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 1.12 2006/09/28 22:29:44 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 vvers;
  91 STATIC struct var voptind;
  92
  93 STATIC const struct varinit varinit[] = {
  94 #ifndef NO_HISTORY
  95         { &vhistsize,   VSTRFIXED|VTEXTFIXED|VUNSET,    "HISTSIZE=",
  96           sethistsize },
  97 #endif
  98         { &vifs,        VSTRFIXED|VTEXTFIXED,           "IFS= \t\n",
  99           NULL },
 100         { &vmail,       VSTRFIXED|VTEXTFIXED|VUNSET,    "MAIL=",
 101           NULL },
 102         { &vmpath,      VSTRFIXED|VTEXTFIXED|VUNSET,    "MAILPATH=",
 103           NULL },
 104         { &vpath,       VSTRFIXED|VTEXTFIXED,           "PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/pkg/bin:/usr/pkg/sbin",
 105           changepath },
 106         { &vppid,       VSTRFIXED|VTEXTFIXED|VUNSET,    "PPID=",
 107           NULL },
 108         /*
 109          * vps1 depends on uid
 110          */
 111         { &vps2,        VSTRFIXED|VTEXTFIXED,           "PS2=> ",
 112           NULL },
 113         { &voptind,     VSTRFIXED|VTEXTFIXED,           "OPTIND=1",
 114           getoptsreset },
 115         { NULL, 0,                              NULL,
 116           NULL }
 117 };
 118
 119 STATIC struct var *vartab[VTABSIZE];
 120
 121 STATIC struct var **hashvar(const char *);
 122 STATIC int varequal(const char *, const char *);
 123 STATIC int localevar(const char *);
 124
 125 /*
 126  * Initialize the variable symbol tables and import the environment.
 127  */
 128
 129 #ifdef mkinit
 130 INCLUDE "var.h"
 131 MKINIT char **environ;
 132 INIT {
 133         char **envp;
 134
 135         initvar();
 136         for (envp = environ ; *envp ; envp++) {
 137                 if (strchr(*envp, '=')) {
 138                         setvareq(*envp, VEXPORT|VTEXTFIXED);
 139                 }
 140         }
 141 }
 142 #endif
 143
 144
 145 /*
 146  * This routine initializes the builtin variables.  It is called when the
 147  * shell is initialized and again when a shell procedure is spawned.
 148  */
 149
 150 void
 151 initvar(void)
 152 {
 153         char ppid[20];
 154         const struct varinit *ip;
 155         struct var *vp;
 156         struct var **vpp;
 157
 158         for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
 159                 if ((vp->flags & VEXPORT) == 0) {
 160                         vpp = hashvar(ip->text);
 161                         vp->next = *vpp;
 162                         *vpp = vp;
 163                         vp->text = strdup(ip->text);
 164                         vp->flags = ip->flags;
 165                         vp->func = ip->func;
 166                 }
 167         }
 168         /*
 169          * PS1 depends on uid
 170          */
 171         if ((vps1.flags & VEXPORT) == 0) {
 172                 vpp = hashvar("PS1=");
 173                 vps1.next = *vpp;
 174                 *vpp = &vps1;
 175                 vps1.text = strdup(geteuid() ? "PS1=$ " : "PS1=# ");
 176                 vps1.flags = VSTRFIXED|VTEXTFIXED;
 177         }
 178         if ((vppid.flags & VEXPORT) == 0) {
 179                 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
 180                 setvarsafe("PPID", ppid, 0);
 181         }
 182 }
 183
 184 /*
 185  * Safe version of setvar, returns 1 on success 0 on failure.
 186  */
 187
 188 int
 189 setvarsafe(const char *name, const char *val, int flags)
 190 {
 191         struct jmploc jmploc;
 192         struct jmploc *volatile savehandler = handler;
 193         int err = 0;
 194 #if __GNUC__
 195         /* Avoid longjmp clobbering */
 196         (void) &err;
 197 #endif
 198
 199         if (setjmp(jmploc.loc))
 200                 err = 1;
 201         else {
 202                 handler = &jmploc;
 203                 setvar(name, val, flags);
 204         }
 205         handler = savehandler;
 206         return err;
 207 }
 208
 209 /*
 210  * Set the value of a variable.  The flags argument is tored with the
 211  * flags of the variable.  If val is NULL, the variable is unset.
