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 1.14 2007/01/14 15:14:52 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 #if __GNUC__ 198 /* Avoid longjmp clobbering */ 199 (void) &err; 200 #endif 201 202 if (setjmp(jmploc.loc)) 203 err = 1; 204 else { 205 handler = &jmploc; 206 setvar(name, val, flags); 207 } 208 handler = savehandler; 209 return err; 210 } 211 212 /* 213 * Set the value of a variable. The flags argument is stored with the 214 * flags of the variable. If val is NULL, the variable is unset. 215 */ 216 217 void 218 setvar(const char *name, const char *val, int flags) 219 { 220 const char *cp; 221 char *p; 222 int len; 223 int namelen; 224 char *nameeq; 225 int isbad; 226 227 isbad = 0; 228 cp = name; 229 if (!is_name(*cp)) 230 isbad = 1; 231 cp++; 232 for (;;) { 233 if (!is_in_name(*cp)) { 234 if (*cp == '\0' || *cp == '=') 235 break; 236 isbad = 1; 237 } 238 cp++; 239 } 240 namelen = cp - 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 cp = name; 251 while (--namelen >= 0) 252 *p++ = *cp++; 253 *p++ = '='; 254 *p = '\0'; 255 if (val) 256 scopy(val, p); 257 setvareq(nameeq, flags); 258 } 259 260 STATIC int 261 localevar(const char *s) 262 { 263 static const char * const lnames[7] = { 264 "ALL", "COLLATE", "CTYPE", "MONETARY", 265 "NUMERIC", "TIME", NULL 266 }; 267 const char * const *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 if (putenv(s) != 0) 323 error("putenv: cannot set %s", s); 324 setlocale(LC_ALL, ""); 325 } 326 INTON; 327 return; 328 } 329 } 330 /* not found */ 331 vp = ckmalloc(sizeof (*vp)); 332 vp->flags = flags; 333 vp->text = s; 334 vp->next = *vpp; 335 vp->func = NULL; 336 INTOFF; 337 *vpp = vp; 338 if ((vp->flags & VEXPORT) && localevar(s)) { 339 if (putenv(s) != 0) 340 error("putenv: cannot set %s", s); 341 setlocale(LC_ALL, ""); 342 } 343 INTON; 344 } 345 346 347 348 /* 349 * Process a linked list of variable assignments. 350 */ 351 352 void 353 listsetvar(struct strlist *list) 354 { 355 struct strlist *lp; 356 357 INTOFF; 358 for (lp = list ; lp ; lp = lp->next) { 359 setvareq(savestr(lp->text), 0); 360 } 361 INTON; 362 } 363 364 365 366 /* 367 * Find the value of a variable. Returns NULL if not set. 368 */ 369 370 char * 371 lookupvar(const char *name) 372 { 373 struct var *v; 374 375 for (v = *hashvar(name) ; v ; v = v->next) { 376 if (varequal(v->text, name)) { 377 if (v->flags & VUNSET) 378 return NULL; 379 return strchr(v->text, '=') + 1; 380 } 381 } 382 return NULL; 383 } 384 385 386 387 /* 388 * Search the environment of a builtin command. If the second argument 389 * is nonzero, return the value of a variable even if it hasn't been 390 * exported. 391 */ 392 393 char * 394 bltinlookup(const char *name, int doall) 395 { 396 struct strlist *sp; 397 struct var *v; 398 399 for (sp = cmdenviron ; sp ; sp = sp->next) { 400 if (varequal(sp->text, name)) 401 return strchr(sp->text, '=') + 1; 402 } 403 for (v = *hashvar(name) ; v ; v = v->next) { 404 if (varequal(v->text, name)) { 405 if ((v->flags & VUNSET) 406 || (!doall && (v->flags & VEXPORT) == 0)) 407 return NULL; 408 return strchr(v->text, '=') + 1; 409 } 410 } 411 return NULL; 412 } 413 414 415 416 /* 417 * Generate a list of exported variables. This routine is used to construct 418 * the third argument to execve when executing a program. 419 */ 420 421 char ** 422 environment(void) 423 { 424 int nenv; 425 struct var **vpp; 426 struct var *vp; 427 char **env, **ep; 428 429 nenv = 0; 430 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 431 for (vp = *vpp ; vp ; vp = vp->next) 432 if (vp->flags & VEXPORT) 433 nenv++; 434 } 435 ep = env = stalloc((nenv + 1) * sizeof *env); 436 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 437 for (vp = *vpp ; vp ; vp = vp->next) 438 if (vp->flags & VEXPORT) 439 *ep++ = vp->text; 440 } 441 *ep = NULL; 442 return env; 443 } 444 445 446 /* 447 * Called when a shell procedure is invoked to clear out nonexported 448 * variables. It is also necessary to reallocate variables of with 449 * VSTACK set since these are currently allocated on the stack. 