bin/sh/var.c

   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 1.15.2.2 2002/08/27 01:36:28 tjr Exp $
  38  * $DragonFly: src/bin/sh/var.c,v 1.15 2007/01/14 17:29:58 pavalos Exp $
  39  */
  40
  41 #include <unistd.h>
  42 #include <stdlib.h>
  43
  44 /*
  45  * Shell variables.
  46  */
  47
  48 #include <locale.h>
  49
  50 #include "shell.h"
  51 #include "output.h"
  52 #include "expand.h"
  53 #include "nodes.h"      /* for other headers */
  54 #include "eval.h"       /* defines cmdenviron */
  55 #include "exec.h"
  56 #include "syntax.h"
  57 #include "options.h"
  58 #include "mail.h"
  59 #include "var.h"
  60 #include "memalloc.h"
  61 #include "error.h"
  62 #include "mystring.h"
  63 #include "parser.h"
  64 #ifndef NO_HISTORY
  65 #include "myhistedit.h"
  66 #endif
  67
  68
  69 #define VTABSIZE 39
  70
  71
  72 struct varinit {
  73         struct var *var;
  74         int flags;
  75         const char *text;
  76         void (*func)(const char *);
  77 };
  78
  79
  80 #ifndef NO_HISTORY
  81 struct var vhistsize;
  82 #endif
  83 struct var vifs;
  84 struct var vmail;
  85 struct var vmpath;
  86 struct var vpath;
  87 struct var vppid;
  88 struct var vps1;
  89 struct var vps2;
  90 struct var vps4;
  91 struct var vvers;
  92 STATIC struct var voptind;
  93
  94 STATIC const struct varinit varinit[] = {
  95 #ifndef NO_HISTORY
  96         { &vhistsize,   VSTRFIXED|VTEXTFIXED|VUNSET,    "HISTSIZE=",
  97           sethistsize },
  98 #endif
  99         { &vifs,        VSTRFIXED|VTEXTFIXED,           "IFS= \t\n",
 100           NULL },
 101         { &vmail,       VSTRFIXED|VTEXTFIXED|VUNSET,    "MAIL=",
 102           NULL },
 103         { &vmpath,      VSTRFIXED|VTEXTFIXED|VUNSET,    "MAILPATH=",
 104           NULL },
 105         { &vpath,       VSTRFIXED|VTEXTFIXED,           "PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/pkg/bin:/usr/pkg/sbin",
 106           changepath },
 107         { &vppid,       VSTRFIXED|VTEXTFIXED|VUNSET,    "PPID=",
 108           NULL },
 109         /*
 110          * vps1 depends on uid
 111          */
 112         { &vps2,        VSTRFIXED|VTEXTFIXED,           "PS2=> ",
 113           NULL },
 114         { &vps4,        VSTRFIXED|VTEXTFIXED,           "PS4=+ ",
 115           NULL },
 116         { &voptind,     VSTRFIXED|VTEXTFIXED,           "OPTIND=1",
 117           getoptsreset },
 118         { NULL, 0,                              NULL,
 119           NULL }
 120 };
 121
 122 STATIC struct var *vartab[VTABSIZE];
 123
 124 STATIC struct var **hashvar(const char *);
 125 STATIC int varequal(const char *, const char *);
 126 STATIC int localevar(const char *);
 127
 128 /*
 129  * Initialize the variable symbol tables and import the environment.
 130  */
 131
 132 #ifdef mkinit
 133 INCLUDE "var.h"
 134 MKINIT char **environ;
 135 INIT {
 136         char **envp;
 137
 138         initvar();
 139         for (envp = environ ; *envp ; envp++) {
 140                 if (strchr(*envp, '=')) {
 141                         setvareq(*envp, VEXPORT|VTEXTFIXED);
 142                 }
 143         }
 144 }
 145 #endif
 146
 147
 148 /*
 149  * This routine initializes the builtin variables.  It is called when the
 150  * shell is initialized and again when a shell procedure is spawned.