 212  */
 213
 214 void
 215 setvar(const char *name, const char *val, int flags)
 216 {
 217         const char *cp;
 218         char *p;
 219         int len;
 220         int namelen;
 221         char *nameeq;
 222         int isbad;
 223
 224         isbad = 0;
 225         cp = name;
 226         if (!is_name(*cp))
 227                 isbad = 1;
 228         cp++;
 229         for (;;) {
 230                 if (!is_in_name(*cp)) {
 231                         if (*cp == '\0' || *cp == '=')
 232                                 break;
 233                         isbad = 1;
 234                 }
 235                 cp++;
 236         }
 237         namelen = cp - name;
 238         if (isbad)
 239                 error("%.*s: bad variable name", namelen, name);
 240         len = namelen + 2;              /* 2 is space for '=' and '\0' */
 241         if (val == NULL) {
 242                 flags |= VUNSET;
 243         } else {
 244                 len += strlen(val);
 245         }
 246         p = nameeq = ckmalloc(len);
 247         cp = name;
 248         while (--namelen >= 0)
 249                 *p++ = *cp++;
 250         *p++ = '=';
 251         *p = '\0';
 252         if (val)
 253                 scopy(val, p);
 254         setvareq(nameeq, flags);
 255 }
 256
 257 STATIC int
 258 localevar(const char *s)
 259 {
 260         static const char * const lnames[7] = {
 261                 "ALL", "COLLATE", "CTYPE", "MONETARY",
 262                 "NUMERIC", "TIME", NULL
 263         };
 264         const char * const *ss;
 265
 266         if (*s != 'L')
 267                 return 0;
 268         if (varequal(s + 1, "ANG"))
 269                 return 1;
 270         if (strncmp(s + 1, "C_", 2) != 0)
 271                 return 0;
 272         for (ss = lnames; *ss ; ss++)
 273                 if (varequal(s + 3, *ss))
 274                         return 1;
 275         return 0;
 276 }
 277
 278 /*
 279  * Same as setvar except that the variable and value are passed in
 280  * the first argument as name=value.  Since the first argument will
 281  * be actually stored in the table, it should not be a string that
 282  * will go away.
 283  */
 284
 285 void
 286 setvareq(char *s, int flags)
 287 {
 288         struct var *vp, **vpp;
 289         int len;
 290
 291         if (aflag)
 292                 flags |= VEXPORT;
 293         vpp = hashvar(s);
 294         for (vp = *vpp ; vp ; vp = vp->next) {
 295                 if (varequal(s, vp->text)) {
 296                         if (vp->flags & VREADONLY) {
 297                                 len = strchr(s, '=') - s;
 298                                 error("%.*s: is read only", len, s);
 299                         }
 300                         INTOFF;
 301
 302                         if (vp->func && (flags & VNOFUNC) == 0)
 303                                 (*vp->func)(strchr(s, '=') + 1);
 304
 305                         if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
 306                                 ckfree(vp->text);
 307
 308                         vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
 309                         vp->flags |= flags;
 310                         vp->text = s;
 311
 312                         /*
 313                          * We could roll this to a function, to handle it as
 314                          * a regular variable function callback, but why bother?
 315                          */
 316                         if (vp == &vmpath || (vp == &vmail && ! mpathset()))
 317                                 chkmail(1);
 318                         if ((vp->flags & VEXPORT) && localevar(s)) {
 319                                 if (putenv(s) != 0)
 320                                         error("putenv: cannot set %s", s);
 321                                 setlocale(LC_ALL, "");
 322                         }
 323                         INTON;
 324                         return;
 325                 }
 326         }
 327         /* not found */
 328         vp = ckmalloc(sizeof (*vp));
 329         vp->flags = flags;
 330         vp->text = s;
 331         vp->next = *vpp;
 332         vp->func = NULL;
 333         INTOFF;
 334         *vpp = vp;
 335         if ((vp->flags & VEXPORT) && localevar(s)) {
 336                 if (putenv(s) != 0)
 337                         error("putenv: cannot set %s", s);
 338                 setlocale(LC_ALL, "");
 339         }
 340         INTON;
 341 }
 342
 343
 344
 345 /*
 346  * Process a linked list of variable assignments.
 347  */
 348
 349 void
 350 listsetvar(struct strlist *list)
 351 {
 352         struct strlist *lp;
 353
 354         INTOFF;
 355         for (lp = list ; lp ; lp = lp->next) {
 356                 setvareq(savestr(lp->text), 0);
 357         }
 358         INTON;
 359 }
 360
 361
 362
 363 /*
 364  * Find the value of a variable.  Returns NULL if not set.
