|VSTACK)) == 0) 342 ckfree(s); 343 return; 344 } 345 INTOFF; 346 347 if (vp->func && (flags & VNOFUNC) == 0) 348 (*vp->func)(s + vp->name_len + 1); 349 350 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) 351 ckfree(vp->text); 352 353 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET); 354 vp->flags |= flags; 355 vp->text = s; 356 357 /* 358 * We could roll this to a function, to handle it as 359 * a regular variable function callback, but why bother? 360 * 361 * Note: this assumes iflag is not set to 1 initially. 362 * As part of initvar(), this is called before arguments 363 * are looked at. 364 */ 365 if ((vp == &vmpath || (vp == &vmail && ! mpathset())) && 366 iflag == 1) 367 chkmail(1); 368 if ((vp->flags & VEXPORT) && localevar(s)) { 369 change_env(s, 1); 370 (void) setlocale(LC_ALL, ""); 371 updatecharset(); 372 } 373 INTON; 374 return; 375 } 376 /* not found */ 377 if (flags & VNOSET) { 378 if ((flags & (VTEXTFIXED|VSTACK)) == 0) 379 ckfree(s); 380 return; 381 } 382 INTOFF; 383 vp = ckmalloc(sizeof (*vp)); 384 vp->flags = flags; 385 vp->text = s; 386 vp->name_len = nlen; 387 vp->next = *vpp; 388 vp->func = NULL; 389 *vpp = vp; 390 if ((vp->flags & VEXPORT) && localevar(s)) { 391 change_env(s, 1); 392 (void) setlocale(LC_ALL, ""); 393 updatecharset(); 394 } 395 INTON; 396} 397 398 399static void 400setvareq_const(const char *s, int flags) 401{ 402 setvareq(__DECONST(char *, s), flags | VTEXTFIXED); 403} 404 405 406/* 407 * Process a linked list of variable assignments. 408 */ 409 410void 411listsetvar(struct arglist *list, int flags) 412{ 413 int i; 414 415 INTOFF; 416 for (i = 0; i < list->count; i++) 417 setvareq(savestr(list->args[i]), flags); 418 INTON; 419} 420 421 422 423/* 424 * Find the value of a variable. Returns NULL if not set. 425 */ 426 427char * 428lookupvar(const char *name) 429{ 430 struct var *v; 431 432 v = find_var(name, NULL, NULL); 433 if (v == NULL || v->flags & VUNSET) 434 return NULL; 435 return v->text + v->name_len + 1; 436} 437 438 439 440/* 441 * Search the environment of a builtin command. If the second argument 442 * is nonzero, return the value of a variable even if it hasn't been 443 * exported. 444 */ 445 446char * 447bltinlookup(const char *name, int doall) 448{ 449 struct var *v; 450 char *result; 451 int i; 452 453 result = NULL; 454 if (cmdenviron) for (i = 0; i < cmdenviron->count; i++) { 455 if (varequal(cmdenviron->args[i], name)) 456 result = strchr(cmdenviron->args[i], '=') + 1; 457 } 458 if (result != NULL) 459 return result; 460 461 v = find_var(name, NULL, NULL); 462 if (v == NULL || v->flags & VUNSET || 463 (!doall && (v->flags & VEXPORT) == 0)) 464 return NULL; 465 return v->text + v->name_len + 1; 466} 467 468 469/* 470 * Set up locale for a builtin (LANG/LC_* assignments). 471 */ 472void 473bltinsetlocale(void) 474{ 475 int act = 0; 476 char *loc, *locdef; 477 int i; 478 479 if (cmdenviron) for (i = 0; i < cmdenviron->count; i++) { 480 if (localevar(cmdenviron->args[i])) { 481 act = 1; 482 break; 483 } 484 } 485 if (!act) 486 return; 487 loc = bltinlookup("LC_ALL", 0); 488 INTOFF; 489 if (loc != NULL) { 490 setlocale(LC_ALL, loc); 491 INTON; 492 updatecharset(); 493 return; 494 } 495 locdef = bltinlookup("LANG", 0); 496 for (i = 0; locale_names[i] != NULL; i++) { 497 loc = bltinlookup(locale_names[i], 0); 498 if (loc == NULL) 499 loc = locdef; 500 if (loc != NULL) 501 setlocale(locale_categories[i], loc); 502 } 503 INTON; 504 updatecharset(); 505} 506 507/* 508 * Undo the effect of bltinlocaleset(). 