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 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95"; 40 #endif 41 #endif /* not lint */ 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include <unistd.h> 46 #include <stdlib.h> 47 48 /* 49 * Shell variables. 50 */ 51 52 #include <locale.h> 53 54 #include "shell.h" 55 #include "output.h" 56 #include "expand.h" 57 #include "nodes.h" /* for other headers */ 58 #include "eval.h" /* defines cmdenviron */ 59 #include "exec.h" 60 #include "syntax.h" 61 #include "options.h" 62 #include "mail.h" 63 #include "var.h" 64 #include "memalloc.h" 65 #include "error.h" 66 #include "mystring.h" 67 #include "parser.h" 68 #ifndef NO_HISTORY 69 #include "myhistedit.h" 70 #endif 71 72 73 #define VTABSIZE 39 74 75 76 struct varinit { 77 struct var *var; 78 int flags; 79 char *text; 80 void (*func)(const char *); 81 }; 82 83 84 #ifndef NO_HISTORY 85 struct var vhistsize; 86 #endif 87 struct var vifs; 88 struct var vmail; 89 struct var vmpath; 90 struct var vpath; 91 struct var vppid; 92 struct var vps1; 93 struct var vps2; 94 struct var vvers; 95 struct var voptind; 96 97 const struct varinit varinit[] = { 98 #ifndef NO_HISTORY 99 { &vhistsize, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE=", 100 sethistsize }, 101 #endif 102 { &vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n", 103 NULL }, 104 { &vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL=", 105 NULL }, 106 { &vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH=", 107 NULL }, 108 { &vpath, VSTRFIXED|VTEXTFIXED, "PATH=/bin:/usr/bin", 109 changepath }, 110 { &vppid, VSTRFIXED|VTEXTFIXED|VUNSET, "PPID=", 111 NULL }, 112 /* 113 * vps1 depends on uid 114 */ 115 { &vps2, VSTRFIXED|VTEXTFIXED, "PS2=> ", 116 NULL }, 117 { &voptind, VSTRFIXED|VTEXTFIXED, "OPTIND=1", 118 getoptsreset }, 119 { NULL, 0, NULL, 120 NULL } 121 }; 122 123 struct var *vartab[VTABSIZE]; 124 125 STATIC struct var **hashvar(char *); 126 STATIC int varequal(char *, char *); 127 STATIC int localevar(char *); 128 129 /* 130 * Initialize the varable symbol tables and import the environment 131 */ 132 133 #ifdef mkinit 134 INCLUDE "var.h" 135 INIT { 136 char **envp; 137 extern char **environ; 138 139 initvar(); 140 for (envp = environ ; *envp ; envp++) { 141 if (strchr(*envp, '=')) { 142 setvareq(*envp, VEXPORT|VTEXTFIXED); 143 } 144 } 145 } 146 #endif 147 148 149 /* 150 * This routine initializes the builtin variables. It is called when the 151 * shell is initialized and again when a shell procedure is spawned. 152 */ 153 154 void 155 initvar(void) 156 { 157 char ppid[20]; 158 const struct varinit *ip; 159 struct var *vp; 160 struct var **vpp; 161 162 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { 163 if ((vp->flags & VEXPORT) == 0) { 164 vpp = hashvar(ip->text); 165 vp->next = *vpp; 166 *vpp = vp; 167 vp->text = ip->text; 168 vp->flags = ip->flags; 169 vp->func = ip->func; 170 } 171 } 172 /* 173 * PS1 depends on uid 174 */ 175 if ((vps1.flags & VEXPORT) == 0) { 176 vpp = hashvar("PS1="); 177 vps1.next = *vpp; 178 *vpp = &vps1; 179 vps1.text = geteuid() ? "PS1=$ " : "PS1=# "; 180 vps1.flags = VSTRFIXED|VTEXTFIXED; 181 } 182 if ((vppid.flags & VEXPORT) == 0) { 183 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid()); 184 setvarsafe("PPID", ppid, 0); 185 } 186 } 187 188 /* 189 * Safe version of setvar, returns 1 on success 0 on failure. 190 */ 191 192 int 193 setvarsafe(char *name, char *val, int flags) 194 { 195 struct jmploc jmploc; 196 struct jmploc *volatile savehandler = handler; 197 int err = 0; 198 #if __GNUC__ 199 /* Avoid longjmp clobbering */ 200 (void) &err; 201 #endif 202 203 if (setjmp(jmploc.loc)) 204 err = 1; 205 else { 206 handler = &jmploc; 207 setvar(name, val, flags); 208 } 209 handler = savehandler; 210 return err; 211 } 212 213 /* 214 * Set the value of a variable. The flags argument is tored with the 215 * flags of the variable. If val is NULL, the variable is unset. 