 365  */
 366
 367 char *
 368 lookupvar(const char *name)
 369 {
 370         struct var *v;
 371
 372         for (v = *hashvar(name) ; v ; v = v->next) {
 373                 if (varequal(v->text, name)) {
 374                         if (v->flags & VUNSET)
 375                                 return NULL;
 376                         return strchr(v->text, '=') + 1;
 377                 }
 378         }
 379         return NULL;
 380 }
 381
 382
 383
 384 /*
 385  * Search the environment of a builtin command.  If the second argument
 386  * is nonzero, return the value of a variable even if it hasn't been
 387  * exported.
 388  */
 389
 390 char *
 391 bltinlookup(const char *name, int doall)
 392 {
 393         struct strlist *sp;
 394         struct var *v;
 395
 396         for (sp = cmdenviron ; sp ; sp = sp->next) {
 397                 if (varequal(sp->text, name))
 398                         return strchr(sp->text, '=') + 1;
 399         }
 400         for (v = *hashvar(name) ; v ; v = v->next) {
 401                 if (varequal(v->text, name)) {
 402                         if ((v->flags & VUNSET)
 403                          || (!doall && (v->flags & VEXPORT) == 0))
 404                                 return NULL;
 405                         return strchr(v->text, '=') + 1;
 406                 }
 407         }
 408         return NULL;
 409 }
 410
 411
 412
 413 /*
 414  * Generate a list of exported variables.  This routine is used to construct
 415  * the third argument to execve when executing a program.
 416  */
 417
 418 char **
 419 environment(void)
 420 {
 421         int nenv;
 422         struct var **vpp;
 423         struct var *vp;
 424         char **env, **ep;
 425
 426         nenv = 0;
 427         for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 428                 for (vp = *vpp ; vp ; vp = vp->next)
 429                         if (vp->flags & VEXPORT)
 430                                 nenv++;
 431         }
 432         ep = env = stalloc((nenv + 1) * sizeof *env);
 433         for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 434                 for (vp = *vpp ; vp ; vp = vp->next)
 435                         if (vp->flags & VEXPORT)
 436                                 *ep++ = vp->text;
 437         }
 438         *ep = NULL;
 439         return env;
 440 }
 441
 442
 443 /*
 444  * Called when a shell procedure is invoked to clear out nonexported
 445  * variables.  It is also necessary to reallocate variables of with
 446  * VSTACK set since these are currently allocated on the stack.
 447  */
 448
 449 #ifdef mkinit
 450 void shprocvar(void);
 451
 452 SHELLPROC {
 453         shprocvar();
 454 }
 455 #endif
 456
 457 void
 458 shprocvar(void)
 459 {
 460         struct var **vpp;
 461         struct var *vp, **prev;
 462
 463         for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 464                 for (prev = vpp ; (vp = *prev) != NULL ; ) {
 465                         if ((vp->flags & VEXPORT) == 0) {
 466                                 *prev = vp->next;
 467                                 if ((vp->flags & VTEXTFIXED) == 0)
 468                                         ckfree(vp->text);
 469                                 if ((vp->flags & VSTRFIXED) == 0)
 470                                         ckfree(vp);
 471                         } else {
 472                                 if (vp->flags & VSTACK) {
 473                                         vp->text = savestr(vp->text);
 474                                         vp->flags &=~ VSTACK;
 475                                 }
 476                                 prev = &vp->next;
 477                         }
 478                 }
 479         }
 480         initvar();
 481 }
 482
 483
 484
 485 /*
 486  * Command to list all variables which are set.  Currently this command
 487  * is invoked from the set command when the set command is called without
 488  * any variables.
 489  */
 490
 491 int
 492 showvarscmd(int argc __unused, char **argv __unused)
 493 {
 494         struct var **vpp;
 495         struct var *vp;
 496         const char *s;
 497
 498         for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 499                 for (vp = *vpp ; vp ; vp = vp->next) {
 500                         if (vp->flags & VUNSET)
 501                                 continue;
 502                         for (s = vp->text; *s != '='; s++)
 503                                 out1c(*s);
 504                         out1c('=');
 505                         out1qstr(s + 1);
 506                         out1c('\n');
 507                 }
 508         }
 509         return 0;
 510 }
 511
 512
 513
 514 /*
 515  * The export and readonly commands.