509 */ 510void 511bltinunsetlocale(void) 512{ 513 int i; 514 515 INTOFF; 516 if (cmdenviron) for (i = 0; i < cmdenviron->count; i++) { 517 if (localevar(cmdenviron->args[i])) { 518 setlocale(LC_ALL, ""); 519 updatecharset(); 520 break; 521 } 522 } 523 INTON; 524} 525 526/* 527 * Update the localeisutf8 flag. 528 */ 529void 530updatecharset(void) 531{ 532 char *charset; 533 534 charset = nl_langinfo(CODESET); 535 localeisutf8 = !strcmp(charset, "UTF-8"); 536} 537 538void 539initcharset(void) 540{ 541 updatecharset(); 542 initial_localeisutf8 = localeisutf8; 543} 544 545/* 546 * Generate a list of exported variables. This routine is used to construct 547 * the third argument to execve when executing a program. 548 */ 549 550char ** 551environment(void) 552{ 553 int nenv; 554 struct var **vpp; 555 struct var *vp; 556 char **env, **ep; 557 558 nenv = 0; 559 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 560 for (vp = *vpp ; vp ; vp = vp->next) 561 if (vp->flags & VEXPORT) 562 nenv++; 563 } 564 ep = env = stalloc((nenv + 1) * sizeof *env); 565 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 566 for (vp = *vpp ; vp ; vp = vp->next) 567 if (vp->flags & VEXPORT) 568 *ep++ = vp->text; 569 } 570 *ep = NULL; 571 return env; 572} 573 574 575static int 576var_compare(const void *a, const void *b) 577{ 578 const char *const *sa, *const *sb; 579 580 sa = a; 581 sb = b; 582 /* 583 * This compares two var=value strings which creates a different 584 * order from what you would probably expect. POSIX is somewhat 585 * ambiguous on what should be sorted exactly. 586 */ 587 return strcoll(*sa, *sb); 588} 589 590 591/* 592 * Command to list all variables which are set. This is invoked from the 593 * set command when it is called without any options or operands. 594 */ 595 596int 597showvarscmd(int argc __unused, char **argv __unused) 598{ 599 struct var **vpp; 600 struct var *vp; 601 const char *s; 602 const char **vars; 603 int i, n; 604 605 /* 606 * POSIX requires us to sort the variables. 607 */ 608 n = 0; 609 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 610 for (vp = *vpp; vp; vp = vp->next) { 611 if (!(vp->flags & VUNSET)) 612 n++; 613 } 614 } 615 616 INTOFF; 617 vars = ckmalloc(n * sizeof(*vars)); 618 i = 0; 619 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 620 for (vp = *vpp; vp; vp = vp->next) { 621 if (!(vp->flags & VUNSET)) 622 vars[i++] = vp->text; 623 } 624 } 625 626 qsort(vars, n, sizeof(*vars), var_compare); 627 for (i = 0; i < n; i++) { 628 /* 629 * Skip improper variable names so the output remains usable as 630 * shell input. 631 */ 632 if (!isassignment(vars[i])) 633 continue; 634 s = strchr(vars[i], '='); 635 s++; 636 outbin(vars[i], s - vars[i], out1); 637 out1qstr(s); 638 out1c('\n'); 639 } 640 ckfree(vars); 641 INTON; 642 643 return 0; 644} 645 646 647 648/* 649 * The export and readonly commands. 