450 */ 451 452 #ifdef mkinit 453 void shprocvar(void); 454 455 SHELLPROC { 456 shprocvar(); 457 } 458 #endif 459 460 void 461 shprocvar(void) 462 { 463 struct var **vpp; 464 struct var *vp, **prev; 465 466 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 467 for (prev = vpp ; (vp = *prev) != NULL ; ) { 468 if ((vp->flags & VEXPORT) == 0) { 469 *prev = vp->next; 470 if ((vp->flags & VTEXTFIXED) == 0) 471 ckfree(vp->text); 472 if ((vp->flags & VSTRFIXED) == 0) 473 ckfree(vp); 474 } else { 475 if (vp->flags & VSTACK) { 476 vp->text = savestr(vp->text); 477 vp->flags &=~ VSTACK; 478 } 479 prev = &vp->next; 480 } 481 } 482 } 483 initvar(); 484 } 485 486 487 static int 488 var_compare(const void *a, const void *b) 489 { 490 const char *const *sa, *const *sb; 491 492 sa = a; 493 sb = b; 494 /* 495 * This compares two var=value strings which creates a different 496 * order from what you would probably expect. POSIX is somewhat 497 * ambiguous on what should be sorted exactly. 498 */ 499 return strcoll(*sa, *sb); 500 } 501 502 503 /* 504 * Command to list all variables which are set. Currently this command 505 * is invoked from the set command when the set command is called without 506 * any variables. 507 */ 508 509 int 510 showvarscmd(int argc __unused, char **argv __unused) 511 { 512 struct var **vpp; 513 struct var *vp; 514 const char *s; 515 const char **vars; 516 int i, n; 517 518 /* 519 * POSIX requires us to sort the variables. 520 */ 521 n = 0; 522 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 523 for (vp = *vpp; vp; vp = vp->next) { 524 if (!(vp->flags & VUNSET)) 525 n++; 526 } 527 } 528 529 INTON; 530 vars = ckmalloc(n * sizeof(*vars)); 531 i = 0; 532 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 533 for (vp = *vpp; vp; vp = vp->next) { 534 if (!(vp->flags & VUNSET)) 535 vars[i++] = vp->text; 536 } 537 } 538 539 qsort(vars, n, sizeof(*vars), var_compare); 540 for (i = 0; i < n; i++) { 541 for (s = vars[i]; *s != '='; s++) 542 out1c(*s); 543 out1c('='); 544 out1qstr(s + 1); 545 out1c('\n'); 546 } 547 ckfree(vars); 548 INTOFF; 549 550 return 0; 551 } 552 553 554 555 /* 556 * The export and readonly commands. 557 */ 558 559 int 560 exportcmd(int argc, char **argv) 561 { 562 struct var **vpp; 563 struct var *vp; 564 char *name; 565 char *p; 566 char *cmdname; 567 int ch, values; 568 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 569 570 cmdname = argv[0]; 571 optreset = optind = 1; 572 opterr = 0; 573 values = 0; 574 while ((ch = getopt(argc, argv, "p")) != -1) { 575 switch (ch) { 576 case 'p': 577 values = 1; 578 break; 579 case '?': 580 default: 581 error("unknown option: -%c", optopt); 582 } 583 } 584 argc -= optind; 585 argv += optind; 586 587 if (values && argc != 0) 588 error("-p requires no arguments"); 589 listsetvar(cmdenviron); 590 if (argc != 0) { 591 while ((name = *argv++) != NULL) { 592 if ((p = strchr(name, '=')) != NULL) { 593 p++; 594 } else { 595 vpp = hashvar(name); 596 for (vp = *vpp ; vp ; vp = vp->next) { 597 if (varequal(vp->text, name)) { 598 599 vp->flags |= flag; 600 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 601 if (putenv(vp->text) != 0) 602 error("putenv: cannot set %s", vp->text); 603 setlocale(LC_ALL, ""); 604 } 605 goto found; 606 } 607 } 608 } 609 setvar(name, p, flag); 610 found:; 611 } 612 } else { 613 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 614 for (vp = *vpp ; vp ; vp = vp->next) { 615 if (vp->flags & flag) { 616 if (values) { 617 out1str(cmdname); 618 out1c(' '); 619 } 620 for (p = vp->text ; *p != '=' ; p++) 621 out1c(*p); 622 if (values && !(vp->flags & VUNSET)) { 623 out1c('='); 624 out1qstr(p + 1); 625 } 626 out1c('\n'); 627 } 628 } 629 } 630 } 631 return 0; 632 } 633 634 635 /* 636 * The "local" command. 