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 #include <langinfo.h> 51 52 #include "shell.h" 53 #include "output.h" 54 #include "expand.h" 55 #include "nodes.h" /* for other headers */ 56 #include "eval.h" /* defines cmdenviron */ 57 #include "exec.h" 58 #include "syntax.h" 59 #include "options.h" 60 #include "mail.h" 61 #include "var.h" 62 #include "memalloc.h" 63 #include "error.h" 64 #include "mystring.h" 65 #include "parser.h" 66 #include "builtins.h" 67 #ifndef NO_HISTORY 68 #include "myhistedit.h" 69 #endif 70 71 72 #define VTABSIZE 39 73 74 75 struct varinit { 76 struct var *var; 77 int flags; 78 const char *text; 79 void (*func)(const char *); 80 }; 81 82 83 #ifndef NO_HISTORY 84 struct var vhistsize; 85 struct var vterm; 86 #endif 87 struct var vifs; 88 struct var vmail; 89 struct var vmpath; 90 struct var vpath; 91 struct var vppid; 92 struct var vps1; 93 struct var vps2; 94 struct var vps4; 95 struct var vvers; 96 static struct var voptind; 97 struct var vdisvfork; 98 99 int forcelocal; 100 101 static const struct varinit varinit[] = { 102 #ifndef NO_HISTORY 103 { &vhistsize, VUNSET, "HISTSIZE=", 104 sethistsize }, 105 #endif 106 { &vifs, 0, "IFS= \t\n", 107 NULL }, 108 { &vmail, VUNSET, "MAIL=", 109 NULL }, 110 { &vmpath, VUNSET, "MAILPATH=", 111 NULL }, 112 { &vpath, 0, "PATH=" _PATH_DEFPATH, 113 changepath }, 114 { &vppid, VUNSET, "PPID=", 115 NULL }, 116 /* 117 * vps1 depends on uid 118 */ 119 { &vps2, 0, "PS2=> ", 120 NULL }, 121 { &vps4, 0, "PS4=+ ", 122 NULL }, 123 #ifndef NO_HISTORY 124 { &vterm, VUNSET, "TERM=", 125 setterm }, 126 #endif 127 { &voptind, 0, "OPTIND=1", 128 getoptsreset }, 129 { &vdisvfork, VUNSET, "SH_DISABLE_VFORK=", 130 NULL }, 131 { NULL, 0, NULL, 132 NULL } 133 }; 134 135 static struct var *vartab[VTABSIZE]; 136 137 static const char *const locale_names[7] = { 138 "LC_COLLATE", "LC_CTYPE", "LC_MONETARY", 139 "LC_NUMERIC", "LC_TIME", "LC_MESSAGES", NULL 140 }; 141 static const int locale_categories[7] = { 142 LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME, LC_MESSAGES, 0 143 }; 144 145 static int varequal(const char *, const char *); 146 static struct var *find_var(const char *, struct var ***, int *); 147 static int localevar(const char *); 148 149 extern char **environ; 150 151 /* 152 * This routine initializes the builtin variables and imports the environment. 153 * It is called when the shell is initialized. 154 */ 155 156 void 157 initvar(void) 158 { 159 char ppid[20]; 160 const struct varinit *ip; 161 struct var *vp; 162 struct var **vpp; 163 char **envp; 164 165 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { 166 if (find_var(ip->text, &vpp, &vp->name_len) != NULL) 167 continue; 168 vp->next = *vpp; 169 *vpp = vp; 170 vp->text = __DECONST(char *, ip->text); 171 vp->flags = ip->flags | VSTRFIXED | VTEXTFIXED; 172 vp->func = ip->func; 173 } 174 /* 175 * PS1 depends on uid 176 */ 177 if (find_var("PS1", &vpp, &vps1.name_len) == NULL) { 178 vps1.next = *vpp; 179 *vpp = &vps1; 180 vps1.text = __DECONST(char *, geteuid() ? "PS1=$ " : "PS1=# "); 181 vps1.flags = VSTRFIXED|VTEXTFIXED; 182 } 183 if ((vppid.flags & VEXPORT) == 0) { 184 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid()); 185 setvarsafe("PPID", ppid, 0); 186 } 187 for (envp = environ ; *envp ; envp++) { 188 if (strchr(*envp, '=')) { 189 setvareq(*envp, VEXPORT|VTEXTFIXED); 190 } 191 } 192 } 193 194 /* 195 * Safe version of setvar, returns 1 on success 0 on failure. 