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 1.15 2007/01/14 17:29:58 pavalos Exp $ 39 */ 40 41 #include <unistd.h> 42 #include <stdlib.h> 43 44 /* 45 * Shell variables. 46 */ 47 48 #include <locale.h> 49 #include <paths.h> 50 51 #include "shell.h" 52 #include "output.h" 53 #include "expand.h" 54 #include "nodes.h" /* for other headers */ 55 #include "eval.h" /* defines cmdenviron */ 56 #include "exec.h" 57 #include "syntax.h" 58 #include "options.h" 59 #include "mail.h" 60 #include "var.h" 61 #include "memalloc.h" 62 #include "error.h" 63 #include "mystring.h" 64 #include "parser.h" 65 #ifndef NO_HISTORY 66 #include "myhistedit.h" 67 #endif 68 69 70 #define VTABSIZE 39 71 72 73 struct varinit { 74 struct var *var; 75 int flags; 76 const char *text; 77 void (*func)(const char *); 78 }; 79 80 81 #ifndef NO_HISTORY 82 struct var vhistsize; 83 #endif 84 struct var vifs; 85 struct var vmail; 86 struct var vmpath; 87 struct var vpath; 88 struct var vppid; 89 struct var vps1; 90 struct var vps2; 91 struct var vps4; 92 struct var vvers; 93 STATIC struct var voptind; 94 95 STATIC const struct varinit varinit[] = { 96 #ifndef NO_HISTORY 97 { &vhistsize, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE=", 98 sethistsize }, 99 #endif 100 { &vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n", 101 NULL }, 102 { &vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL=", 103 NULL }, 104 { &vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH=", 105 NULL }, 106 { &vpath, VSTRFIXED|VTEXTFIXED|VEXPORT, 107 #ifdef _PATH_DEFPATH 108 "PATH=" _PATH_DEFPATH, 109 #else 110 "PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/pkg/bin:/usr/pkg/sbin", 111 #endif 112 changepath }, 113 { &vppid, VSTRFIXED|VTEXTFIXED|VUNSET, "PPID=", 114 NULL }, 115 /* 116 * vps1 depends on uid 117 */ 118 { &vps2, VSTRFIXED|VTEXTFIXED, "PS2=> ", 119 NULL }, 120 { &vps4, VSTRFIXED|VTEXTFIXED, "PS4=+ ", 121 NULL }, 122 { &voptind, VSTRFIXED|VTEXTFIXED, "OPTIND=1", 123 getoptsreset }, 124 { NULL, 0, NULL, 125 NULL } 126 }; 127 128 STATIC struct var *vartab[VTABSIZE]; 129 130 STATIC struct var **hashvar(const char *); 131 STATIC int varequal(const char *, const char *); 132 STATIC int localevar(const char *); 133 134 /* 135 * Initialize the variable symbol tables and import the environment. 136 */ 137 138 #ifdef mkinit 139 INCLUDE "var.h" 140 MKINIT char **environ; 141 INIT { 142 char **envp; 143 144 initvar(); 145 for (envp = environ ; *envp ; envp++) { 146 if (strchr(*envp, '=')) { 147 setvareq(*envp, VEXPORT|VTEXTFIXED); 148 } 149 } 150 } 151 #endif 152 153 154 /* 155 * This routine initializes the builtin variables. It is called when the 156 * shell is initialized and again when a shell procedure is spawned. 157 */ 158 159 void 160 initvar(void) 161 { 162 char ppid[20]; 163 const struct varinit *ip; 164 struct var *vp; 165 struct var **vpp; 166 167 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { 168 if ((vp->flags & VEXPORT) == 0) { 169 vpp = hashvar(ip->text); 170 vp->next = *vpp; 171 *vpp = vp; 172 vp->text = strdup(ip->text); 173 vp->flags = ip->flags; 174 vp->func = ip->func; 175 } 176 } 177 /* 178 * PS1 depends on uid 179 */ 180 if ((vps1.flags & VEXPORT) == 0) { 181 vpp = hashvar("PS1="); 182 vps1.next = *vpp; 183 *vpp = &vps1; 184 vps1.text = strdup(geteuid() ? "PS1=$ " : "PS1=# "); 185 vps1.flags = VSTRFIXED|VTEXTFIXED; 186 } 187 if ((vppid.flags & VEXPORT) == 0) { 188 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid()); 189 setvarsafe("PPID", ppid, 0); 190 } 191 } 192 193 /* 194 * Safe version of setvar, returns 1 on success 0 on failure. 