var.c revision 45263
1240616Sjimharris/*- 2295705Sjimharris * Copyright (c) 1991, 1993 3240616Sjimharris * The Regents of the University of California. All rights reserved. 4240616Sjimharris * 5240616Sjimharris * This code is derived from software contributed to Berkeley by 6240616Sjimharris * Kenneth Almquist. 7240616Sjimharris * 8240616Sjimharris * Redistribution and use in source and binary forms, with or without 9240616Sjimharris * modification, are permitted provided that the following conditions 10240616Sjimharris * are met: 11240616Sjimharris * 1. Redistributions of source code must retain the above copyright 12240616Sjimharris * notice, this list of conditions and the following disclaimer. 13240616Sjimharris * 2. Redistributions in binary form must reproduce the above copyright 14240616Sjimharris * notice, this list of conditions and the following disclaimer in the 15240616Sjimharris * documentation and/or other materials provided with the distribution. 16240616Sjimharris * 3. All advertising materials mentioning features or use of this software 17240616Sjimharris * must display the following acknowledgement: 18240616Sjimharris * This product includes software developed by the University of 19240616Sjimharris * California, Berkeley and its contributors. 20240616Sjimharris * 4. Neither the name of the University nor the names of its contributors 21240616Sjimharris * may be used to endorse or promote products derived from this software 22240616Sjimharris * without specific prior written permission. 23240616Sjimharris * 24240616Sjimharris * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25240616Sjimharris * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26240616Sjimharris * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27240616Sjimharris * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28240616Sjimharris * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29240616Sjimharris * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30240616Sjimharris * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31240616Sjimharris * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32240616Sjimharris * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33240616Sjimharris * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34240616Sjimharris * SUCH DAMAGE. 35295705Sjimharris */ 36240616Sjimharris 37240616Sjimharris#ifndef lint 38240616Sjimharris#if 0 39240616Sjimharrisstatic char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95"; 40240616Sjimharris#endif 41240616Sjimharrisstatic const char rcsid[] = 42240616Sjimharris "$Id: var.c,v 1.12 1998/05/18 06:44:24 charnier Exp $"; 43240616Sjimharris#endif /* not lint */ 44253476Sjimharris 45253476Sjimharris#include <unistd.h> 46240616Sjimharris#include <stdlib.h> 47240616Sjimharris 48240616Sjimharris/* 49240616Sjimharris * Shell variables. 50240616Sjimharris */ 51293665Sjimharris 52293665Sjimharris#include <locale.h> 53248765Sjimharris 54240616Sjimharris#include "shell.h" 55240616Sjimharris#include "output.h" 56248765Sjimharris#include "expand.h" 57248767Sjimharris#include "nodes.h" /* for other headers */ 58248765Sjimharris#include "eval.h" /* defines cmdenviron */ 59240616Sjimharris#include "exec.h" 60240616Sjimharris#include "syntax.h" 61240616Sjimharris#include "options.h" 62240616Sjimharris#include "mail.h" 63240616Sjimharris#include "var.h" 64240616Sjimharris#include "memalloc.h" 65240616Sjimharris#include "error.h" 66240616Sjimharris#include "mystring.h" 67240616Sjimharris#include "parser.h" 68240616Sjimharris#ifndef NO_HISTORY 69240616Sjimharris#include "myhistedit.h" 70240616Sjimharris#endif 71240616Sjimharris 72240616Sjimharris 73240616Sjimharris#define VTABSIZE 39 74240616Sjimharris 75240616Sjimharris 76240616Sjimharrisstruct varinit { 77293666Sjimharris struct var *var; 78240616Sjimharris int flags; 79248765Sjimharris char *text; 80248765Sjimharris void (*func) __P((const char *)); 81240616Sjimharris}; 82240616Sjimharris 83248765Sjimharris 84240616Sjimharris#if ATTY 85248765Sjimharrisstruct var vatty; 86248765Sjimharris#endif 87248765Sjimharris#ifndef NO_HISTORY 88248765Sjimharrisstruct var vhistsize; 89248765Sjimharris#endif 90248765Sjimharrisstruct var vifs; 91248765Sjimharrisstruct var vmail; 92295705Sjimharrisstruct var vmpath; 93295705Sjimharrisstruct var vpath; 94295705Sjimharrisstruct var vps1; 95295705Sjimharrisstruct var vps2; 96295705Sjimharrisstruct var vvers; 97295705Sjimharris#if ATTY 98295705Sjimharrisstruct var vterm; 99295705Sjimharris#endif 100295705Sjimharrisstruct var voptind; 101295705Sjimharris 102295705Sjimharrisconst struct varinit varinit[] = { 103295705Sjimharris#if ATTY 104295705Sjimharris { &vatty, VSTRFIXED|VTEXTFIXED|VUNSET, "ATTY=", 105240616Sjimharris NULL }, 106240616Sjimharris#endif 107240616Sjimharris#ifndef NO_HISTORY 108240616Sjimharris { &vhistsize, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE=", 109240616Sjimharris sethistsize }, 110240616Sjimharris#endif 111240616Sjimharris { &vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n", 112240616Sjimharris NULL }, 113240616Sjimharris { &vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL=", 114240616Sjimharris NULL }, 115240616Sjimharris { &vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH=", 116240616Sjimharris NULL }, 117240616Sjimharris { &vpath, VSTRFIXED|VTEXTFIXED, "PATH=/bin:/usr/bin", 118240616Sjimharris changepath }, 119240616Sjimharris /* 120240616Sjimharris * vps1 depends on uid 121240616Sjimharris */ 122240616Sjimharris { &vps2, VSTRFIXED|VTEXTFIXED, "PS2=> ", 123240616Sjimharris NULL }, 124253476Sjimharris#if ATTY 125240616Sjimharris { &vterm, VSTRFIXED|VTEXTFIXED|VUNSET, "TERM=", 126241394Skevlo NULL }, 127240616Sjimharris#endif 128240616Sjimharris { &voptind, VSTRFIXED|VTEXTFIXED, "OPTIND=1", 129240616Sjimharris getoptsreset }, 130240616Sjimharris { NULL, 0, NULL, 131240616Sjimharris NULL } 132240616Sjimharris}; 133240616Sjimharris 134240616Sjimharrisstruct var *vartab[VTABSIZE]; 135240616Sjimharris 136240616SjimharrisSTATIC struct var **hashvar __P((char *)); 137248765SjimharrisSTATIC int varequal __P((char *, char *)); 138248765SjimharrisSTATIC int localevar __P((char *)); 139240616Sjimharris 140248765Sjimharris/* 141248767Sjimharris * Initialize the varable symbol tables and import the environment 142248765Sjimharris */ 143240616Sjimharris 144240616Sjimharris#ifdef mkinit 145240616SjimharrisINCLUDE "var.h" 146240616SjimharrisINIT { 147240616Sjimharris char **envp; 148240616Sjimharris extern char **environ; 149248765Sjimharris 150248765Sjimharris initvar(); 151240616Sjimharris for (envp = environ ; *envp ; envp++) { 152248765Sjimharris if (strchr(*envp, '=')) { 153248765Sjimharris setvareq(*envp, VEXPORT|VTEXTFIXED); 154248765Sjimharris } 155248765Sjimharris } 156240616Sjimharris} 157240616Sjimharris#endif 158248765Sjimharris 159248765Sjimharris 160248765Sjimharris/* 161248765Sjimharris * This routine initializes the builtin variables. It is called when the 162248765Sjimharris * shell is initialized and again when a shell procedure is spawned. 