196 */ 197 198 int 199 setvarsafe(const char *name, const char *val, int flags) 200 { 201 struct jmploc jmploc; 202 struct jmploc *const savehandler = handler; 203 int err = 0; 204 int inton; 205 206 inton = is_int_on(); 207 if (setjmp(jmploc.loc)) 208 err = 1; 209 else { 210 handler = &jmploc; 211 setvar(name, val, flags); 212 } 213 handler = savehandler; 214 SETINTON(inton); 215 return err; 216 } 217 218 /* 219 * Set the value of a variable. The flags argument is stored with the 220 * flags of the variable. If val is NULL, the variable is unset. 221 */ 222 223 void 224 setvar(const char *name, const char *val, int flags) 225 { 226 const char *p; 227 size_t len; 228 size_t namelen; 229 size_t vallen; 230 char *nameeq; 231 int isbad; 232 233 isbad = 0; 234 p = name; 235 if (! is_name(*p)) 236 isbad = 1; 237 p++; 238 for (;;) { 239 if (! is_in_name(*p)) { 240 if (*p == '\0' || *p == '=') 241 break; 242 isbad = 1; 243 } 244 p++; 245 } 246 namelen = p - name; 247 if (isbad) 248 error("%.*s: bad variable name", (int)namelen, name); 249 len = namelen + 2; /* 2 is space for '=' and '\0' */ 250 if (val == NULL) { 251 flags |= VUNSET; 252 vallen = 0; 253 } else { 254 vallen = strlen(val); 255 len += vallen; 256 } 257 nameeq = ckmalloc(len); 258 memcpy(nameeq, name, namelen); 259 nameeq[namelen] = '='; 260 if (val) 261 memcpy(nameeq + namelen + 1, val, vallen + 1); 262 else 263 nameeq[namelen + 1] = '\0'; 264 setvareq(nameeq, flags); 265 } 266 267 static int 268 localevar(const char *s) 269 { 270 const char *const *ss; 271 272 if (*s != 'L') 273 return 0; 274 if (varequal(s + 1, "ANG")) 275 return 1; 276 if (strncmp(s + 1, "C_", 2) != 0) 277 return 0; 278 if (varequal(s + 3, "ALL")) 279 return 1; 280 for (ss = locale_names; *ss ; ss++) 281 if (varequal(s + 3, *ss + 3)) 282 return 1; 283 return 0; 284 } 285 286 287 /* 288 * Sets/unsets an environment variable from a pointer that may actually be a 289 * pointer into environ where the string should not be manipulated. 290 */ 291 static void 292 change_env(const char *s, int set) 293 { 294 char *eqp; 295 char *ss; 296 297 ss = savestr(s); 298 if ((eqp = strchr(ss, '=')) != NULL) 299 *eqp = '\0'; 300 if (set && eqp != NULL) 301 (void) setenv(ss, eqp + 1, 1); 302 else 303 (void) unsetenv(ss); 304 ckfree(ss); 305 306 return; 307 } 308 309 310 /* 311 * Same as setvar except that the variable and value are passed in 312 * the first argument as name=value. Since the first argument will 313 * be actually stored in the table, it should not be a string that 314 * will go away. 315 */ 316 317 void 318 setvareq(char *s, int flags) 319 { 320 struct var *vp, **vpp; 321 int nlen; 322 323 if (aflag) 324 flags |= VEXPORT; 325 if (forcelocal && !(flags & (VNOSET | VNOLOCAL))) 326 mklocal(s); 327 vp = find_var(s, &vpp, &nlen); 328 if (vp != NULL) { 329 if (vp->flags & VREADONLY) 330 error("%.*s: is read only", vp->name_len, s); 331 if (flags & VNOSET) 332 return; 333 INTOFF; 334 335 if (vp->func && (flags & VNOFUNC) == 0) 336 (*vp->func)(s + vp->name_len + 1); 337 338 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) 339 ckfree(vp->text); 340 341 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET); 342 vp->flags |= flags; 343 vp->text = s; 344 345 /* 346 * We could roll this to a function, to handle it as 347 * a regular variable function callback, but why bother? 348 * 349 * Note: this assumes iflag is not set to 1 initially. 350 * As part of initvar(), this is called before arguments 351 * are looked at. 352 */ 353 if ((vp == &vmpath || (vp == &vmail && ! mpathset())) && 354 iflag == 1) 355 chkmail(1); 356 if ((vp->flags & VEXPORT) && localevar(s)) { 357 change_env(s, 1); 358 (void) setlocale(LC_ALL, ""); 359 updatecharset(); 360 } 361 INTON; 362 return; 363 } 364 /* not found */ 365 if (flags & VNOSET) 366 return; 367 vp = ckmalloc(sizeof (*vp)); 368 vp->flags = flags; 369 vp->text = s; 370 vp->name_len = nlen; 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 updatecharset(); 379 } 380 INTON; 381 } 382 383 384 385 /* 386 * Process a linked list of variable assignments. 