var.c revision 221668
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 35static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95"; 36#endif 37#endif /* not lint */ 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: head/bin/sh/var.c 221668 2011-05-08 16:15:50Z jilles $"); 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#ifndef NO_HISTORY 67#include "myhistedit.h" 68#endif 69 70 71#define VTABSIZE 39 72 73 74struct varinit { 75 struct var *var; 76 int flags; 77 const char *text; 78 void (*func)(const char *); 79}; 80 81 82#ifndef NO_HISTORY 83struct var vhistsize; 84struct var vterm; 85#endif 86struct var vifs; 87struct var vmail; 88struct var vmpath; 89struct var vpath; 90struct var vppid; 91struct var vps1; 92struct var vps2; 93struct var vps4; 94struct var vvers; 95static struct var voptind; 96 97static const struct varinit varinit[] = { 98#ifndef NO_HISTORY 99 { &vhistsize, VUNSET, "HISTSIZE=", 100 sethistsize }, 101#endif 102 { &vifs, 0, "IFS= \t\n", 103 NULL }, 104 { &vmail, VUNSET, "MAIL=", 105 NULL }, 106 { &vmpath, VUNSET, "MAILPATH=", 107 NULL }, 108 { &vpath, 0, "PATH=" _PATH_DEFPATH, 109 changepath }, 110 { &vppid, VUNSET, "PPID=", 111 NULL }, 112 /* 113 * vps1 depends on uid 114 */ 115 { &vps2, 0, "PS2=> ", 116 NULL }, 117 { &vps4, 0, "PS4=+ ", 118 NULL }, 119#ifndef NO_HISTORY 120 { &vterm, VUNSET, "TERM=", 121 setterm }, 122#endif 123 { &voptind, 0, "OPTIND=1", 124 getoptsreset }, 125 { NULL, 0, NULL, 126 NULL } 127}; 128 129static struct var *vartab[VTABSIZE]; 130 131static const char *const locale_names[7] = { 132 "LC_COLLATE", "LC_CTYPE", "LC_MONETARY", 133 "LC_NUMERIC", "LC_TIME", "LC_MESSAGES", NULL 134}; 135static const int locale_categories[7] = { 136 LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME, LC_MESSAGES, 0 137}; 138 139static int varequal(const char *, const char *); 140static struct var *find_var(const char *, struct var ***, int *); 141static int localevar(const char *); 142 143/* 144 * Initialize the variable symbol tables and import the environment. 145 */ 146 147#ifdef mkinit 148INCLUDE "var.h" 149MKINIT char **environ; 150INIT { 151 char **envp; 152 153 initvar(); 154 for (envp = environ ; *envp ; envp++) { 155 if (strchr(*envp, '=')) { 156 setvareq(*envp, VEXPORT|VTEXTFIXED); 157 } 158 } 159} 160#endif 161 162 163/* 164 * This routine initializes the builtin variables. It is called when the 165 * shell is initialized. 166 */ 167 168void 169initvar(void) 170{ 171 char ppid[20]; 172 const struct varinit *ip; 173 struct var *vp; 174 struct var **vpp; 175 176 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { 177 if (find_var(ip->text, &vpp, &vp->name_len) != NULL) 178 continue; 179 vp->next = *vpp; 180 *vpp = vp; 181 vp->text = __DECONST(char *, ip->text); 182 vp->flags = ip->flags | VSTRFIXED | VTEXTFIXED; 183 vp->func = ip->func; 184 } 185 /* 186 * PS1 depends on uid 187 */ 188 if (find_var("PS1", &vpp, &vps1.name_len) == NULL) { 189 vps1.next = *vpp; 190 *vpp = &vps1; 191 vps1.text = __DECONST(char *, geteuid() ? "PS1=$ " : "PS1=# "); 192 vps1.flags = VSTRFIXED|VTEXTFIXED; 193 } 194 if ((vppid.flags & VEXPORT) == 0) { 195 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid()); 196 setvarsafe("PPID", ppid, 0); 197 } 198} 199 200/* 201 * Safe version of setvar, returns 1 on success 0 on failure. 