195 */ 196 197 int 198 setvarsafe(const char *name, const char *val, int flags) 199 { 200 struct jmploc jmploc; 201 struct jmploc *volatile savehandler = handler; 202 int err = 0; 203 204 if (setjmp(jmploc.loc)) 205 err = 1; 206 else { 207 handler = &jmploc; 208 setvar(name, val, flags); 209 } 210 handler = savehandler; 211 return err; 212 } 213 214 /* 215 * Set the value of a variable. The flags argument is stored with the 216 * flags of the variable. If val is NULL, the variable is unset. 217 */ 218 219 void 220 setvar(const char *name, const char *val, int flags) 221 { 222 const char *cp; 223 char *p; 224 int len; 225 int namelen; 226 char *nameeq; 227 int isbad; 228 229 isbad = 0; 230 cp = name; 231 if (!is_name(*cp)) 232 isbad = 1; 233 cp++; 234 for (;;) { 235 if (!is_in_name(*cp)) { 236 if (*cp == '\0' || *cp == '=') 237 break; 238 isbad = 1; 239 } 240 cp++; 241 } 242 namelen = cp - name; 243 if (isbad) 244 error("%.*s: bad variable name", namelen, name); 245 len = namelen + 2; /* 2 is space for '=' and '\0' */ 246 if (val == NULL) { 247 flags |= VUNSET; 248 } else { 249 len += strlen(val); 250 } 251 p = nameeq = ckmalloc(len); 252 cp = name; 253 while (--namelen >= 0) 254 *p++ = *cp++; 255 *p++ = '='; 256 *p = '\0'; 257 if (val) 258 scopy(val, p); 259 setvareq(nameeq, flags); 260 } 261 262 STATIC int 263 localevar(const char *s) 264 { 265 static const char * const lnames[7] = { 266 "ALL", "COLLATE", "CTYPE", "MONETARY", 267 "NUMERIC", "TIME", NULL 268 }; 269 const char * const *ss; 270 271 if (*s != 'L') 272 return 0; 273 if (varequal(s + 1, "ANG")) 274 return 1; 275 if (strncmp(s + 1, "C_", 2) != 0) 276 return 0; 277 for (ss = lnames; *ss ; ss++) 278 if (varequal(s + 3, *ss)) 279 return 1; 280 return 0; 281 } 282 283 /* 284 * Same as setvar except that the variable and value are passed in 285 * the first argument as name=value. Since the first argument will 286 * be actually stored in the table, it should not be a string that 287 * will go away. 288 */ 289 290 void 291 setvareq(char *s, int flags) 292 { 293 struct var *vp, **vpp; 294 int len; 295 296 if (aflag) 297 flags |= VEXPORT; 298 vpp = hashvar(s); 299 for (vp = *vpp ; vp ; vp = vp->next) { 300 if (varequal(s, vp->text)) { 301 if (vp->flags & VREADONLY) { 302 len = strchr(s, '=') - s; 303 error("%.*s: is read only", len, s); 304 } 305 INTOFF; 306 307 if (vp->func && (flags & VNOFUNC) == 0) 308 (*vp->func)(strchr(s, '=') + 1); 309 310 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) 311 ckfree(vp->text); 312 313 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET); 314 vp->flags |= flags; 315 vp->text = s; 316 317 /* 318 * We could roll this to a function, to handle it as 319 * a regular variable function callback, but why bother? 320 */ 321 if (vp == &vmpath || (vp == &vmail && ! mpathset())) 322 chkmail(1); 323 if ((vp->flags & VEXPORT) && localevar(s)) { 324 if (putenv(s) != 0) 325 error("putenv: cannot set %s", s); 326 setlocale(LC_ALL, ""); 327 } 328 INTON; 329 return; 330 } 331 } 332 /* not found */ 333 vp = ckmalloc(sizeof (*vp)); 334 vp->flags = flags; 335 vp->text = s; 336 vp->next = *vpp; 337 vp->func = NULL; 338 INTOFF; 339 *vpp = vp; 340 if ((vp->flags & VEXPORT) && localevar(s)) { 341 if (putenv(s) != 0) 342 error("putenv: cannot set %s", s); 343 setlocale(LC_ALL, ""); 344 } 345 INTON; 346 } 347 348 349 350 /* 351 * Process a linked list of variable assignments. 