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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)var.c 8.3 (Berkeley) 5/4/95 37 * $FreeBSD: src/bin/sh/var.c,v 1.57 2011/05/06 22:31:27 jilles Exp $ 38 */ 39 40 #include <unistd.h> 41 #include <stdlib.h> 42 43 /* 44 * Shell variables. 45 */ 46 47 #include <locale.h> 48 #include <langinfo.h> 49 #include <paths.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. 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 * Sets/unsets an environment variable from a pointer that may actually be a 292 * pointer into environ where the string should not be manipulated. 293 */ 294 static void 295 change_env(const char *s, int set) 296 { 297 char *eqp; 298 char *ss; 299 300 ss = savestr(s); 301 if ((eqp = strchr(ss, '=')) != NULL) 302 *eqp = '\0'; 303 if (set && eqp != NULL) { 304 if (setenv(ss, eqp + 1, 1) != 0) 305 error("setenv: cannot set %s=%s", ss, eqp + 1); 306 } else 307 unsetenv(ss); 308 ckfree(ss); 309 } 310 311 312 /* 313 * Same as setvar except that the variable and value are passed in 314 * the first argument as name=value. Since the first argument will 315 * be actually stored in the table, it should not be a string that 316 * will go away. 317 */ 318 319 void 320 setvareq(char *s, int flags) 321 { 322 struct var *vp, **vpp; 323 int len; 324 325 if (aflag) 326 flags |= VEXPORT; 327 vpp = hashvar(s); 328 for (vp = *vpp ; vp ; vp = vp->next) { 329 if (varequal(s, vp->text)) { 330 if (vp->flags & VREADONLY) { 331 len = strchr(s, '=') - s; 332 error("%.*s: is read only", len, s); 333 } 334 if (flags & VNOSET) 335 return; 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 setlocale(LC_ALL, ""); 362 updatecharset(); 363 } 364 INTON; 365 return; 366 } 367 } 368 /* not found */ 369 if (flags & VNOSET) 370 return; 371 vp = ckmalloc(sizeof (*vp)); 372 vp->flags = flags; 373 vp->text = s; 374 vp->next = *vpp; 375 vp->func = NULL; 376 INTOFF; 377 *vpp = vp; 378 if ((vp->flags & VEXPORT) && localevar(s)) { 379 change_env(s, 1); 380 setlocale(LC_ALL, ""); 381 updatecharset(); 382 } 383 INTON; 384 } 385 386 387 388 /* 389 * Process a linked list of variable assignments. 390 */ 391 392 void 393 listsetvar(struct strlist *list, int flags) 394 { 395 struct strlist *lp; 396 397 INTOFF; 398 for (lp = list ; lp ; lp = lp->next) { 399 setvareq(savestr(lp->text), flags); 400 } 401 INTON; 402 } 403 404 405 406 /* 407 * Find the value of a variable. Returns NULL if not set. 408 */ 409 410 char * 411 lookupvar(const char *name) 412 { 413 struct var *v; 414 415 for (v = *hashvar(name) ; v ; v = v->next) { 416 if (varequal(v->text, name)) { 417 if (v->flags & VUNSET) 418 return NULL; 419 return strchr(v->text, '=') + 1; 420 } 421 } 422 return NULL; 423 } 424 425 426 427 /* 428 * Search the environment of a builtin command. If the second argument 429 * is nonzero, return the value of a variable even if it hasn't been 430 * exported. 431 */ 432 433 char * 434 bltinlookup(const char *name, int doall) 435 { 436 struct strlist *sp; 437 struct var *v; 438 char *result; 439 440 result = NULL; 441 for (sp = cmdenviron ; sp ; sp = sp->next) { 442 if (varequal(sp->text, name)) 443 result = strchr(sp->text, '=') + 1; 444 } 445 if (result != NULL) 446 return result; 447 for (v = *hashvar(name) ; v ; v = v->next) { 448 if (varequal(v->text, name)) { 449 if ((v->flags & VUNSET) 450 || (!doall && (v->flags & VEXPORT) == 0)) 451 return NULL; 452 return strchr(v->text, '=') + 1; 453 } 454 } 455 return NULL; 456 } 457 458 459 /* 460 * Set up locale for a builtin (LANG/LC_* assignments). 461 */ 462 void 463 bltinsetlocale(void) 464 { 465 struct strlist *lp; 466 int act = 0; 467 char *loc, *locdef; 468 int i; 469 470 for (lp = cmdenviron ; lp ; lp = lp->next) { 471 if (localevar(lp->text)) { 472 act = 1; 473 break; 474 } 475 } 476 if (!act) 477 return; 478 loc = bltinlookup("LC_ALL", 0); 479 INTOFF; 480 if (loc != NULL) { 481 setlocale(LC_ALL, loc); 482 INTON; 483 updatecharset(); 484 return; 485 } 486 locdef = bltinlookup("LANG", 0); 487 for (i = 0; locale_names[i] != NULL; i++) { 488 loc = bltinlookup(locale_names[i], 0); 489 if (loc == NULL) 490 loc = locdef; 491 if (loc != NULL) 492 setlocale(locale_categories[i], loc); 493 } 494 INTON; 495 updatecharset(); 496 } 497 498 /* 499 * Undo the effect of bltinlocaleset(). 