 516  */
 517
 518 int
 519 exportcmd(int argc, char **argv)
 520 {
 521         struct var **vpp;
 522         struct var *vp;
 523         char *name;
 524         char *p;
 525         char *cmdname;
 526         int ch, values;
 527         int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
 528
 529         cmdname = argv[0];
 530         optreset = optind = 1;
 531         opterr = 0;
 532         values = 0;
 533         while ((ch = getopt(argc, argv, "p")) != -1) {
 534                 switch (ch) {
 535                 case 'p':
 536                         values = 1;
 537                         break;
 538                 case '?':
 539                 default:
 540                         error("unknown option: -%c", optopt);
 541                 }
 542         }
 543         argc -= optind;
 544         argv += optind;
 545
 546         listsetvar(cmdenviron);
 547         if (argc != 0) {
 548                 while ((name = *argptr++) != NULL) {
 549                         if ((p = strchr(name, '=')) != NULL) {
 550                                 p++;
 551                         } else {
 552                                 vpp = hashvar(name);
 553                                 for (vp = *vpp ; vp ; vp = vp->next) {
 554                                         if (varequal(vp->text, name)) {
 555
 556                                                 vp->flags |= flag;
 557                                                 if ((vp->flags & VEXPORT) && localevar(vp->text)) {
 558                                                         if (putenv(vp->text) != 0)
 559                                                                 error("putenv: cannot set %s", vp->text);
 560                                                         setlocale(LC_ALL, "");
 561                                                 }
 562                                                 goto found;
 563                                         }
 564                                 }
 565                         }
 566                         setvar(name, p, flag);
 567 found:;
 568                 }
 569         } else {
 570                 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 571                         for (vp = *vpp ; vp ; vp = vp->next) {
 572                                 if (vp->flags & flag) {
 573                                         if (values) {
 574                                                 out1str(cmdname);
 575                                                 out1c(' ');
 576                                         }
 577                                         for (p = vp->text ; *p != '=' ; p++)
 578                                                 out1c(*p);
 579                                         if (values && !(vp->flags & VUNSET)) {
 580                                                 out1c('=');
 581                                                 out1qstr(p + 1);
 582                                         }
 583                                         out1c('\n');
 584                                 }
 585                         }
 586                 }
 587         }
 588         return 0;
 589 }
 590
 591
 592 /*
 593  * The "local" command.
 594  */
 595
 596 int
 597 localcmd(int argc __unused, char **argv __unused)
 598 {
 599         char *name;
 600
 601         if (! in_function())
 602                 error("Not in a function");
 603         while ((name = *argptr++) != NULL) {
 604                 mklocal(name);
 605         }
 606         return 0;
 607 }
 608
 609
 610 /*
 611  * Make a variable a local variable.  When a variable is made local, it's
 612  * value and flags are saved in a localvar structure.  The saved values
 613  * will be restored when the shell function returns.  We handle the name
 614  * "-" as a special case.
 615  */
 616
 617 void
 618 mklocal(char *name)
 619 {
 620         struct localvar *lvp;
 621         struct var **vpp;
 622         struct var *vp;
 623
 624         INTOFF;
 625         lvp = ckmalloc(sizeof (struct localvar));
 626         if (name[0] == '-' && name[1] == '\0') {
 627                 lvp->text = ckmalloc(sizeof optlist);
 628                 memcpy(lvp->text, optlist, sizeof optlist);
 629                 vp = NULL;
 630         } else {
 631                 vpp = hashvar(name);
 632                 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
 633                 if (vp == NULL) {
 634                         if (strchr(name, '='))
 635                                 setvareq(savestr(name), VSTRFIXED);
 636                         else
 637                                 setvar(name, NULL, VSTRFIXED);
 638                         vp = *vpp;      /* the new variable */
 639                         lvp->text = NULL;
 640                         lvp->flags = VUNSET;
 641                 } else {
 642                         lvp->text = vp->text;
 643                         lvp->flags = vp->flags;
 644                         vp->flags |= VSTRFIXED|VTEXTFIXED;
 645                         if (strchr(name, '='))
 646                                 setvareq(savestr(name), 0);
 647                 }
 648         }
 649         lvp->vp = vp;
 650         lvp->next = localvars;
 651         localvars = lvp;
 652         INTON;
 653 }
 654
 655
 656 /*
 657  * Called after a function returns.