387 */ 388 389 void 390 listsetvar(struct strlist *list, int flags) 391 { 392 struct strlist *lp; 393 394 INTOFF; 395 for (lp = list ; lp ; lp = lp->next) { 396 setvareq(savestr(lp->text), flags); 397 } 398 INTON; 399 } 400 401 402 403 /* 404 * Find the value of a variable. Returns NULL if not set. 405 */ 406 407 char * 408 lookupvar(const char *name) 409 { 410 struct var *v; 411 412 v = find_var(name, NULL, NULL); 413 if (v == NULL || v->flags & VUNSET) 414 return NULL; 415 return v->text + v->name_len + 1; 416 } 417 418 419 420 /* 421 * Search the environment of a builtin command. If the second argument 422 * is nonzero, return the value of a variable even if it hasn't been 423 * exported. 424 */ 425 426 char * 427 bltinlookup(const char *name, int doall) 428 { 429 struct strlist *sp; 430 struct var *v; 431 char *result; 432 433 result = NULL; 434 for (sp = cmdenviron ; sp ; sp = sp->next) { 435 if (varequal(sp->text, name)) 436 result = strchr(sp->text, '=') + 1; 437 } 438 if (result != NULL) 439 return result; 440 441 v = find_var(name, NULL, NULL); 442 if (v == NULL || v->flags & VUNSET || 443 (!doall && (v->flags & VEXPORT) == 0)) 444 return NULL; 445 return v->text + v->name_len + 1; 446 } 447 448 449 /* 450 * Set up locale for a builtin (LANG/LC_* assignments). 451 */ 452 void 453 bltinsetlocale(void) 454 { 455 struct strlist *lp; 456 int act = 0; 457 char *loc, *locdef; 458 int i; 459 460 for (lp = cmdenviron ; lp ; lp = lp->next) { 461 if (localevar(lp->text)) { 462 act = 1; 463 break; 464 } 465 } 466 if (!act) 467 return; 468 loc = bltinlookup("LC_ALL", 0); 469 INTOFF; 470 if (loc != NULL) { 471 setlocale(LC_ALL, loc); 472 INTON; 473 updatecharset(); 474 return; 475 } 476 locdef = bltinlookup("LANG", 0); 477 for (i = 0; locale_names[i] != NULL; i++) { 478 loc = bltinlookup(locale_names[i], 0); 479 if (loc == NULL) 480 loc = locdef; 481 if (loc != NULL) 482 setlocale(locale_categories[i], loc); 483 } 484 INTON; 485 updatecharset(); 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 updatecharset(); 501 return; 502 } 503 } 504 INTON; 505 } 506 507 /* 508 * Update the localeisutf8 flag. 509 */ 510 void 511 updatecharset(void) 512 { 513 char *charset; 514 515 charset = nl_langinfo(CODESET); 516 localeisutf8 = !strcmp(charset, "UTF-8"); 517 } 518 519 void 520 initcharset(void) 521 { 522 updatecharset(); 523 initial_localeisutf8 = localeisutf8; 524 } 525 526 /* 527 * Generate a list of exported variables. This routine is used to construct 528 * the third argument to execve when executing a program. 529 */ 530 531 char ** 532 environment(void) 533 { 534 int nenv; 535 struct var **vpp; 536 struct var *vp; 537 char **env, **ep; 538 539 nenv = 0; 540 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 541 for (vp = *vpp ; vp ; vp = vp->next) 542 if (vp->flags & VEXPORT) 543 nenv++; 544 } 545 ep = env = stalloc((nenv + 1) * sizeof *env); 546 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 547 for (vp = *vpp ; vp ; vp = vp->next) 548 if (vp->flags & VEXPORT) 549 *ep++ = vp->text; 550 } 551 *ep = NULL; 552 return env; 553 } 554 555 556 static int 557 var_compare(const void *a, const void *b) 558 { 559 const char *const *sa, *const *sb; 560 561 sa = a; 562 sb = b; 563 /* 564 * This compares two var=value strings which creates a different 565 * order from what you would probably expect. POSIX is somewhat 566 * ambiguous on what should be sorted exactly. 567 */ 568 return strcoll(*sa, *sb); 569 } 570 571 572 /* 573 * Command to list all variables which are set. This is invoked from the 574 * set command when it is called without any options or operands. 