352 */ 353 354 void 355 listsetvar(struct strlist *list) 356 { 357 struct strlist *lp; 358 359 INTOFF; 360 for (lp = list ; lp ; lp = lp->next) { 361 setvareq(savestr(lp->text), 0); 362 } 363 INTON; 364 } 365 366 367 368 /* 369 * Find the value of a variable. Returns NULL if not set. 370 */ 371 372 char * 373 lookupvar(const char *name) 374 { 375 struct var *v; 376 377 for (v = *hashvar(name) ; v ; v = v->next) { 378 if (varequal(v->text, name)) { 379 if (v->flags & VUNSET) 380 return NULL; 381 return strchr(v->text, '=') + 1; 382 } 383 } 384 return NULL; 385 } 386 387 388 389 /* 390 * Search the environment of a builtin command. If the second argument 391 * is nonzero, return the value of a variable even if it hasn't been 392 * exported. 393 */ 394 395 char * 396 bltinlookup(const char *name, int doall) 397 { 398 struct strlist *sp; 399 struct var *v; 400 401 for (sp = cmdenviron ; sp ; sp = sp->next) { 402 if (varequal(sp->text, name)) 403 return strchr(sp->text, '=') + 1; 404 } 405 for (v = *hashvar(name) ; v ; v = v->next) { 406 if (varequal(v->text, name)) { 407 if ((v->flags & VUNSET) 408 || (!doall && (v->flags & VEXPORT) == 0)) 409 return NULL; 410 return strchr(v->text, '=') + 1; 411 } 412 } 413 return NULL; 414 } 415 416 417 418 /* 419 * Generate a list of exported variables. This routine is used to construct 420 * the third argument to execve when executing a program. 421 */ 422 423 char ** 424 environment(void) 425 { 426 int nenv; 427 struct var **vpp; 428 struct var *vp; 429 char **env, **ep; 430 431 nenv = 0; 432 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 433 for (vp = *vpp ; vp ; vp = vp->next) 434 if (vp->flags & VEXPORT) 435 nenv++; 436 } 437 ep = env = stalloc((nenv + 1) * sizeof *env); 438 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 439 for (vp = *vpp ; vp ; vp = vp->next) 440 if (vp->flags & VEXPORT) 441 *ep++ = vp->text; 442 } 443 *ep = NULL; 444 return env; 445 } 446 447 448 /* 449 * Called when a shell procedure is invoked to clear out nonexported 450 * variables. It is also necessary to reallocate variables of with 451 * VSTACK set since these are currently allocated on the stack. 452 */ 453 454 #ifdef mkinit 455 void shprocvar(void); 456 457 SHELLPROC { 458 shprocvar(); 459 } 460 #endif 461 462 void 463 shprocvar(void) 464 { 465 struct var **vpp; 466 struct var *vp, **prev; 467 468 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 469 for (prev = vpp ; (vp = *prev) != NULL ; ) { 470 if ((vp->flags & VEXPORT) == 0) { 471 *prev = vp->next; 472 if ((vp->flags & VTEXTFIXED) == 0) 473 ckfree(vp->text); 474 if ((vp->flags & VSTRFIXED) == 0) 475 ckfree(vp); 476 } else { 477 if (vp->flags & VSTACK) { 478 vp->text = savestr(vp->text); 479 vp->flags &=~ VSTACK; 480 } 481 prev = &vp->next; 482 } 483 } 484 } 485 initvar(); 486 } 487 488 489 static int 490 var_compare(const void *a, const void *b) 491 { 492 const char *const *sa, *const *sb; 493 494 sa = a; 495 sb = b; 496 /* 497 * This compares two var=value strings which creates a different 498 * order from what you would probably expect. POSIX is somewhat 499 * ambiguous on what should be sorted exactly. 500 */ 501 return strcoll(*sa, *sb); 502 } 503 504 505 /* 506 * Command to list all variables which are set. Currently this command 507 * is invoked from the set command when the set command is called without 508 * any variables. 