163248765Sjimharris */ 164248765Sjimharris 165240616Sjimharrisvoid 166240616Sjimharrisinitvar() { 167240616Sjimharris const struct varinit *ip; 168293665Sjimharris struct var *vp; 169293665Sjimharris struct var **vpp; 170293665Sjimharris 171293665Sjimharris for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { 172293665Sjimharris if ((vp->flags & VEXPORT) == 0) { 173293665Sjimharris vpp = hashvar(ip->text); 174293665Sjimharris vp->next = *vpp; 175293665Sjimharris *vpp = vp; 176293665Sjimharris vp->text = ip->text; 177293665Sjimharris vp->flags = ip->flags; 178293666Sjimharris vp->func = ip->func; 179293666Sjimharris } 180293665Sjimharris } 181293665Sjimharris /* 182293665Sjimharris * PS1 depends on uid 183293665Sjimharris */ 184293665Sjimharris if ((vps1.flags & VEXPORT) == 0) { 185293665Sjimharris vpp = hashvar("PS1="); 186293665Sjimharris vps1.next = *vpp; 187293665Sjimharris *vpp = &vps1; 188293665Sjimharris vps1.text = geteuid() ? "PS1=$ " : "PS1=# "; 189293665Sjimharris vps1.flags = VSTRFIXED|VTEXTFIXED; 190240616Sjimharris } 191240616Sjimharris} 192240616Sjimharris 193240616Sjimharris/* 194240616Sjimharris * Safe version of setvar, returns 1 on success 0 on failure. 195240616Sjimharris */ 196240616Sjimharris 197293666Sjimharrisint 198293666Sjimharrissetvarsafe(name, val, flags) 199293666Sjimharris char *name, *val; 200293666Sjimharris int flags; 201293666Sjimharris{ 202293666Sjimharris struct jmploc jmploc; 203293666Sjimharris struct jmploc *volatile savehandler = handler; 204293666Sjimharris int err = 0; 205293666Sjimharris#if __GNUC__ 206293666Sjimharris /* Avoid longjmp clobbering */ 207293666Sjimharris (void) &err; 208293666Sjimharris#endif 209240616Sjimharris 210240616Sjimharris if (setjmp(jmploc.loc)) 211240616Sjimharris err = 1; 212240616Sjimharris else { 213240616Sjimharris handler = &jmploc; 214240616Sjimharris setvar(name, val, flags); 215240616Sjimharris } 216240616Sjimharris handler = savehandler; 217240616Sjimharris return err; 218240616Sjimharris} 219240616Sjimharris 220240616Sjimharris/* 221240616Sjimharris * Set the value of a variable. The flags argument is stored with the 222240616Sjimharris * flags of the variable. If val is NULL, the variable is unset. 223240616Sjimharris */ 224240616Sjimharris 225240616Sjimharrisvoid 226240616Sjimharrissetvar(name, val, flags) 227240616Sjimharris char *name, *val; 228240616Sjimharris int flags; 229240616Sjimharris{ 230248756Sjimharris char *p, *q; 231240616Sjimharris int len; 232240616Sjimharris int namelen; 233240616Sjimharris char *nameeq; 234240616Sjimharris int isbad; 235240616Sjimharris 236240616Sjimharris isbad = 0; 237240616Sjimharris p = name; 238240616Sjimharris if (! is_name(*p)) 239241665Sjimharris isbad = 1; 240293666Sjimharris p++; 241293666Sjimharris for (;;) { 242240616Sjimharris if (! is_in_name(*p)) { 243240616Sjimharris if (*p == '\0' || *p == '=') 244240616Sjimharris break; 245240616Sjimharris isbad = 1; 246240616Sjimharris } 247240616Sjimharris p++; 248240616Sjimharris } 249240616Sjimharris namelen = p - name; 250240616Sjimharris if (isbad) 251240616Sjimharris error("%.