 658  */
 659
 660 void
 661 poplocalvars(void)
 662 {
 663         struct localvar *lvp;
 664         struct var *vp;
 665
 666         while ((lvp = localvars) != NULL) {
 667                 localvars = lvp->next;
 668                 vp = lvp->vp;
 669                 if (vp == NULL) {       /* $- saved */
 670                         memcpy(optlist, lvp->text, sizeof optlist);
 671                         ckfree(lvp->text);
 672                 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
 673                         unsetvar(vp->text);
 674                 } else {
 675                         if ((vp->flags & VTEXTFIXED) == 0)
 676                                 ckfree(vp->text);
 677                         vp->flags = lvp->flags;
 678                         vp->text = lvp->text;
 679                 }
 680                 ckfree(lvp);
 681         }
 682 }
 683
 684
 685 int
 686 setvarcmd(int argc, char **argv)
 687 {
 688         if (argc <= 2)
 689                 return unsetcmd(argc, argv);
 690         else if (argc == 3)
 691                 setvar(argv[1], argv[2], 0);
 692         else
 693                 error("List assignment not implemented");
 694         return 0;
 695 }
 696
 697
 698 /*
 699  * The unset builtin command.  We unset the function before we unset the
 700  * variable to allow a function to be unset when there is a readonly variable
 701  * with the same name.
 702  */
 703
 704 int
 705 unsetcmd(int argc __unused, char **argv __unused)
 706 {
 707         char **ap;
 708         int i;
 709         int flg_func = 0;
 710         int flg_var = 0;
 711         int ret = 0;
 712
 713         while ((i = nextopt("vf")) != '\0') {
 714                 if (i == 'f')
 715                         flg_func = 1;
 716                 else
 717                         flg_var = 1;
 718         }
 719         if (flg_func == 0 && flg_var == 0)
 720                 flg_var = 1;
 721
 722         for (ap = argptr; *ap ; ap++) {
 723                 if (flg_func)
 724                         ret |= unsetfunc(*ap);
 725                 if (flg_var)
 726                         ret |= unsetvar(*ap);
 727         }
 728         return ret;
 729 }
 730
 731
 732 /*
 733  * Unset the specified variable.
 734  */
 735
 736 int
 737 unsetvar(const char *s)
 738 {
 739         struct var **vpp;
 740         struct var *vp;
 741
 742         vpp = hashvar(s);
 743         for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
 744                 if (varequal(vp->text, s)) {
 745                         if (vp->flags & VREADONLY)
 746                                 return (1);
 747                         INTOFF;
 748                         if (*(strchr(vp->text, '=') + 1) != '\0')
 749                                 setvar(s, nullstr, 0);
 750                         if ((vp->flags & VEXPORT) && localevar(vp->text)) {
 751                                 unsetenv(s);
 752                                 setlocale(LC_ALL, "");
 753                         }
 754                         vp->flags &= ~VEXPORT;
 755                         vp->flags |= VUNSET;
 756                         if ((vp->flags & VSTRFIXED) == 0) {
 757                                 if ((vp->flags & VTEXTFIXED) == 0)
 758                                         ckfree(vp->text);
 759                                 *vpp = vp->next;
 760                                 ckfree(vp);
 761                         }
 762                         INTON;
 763                         return (0);
 764                 }
 765         }
 766         return (0);
 767 }
 768
 769
 770
 771 /*
 772  * Find the appropriate entry in the hash table from the name.
 773  */
 774
 775 STATIC struct var **
 776 hashvar(const char *p)
 777 {
 778         unsigned int hashval;
 779
 780         hashval = ((unsigned char) *p) << 4;
 781         while (*p && *p != '=')
 782                 hashval += (unsigned char) *p++;
 783         return &vartab[hashval % VTABSIZE];
 784 }
 785
 786
 787
 788 /*
 789  * Returns true if the two strings specify the same varable.  The first
 790  * variable name is terminated by '='; the second may be terminated by
 791  * either '=' or '\0'.
 792  */
 793
 794 STATIC int
 795 varequal(const char *p, const char *q)
 796 {
 797         while (*p == *q++) {
 798                 if (*p++ == '=')
 799                         return 1;
 800         }
 801         if (*p == '=' && *(q - 1) == '\0')
 802                 return 1;
 803         return 0;
 804 }