575 */ 576 577 int 578 showvarscmd(int argc __unused, char **argv __unused) 579 { 580 struct var **vpp; 581 struct var *vp; 582 const char *s; 583 const char **vars; 584 int i, n; 585 586 /* 587 * POSIX requires us to sort the variables. 588 */ 589 n = 0; 590 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 591 for (vp = *vpp; vp; vp = vp->next) { 592 if (!(vp->flags & VUNSET)) 593 n++; 594 } 595 } 596 597 INTOFF; 598 vars = ckmalloc(n * sizeof(*vars)); 599 i = 0; 600 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 601 for (vp = *vpp; vp; vp = vp->next) { 602 if (!(vp->flags & VUNSET)) 603 vars[i++] = vp->text; 604 } 605 } 606 607 qsort(vars, n, sizeof(*vars), var_compare); 608 for (i = 0; i < n; i++) { 609 /* 610 * Skip improper variable names so the output remains usable as 611 * shell input. 612 */ 613 if (!isassignment(vars[i])) 614 continue; 615 s = strchr(vars[i], '='); 616 s++; 617 outbin(vars[i], s - vars[i], out1); 618 out1qstr(s); 619 out1c('\n'); 620 } 621 ckfree(vars); 622 INTON; 623 624 return 0; 625 } 626 627 628 629 /* 630 * The export and readonly commands. 631 */ 632 633 int 634 exportcmd(int argc __unused, char **argv) 635 { 636 struct var **vpp; 637 struct var *vp; 638 char **ap; 639 char *name; 640 char *p; 641 char *cmdname; 642 int ch, values; 643 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 644 645 cmdname = argv[0]; 646 values = 0; 647 while ((ch = nextopt("p")) != '\0') { 648 switch (ch) { 649 case 'p': 650 values = 1; 651 break; 652 } 653 } 654 655 if (values && *argptr != NULL) 656 error("-p requires no arguments"); 657 if (*argptr != NULL) { 658 for (ap = argptr; (name = *ap) != NULL; ap++) { 659 if ((p = strchr(name, '=')) != NULL) { 660 p++; 661 } else { 662 vp = find_var(name, NULL, NULL); 663 if (vp != NULL) { 664 vp->flags |= flag; 665 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 666 change_env(vp->text, 1); 667 (void) setlocale(LC_ALL, ""); 668 updatecharset(); 669 } 670 continue; 671 } 672 } 673 setvar(name, p, flag); 674 } 675 } else { 676 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 677 for (vp = *vpp ; vp ; vp = vp->next) { 678 if (vp->flags & flag) { 679 if (values) { 680 /* 681 * Skip improper variable names 682 * so the output remains usable 683 * as shell input. 684 */ 685 if (!isassignment(vp->text)) 686 continue; 687 out1str(cmdname); 688 out1c(' '); 689 } 690 if (values && !(vp->flags & VUNSET)) { 691 outbin(vp->text, 692 vp->name_len + 1, out1); 693 out1qstr(vp->text + 694 vp->name_len + 1); 695 } else 696 outbin(vp->text, vp->name_len, 697 out1); 698 out1c('\n'); 699 } 700 } 701 } 702 } 703 return 0; 704 } 705 706 707 /* 708 * The "local" command. 709 */ 710 711 int 712 localcmd(int argc __unused, char **argv __unused) 713 { 714 char *name; 715 716 nextopt(""); 717 if (! in_function()) 718 error("Not in a function"); 719 while ((name = *argptr++) != NULL) { 720 mklocal(name); 721 } 722 return 0; 723 } 724 725 726 /* 727 * Make a variable a local variable. When a variable is made local, it's 728 * value and flags are saved in a localvar structure. The saved values 729 * will be restored when the shell function returns. We handle the name 730 * "-" as a special case. 731 */ 732 733 void 734 mklocal(char *name) 735 { 736 struct localvar *lvp; 737 struct var **vpp; 738 struct var *vp; 739 740 INTOFF; 741 lvp = ckmalloc(sizeof (struct localvar)); 742 if (name[0] == '-' && name[1] == '\0') { 743 lvp->text = ckmalloc(sizeof optlist); 744 memcpy(lvp->text, optlist, sizeof optlist); 745 vp = NULL; 746 } else { 747 vp = find_var(name, &vpp, NULL); 748 if (vp == NULL) { 749 if (strchr(name, '=')) 750 setvareq(savestr(name), VSTRFIXED | VNOLOCAL); 751 else 752 setvar(name, NULL, VSTRFIXED | VNOLOCAL); 753 vp = *vpp; /* the new variable */ 754 lvp->text = NULL; 755 lvp->flags = VUNSET; 756 } else { 757 lvp->text = vp->text; 758 lvp->flags = vp->flags; 759 vp->flags |= VSTRFIXED|VTEXTFIXED; 760 if (name[vp->name_len] == '=') 761 setvareq(savestr(name), VNOLOCAL); 762 } 763 } 764 lvp->vp = vp; 765 lvp->next = localvars; 766 localvars = lvp; 767 INTON; 768 } 769 770 771 /* 772 * Called after a function returns. 