*s: bad variable name", namelen, name); 252240616Sjimharris len = namelen + 2; /* 2 is space for '=' and '\0' */ 253240616Sjimharris if (val == NULL) { 254240616Sjimharris flags |= VUNSET; 255240616Sjimharris } else { 256240616Sjimharris len += strlen(val); 257240616Sjimharris } 258240616Sjimharris p = nameeq = ckmalloc(len); 259293665Sjimharris q = name; 260293664Sjimharris while (--namelen >= 0) 261240616Sjimharris *p++ = *q++; 262240616Sjimharris *p++ = '='; 263240616Sjimharris *p = '\0'; 264240616Sjimharris if (val) 265240616Sjimharris scopy(val, p); 266240616Sjimharris setvareq(nameeq, flags); 267240616Sjimharris} 268240616Sjimharris 269240616SjimharrisSTATIC int 270240616Sjimharrislocalevar(s) 271240616Sjimharris char *s; 272240616Sjimharris { 273240616Sjimharris static char *lnames[7] = { 274240616Sjimharris "ALL", "COLLATE", "CTYPE", "MONETARY", 275240616Sjimharris "NUMERIC", "TIME", NULL 276240616Sjimharris }; 277240616Sjimharris char **ss; 278248738Sjimharris 279248765Sjimharris if (*s != 'L') 280240616Sjimharris return 0; 281248765Sjimharris if (varequal(s + 1, "ANG")) 282240616Sjimharris return 1; 283248765Sjimharris if (strncmp(s + 1, "C_", 2) != 0) 284248770Sjimharris return 0; 285248765Sjimharris for (ss = lnames; *ss ; ss++) 286248765Sjimharris if (varequal(s + 3, *ss)) 287248765Sjimharris return 1; 288248765Sjimharris return 0; 289248765Sjimharris} 290248765Sjimharris 291248765Sjimharris/* 292248765Sjimharris * Same as setvar except that the variable and value are passed in 293248765Sjimharris * the first argument as name=value. Since the first argument will 294248765Sjimharris * be actually stored in the table, it should not be a string that 295253476Sjimharris * will go away. 296248765Sjimharris */ 297248765Sjimharris 298248765Sjimharrisvoid 299248765Sjimharrissetvareq(s, flags) 300248770Sjimharris char *s; 301240616Sjimharris int flags; 302240616Sjimharris{ 303240616Sjimharris struct var *vp, **vpp; 304240616Sjimharris 305253476Sjimharris if (aflag) 306240616Sjimharris flags |= VEXPORT; 307240616Sjimharris vpp = hashvar(s); 308240616Sjimharris for (vp = *vpp ; vp ; vp = vp->next) { 309240616Sjimharris if (varequal(s, vp->text)) { 310240616Sjimharris if (vp->flags & VREADONLY) { 311285915Sjimharris size_t len = strchr(s, '=') - s; 312295705Sjimharris error("%.*s: is read only", len, s); 313295705Sjimharris } 314294711Ssmh INTOFF; 315240616Sjimharris 316248765Sjimharris if (vp->func && (flags & VNOFUNC) == 0) 317240616Sjimharris (*vp->func)(strchr(s, '=') + 1); 318240616Sjimharris 319248765Sjimharris if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) 320248765Sjimharris ckfree(vp->text); 321240616Sjimharris 322293662Sjimharris vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET); 323240616Sjimharris vp->flags |= flags; 324240616Sjimharris vp->text = s; 325240616Sjimharris 326240616Sjimharris /* 327240616Sjimharris * We could roll this to a function, to handle it as 328240616Sjimharris * a regular variable function callback, but why bother? 329240616Sjimharris */ 330248977Sjimharris if (vp == &vmpath || (vp == &vmail && ! mpathset())) 331248977Sjimharris chkmail(1); 332248977Sjimharris if ((vp->flags & VEXPORT) && localevar(s)) { 333248977Sjimharris putenv(s); 334248977Sjimharris (void) setlocale(LC_ALL, ""); 335253437Sjimharris } 336253437Sjimharris INTON; 337253437Sjimharris return; 338253437Sjimharris } 339253476Sjimharris } 340253476Sjimharris /* not found */ 341240616Sjimharris vp = ckmalloc(sizeof (*vp)); 342253476Sjimharris vp->flags = flags; 343253476Sjimharris vp->text = s; 344253476Sjimharris vp->next = *vpp; 345240616Sjimharris vp->func = NULL; 346253476Sjimharris INTOFF; 347240616Sjimharris *vpp = vp; 348240616Sjimharris if ((vp->flags & VEXPORT) && localevar(s)) { 349240616Sjimharris putenv(s); 350240616Sjimharris (void) setlocale(LC_ALL, ""); 351240616Sjimharris } 352293666Sjimharris INTON; 353240616Sjimharris} 354240616Sjimharris 355240616Sjimharris 356240616Sjimharris 357240616Sjimharris/* 358240616Sjimharris * Process a linked list of variable assignments. 