509 */ 510 511 int 512 showvarscmd(int argc __unused, char **argv __unused) 513 { 514 struct var **vpp; 515 struct var *vp; 516 const char *s; 517 const char **vars; 518 int i, n; 519 520 /* 521 * POSIX requires us to sort the variables. 522 */ 523 n = 0; 524 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 525 for (vp = *vpp; vp; vp = vp->next) { 526 if (!(vp->flags & VUNSET)) 527 n++; 528 } 529 } 530 531 INTON; 532 vars = ckmalloc(n * sizeof(*vars)); 533 i = 0; 534 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 535 for (vp = *vpp; vp; vp = vp->next) { 536 if (!(vp->flags & VUNSET)) 537 vars[i++] = vp->text; 538 } 539 } 540 541 qsort(vars, n, sizeof(*vars), var_compare); 542 for (i = 0; i < n; i++) { 543 for (s = vars[i]; *s != '='; s++) 544 out1c(*s); 545 out1c('='); 546 out1qstr(s + 1); 547 out1c('\n'); 548 } 549 ckfree(vars); 550 INTOFF; 551 552 return 0; 553 } 554 555 556 557 /* 558 * The export and readonly commands. 559 */ 560 561 int 562 exportcmd(int argc, char **argv) 563 { 564 struct var **vpp; 565 struct var *vp; 566 char *name; 567 char *p; 568 char *cmdname; 569 int ch, values; 570 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 571 572 cmdname = argv[0]; 573 optreset = optind = 1; 574 opterr = 0; 575 values = 0; 576 while ((ch = getopt(argc, argv, "p")) != -1) { 577 switch (ch) { 578 case 'p': 579 values = 1; 580 break; 581 case '?': 582 default: 583 error("unknown option: -%c", optopt); 584 } 585 } 586 argc -= optind; 587 argv += optind; 588 589 if (values && argc != 0) 590 error("-p requires no arguments"); 591 listsetvar(cmdenviron); 592 if (argc != 0) { 593 while ((name = *argv++) != NULL) { 594 if ((p = strchr(name, '=')) != NULL) { 595 p++; 596 } else { 597 vpp = hashvar(name); 598 for (vp = *vpp ; vp ; vp = vp->next) { 599 if (varequal(vp->text, name)) { 600 601 vp->flags |= flag; 602 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 603 if (putenv(vp->text) != 0) 604 error("putenv: cannot set %s", vp->text); 605 setlocale(LC_ALL, ""); 606 } 607 goto found; 608 } 609 } 610 } 611 setvar(name, p, flag); 612 found:; 613 } 614 } else { 615 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 616 for (vp = *vpp ; vp ; vp = vp->next) { 617 if (vp->flags & flag) { 618 if (values) { 619 out1str(cmdname); 620 out1c(' '); 621 } 622 for (p = vp->text ; *p != '=' ; p++) 623 out1c(*p); 624 if (values && !(vp->flags & VUNSET)) { 625 out1c('='); 626 out1qstr(p + 1); 627 } 628 out1c('\n'); 629 } 630 } 631 } 632 } 633 return 0; 634 } 635 636 637 /* 638 * The "local" command. 639 */ 640 641 int 642 localcmd(int argc __unused, char **argv __unused) 643 { 644 char *name; 645 646 if (! in_function()) 647 error("Not in a function"); 648 while ((name = *argptr++) != NULL) { 649 mklocal(name); 650 } 651 return 0; 652 } 653 654 655 /* 656 * Make a variable a local variable. When a variable is made local, it's 657 * value and flags are saved in a localvar structure. The saved values 658 * will be restored when the shell function returns. We handle the name 659 * "-" as a special case. 660 */ 661 662 void 663 mklocal(char *name) 664 { 665 struct localvar *lvp; 666 struct var **vpp; 667 struct var *vp; 668 669 INTOFF; 670 lvp = ckmalloc(sizeof (struct localvar)); 671 if (name[0] == '-' && name[1] == '\0') { 672 lvp->text = ckmalloc(sizeof optlist); 673 memcpy(lvp->text, optlist, sizeof optlist); 674 vp = NULL; 675 } else { 676 vpp = hashvar(name); 677 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); 678 if (vp == NULL) { 679 if (strchr(name, '=')) 680 setvareq(savestr(name), VSTRFIXED); 681 else 682 setvar(name, NULL, VSTRFIXED); 683 vp = *vpp; /* the new variable */ 684 lvp->text = NULL; 685 lvp->flags = VUNSET; 686 } else { 687 lvp->text = vp->text; 688 lvp->flags = vp->flags; 689 vp->flags |= VSTRFIXED|VTEXTFIXED; 690 if (strchr(name, '=')) 691 setvareq(savestr(name), 0); 692 } 693 } 694 lvp->vp = vp; 695 lvp->next = localvars; 696 localvars = lvp; 697 INTON; 698 } 699 700 701 /* 702 * Called after a function returns. 