 151  */
 152
 153 void
 154 initvar(void)
 155 {
 156         char ppid[20];
 157         const struct varinit *ip;
 158         struct var *vp;
 159         struct var **vpp;
 160
 161         for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
 162                 if ((vp->flags & VEXPORT) == 0) {
 163                         vpp = hashvar(ip->text);
 164                         vp->next = *vpp;
 165                         *vpp = vp;
 166                         vp->text = strdup(ip->text);
 167                         vp->flags = ip->flags;
 168                         vp->func = ip->func;
 169                 }
 170         }
 171         /*
 172          * PS1 depends on uid
 173          */
 174         if ((vps1.flags & VEXPORT) == 0) {
 175                 vpp = hashvar("PS1=");
 176                 vps1.next = *vpp;
 177                 *vpp = &vps1;
 178                 vps1.text = strdup(geteuid() ? "PS1=$ " : "PS1=# ");
 179                 vps1.flags = VSTRFIXED|VTEXTFIXED;
 180         }
 181         if ((vppid.flags & VEXPORT) == 0) {
 182                 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
 183                 setvarsafe("PPID", ppid, 0);
 184         }
 185 }
 186
 187 /*
 188  * Safe version of setvar, returns 1 on success 0 on failure.
 189  */
 190
 191 int
 192 setvarsafe(const char *name, const char *val, int flags)
 193 {
 194         struct jmploc jmploc;
 195         struct jmploc *volatile savehandler = handler;
 196         int err = 0;
 197
 198         if (setjmp(jmploc.loc))
 199                 err = 1;
 200         else {
 201                 handler = &jmploc;
 202                 setvar(name, val, flags);
 203         }
 204         handler = savehandler;
 205         return err;
 206 }
 207
 208 /*
 209  * Set the value of a variable.  The flags argument is stored with the
 210  * flags of the variable.  If val is NULL, the variable is unset.
 211  */
 212
 213 void
 214 setvar(const char *name, const char *val, int flags)
 215 {
 216         const char *cp;
 217         char *p;
 218         int len;
 219         int namelen;
 220         char *nameeq;
 221         int isbad;
 222
 223         isbad = 0;
 224         cp = name;
 225         if (!is_name(*cp))
 226                 isbad = 1;
 227         cp++;
 228         for (;;) {
 229                 if (!is_in_name(*cp)) {
 230                         if (*cp == '\0' || *cp == '=')
 231                                 break;
 232                         isbad = 1;
 233                 }
 234                 cp++;
 235         }
 236         namelen = cp - name;
 237         if (isbad)
 238                 error("%.*s: bad variable name", namelen, name);
 239         len = namelen + 2;              /* 2 is space for '=' and '\0' */
 240         if (val == NULL) {
 241                 flags |= VUNSET;
 242         } else {
 243                 len += strlen(val);
 244         }
 245         p = nameeq = ckmalloc(len);
 246         cp = name;
 247         while (--namelen >= 0)
 248                 *p++ = *cp++;
 249         *p++ = '=';
 250         *p = '\0';
 251         if (val)
 252                 scopy(val, p);
 253         setvareq(nameeq, flags);
 254 }
 255
 256 STATIC int
 257 localevar(const char *s)
 258 {
 259         static const char * const lnames[7] = {
 260                 "ALL", "COLLATE", "CTYPE", "MONETARY",
 261                 "NUMERIC", "TIME", NULL
 262         };
 263         const char * const *ss;
 264
 265         if (*s != 'L')
 266                 return 0;
 267         if (varequal(s + 1, "ANG"))
 268                 return 1;
 269         if (strncmp(s + 1, "C_", 2) != 0)
 270                 return 0;
 271         for (ss = lnames; *ss ; ss++)
 272                 if (varequal(s + 3, *ss))
 273                         return 1;
 274         return 0;
 275 }
 276
 277 /*
 278  * Same as setvar except that the variable and value are passed in
 279  * the first argument as name=value.  Since the first argument will
 280  * be actually stored in the table, it should not be a string that
 281  * will go away.