202 */ 203 204int 205setvarsafe(const char *name, const char *val, int flags) 206{ 207 struct jmploc jmploc; 208 struct jmploc *const savehandler = handler; 209 int err = 0; 210 int inton; 211 212 inton = is_int_on(); 213 if (setjmp(jmploc.loc)) 214 err = 1; 215 else { 216 handler = &jmploc; 217 setvar(name, val, flags); 218 } 219 handler = savehandler; 220 SETINTON(inton); 221 return err; 222} 223 224/* 225 * Set the value of a variable. The flags argument is stored with the 226 * flags of the variable. If val is NULL, the variable is unset. 227 */ 228 229void 230setvar(const char *name, const char *val, int flags) 231{ 232 const char *p; 233 int len; 234 int namelen; 235 char *nameeq; 236 int isbad; 237 238 isbad = 0; 239 p = name; 240 if (! is_name(*p)) 241 isbad = 1; 242 p++; 243 for (;;) { 244 if (! is_in_name(*p)) { 245 if (*p == '\0' || *p == '=') 246 break; 247 isbad = 1; 248 } 249 p++; 250 } 251 namelen = p - name; 252 if (isbad) 253 error("%.*s: bad variable name", namelen, name); 254 len = namelen + 2; /* 2 is space for '=' and '\0' */ 255 if (val == NULL) { 256 flags |= VUNSET; 257 } else { 258 len += strlen(val); 259 } 260 nameeq = ckmalloc(len); 261 memcpy(nameeq, name, namelen); 262 nameeq[namelen] = '='; 263 if (val) 264 scopy(val, nameeq + namelen + 1); 265 else 266 nameeq[namelen + 1] = '\0'; 267 setvareq(nameeq, flags); 268} 269 270static int 271localevar(const char *s) 272{ 273 const char *const *ss; 274 275 if (*s != 'L') 276 return 0; 277 if (varequal(s + 1, "ANG")) 278 return 1; 279 if (strncmp(s + 1, "C_", 2) != 0) 280 return 0; 281 if (varequal(s + 3, "ALL")) 282 return 1; 283 for (ss = locale_names; *ss ; ss++) 284 if (varequal(s + 3, *ss + 3)) 285 return 1; 286 return 0; 287} 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 */ 294static void 295change_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 (void) setenv(ss, eqp + 1, 1); 305 else 306 (void) unsetenv(ss); 307 ckfree(ss); 308 309 return; 310} 311 312 313/* 314 * Same as setvar except that the variable and value are passed in 315 * the first argument as name=value. Since the first argument will 316 * be actually stored in the table, it should not be a string that 317 * will go away. 318 */ 319 320void 321setvareq(char *s, int flags) 322{ 323 struct var *vp, **vpp; 324 int nlen; 325 326 if (aflag) 327 flags |= VEXPORT; 328 vp = find_var(s, &vpp, &nlen); 329 if (vp != NULL) { 330 if (vp->flags & VREADONLY) 331 error("%.*s: is read only", vp->name_len, s); 332 if (flags & VNOSET) 333 return; 334 INTOFF; 335 336 if (vp->func && (flags & VNOFUNC) == 0) 337 (*vp->func)(s + vp->name_len + 1); 338 339 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) 340 ckfree(vp->text); 341 342 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET); 343 vp->flags |= flags; 344 vp->text = s; 345 346 /* 347 * We could roll this to a function, to handle it as 348 * a regular variable function callback, but why bother? 349 * 350 * Note: this assumes iflag is not set to 1 initially. 351 * As part of init(), this is called before arguments 352 * are looked at. 353 */ 354 if ((vp == &vmpath || (vp == &vmail && ! mpathset())) && 355 iflag == 1) 356 chkmail(1); 357 if ((vp->flags & VEXPORT) && localevar(s)) { 358 change_env(s, 1); 359 (void) setlocale(LC_ALL, ""); 360 updatecharset(); 361 } 362 INTON; 363 return; 364 } 365 /* not found */ 366 if (flags & VNOSET) 367 return; 368 vp = ckmalloc(sizeof (*vp)); 369 vp->flags = flags; 370 vp->text = s; 371 vp->name_len = nlen; 372 vp->next = *vpp; 373 vp->func = NULL; 374 INTOFF; 375 *vpp = vp; 376 if ((vp->flags & VEXPORT) && localevar(s)) { 377 change_env(s, 1); 378 (void) setlocale(LC_ALL, ""); 379 updatecharset(); 380 } 381 INTON; 382} 383 384 385 386/* 387 * Process a linked list of variable assignments. 