500 */ 501 void 502 bltinunsetlocale(void) 503 { 504 struct strlist *lp; 505 506 INTOFF; 507 for (lp = cmdenviron ; lp ; lp = lp->next) { 508 if (localevar(lp->text)) { 509 setlocale(LC_ALL, ""); 510 updatecharset(); 511 return; 512 } 513 } 514 INTON; 515 } 516 517 /* 518 * Update the localeisutf8 flag. 519 */ 520 void 521 updatecharset(void) 522 { 523 char *charset; 524 525 charset = nl_langinfo(CODESET); 526 localeisutf8 = !strcmp(charset, "UTF-8"); 527 } 528 529 /* 530 * Generate a list of exported variables. This routine is used to construct 531 * the third argument to execve when executing a program. 532 */ 533 534 char ** 535 environment(void) 536 { 537 int nenv; 538 struct var **vpp; 539 struct var *vp; 540 char **env, **ep; 541 542 nenv = 0; 543 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 544 for (vp = *vpp ; vp ; vp = vp->next) 545 if (vp->flags & VEXPORT) 546 nenv++; 547 } 548 ep = env = stalloc((nenv + 1) * sizeof *env); 549 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 550 for (vp = *vpp ; vp ; vp = vp->next) 551 if (vp->flags & VEXPORT) 552 *ep++ = vp->text; 553 } 554 *ep = NULL; 555 return env; 556 } 557 558 559 static int 560 var_compare(const void *a, const void *b) 561 { 562 const char *const *sa, *const *sb; 563 564 sa = a; 565 sb = b; 566 /* 567 * This compares two var=value strings which creates a different 568 * order from what you would probably expect. POSIX is somewhat 569 * ambiguous on what should be sorted exactly. 570 */ 571 return strcoll(*sa, *sb); 572 } 573 574 575 /* 576 * Command to list all variables which are set. This is invoked from the 577 * set command when it is called without any options or operands. 578 */ 579 580 int 581 showvarscmd(int argc __unused, char **argv __unused) 582 { 583 struct var **vpp; 584 struct var *vp; 585 const char *s; 586 const char **vars; 587 int i, n; 588 589 /* 590 * POSIX requires us to sort the variables. 591 */ 592 n = 0; 593 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 594 for (vp = *vpp; vp; vp = vp->next) { 595 if (!(vp->flags & VUNSET)) 596 n++; 597 } 598 } 599 600 INTON; 601 vars = ckmalloc(n * sizeof(*vars)); 602 i = 0; 603 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 604 for (vp = *vpp; vp; vp = vp->next) { 605 if (!(vp->flags & VUNSET)) 606 vars[i++] = vp->text; 607 } 608 } 609 610 qsort(vars, n, sizeof(*vars), var_compare); 611 for (i = 0; i < n; i++) { 612 s = strchr(vars[i], '='); 613 s++; 614 outbin(vars[i], s - vars[i], out1); 615 out1qstr(s); 616 out1c('\n'); 617 } 618 ckfree(vars); 619 INTOFF; 620 621 return 0; 622 } 623 624 625 626 /* 627 * The export and readonly commands. 628 */ 629 630 int 631 exportcmd(int argc, char **argv) 632 { 633 struct var **vpp; 634 struct var *vp; 635 char *name; 636 char *p; 637 char *cmdname; 638 int ch, values; 639 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 640 641 cmdname = argv[0]; 642 optreset = optind = 1; 643 opterr = 0; 644 values = 0; 645 while ((ch = getopt(argc, argv, "p")) != -1) { 646 switch (ch) { 647 case 'p': 648 values = 1; 649 break; 650 case '?': 651 default: 652 error("unknown option: -%c", optopt); 653 } 654 } 655 argc -= optind; 656 argv += optind; 657 658 if (values && argc != 0) 659 error("-p requires no arguments"); 660 if (argc != 0) { 661 while ((name = *argv++) != NULL) { 662 if ((p = strchr(name, '=')) != NULL) { 663 p++; 664 } else { 665 vpp = hashvar(name); 666 for (vp = *vpp ; vp ; vp = vp->next) { 667 if (varequal(vp->text, name)) { 668 669 vp->flags |= flag; 670 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 671 change_env(vp->text, 1); 672 setlocale(LC_ALL, ""); 673 updatecharset(); 674 } 675 goto found; 676 } 677 } 678 } 679 setvar(name, p, flag); 680 found:; 681 } 682 } else { 683 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 684 for (vp = *vpp ; vp ; vp = vp->next) { 685 if (vp->flags & flag) { 686 if (values) { 687 out1str(cmdname); 688 out1c(' '); 689 } 690 p = strchr(vp->text, '='); 691 if (values && !