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