216 */ 217 218 void 219 setvar(char *name, char *val, int flags) 220 { 221 char *p, *q; 222 int len; 223 int namelen; 224 char *nameeq; 225 int isbad; 226 227 isbad = 0; 228 p = name; 229 if (! is_name(*p)) 230 isbad = 1; 231 p++; 232 for (;;) { 233 if (! is_in_name(*p)) { 234 if (*p == '\0' || *p == '=') 235 break; 236 isbad = 1; 237 } 238 p++; 239 } 240 namelen = p - name; 241 if (isbad) 242 error("%.*s: bad variable name", namelen, name); 243 len = namelen + 2; /* 2 is space for '=' and '\0' */ 244 if (val == NULL) { 245 flags |= VUNSET; 246 } else { 247 len += strlen(val); 248 } 249 p = nameeq = ckmalloc(len); 250 q = name; 251 while (--namelen >= 0) 252 *p++ = *q++; 253 *p++ = '='; 254 *p = '\0'; 255 if (val) 256 scopy(val, p); 257 setvareq(nameeq, flags); 258 } 259 260 STATIC int 261 localevar(char *s) 262 { 263 static char *lnames[7] = { 264 "ALL", "COLLATE", "CTYPE", "MONETARY", 265 "NUMERIC", "TIME", NULL 266 }; 267 char **ss; 268 269 if (*s != 'L') 270 return 0; 271 if (varequal(s + 1, "ANG")) 272 return 1; 273 if (strncmp(s + 1, "C_", 2) != 0) 274 return 0; 275 for (ss = lnames; *ss ; ss++) 276 if (varequal(s + 3, *ss)) 277 return 1; 278 return 0; 279 } 280 281 /* 282 * Same as setvar except that the variable and value are passed in 283 * the first argument as name=value. Since the first argument will 284 * be actually stored in the table, it should not be a string that 285 * will go away. 286 */ 287 288 void 289 setvareq(char *s, int flags) 290 { 291 struct var *vp, **vpp; 292 int len; 293 294 if (aflag) 295 flags |= VEXPORT; 296 vpp = hashvar(s); 297 for (vp = *vpp ; vp ; vp = vp->next) { 298 if (varequal(s, vp->text)) { 299 if (vp->flags & VREADONLY) { 300 len = strchr(s, '=') - s; 301 error("%.*s: is read only", len, s); 302 } 303 INTOFF; 304 305 if (vp->func && (flags & VNOFUNC) == 0) 306 (*vp->func)(strchr(s, '=') + 1); 307 308 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) 309 ckfree(vp->text); 310 311 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET); 312 vp->flags |= flags; 313 vp->text = s; 314 315 /* 316 * We could roll this to a function, to handle it as 317 * a regular variable function callback, but why bother? 318 */ 319 if (vp == &vmpath || (vp == &vmail && ! mpathset())) 320 chkmail(1); 321 if ((vp->flags & VEXPORT) && localevar(s)) { 322 putenv(s); 323 (void) setlocale(LC_ALL, ""); 324 } 325 INTON; 326 return; 327 } 328 } 329 /* not found */ 330 vp = ckmalloc(sizeof (*vp)); 331 vp->flags = flags; 332 vp->text = s; 333 vp->next = *vpp; 334 vp->func = NULL; 335 INTOFF; 336 *vpp = vp; 337 if ((vp->flags & VEXPORT) && localevar(s)) { 338 putenv(s); 339 (void) setlocale(LC_ALL, ""); 340 } 341 INTON; 342 } 343 344 345 346 /* 347 * Process a linked list of variable assignments. 348 */ 349 350 void 351 listsetvar(struct strlist *list) 352 { 353 struct strlist *lp; 354 355 INTOFF; 356 for (lp = list ; lp ; lp = lp->next) { 357 setvareq(savestr(lp->text), 0); 358 } 359 INTON; 360 } 361 362 363 364 /* 365 * Find the value of a variable. Returns NULL if not set. 366 */ 367 368 char * 369 lookupvar(char *name) 370 { 371 struct var *v; 372 373 for (v = *hashvar(name) ; v ; v = v->next) { 374 if (varequal(v->text, name)) { 375 if (v->flags & VUNSET) 376 return NULL; 377 return strchr(v->text, '=') + 1; 378 } 379 } 380 return NULL; 381 } 382 383 384 385 /* 386 * Search the environment of a builtin command. If the second argument 387 * is nonzero, return the value of a variable even if it hasn't been 388 * exported. 389 */ 390 391 char * 392 bltinlookup(char *name, int doall) 393 { 394 struct strlist *sp; 395 struct var *v; 396 397 for (sp = cmdenviron ; sp ; sp = sp->next) { 398 if (varequal(sp->text, name)) 399 return strchr(sp->text, '=') + 1; 400 } 401 for (v = *hashvar(name) ; v ; v = v->next) { 402 if (varequal(v->text, name)) { 403 if ((v->flags & VUNSET) 404 || (!doall && (v->flags & VEXPORT) == 0)) 405 return NULL; 406 return strchr(v->text, '=') + 1; 407 } 408 } 409 return NULL; 410 } 411 412 413 414 /* 415 * Generate a list of exported variables. This routine is used to construct 416 * the third argument to execve when executing a program. 