 282  */
 283
 284 void
 285 setvareq(char *s, int flags)
 286 {
 287         struct var *vp, **vpp;
 288         int len;
 289
 290         if (aflag)
 291                 flags |= VEXPORT;
 292         vpp = hashvar(s);
 293         for (vp = *vpp ; vp ; vp = vp->next) {
 294                 if (varequal(s, vp->text)) {
 295                         if (vp->flags & VREADONLY) {
 296                                 len = strchr(s, '=') - s;
 297                                 error("%.*s: is read only", len, s);
 298                         }
 299                         INTOFF;
 300
 301                         if (vp->func && (flags & VNOFUNC) == 0)
 302                                 (*vp->func)(strchr(s, '=') + 1);
 303
 304                         if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
 305                                 ckfree(vp->text);
 306
 307                         vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
 308                         vp->flags |= flags;
 309                         vp->text = s;
 310
 311                         /*
 312                          * We could roll this to a function, to handle it as
 313                          * a regular variable function callback, but why bother?
 314                          */
 315                         if (vp == &vmpath || (vp == &vmail && ! mpathset()))
 316                                 chkmail(1);
 317                         if ((vp->flags & VEXPORT) && localevar(s)) {
 318                                 if (putenv(s) != 0)
 319                                         error("putenv: cannot set %s", s);
 320                                 setlocale(LC_ALL, "");
 321                         }
 322                         INTON;
 323                         return;
 324                 }
 325         }
 326         /* not found */
 327         vp = ckmalloc(sizeof (*vp));
 328         vp->flags = flags;
 329         vp->text = s;
 330         vp->next = *vpp;
 331         vp->func = NULL;
 332         INTOFF;
 333         *vpp = vp;
 334         if ((vp->flags & VEXPORT) && localevar(s)) {
 335                 if (putenv(s) != 0)
 336                         error("putenv: cannot set %s", s);
 337                 setlocale(LC_ALL, "");
 338         }
 339         INTON;
 340 }
 341
 342
 343
 344 /*
 345  * Process a linked list of variable assignments.
 346  */
 347
 348 void
 349 listsetvar(struct strlist *list)
 350 {
 351         struct strlist *lp;
 352
 353         INTOFF;
 354         for (lp = list ; lp ; lp = lp->next) {
 355                 setvareq(savestr(lp->text), 0);
 356         }
 357         INTON;
 358 }
 359
 360
 361
 362 /*
 363  * Find the value of a variable.  Returns NULL if not set.
 364  */
 365
 366 char *
 367 lookupvar(const char *name)
 368 {
 369         struct var *v;
 370
 371         for (v = *hashvar(name) ; v ; v = v->next) {
 372                 if (varequal(v->text, name)) {
 373                         if (v->flags & VUNSET)
 374                                 return NULL;
 375                         return strchr(v->text, '=') + 1;
 376                 }
 377         }
 378         return NULL;
 379 }
 380
 381
 382
 383 /*
 384  * Search the environment of a builtin command.  If the second argument
 385  * is nonzero, return the value of a variable even if it hasn't been
 386  * exported.
 387  */
 388
 389 char *
 390 bltinlookup(const char *name, int doall)
 391 {
 392         struct strlist *sp;
 393         struct var *v;
 394
 395         for (sp = cmdenviron ; sp ; sp = sp->next) {
 396                 if (varequal(sp->text, name))
 397                         return strchr(sp->text, '=') + 1;
 398         }
 399         for (v = *hashvar(name) ; v ; v = v->next) {
 400                 if (varequal(v->text, name)) {
 401                         if ((v->flags & VUNSET)
 402                          || (!doall && (v->flags & VEXPORT) == 0))
 403                                 return NULL;
 404                         return strchr(v->text, '=') + 1;
 405                 }
 406         }
 407         return NULL;
 408 }
 409
 410
 411
 412 /*
 413  * Generate a list of exported variables.  This routine is used to construct
 414  * the third argument to execve when executing a program.