388 */ 389 390void 391listsetvar(struct strlist *list, int flags) 392{ 393 struct strlist *lp; 394 395 INTOFF; 396 for (lp = list ; lp ; lp = lp->next) { 397 setvareq(savestr(lp->text), flags); 398 } 399 INTON; 400} 401 402 403 404/* 405 * Find the value of a variable. Returns NULL if not set. 406 */ 407 408char * 409lookupvar(const char *name) 410{ 411 struct var *v; 412 413 v = find_var(name, NULL, NULL); 414 if (v == NULL || v->flags & VUNSET) 415 return NULL; 416 return v->text + v->name_len + 1; 417} 418 419 420 421/* 422 * Search the environment of a builtin command. If the second argument 423 * is nonzero, return the value of a variable even if it hasn't been 424 * exported. 425 */ 426 427char * 428bltinlookup(const char *name, int doall) 429{ 430 struct strlist *sp; 431 struct var *v; 432 char *result; 433 434 result = NULL; 435 for (sp = cmdenviron ; sp ; sp = sp->next) { 436 if (varequal(sp->text, name)) 437 result = strchr(sp->text, '=') + 1; 438 } 439 if (result != NULL) 440 return result; 441 442 v = find_var(name, NULL, NULL); 443 if (v == NULL || v->flags & VUNSET || 444 (!doall && (v->flags & VEXPORT) == 0)) 445 return NULL; 446 return v->text + v->name_len + 1; 447} 448 449 450/* 451 * Set up locale for a builtin (LANG/LC_* assignments). 452 */ 453void 454bltinsetlocale(void) 455{ 456 struct strlist *lp; 457 int act = 0; 458 char *loc, *locdef; 459 int i; 460 461 for (lp = cmdenviron ; lp ; lp = lp->next) { 462 if (localevar(lp->text)) { 463 act = 1; 464 break; 465 } 466 } 467 if (!act) 468 return; 469 loc = bltinlookup("LC_ALL", 0); 470 INTOFF; 471 if (loc != NULL) { 472 setlocale(LC_ALL, loc); 473 INTON; 474 updatecharset(); 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 updatecharset(); 487} 488 489/* 490 * Undo the effect of bltinlocaleset(). 491 */ 492void 493bltinunsetlocale(void) 494{ 495 struct strlist *lp; 496 497 INTOFF; 498 for (lp = cmdenviron ; lp ; lp = lp->next) { 499 if (localevar(lp->text)) { 500 setlocale(LC_ALL, ""); 501 updatecharset(); 502 return; 503 } 504 } 505 INTON; 506} 507 508/* 509 * Update the localeisutf8 flag. 510 */ 511void 512updatecharset(void) 513{ 514 char *charset; 515 516 charset = nl_langinfo(CODESET); 517 localeisutf8 = !strcmp(charset, "UTF-8"); 518} 519 520/* 521 * Generate a list of exported variables. This routine is used to construct 522 * the third argument to execve when executing a program. 523 */ 524 525char ** 526environment(void) 527{ 528 int nenv; 529 struct var **vpp; 530 struct var *vp; 531 char **env, **ep; 532 533 nenv = 0; 534 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 535 for (vp = *vpp ; vp ; vp = vp->next) 536 if (vp->flags & VEXPORT) 537 nenv++; 538 } 539 ep = env = stalloc((nenv + 1) * sizeof *env); 540 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 541 for (vp = *vpp ; vp ; vp = vp->next) 542 if (vp->flags & VEXPORT) 543 *ep++ = vp->text; 544 } 545 *ep = NULL; 546 return env; 547} 548 549 550static int 551var_compare(const void *a, const void *b) 552{ 553 const char *const *sa, *const *sb; 554 555 sa = a; 556 sb = b; 557 /* 558 * This compares two var=value strings which creates a different 559 * order from what you would probably expect. POSIX is somewhat 560 * ambiguous on what should be sorted exactly. 561 */ 562 return strcoll(*sa, *sb); 563} 564 565 566/* 567 * Command to list all variables which are set. This is invoked from the 568 * set command when it is called without any options or operands. 