417 */ 418 419 char ** 420 environment(void) 421 { 422 int nenv; 423 struct var **vpp; 424 struct var *vp; 425 char **env, **ep; 426 427 nenv = 0; 428 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 429 for (vp = *vpp ; vp ; vp = vp->next) 430 if (vp->flags & VEXPORT) 431 nenv++; 432 } 433 ep = env = stalloc((nenv + 1) * sizeof *env); 434 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 435 for (vp = *vpp ; vp ; vp = vp->next) 436 if (vp->flags & VEXPORT) 437 *ep++ = vp->text; 438 } 439 *ep = NULL; 440 return env; 441 } 442 443 444 /* 445 * Called when a shell procedure is invoked to clear out nonexported 446 * variables. It is also necessary to reallocate variables of with 447 * VSTACK set since these are currently allocated on the stack. 448 */ 449 450 #ifdef mkinit 451 MKINIT void shprocvar(); 452 453 SHELLPROC { 454 shprocvar(); 455 } 456 #endif 457 458 void 459 shprocvar(void) 460 { 461 struct var **vpp; 462 struct var *vp, **prev; 463 464 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 465 for (prev = vpp ; (vp = *prev) != NULL ; ) { 466 if ((vp->flags & VEXPORT) == 0) { 467 *prev = vp->next; 468 if ((vp->flags & VTEXTFIXED) == 0) 469 ckfree(vp->text); 470 if ((vp->flags & VSTRFIXED) == 0) 471 ckfree(vp); 472 } else { 473 if (vp->flags & VSTACK) { 474 vp->text = savestr(vp->text); 475 vp->flags &=~ VSTACK; 476 } 477 prev = &vp->next; 478 } 479 } 480 } 481 initvar(); 482 } 483 484 485 486 /* 487 * Command to list all variables which are set. Currently this command 488 * is invoked from the set command when the set command is called without 489 * any variables. 490 */ 491 492 int 493 showvarscmd(int argc __unused, char **argv __unused) 494 { 495 struct var **vpp; 496 struct var *vp; 497 const char *s; 498 499 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 500 for (vp = *vpp ; vp ; vp = vp->next) { 501 if (vp->flags & VUNSET) 502 continue; 503 for (s = vp->text; *s != '='; s++) 504 out1c(*s); 505 out1c('='); 506 out1qstr(s + 1); 507 out1c('\n'); 508 } 509 } 510 return 0; 511 } 512 513 514 515 /* 516 * The export and readonly commands. 517 */ 518 519 int 520 exportcmd(int argc, char **argv) 521 { 522 struct var **vpp; 523 struct var *vp; 524 char *name; 525 char *p; 526 char *cmdname; 527 int ch, values; 528 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 529 530 cmdname = argv[0]; 531 optreset = optind = 1; 532 opterr = 0; 533 values = 0; 534 while ((ch = getopt(argc, argv, "p")) != -1) { 535 switch (ch) { 536 case 'p': 537 values = 1; 538 break; 539 case '?': 540 default: 541 error("unknown option: -%c", optopt); 542 } 543 } 544 argc -= optind; 545 argv += optind; 546 547 listsetvar(cmdenviron); 548 if (argc != 0) { 549 while ((name = *argptr++) != NULL) { 550 if ((p = strchr(name, '=')) != NULL) { 551 p++; 552 } else { 553 vpp = hashvar(name); 554 for (vp = *vpp ; vp ; vp = vp->next) { 555 if (varequal(vp->text, name)) { 556 557 vp->flags |= flag; 558 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 559 putenv(vp->text); 560 (void) 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 (void)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(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 } 766 767 return (1); 768 } 769 770 771 772 /* 773 * Find the appropriate entry in the hash table from the name. 774 */ 775 776 STATIC struct var ** 777 hashvar(char *p) 778 { 779 unsigned int hashval; 780 781 hashval = ((unsigned char) *p) << 4; 782 while (*p && *p != '=') 783 hashval += (unsigned char) *p++; 784 return &vartab[hashval % VTABSIZE]; 785 } 786 787 788 789 /* 790 * Returns true if the two strings specify the same varable. The first 791 * variable name is terminated by '='; the second may be terminated by 792 * either '=' or '\0'. 793 */ 794 795 STATIC int 796 varequal(char *p, char *q) 797 { 798 while (*p == *q++) { 799 if (*p++ == '=') 800 return 1; 801 } 802 if (*p == '=' && *(q - 1) == '\0') 803 return 1; 804 return 0; 805 } 806