650 */ 651 652int 653exportcmd(int argc __unused, char **argv) 654{ 655 struct var **vpp; 656 struct var *vp; 657 char **ap; 658 char *name; 659 char *p; 660 char *cmdname; 661 int ch, values; 662 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 663 664 cmdname = argv[0]; 665 values = 0; 666 while ((ch = nextopt("p")) != '\0') { 667 switch (ch) { 668 case 'p': 669 values = 1; 670 break; 671 } 672 } 673 674 if (values && *argptr != NULL) 675 error("-p requires no arguments"); 676 if (*argptr != NULL) { 677 for (ap = argptr; (name = *ap) != NULL; ap++) { 678 if ((p = strchr(name, '=')) != NULL) { 679 p++; 680 } else { 681 vp = find_var(name, NULL, NULL); 682 if (vp != NULL) { 683 vp->flags |= flag; 684 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 685 change_env(vp->text, 1); 686 (void) setlocale(LC_ALL, ""); 687 updatecharset(); 688 } 689 continue; 690 } 691 } 692 setvar(name, p, flag); 693 } 694 } else { 695 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 696 for (vp = *vpp ; vp ; vp = vp->next) { 697 if (vp->flags & flag) { 698 if (values) { 699 /* 700 * Skip improper variable names 701 * so the output remains usable 702 * as shell input. 703 */ 704 if (!isassignment(vp->text)) 705 continue; 706 out1str(cmdname); 707 out1c(' '); 708 } 709 if (values && !(vp->flags & VUNSET)) { 710 outbin(vp->text, 711 vp->name_len + 1, out1); 712 out1qstr(vp->text + 713 vp->name_len + 1); 714 } else 715 outbin(vp->text, vp->name_len, 716 out1); 717 out1c('\n'); 718 } 719 } 720 } 721 } 722 return 0; 723} 724 725 726/* 727 * The "local" command. 728 */ 729 730int 731localcmd(int argc __unused, char **argv __unused) 732{ 733 char *name; 734 735 nextopt(""); 736 if (! in_function()) 737 error("Not in a function"); 738 while ((name = *argptr++) != NULL) { 739 mklocal(name); 740 } 741 return 0; 742} 743 744 745/* 746 * Make a variable a local variable. When a variable is made local, it's 747 * value and flags are saved in a localvar structure. The saved values 748 * will be restored when the shell function returns. We handle the name 749 * "-" as a special case. 750 */ 751 752void 753mklocal(char *name) 754{ 755 struct localvar *lvp; 756 struct var **vpp; 757 struct var *vp; 758 759 INTOFF; 760 lvp = ckmalloc(sizeof (struct localvar)); 761 if (name[0] == '-' && name[1] == '\0') { 762 lvp->text = ckmalloc(sizeof optval); 763 memcpy(lvp->text, optval, sizeof optval); 764 vp = NULL; 765 } else { 766 vp = find_var(name, &vpp, NULL); 767 if (vp == NULL) { 768 if (strchr(name, '=')) 769 setvareq(savestr(name), VSTRFIXED | VNOLOCAL); 770 else 771 setvar(name, NULL, VSTRFIXED | VNOLOCAL); 772 vp = *vpp; /* the new variable */ 773 lvp->text = NULL; 774 lvp->flags = VUNSET; 775 } else { 776 lvp->text = vp->text; 777 lvp->flags = vp->flags; 778 vp->flags |= VSTRFIXED|VTEXTFIXED; 779 if (name[vp->name_len] == '=') 780 setvareq(savestr(name), VNOLOCAL); 781 } 782 } 783 lvp->vp = vp; 784 lvp->next = localvars; 785 localvars = lvp; 786 INTON; 787} 788 789 790/* 791 * Called after a function returns. 