637 */ 638 639 int 640 localcmd(int argc __unused, char **argv __unused) 641 { 642 char *name; 643 644 if (! in_function()) 645 error("Not in a function"); 646 while ((name = *argptr++) != NULL) { 647 mklocal(name); 648 } 649 return 0; 650 } 651 652 653 /* 654 * Make a variable a local variable. When a variable is made local, it's 655 * value and flags are saved in a localvar structure. The saved values 656 * will be restored when the shell function returns. We handle the name 657 * "-" as a special case. 658 */ 659 660 void 661 mklocal(char *name) 662 { 663 struct localvar *lvp; 664 struct var **vpp; 665 struct var *vp; 666 667 INTOFF; 668 lvp = ckmalloc(sizeof (struct localvar)); 669 if (name[0] == '-' && name[1] == '\0') { 670 lvp->text = ckmalloc(sizeof optlist); 671 memcpy(lvp->text, optlist, sizeof optlist); 672 vp = NULL; 673 } else { 674 vpp = hashvar(name); 675 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); 676 if (vp == NULL) { 677 if (strchr(name, '=')) 678 setvareq(savestr(name), VSTRFIXED); 679 else 680 setvar(name, NULL, VSTRFIXED); 681 vp = *vpp; /* the new variable */ 682 lvp->text = NULL; 683 lvp->flags = VUNSET; 684 } else { 685 lvp->text = vp->text; 686 lvp->flags = vp->flags; 687 vp->flags |= VSTRFIXED|VTEXTFIXED; 688 if (strchr(name, '=')) 689 setvareq(savestr(name), 0); 690 } 691 } 692 lvp->vp = vp; 693 lvp->next = localvars; 694 localvars = lvp; 695 INTON; 696 } 697 698 699 /* 700 * Called after a function returns. 701 */ 702 703 void 704 poplocalvars(void) 705 { 706 struct localvar *lvp; 707 struct var *vp; 708 709 while ((lvp = localvars) != NULL) { 710 localvars = lvp->next; 711 vp = lvp->vp; 712 if (vp == NULL) { /* $- saved */ 713 memcpy(optlist, lvp->text, sizeof optlist); 714 ckfree(lvp->text); 715 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 716 unsetvar(vp->text); 717 } else { 718 if ((vp->flags & VTEXTFIXED) == 0) 719 ckfree(vp->text); 720 vp->flags = lvp->flags; 721 vp->text = lvp->text; 722 } 723 ckfree(lvp); 724 } 725 } 726 727 728 int 729 setvarcmd(int argc, char **argv) 730 { 731 if (argc <= 2) 732 return unsetcmd(argc, argv); 733 else if (argc == 3) 734 setvar(argv[1], argv[2], 0); 735 else 736 error("List assignment not implemented"); 737 return 0; 738 } 739 740 741 /* 742 * The unset builtin command. We unset the function before we unset the 743 * variable to allow a function to be unset when there is a readonly variable 744 * with the same name. 745 */ 746 747 int 748 unsetcmd(int argc __unused, char **argv __unused) 749 { 750 char **ap; 751 int i; 752 int flg_func = 0; 753 int flg_var = 0; 754 int ret = 0; 755 756 while ((i = nextopt("vf")) != '\0') { 757 if (i == 'f') 758 flg_func = 1; 759 else 760 flg_var = 1; 761 } 762 if (flg_func == 0 && flg_var == 0) 763 flg_var = 1; 764 765 for (ap = argptr; *ap ; ap++) { 766 if (flg_func) 767 ret |= unsetfunc(*ap); 768 if (flg_var) 769 ret |= unsetvar(*ap); 770 } 771 return ret; 772 } 773 774 775 /* 776 * Unset the specified variable. 777 */ 778 779 int 780 unsetvar(const char *s) 781 { 782 struct var **vpp; 783 struct var *vp; 784 785 vpp = hashvar(s); 786 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 787 if (varequal(vp->text, s)) { 788 if (vp->flags & VREADONLY) 789 return (1); 790 INTOFF; 791 if (*(strchr(vp->text, '=') + 1) != '\0') 792 setvar(s, nullstr, 0); 793 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 794 unsetenv(s); 795 setlocale(LC_ALL, ""); 796 } 797 vp->flags &= ~VEXPORT; 798 vp->flags |= VUNSET; 799 if ((vp->flags & VSTRFIXED) == 0) { 800 if ((vp->flags & VTEXTFIXED) == 0) 801 ckfree(vp->text); 802 *vpp = vp->next; 803 ckfree(vp); 804 } 805 INTON; 806 return (0); 807 } 808 } 809 return (0); 810 } 811 812 813 814 /* 815 * Find the appropriate entry in the hash table from the name. 816 */ 817 818 STATIC struct var ** 819 hashvar(const char *p) 820 { 821 unsigned int hashval; 822 823 hashval = ((unsigned char) *p) << 4; 824 while (*p && *p != '=') 825 hashval += (unsigned char) *p++; 826 return &vartab[hashval % VTABSIZE]; 827 } 828 829 830 831 /* 832 * Returns true if the two strings specify the same varable. The first 833 * variable name is terminated by '='; the second may be terminated by 834 * either '=' or '\0'. 835 */ 836 837 STATIC int 838 varequal(const char *p, const char *q) 839 { 840 while (*p == *q++) { 841 if (*p++ == '=') 842 return 1; 843 } 844 if (*p == '=' && *(q - 1) == '\0') 845 return 1; 846 return 0; 847 } 848