703 */ 704 705 void 706 poplocalvars(void) 707 { 708 struct localvar *lvp; 709 struct var *vp; 710 711 while ((lvp = localvars) != NULL) { 712 localvars = lvp->next; 713 vp = lvp->vp; 714 if (vp == NULL) { /* $- saved */ 715 memcpy(optlist, lvp->text, sizeof optlist); 716 ckfree(lvp->text); 717 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 718 unsetvar(vp->text); 719 } else { 720 if ((vp->flags & VTEXTFIXED) == 0) 721 ckfree(vp->text); 722 vp->flags = lvp->flags; 723 vp->text = lvp->text; 724 } 725 ckfree(lvp); 726 } 727 } 728 729 730 int 731 setvarcmd(int argc, char **argv) 732 { 733 if (argc <= 2) 734 return unsetcmd(argc, argv); 735 else if (argc == 3) 736 setvar(argv[1], argv[2], 0); 737 else 738 error("List assignment not implemented"); 739 return 0; 740 } 741 742 743 /* 744 * The unset builtin command. We unset the function before we unset the 745 * variable to allow a function to be unset when there is a readonly variable 746 * with the same name. 747 */ 748 749 int 750 unsetcmd(int argc __unused, char **argv __unused) 751 { 752 char **ap; 753 int i; 754 int flg_func = 0; 755 int flg_var = 0; 756 int ret = 0; 757 758 while ((i = nextopt("vf")) != '\0') { 759 if (i == 'f') 760 flg_func = 1; 761 else 762 flg_var = 1; 763 } 764 if (flg_func == 0 && flg_var == 0) 765 flg_var = 1; 766 767 for (ap = argptr; *ap ; ap++) { 768 if (flg_func) 769 ret |= unsetfunc(*ap); 770 if (flg_var) 771 ret |= unsetvar(*ap); 772 } 773 return ret; 774 } 775 776 777 /* 778 * Unset the specified variable. 779 */ 780 781 int 782 unsetvar(const char *s) 783 { 784 struct var **vpp; 785 struct var *vp; 786 787 vpp = hashvar(s); 788 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 789 if (varequal(vp->text, s)) { 790 if (vp->flags & VREADONLY) 791 return (1); 792 INTOFF; 793 if (*(strchr(vp->text, '=') + 1) != '\0') 794 setvar(s, nullstr, 0); 795 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 796 unsetenv(s); 797 setlocale(LC_ALL, ""); 798 } 799 vp->flags &= ~VEXPORT; 800 vp->flags |= VUNSET; 801 if ((vp->flags & VSTRFIXED) == 0) { 802 if ((vp->flags & VTEXTFIXED) == 0) 803 ckfree(vp->text); 804 *vpp = vp->next; 805 ckfree(vp); 806 } 807 INTON; 808 return (0); 809 } 810 } 811 return (0); 812 } 813 814 815 816 /* 817 * Find the appropriate entry in the hash table from the name. 818 */ 819 820 STATIC struct var ** 821 hashvar(const char *p) 822 { 823 unsigned int hashval; 824 825 hashval = ((unsigned char) *p) << 4; 826 while (*p && *p != '=') 827 hashval += (unsigned char) *p++; 828 return &vartab[hashval % VTABSIZE]; 829 } 830 831 832 833 /* 834 * Returns true if the two strings specify the same varable. The first 835 * variable name is terminated by '='; the second may be terminated by 836 * either '=' or '\0'. 837 */ 838 839 STATIC int 840 varequal(const char *p, const char *q) 841 { 842 while (*p == *q++) { 843 if (*p++ == '=') 844 return 1; 845 } 846 if (*p == '=' && *(q - 1) == '\0') 847 return 1; 848 return 0; 849 } 850