 415  */
 416
 417 char **
 418 environment(void)
 419 {
 420         int nenv;
 421         struct var **vpp;
 422         struct var *vp;
 423         char **env, **ep;
 424
 425         nenv = 0;
 426         for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 427                 for (vp = *vpp ; vp ; vp = vp->next)
 428                         if (vp->flags & VEXPORT)
 429                                 nenv++;
 430         }
 431         ep = env = stalloc((nenv + 1) * sizeof *env);
 432         for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 433                 for (vp = *vpp ; vp ; vp = vp->next)
 434                         if (vp->flags & VEXPORT)
 435                                 *ep++ = vp->text;
 436         }
 437         *ep = NULL;
 438         return env;
 439 }
 440
 441
 442 /*
 443  * Called when a shell procedure is invoked to clear out nonexported
 444  * variables.  It is also necessary to reallocate variables of with
 445  * VSTACK set since these are currently allocated on the stack.
 446  */
 447
 448 #ifdef mkinit
 449 void shprocvar(void);
 450
 451 SHELLPROC {
 452         shprocvar();
 453 }
 454 #endif
 455
 456 void
 457 shprocvar(void)
 458 {
 459         struct var **vpp;
 460         struct var *vp, **prev;
 461
 462         for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 463                 for (prev = vpp ; (vp = *prev) != NULL ; ) {
 464                         if ((vp->flags & VEXPORT) == 0) {
 465                                 *prev = vp->next;
 466                                 if ((vp->flags & VTEXTFIXED) == 0)
 467                                         ckfree(vp->text);
 468                                 if ((vp->flags & VSTRFIXED) == 0)
 469                                         ckfree(vp);
 470                         } else {
 471                                 if (vp->flags & VSTACK) {
 472                                         vp->text = savestr(vp->text);
 473                                         vp->flags &=~ VSTACK;
 474                                 }
 475                                 prev = &vp->next;
 476                         }
 477                 }
 478         }
 479         initvar();
 480 }
 481
 482
 483 static int
 484 var_compare(const void *a, const void *b)
 485 {
 486         const char *const *sa, *const *sb;
 487
 488         sa = a;
 489         sb = b;
 490         /*
 491          * This compares two var=value strings which creates a different
 492          * order from what you would probably expect.  POSIX is somewhat
 493          * ambiguous on what should be sorted exactly.
 494          */
 495         return strcoll(*sa, *sb);
 496 }
 497
 498
 499 /*
 500  * Command to list all variables which are set.  Currently this command
 501  * is invoked from the set command when the set command is called without
 502  * any variables.
 503  */
 504
 505 int
 506 showvarscmd(int argc __unused, char **argv __unused)
 507 {
 508         struct var **vpp;
 509         struct var *vp;
 510         const char *s;
 511         const char **vars;
 512         int i, n;
 513
 514         /*
 515          * POSIX requires us to sort the variables.
 516          */
 517         n = 0;
 518         for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) {
 519                 for (vp = *vpp; vp; vp = vp->next) {
 520                         if (!(vp->flags & VUNSET))
 521                                 n++;
 522                 }
 523         }
 524
 525         INTON;
 526         vars = ckmalloc(n * sizeof(*vars));
 527         i = 0;
 528         for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) {
 529                 for (vp = *vpp; vp; vp = vp->next) {
 530                         if (!(vp->flags & VUNSET))
 531                                 vars[i++] = vp->text;
 532                 }
 533         }
 534
 535         qsort(vars, n, sizeof(*vars), var_compare);
 536         for (i = 0; i < n; i++) {
 537                 for (s = vars[i]; *s != '='; s++)
 538                         out1c(*s);
 539                 out1c('=');
 540                 out1qstr(s + 1);
 541                 out1c('\n');
 542         }
 543         ckfree(vars);
 544         INTOFF;
 545
 546         return 0;
 547 }
 548
 549
 550
 551 /*
 552  * The export and readonly commands.