569 */ 570 571int 572showvarscmd(int argc __unused, char **argv __unused) 573{ 574 struct var **vpp; 575 struct var *vp; 576 const char *s; 577 const char **vars; 578 int i, n; 579 580 /* 581 * POSIX requires us to sort the variables. 582 */ 583 n = 0; 584 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 585 for (vp = *vpp; vp; vp = vp->next) { 586 if (!(vp->flags & VUNSET)) 587 n++; 588 } 589 } 590 591 INTON; 592 vars = ckmalloc(n * sizeof(*vars)); 593 i = 0; 594 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 595 for (vp = *vpp; vp; vp = vp->next) { 596 if (!(vp->flags & VUNSET)) 597 vars[i++] = vp->text; 598 } 599 } 600 601 qsort(vars, n, sizeof(*vars), var_compare); 602 for (i = 0; i < n; i++) { 603 s = strchr(vars[i], '='); 604 s++; 605 outbin(vars[i], s - vars[i], out1); 606 out1qstr(s); 607 out1c('\n'); 608 } 609 ckfree(vars); 610 INTOFF; 611 612 return 0; 613} 614 615 616 617/* 618 * The export and readonly commands. 619 */ 620 621int 622exportcmd(int argc, char **argv) 623{ 624 struct var **vpp; 625 struct var *vp; 626 char *name; 627 char *p; 628 char *cmdname; 629 int ch, values; 630 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 631 632 cmdname = argv[0]; 633 optreset = optind = 1; 634 opterr = 0; 635 values = 0; 636 while ((ch = getopt(argc, argv, "p")) != -1) { 637 switch (ch) { 638 case 'p': 639 values = 1; 640 break; 641 case '?': 642 default: 643 error("unknown option: -%c", optopt); 644 } 645 } 646 argc -= optind; 647 argv += optind; 648 649 if (values && argc != 0) 650 error("-p requires no arguments"); 651 if (argc != 0) { 652 while ((name = *argv++) != NULL) { 653 if ((p = strchr(name, '=')) != NULL) { 654 p++; 655 } else { 656 vp = find_var(name, NULL, NULL); 657 if (vp != NULL) { 658 vp->flags |= flag; 659 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 660 change_env(vp->text, 1); 661 (void) setlocale(LC_ALL, ""); 662 updatecharset(); 663 } 664 continue; 665 } 666 } 667 setvar(name, p, flag); 668 } 669 } else { 670 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 671 for (vp = *vpp ; vp ; vp = vp->next) { 672 if (vp->flags & flag) { 673 if (values) { 674 out1str(cmdname); 675 out1c(' '); 676 } 677 p = strchr(vp->text, '='); 678 if (values && !(vp->flags & VUNSET)) { 679 p++; 680 outbin(vp->text, p - vp->text, 681 out1); 682 out1qstr(p); 683 } else 684 outbin(vp->text, p - vp->text, 685 out1); 686 out1c('\n'); 687 } 688 } 689 } 690 } 691 return 0; 692} 693 694 695/* 696 * The "local" command. 697 */ 698 699int 700localcmd(int argc __unused, char **argv __unused) 701{ 702 char *name; 703 704 if (! in_function()) 705 error("Not in a function"); 706 while ((name = *argptr++) != NULL) { 707 mklocal(name); 708 } 709 return 0; 710} 711 712 713/* 714 * Make a variable a local variable. When a variable is made local, it's 715 * value and flags are saved in a localvar structure. The saved values 716 * will be restored when the shell function returns. We handle the name 717 * "-" as a special case. 718 */ 719 720void 721mklocal(char *name) 722{ 723 struct localvar *lvp; 724 struct var **vpp; 725 struct var *vp; 726 727 INTOFF; 728 lvp = ckmalloc(sizeof (struct localvar)); 729 if (name[0] == '-' && name[1] == '\0') { 730 lvp->text = ckmalloc(sizeof optlist); 731 memcpy(lvp->text, optlist, sizeof optlist); 732 vp = NULL; 733 } else { 734 vp = find_var(name, &vpp, NULL); 735 if (vp == NULL) { 736 if (strchr(name, '=')) 737 setvareq(savestr(name), VSTRFIXED); 738 else 739 setvar(name, NULL, VSTRFIXED); 740 vp = *vpp; /* the new variable */ 741 lvp->text = NULL; 742 lvp->flags = VUNSET; 743 } else { 744 lvp->text = vp->text; 745 lvp->flags = vp->flags; 746 vp->flags |= VSTRFIXED|VTEXTFIXED; 747 if (name[vp->name_len] == '=') 748 setvareq(savestr(name), 0); 749 } 750 } 751 lvp->vp = vp; 752 lvp->next = localvars; 753 localvars = lvp; 754 INTON; 755} 756 757 758/* 759 * Called after a function returns. 