359240616Sjimharris */ 360240616Sjimharris 361240616Sjimharrisvoid 362248765Sjimharrislistsetvar(list) 363248765Sjimharris struct strlist *list; 364248738Sjimharris { 365253473Sjimharris struct strlist *lp; 366253473Sjimharris 367253476Sjimharris INTOFF; 368253476Sjimharris for (lp = list ; lp ; lp = lp->next) { 369253476Sjimharris setvareq(savestr(lp->text), 0); 370253476Sjimharris } 371253476Sjimharris INTON; 372253476Sjimharris} 373248738Sjimharris 374240616Sjimharris 375240616Sjimharris 376240616Sjimharris/* 377240616Sjimharris * Find the value of a variable. Returns NULL if not set. 378240616Sjimharris */ 379253476Sjimharris 380253476Sjimharrischar * 381253476Sjimharrislookupvar(name) 382253476Sjimharris char *name; 383240616Sjimharris { 384253476Sjimharris struct var *v; 385253476Sjimharris 386240616Sjimharris for (v = *hashvar(name) ; v ; v = v->next) { 387253476Sjimharris if (varequal(v->text, name)) { 388240616Sjimharris if (v->flags & VUNSET) 389240616Sjimharris return NULL; 390240616Sjimharris return strchr(v->text, '=') + 1; 391240616Sjimharris } 392240616Sjimharris } 393240616Sjimharris return NULL; 394240616Sjimharris} 395240616Sjimharris 396240616Sjimharris 397240616Sjimharris 398253476Sjimharris/* 399240616Sjimharris * Search the environment of a builtin command. If the second argument 400240616Sjimharris * is nonzero, return the value of a variable even if it hasn't been 401253476Sjimharris * exported. 402253476Sjimharris */ 403253476Sjimharris 404253476Sjimharrischar * 405240616Sjimharrisbltinlookup(name, doall) 406240616Sjimharris char *name; 407240616Sjimharris int doall; 408240616Sjimharris{ 409248767Sjimharris struct strlist *sp; 410248767Sjimharris struct var *v; 411248767Sjimharris 412248767Sjimharris for (sp = cmdenviron ; sp ; sp = sp->next) { 413248767Sjimharris if (varequal(sp->text, name)) 414248767Sjimharris return strchr(sp->text, '=') + 1; 415248767Sjimharris } 416248767Sjimharris for (v = *hashvar(name) ; v ; v = v->next) { 417248767Sjimharris if (varequal(v->text, name)) { 418248767Sjimharris if ((v->flags & VUNSET) 419248767Sjimharris || (!doall && (v->flags & VEXPORT) == 0)) 420248767Sjimharris return NULL; 421248767Sjimharris return strchr(v->text, '=') + 1; 422248767Sjimharris } 423248767Sjimharris } 424248767Sjimharris return NULL; 425248767Sjimharris} 426248767Sjimharris 427248767Sjimharris 428 429/* 430 * Generate a list of exported variables. This routine is used to construct 431 * the third argument to execve when executing a program. 432 */ 433 434char ** 435environment() { 436 int nenv; 437 struct var **vpp; 438 struct var *vp; 439 char **env, **ep; 440 441 nenv = 0; 442 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 443 for (vp = *vpp ; vp ; vp = vp->next) 444 if (vp->flags & VEXPORT) 445 nenv++; 446 } 447 ep = env = stalloc((nenv + 1) * sizeof *env); 448 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 449 for (vp = *vpp ; vp ; vp = vp->next) 450 if (vp->flags & VEXPORT) 451 *ep++ = vp->text; 452 } 453 *ep = NULL; 454 return env; 455} 456 457 458/* 459 * Called when a shell procedure is invoked to clear out nonexported 460 * variables. It is also necessary to reallocate variables of with 461 * VSTACK set since these are currently allocated on the stack. 