 553  */
 554
 555 int
 556 exportcmd(int argc, char **argv)
 557 {
 558         struct var **vpp;
 559         struct var *vp;
 560         char *name;
 561         char *p;
 562         char *cmdname;
 563         int ch, values;
 564         int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
 565
 566         cmdname = argv[0];
 567         optreset = optind = 1;
 568         opterr = 0;
 569         values = 0;
 570         while ((ch = getopt(argc, argv, "p")) != -1) {
 571                 switch (ch) {
 572                 case 'p':
 573                         values = 1;
 574                         break;
 575                 case '?':
 576                 default:
 577                         error("unknown option: -%c", optopt);
 578                 }
 579         }
 580         argc -= optind;
 581         argv += optind;
 582
 583         if (values && argc != 0)
 584                 error("-p requires no arguments");
 585         listsetvar(cmdenviron);
 586         if (argc != 0) {
 587                 while ((name = *argv++) != NULL) {
 588                         if ((p = strchr(name, '=')) != NULL) {
 589                                 p++;
 590                         } else {
 591                                 vpp = hashvar(name);
 592                                 for (vp = *vpp ; vp ; vp = vp->next) {
 593                                         if (varequal(vp->text, name)) {
 594
 595                                                 vp->flags |= flag;
 596                                                 if ((vp->flags & VEXPORT) && localevar(vp->text)) {
 597                                                         if (putenv(vp->text) != 0)
 598                                                                 error("putenv: cannot set %s", vp->text);
 599                                                         setlocale(LC_ALL, "");
 600                                                 }
 601                                                 goto found;
 602                                         }
 603                                 }
 604                         }
 605                         setvar(name, p, flag);
 606 found:;
 607                 }
 608         } else {
 609                 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 610                         for (vp = *vpp ; vp ; vp = vp->next) {
 611                                 if (vp->flags & flag) {
 612                                         if (values) {
 613                                                 out1str(cmdname);
 614                                                 out1c(' ');
 615                                         }
 616                                         for (p = vp->text ; *p != '=' ; p++)
 617                                                 out1c(*p);
 618                                         if (values && !(vp->flags & VUNSET)) {
 619                                                 out1c('=');
 620                                                 out1qstr(p + 1);
 621                                         }
 622                                         out1c('\n');
 623                                 }
 624                         }
 625                 }
 626         }
 627         return 0;
 628 }
 629
 630
 631 /*
 632  * The "local" command.
 633  */
 634
 635 int
 636 localcmd(int argc __unused, char **argv __unused)
 637 {
 638         char *name;
 639
 640         if (! in_function())
 641                 error("Not in a function");
 642         while ((name = *argptr++) != NULL) {
 643                 mklocal(name);
 644         }
 645         return 0;
 646 }
 647
 648
 649 /*
 650  * Make a variable a local variable.  When a variable is made local, it's
 651  * value and flags are saved in a localvar structure.  The saved values
 652  * will be restored when the shell function returns.  We handle the name
 653  * "-" as a special case.
 654  */
 655
 656 void
 657 mklocal(char *name)
 658 {
 659         struct localvar *lvp;
 660         struct var **vpp;
 661         struct var *vp;
 662
 663         INTOFF;
 664         lvp = ckmalloc(sizeof (struct localvar));
 665         if (name[0] == '-' && name[1] == '\0') {
 666                 lvp->text = ckmalloc(sizeof optlist);
 667                 memcpy(lvp->text, optlist, sizeof optlist);
 668                 vp = NULL;
 669         } else {
 670                 vpp = hashvar(name);
 671                 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
 672                 if (vp == NULL) {
 673                         if (strchr(name, '='))
 674                                 setvareq(savestr(name), VSTRFIXED);
 675                         else
 676                                 setvar(name, NULL, VSTRFIXED);
 677                         vp = *vpp;      /* the new variable */
 678                         lvp->text = NULL;
 679                         lvp->flags = VUNSET;
 680                 } else {
 681                         lvp->text = vp->text;
 682                         lvp->flags = vp->flags;
 683                         vp->flags |= VSTRFIXED|VTEXTFIXED;
 684                         if (strchr(name, '='))
 685                                 setvareq(savestr(name), 0);
 686                 }
 687         }
 688         lvp->vp = vp;
 689         lvp->next = localvars;
 690         localvars = lvp;
 691         INTON;
 692 }
 693
 694
 695 /*
 696  * Called after a function returns.