773 */ 774 775 void 776 poplocalvars(void) 777 { 778 struct localvar *lvp; 779 struct var *vp; 780 781 while ((lvp = localvars) != NULL) { 782 localvars = lvp->next; 783 vp = lvp->vp; 784 if (vp == NULL) { /* $- saved */ 785 memcpy(optlist, lvp->text, sizeof optlist); 786 ckfree(lvp->text); 787 optschanged(); 788 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 789 (void)unsetvar(vp->text); 790 } else { 791 if ((vp->flags & VTEXTFIXED) == 0) 792 ckfree(vp->text); 793 vp->flags = lvp->flags; 794 vp->text = lvp->text; 795 } 796 ckfree(lvp); 797 } 798 } 799 800 801 int 802 setvarcmd(int argc, char **argv) 803 { 804 if (argc <= 2) 805 return unsetcmd(argc, argv); 806 else if (argc == 3) 807 setvar(argv[1], argv[2], 0); 808 else 809 error("too many arguments"); 810 return 0; 811 } 812 813 814 /* 815 * The unset builtin command. 816 */ 817 818 int 819 unsetcmd(int argc __unused, char **argv __unused) 820 { 821 char **ap; 822 int i; 823 int flg_func = 0; 824 int flg_var = 0; 825 int ret = 0; 826 827 while ((i = nextopt("vf")) != '\0') { 828 if (i == 'f') 829 flg_func = 1; 830 else 831 flg_var = 1; 832 } 833 if (flg_func == 0 && flg_var == 0) 834 flg_var = 1; 835 836 for (ap = argptr; *ap ; ap++) { 837 if (flg_func) 838 ret |= unsetfunc(*ap); 839 if (flg_var) 840 ret |= unsetvar(*ap); 841 } 842 return ret; 843 } 844 845 846 /* 847 * Unset the specified variable. 848 */ 849 850 int 851 unsetvar(const char *s) 852 { 853 struct var **vpp; 854 struct var *vp; 855 856 vp = find_var(s, &vpp, NULL); 857 if (vp == NULL) 858 return (0); 859 if (vp->flags & VREADONLY) 860 return (1); 861 INTOFF; 862 if (vp->text[vp->name_len + 1] != '\0') 863 setvar(s, nullstr, 0); 864 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 865 change_env(s, 0); 866 setlocale(LC_ALL, ""); 867 updatecharset(); 868 } 869 vp->flags &= ~VEXPORT; 870 vp->flags |= VUNSET; 871 if ((vp->flags & VSTRFIXED) == 0) { 872 if ((vp->flags & VTEXTFIXED) == 0) 873 ckfree(vp->text); 874 *vpp = vp->next; 875 ckfree(vp); 876 } 877 INTON; 878 return (0); 879 } 880 881 882 883 /* 884 * Returns true if the two strings specify the same variable. The first 885 * variable name is terminated by '='; the second may be terminated by 886 * either '=' or '\0'. 887 */ 888 889 static int 890 varequal(const char *p, const char *q) 891 { 892 while (*p == *q++) { 893 if (*p++ == '=') 894 return 1; 895 } 896 if (*p == '=' && *(q - 1) == '\0') 897 return 1; 898 return 0; 899 } 900 901 /* 902 * Search for a variable. 903 * 'name' may be terminated by '=' or a NUL. 904 * vppp is set to the pointer to vp, or the list head if vp isn't found 905 * lenp is set to the number of characters in 'name' 906 */ 907 908 static struct var * 909 find_var(const char *name, struct var ***vppp, int *lenp) 910 { 911 unsigned int hashval; 912 int len; 913 struct var *vp, **vpp; 914 const char *p = name; 915 916 hashval = 0; 917 while (*p && *p != '=') 918 hashval = 2 * hashval + (unsigned char)*p++; 919 len = p - name; 920 921 if (lenp) 922 *lenp = len; 923 vpp = &vartab[hashval % VTABSIZE]; 924 if (vppp) 925 *vppp = vpp; 926 927 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 928 if (vp->name_len != len) 929 continue; 930 if (memcmp(vp->text, name, len) != 0) 931 continue; 932 if (vppp) 933 *vppp = vpp; 934 return vp; 935 } 936 return NULL; 937 } 938