462 */ 463 464#ifdef mkinit 465MKINIT void shprocvar(); 466 467SHELLPROC { 468 shprocvar(); 469} 470#endif 471 472void 473shprocvar() { 474 struct var **vpp; 475 struct var *vp, **prev; 476 477 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 478 for (prev = vpp ; (vp = *prev) != NULL ; ) { 479 if ((vp->flags & VEXPORT) == 0) { 480 *prev = vp->next; 481 if ((vp->flags & VTEXTFIXED) == 0) 482 ckfree(vp->text); 483 if ((vp->flags & VSTRFIXED) == 0) 484 ckfree(vp); 485 } else { 486 if (vp->flags & VSTACK) { 487 vp->text = savestr(vp->text); 488 vp->flags &=~ VSTACK; 489 } 490 prev = &vp->next; 491 } 492 } 493 } 494 initvar(); 495} 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 505int 506showvarscmd(argc, argv) 507 int argc __unused; 508 char **argv __unused; 509{ 510 struct var **vpp; 511 struct var *vp; 512 513 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 514 for (vp = *vpp ; vp ; vp = vp->next) { 515 if ((vp->flags & VUNSET) == 0) 516 out1fmt("%s\n", vp->text); 517 } 518 } 519 return 0; 520} 521 522 523 524/* 525 * The export and readonly commands. 526 */ 527 528int 529exportcmd(argc, argv) 530 int argc; 531 char **argv; 532{ 533 struct var **vpp; 534 struct var *vp; 535 char *name; 536 char *p; 537 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 538 539 listsetvar(cmdenviron); 540 if (argc > 1) { 541 while ((name = *argptr++) != NULL) { 542 if ((p = strchr(name, '=')) != NULL) { 543 p++; 544 } else { 545 vpp = hashvar(name); 546 for (vp = *vpp ; vp ; vp = vp->next) { 547 if (varequal(vp->text, name)) { 548 vp->flags |= flag; 549 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 550 putenv(vp->text); 551 (void) setlocale(LC_ALL, ""); 552 } 553 goto found; 554 } 555 } 556 } 557 setvar(name, p, flag); 558found:; 559 } 560 } else { 561 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 562 for (vp = *vpp ; vp ; vp = vp->next) { 563 if (vp->flags & flag) { 564 for (p = vp->text ; *p != '=' ; p++) 565 out1c(*p); 566 out1c('\n'); 567 } 568 } 569 } 570 } 571 return 0; 572} 573 574 575/* 576 * The "local" command. 577 */ 578 579int 580localcmd(argc, argv) 581 int argc __unused; 582 char **argv __unused; 583{ 584 char *name; 585 586 if (! in_function()) 587 error("Not in a function"); 588 while ((name = *argptr++) != NULL) { 589 mklocal(name); 590 } 591 return 0; 592} 593 594 595/* 596 * Make a variable a local variable. When a variable is made local, it's 597 * value and flags are saved in a localvar structure. The saved values 598 * will be restored when the shell function returns. We handle the name 599 * "-" as a special case. 600 */ 601 602void 603mklocal(name) 604 char *name; 605 { 606 struct localvar *lvp; 607 struct var **vpp; 608 struct var *vp; 609 610 INTOFF; 611 lvp = ckmalloc(sizeof (struct localvar)); 612 if (name[0] == '-' && name[1] == '\0') { 613 lvp->text = ckmalloc(sizeof optlist); 614 memcpy(lvp->text, optlist, sizeof optlist); 615 vp = NULL; 616 } else { 617 vpp = hashvar(name); 618 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); 619 if (vp == NULL) { 620 if (strchr(name, '=')) 621 setvareq(savestr(name), VSTRFIXED); 622 else 623 setvar(name, NULL, VSTRFIXED); 624 vp = *vpp; /* the new variable */ 625 lvp->text = NULL; 626 lvp->flags = VUNSET; 627 } else { 628 lvp->text = vp->text; 629 lvp->flags = vp->flags; 630 vp->flags |= VSTRFIXED|VTEXTFIXED; 631 if (strchr(name, '=')) 632 setvareq(savestr(name), 0); 633 } 634 } 635 lvp->vp = vp; 636 lvp->next = localvars; 637 localvars = lvp; 638 INTON; 639} 640 641 642/* 643 * Called after a function returns. 