(vp->flags & VUNSET)) { 692 p++; 693 outbin(vp->text, p - vp->text, 694 out1); 695 out1qstr(p); 696 } else 697 outbin(vp->text, p - vp->text, 698 out1); 699 out1c('\n'); 700 } 701 } 702 } 703 } 704 return 0; 705 } 706 707 708 /* 709 * The "local" command. 710 */ 711 712 int 713 localcmd(int argc __unused, char **argv __unused) 714 { 715 char *name; 716 717 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 vpp = hashvar(name); 748 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); 749 if (vp == NULL) { 750 if (strchr(name, '=')) 751 setvareq(savestr(name), VSTRFIXED); 752 else 753 setvar(name, NULL, VSTRFIXED); 754 vp = *vpp; /* the new variable */ 755 lvp->text = NULL; 756 lvp->flags = VUNSET; 757 } else { 758 lvp->text = vp->text; 759 lvp->flags = vp->flags; 760 vp->flags |= VSTRFIXED|VTEXTFIXED; 761 if (strchr(name, '=')) 762 setvareq(savestr(name), 0); 763 } 764 } 765 lvp->vp = vp; 766 lvp->next = localvars; 767 localvars = lvp; 768 INTON; 769 } 770 771 772 /* 773 * Called after a function returns. 774 */ 775 776 void 777 poplocalvars(void) 778 { 779 struct localvar *lvp; 780 struct var *vp; 781 782 while ((lvp = localvars) != NULL) { 783 localvars = lvp->next; 784 vp = lvp->vp; 785 if (vp == NULL) { /* $- saved */ 786 memcpy(optlist, lvp->text, sizeof optlist); 787 ckfree(lvp->text); 788 optschanged(); 789 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 790 unsetvar(vp->text); 791 } else { 792 if ((vp->flags & VTEXTFIXED) == 0) 793 ckfree(vp->text); 794 vp->flags = lvp->flags; 795 vp->text = lvp->text; 796 } 797 ckfree(lvp); 798 } 799 } 800 801 802 int 803 setvarcmd(int argc, char **argv) 804 { 805 if (argc <= 2) 806 return unsetcmd(argc, argv); 807 else if (argc == 3) 808 setvar(argv[1], argv[2], 0); 809 else 810 error("too many arguments"); 811 return 0; 812 } 813 814 815 /* 816 * The unset builtin command. 817 */ 818 819 int 820 unsetcmd(int argc __unused, char **argv __unused) 821 { 822 char **ap; 823 int i; 824 int flg_func = 0; 825 int flg_var = 0; 826 int ret = 0; 827 828 while ((i = nextopt("vf")) != '\0') { 829 if (i == 'f') 830 flg_func = 1; 831 else 832 flg_var = 1; 833 } 834 if (flg_func == 0 && flg_var == 0) 835 flg_var = 1; 836 837 for (ap = argptr; *ap ; ap++) { 838 if (flg_func) 839 ret |= unsetfunc(*ap); 840 if (flg_var) 841 ret |= unsetvar(*ap); 842 } 843 return ret; 844 } 845 846 847 /* 848 * Unset the specified variable. 849 */ 850 851 int 852 unsetvar(const char *s) 853 { 854 struct var **vpp; 855 struct var *vp; 856 857 vpp = hashvar(s); 858 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 859 if (varequal(vp->text, s)) { 860 if (vp->flags & VREADONLY) 861 return (1); 862 INTOFF; 863 if (*(strchr(vp->text, '=') + 1) != '\0') 864 setvar(s, nullstr, 0); 865 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 866 change_env(__DECONST(char *, s), 0); 867 setlocale(LC_ALL, ""); 868 updatecharset(); 869 } 870 vp->flags &= ~VEXPORT; 871 vp->flags |= VUNSET; 872 if ((vp->flags & VSTRFIXED) == 0) { 873 if ((vp->flags & VTEXTFIXED) == 0) 874 ckfree(vp->text); 875 *vpp = vp->next; 876 ckfree(vp); 877 } 878 INTON; 879 return (0); 880 } 881 } 882 return (0); 883 } 884 885 886 887 /* 888 * Find the appropriate entry in the hash table from the name. 889 */ 890 891 static struct var ** 892 hashvar(const char *p) 893 { 894 unsigned int hashval; 895 896 hashval = ((unsigned char) *p) << 4; 897 while (*p && *p != '=') 898 hashval += (unsigned char) *p++; 899 return &vartab[hashval % VTABSIZE]; 900 } 901 902 903 904 /* 905 * Returns true if the two strings specify the same varable. The first 906 * variable name is terminated by '='; the second may be terminated by 907 * either '=' or '\0'. 908 */ 909 910 static int 911 varequal(const char *p, const char *q) 912 { 913 while (*p == *q++) { 914 if (*p++ == '=') 915 return 1; 916 } 917 if (*p == '=' && *(q - 1) == '\0') 918 return 1; 919 return 0; 920 } 921