792 */ 793 794void 795poplocalvars(void) 796{ 797 struct localvar *lvp; 798 struct var *vp; 799 int islocalevar; 800 801 INTOFF; 802 while ((lvp = localvars) != NULL) { 803 localvars = lvp->next; 804 vp = lvp->vp; 805 if (vp == NULL) { /* $- saved */ 806 memcpy(optval, lvp->text, sizeof optval); 807 ckfree(lvp->text); 808 optschanged(); 809 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 810 vp->flags &= ~VREADONLY; 811 (void)unsetvar(vp->text); 812 } else { 813 islocalevar = (vp->flags | lvp->flags) & VEXPORT && 814 localevar(lvp->text); 815 if ((vp->flags & VTEXTFIXED) == 0) 816 ckfree(vp->text); 817 vp->flags = lvp->flags; 818 vp->text = lvp->text; 819 if (vp->func) 820 (*vp->func)(vp->text + vp->name_len + 1); 821 if (islocalevar) { 822 change_env(vp->text, vp->flags & VEXPORT && 823 (vp->flags & VUNSET) == 0); 824 setlocale(LC_ALL, ""); 825 updatecharset(); 826 } 827 } 828 ckfree(lvp); 829 } 830 INTON; 831} 832 833 834int 835setvarcmd(int argc, char **argv) 836{ 837 if (argc <= 2) 838 return unsetcmd(argc, argv); 839 else if (argc == 3) 840 setvar(argv[1], argv[2], 0); 841 else 842 error("too many arguments"); 843 return 0; 844} 845 846 847/* 848 * The unset builtin command. 849 */ 850 851int 852unsetcmd(int argc __unused, char **argv __unused) 853{ 854 char **ap; 855 int i; 856 int flg_func = 0; 857 int flg_var = 0; 858 int ret = 0; 859 860 while ((i = nextopt("vf")) != '\0') { 861 if (i == 'f') 862 flg_func = 1; 863 else 864 flg_var = 1; 865 } 866 if (flg_func == 0 && flg_var == 0) 867 flg_var = 1; 868 869 INTOFF; 870 for (ap = argptr; *ap ; ap++) { 871 if (flg_func) 872 ret |= unsetfunc(*ap); 873 if (flg_var) 874 ret |= unsetvar(*ap); 875 } 876 INTON; 877 return ret; 878} 879 880 881/* 882 * Unset the specified variable. 883 * Called with interrupts off. 884 */ 885 886int 887unsetvar(const char *s) 888{ 889 struct var **vpp; 890 struct var *vp; 891 892 vp = find_var(s, &vpp, NULL); 893 if (vp == NULL) 894 return (0); 895 if (vp->flags & VREADONLY) 896 return (1); 897 if (vp->text[vp->name_len + 1] != '\0') 898 setvar(s, "", 0); 899 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 900 change_env(s, 0); 901 setlocale(LC_ALL, ""); 902 updatecharset(); 903 } 904 vp->flags &= ~VEXPORT; 905 vp->flags |= VUNSET; 906 if ((vp->flags & VSTRFIXED) == 0) { 907 if ((vp->flags & VTEXTFIXED) == 0) 908 ckfree(vp->text); 909 *vpp = vp->next; 910 ckfree(vp); 911 } 912 return (0); 913} 914 915 916 917/* 918 * Returns true if the two strings specify the same variable. The first 919 * variable name is terminated by '='; the second may be terminated by 920 * either '=' or '\0'. 921 */ 922 923static int 924varequal(const char *p, const char *q) 925{ 926 while (*p == *q++) { 927 if (*p++ == '=') 928 return 1; 929 } 930 if (*p == '=' && *(q - 1) == '\0') 931 return 1; 932 return 0; 933} 934 935/* 936 * Search for a variable. 937 * 'name' may be terminated by '=' or a NUL. 938 * vppp is set to the pointer to vp, or the list head if vp isn't found 939 * lenp is set to the number of characters in 'name' 940 */ 941 942static struct var * 943find_var(const char *name, struct var ***vppp, int *lenp) 944{ 945 unsigned int hashval; 946 int len; 947 struct var *vp, **vpp; 948 const char *p = name; 949 950 hashval = 0; 951 while (*p && *p != '=') 952 hashval = 2 * hashval + (unsigned char)*p++; 953 len = p - name; 954 955 if (lenp) 956 *lenp = len; 957 vpp = &vartab[hashval % VTABSIZE]; 958 if (vppp) 959 *vppp = vpp; 960 961 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 962 if (vp->name_len != len) 963 continue; 964 if (memcmp(vp->text, name, len) != 0) 965 continue; 966 if (vppp) 967 *vppp = vpp; 968 return vp; 969 } 970 return NULL; 971} 972