760 */ 761 762void 763poplocalvars(void) 764{ 765 struct localvar *lvp; 766 struct var *vp; 767 768 while ((lvp = localvars) != NULL) { 769 localvars = lvp->next; 770 vp = lvp->vp; 771 if (vp == NULL) { /* $- saved */ 772 memcpy(optlist, lvp->text, sizeof optlist); 773 ckfree(lvp->text); 774 optschanged(); 775 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 776 (void)unsetvar(vp->text); 777 } else { 778 if ((vp->flags & VTEXTFIXED) == 0) 779 ckfree(vp->text); 780 vp->flags = lvp->flags; 781 vp->text = lvp->text; 782 } 783 ckfree(lvp); 784 } 785} 786 787 788int 789setvarcmd(int argc, char **argv) 790{ 791 if (argc <= 2) 792 return unsetcmd(argc, argv); 793 else if (argc == 3) 794 setvar(argv[1], argv[2], 0); 795 else 796 error("too many arguments"); 797 return 0; 798} 799 800 801/* 802 * The unset builtin command. 803 */ 804 805int 806unsetcmd(int argc __unused, char **argv __unused) 807{ 808 char **ap; 809 int i; 810 int flg_func = 0; 811 int flg_var = 0; 812 int ret = 0; 813 814 while ((i = nextopt("vf")) != '\0') { 815 if (i == 'f') 816 flg_func = 1; 817 else 818 flg_var = 1; 819 } 820 if (flg_func == 0 && flg_var == 0) 821 flg_var = 1; 822 823 for (ap = argptr; *ap ; ap++) { 824 if (flg_func) 825 ret |= unsetfunc(*ap); 826 if (flg_var) 827 ret |= unsetvar(*ap); 828 } 829 return ret; 830} 831 832 833/* 834 * Unset the specified variable. 835 */ 836 837int 838unsetvar(const char *s) 839{ 840 struct var **vpp; 841 struct var *vp; 842 843 vp = find_var(s, &vpp, NULL); 844 if (vp == NULL) 845 return (0); 846 if (vp->flags & VREADONLY) 847 return (1); 848 INTOFF; 849 if (vp->text[vp->name_len + 1] != '\0') 850 setvar(s, nullstr, 0); 851 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 852 change_env(s, 0); 853 setlocale(LC_ALL, ""); 854 updatecharset(); 855 } 856 vp->flags &= ~VEXPORT; 857 vp->flags |= VUNSET; 858 if ((vp->flags & VSTRFIXED) == 0) { 859 if ((vp->flags & VTEXTFIXED) == 0) 860 ckfree(vp->text); 861 *vpp = vp->next; 862 ckfree(vp); 863 } 864 INTON; 865 return (0); 866} 867 868 869 870/* 871 * Returns true if the two strings specify the same varable. The first 872 * variable name is terminated by '='; the second may be terminated by 873 * either '=' or '\0'. 874 */ 875 876static int 877varequal(const char *p, const char *q) 878{ 879 while (*p == *q++) { 880 if (*p++ == '=') 881 return 1; 882 } 883 if (*p == '=' && *(q - 1) == '\0') 884 return 1; 885 return 0; 886} 887 888/* 889 * Search for a variable. 890 * 'name' may be terminated by '=' or a NUL. 891 * vppp is set to the pointer to vp, or the list head if vp isn't found 892 * lenp is set to the number of charactets in 'name' 893 */ 894 895static struct var * 896find_var(const char *name, struct var ***vppp, int *lenp) 897{ 898 unsigned int hashval; 899 int len; 900 struct var *vp, **vpp; 901 const char *p = name; 902 903 hashval = 0; 904 while (*p && *p != '=') 905 hashval = 2 * hashval + (unsigned char)*p++; 906 len = p - name; 907 908 if (lenp) 909 *lenp = len; 910 vpp = &vartab[hashval % VTABSIZE]; 911 if (vppp) 912 *vppp = vpp; 913 914 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 915 if (vp->name_len != len) 916 continue; 917 if (memcmp(vp->text, name, len) != 0) 918 continue; 919 if (vppp) 920 *vppp = vpp; 921 return vp; 922 } 923 return NULL; 924} 925