644 */ 645 646void 647poplocalvars() { 648 struct localvar *lvp; 649 struct var *vp; 650 651 while ((lvp = localvars) != NULL) { 652 localvars = lvp->next; 653 vp = lvp->vp; 654 if (vp == NULL) { /* $- saved */ 655 memcpy(optlist, lvp->text, sizeof optlist); 656 ckfree(lvp->text); 657 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 658 (void)unsetvar(vp->text); 659 } else { 660 if ((vp->flags & VTEXTFIXED) == 0) 661 ckfree(vp->text); 662 vp->flags = lvp->flags; 663 vp->text = lvp->text; 664 } 665 ckfree(lvp); 666 } 667} 668 669 670int 671setvarcmd(argc, argv) 672 int argc; 673 char **argv; 674{ 675 if (argc <= 2) 676 return unsetcmd(argc, argv); 677 else if (argc == 3) 678 setvar(argv[1], argv[2], 0); 679 else 680 error("List assignment not implemented"); 681 return 0; 682} 683 684 685/* 686 * The unset builtin command. We unset the function before we unset the 687 * variable to allow a function to be unset when there is a readonly variable 688 * with the same name. 689 */ 690 691int 692unsetcmd(argc, argv) 693 int argc __unused; 694 char **argv __unused; 695{ 696 char **ap; 697 int i; 698 int flg_func = 0; 699 int flg_var = 0; 700 int ret = 0; 701 702 while ((i = nextopt("vf")) != '\0') { 703 if (i == 'f') 704 flg_func = 1; 705 else 706 flg_var = 1; 707 } 708 if (flg_func == 0 && flg_var == 0) 709 flg_var = 1; 710 711 for (ap = argptr; *ap ; ap++) { 712 if (flg_func) 713 ret |= unsetfunc(*ap); 714 if (flg_var) 715 ret |= unsetvar(*ap); 716 } 717 return ret; 718} 719 720 721/* 722 * Unset the specified variable. 723 */ 724 725int 726unsetvar(s) 727 char *s; 728 { 729 struct var **vpp; 730 struct var *vp; 731 732 vpp = hashvar(s); 733 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 734 if (varequal(vp->text, s)) { 735 if (vp->flags & VREADONLY) 736 return (1); 737 INTOFF; 738 if (*(strchr(vp->text, '=') + 1) != '\0') 739 setvar(s, nullstr, 0); 740 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 741 unsetenv(s); 742 setlocale(LC_ALL, ""); 743 } 744 vp->flags &= ~VEXPORT; 745 vp->flags |= VUNSET; 746 if ((vp->flags & VSTRFIXED) == 0) { 747 if ((vp->flags & VTEXTFIXED) == 0) 748 ckfree(vp->text); 749 *vpp = vp->next; 750 ckfree(vp); 751 } 752 INTON; 753 return (0); 754 } 755 } 756 757 return (1); 758} 759 760 761 762/* 763 * Find the appropriate entry in the hash table from the name. 764 */ 765 766STATIC struct var ** 767hashvar(p) 768 char *p; 769 { 770 unsigned int hashval; 771 772 hashval = ((unsigned char) *p) << 4; 773 while (*p && *p != '=') 774 hashval += (unsigned char) *p++; 775 return &vartab[hashval % VTABSIZE]; 776} 777 778 779 780/* 781 * Returns true if the two strings specify the same varable. The first 782 * variable name is terminated by '='; the second may be terminated by 783 * either '=' or '\0'. 784 */ 785 786STATIC int 787varequal(p, q) 788 char *p, *q; 789 { 790 while (*p == *q++) { 791 if (*p++ == '=') 792 return 1; 793 } 794 if (*p == '=' && *(q - 1) == '\0') 795 return 1; 796 return 0; 797} 798