 697  */
 698
 699 void
 700 poplocalvars(void)
 701 {
 702         struct localvar *lvp;
 703         struct var *vp;
 704
 705         while ((lvp = localvars) != NULL) {
 706                 localvars = lvp->next;
 707                 vp = lvp->vp;
 708                 if (vp == NULL) {       /* $- saved */
 709                         memcpy(optlist, lvp->text, sizeof optlist);
 710                         ckfree(lvp->text);
 711                 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
 712                         unsetvar(vp->text);
 713                 } else {
 714                         if ((vp->flags & VTEXTFIXED) == 0)
 715                                 ckfree(vp->text);
 716                         vp->flags = lvp->flags;
 717                         vp->text = lvp->text;
 718                 }
 719                 ckfree(lvp);
 720         }
 721 }
 722
 723
 724 int
 725 setvarcmd(int argc, char **argv)
 726 {
 727         if (argc <= 2)
 728                 return unsetcmd(argc, argv);
 729         else if (argc == 3)
 730                 setvar(argv[1], argv[2], 0);
 731         else
 732                 error("List assignment not implemented");
 733         return 0;
 734 }
 735
 736
 737 /*
 738  * The unset builtin command.  We unset the function before we unset the
 739  * variable to allow a function to be unset when there is a readonly variable
 740  * with the same name.
 741  */
 742
 743 int
 744 unsetcmd(int argc __unused, char **argv __unused)
 745 {
 746         char **ap;
 747         int i;
 748         int flg_func = 0;
 749         int flg_var = 0;
 750         int ret = 0;
 751
 752         while ((i = nextopt("vf")) != '\0') {
 753                 if (i == 'f')
 754                         flg_func = 1;
 755                 else
 756                         flg_var = 1;
 757         }
 758         if (flg_func == 0 && flg_var == 0)
 759                 flg_var = 1;
 760
 761         for (ap = argptr; *ap ; ap++) {
 762                 if (flg_func)
 763                         ret |= unsetfunc(*ap);
 764                 if (flg_var)
 765                         ret |= unsetvar(*ap);
 766         }
 767         return ret;
 768 }
 769
 770
 771 /*
 772  * Unset the specified variable.
 773  */
 774
 775 int
 776 unsetvar(const char *s)
 777 {
 778         struct var **vpp;
 779         struct var *vp;
 780
 781         vpp = hashvar(s);
 782         for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
 783                 if (varequal(vp->text, s)) {
 784                         if (vp->flags & VREADONLY)
 785                                 return (1);
 786                         INTOFF;
 787                         if (*(strchr(vp->text, '=') + 1) != '\0')
 788                                 setvar(s, nullstr, 0);
 789                         if ((vp->flags & VEXPORT) && localevar(vp->text)) {
 790                                 unsetenv(s);
 791                                 setlocale(LC_ALL, "");
 792                         }
 793                         vp->flags &= ~VEXPORT;
 794                         vp->flags |= VUNSET;
 795                         if ((vp->flags & VSTRFIXED) == 0) {
 796                                 if ((vp->flags & VTEXTFIXED) == 0)
 797                                         ckfree(vp->text);
 798                                 *vpp = vp->next;
 799                                 ckfree(vp);
 800                         }
 801                         INTON;
 802                         return (0);
 803                 }
 804         }
 805         return (0);
 806 }
 807
 808
 809
 810 /*
 811  * Find the appropriate entry in the hash table from the name.
 812  */
 813
 814 STATIC struct var **
 815 hashvar(const char *p)
 816 {
 817         unsigned int hashval;
 818
 819         hashval = ((unsigned char) *p) << 4;
 820         while (*p && *p != '=')
 821                 hashval += (unsigned char) *p++;
 822         return &vartab[hashval % VTABSIZE];
 823 }
 824
 825
 826
 827 /*
 828  * Returns true if the two strings specify the same varable.  The first
 829  * variable name is terminated by '='; the second may be terminated by
 830  * either '=' or '\0'.
 831  */
 832
 833 STATIC int
 834 varequal(const char *p, const char *q)
 835 {
 836         while (*p == *q++) {
 837                 if (*p++ == '=')
 838                         return 1;
 839         }
 840         if (*p == '=' && *(q - 1) == '\0')
 841                 return 1;
 842         return 0;
 843 }