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 1.11 2006/01/12 13:43:10 corecode 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 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 vvers; 91 STATIC struct var voptind; 92 93 STATIC const struct varinit varinit[] = { 94 #ifndef NO_HISTORY 95 { &vhistsize, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE=", 96 sethistsize }, 97 #endif 98 { &vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n", 99 NULL }, 100 { &vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL=", 101 NULL }, 102 { &vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH=", 103 NULL }, 104 { &vpath, VSTRFIXED|VTEXTFIXED, "PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/pkg/bin:/usr/pkg/sbin", 105 changepath }, 106 { &vppid, VSTRFIXED|VTEXTFIXED|VUNSET, "PPID=", 107 NULL }, 108 /* 109 * vps1 depends on uid 110 */ 111 { &vps2, VSTRFIXED|VTEXTFIXED, "PS2=> ", 112 NULL }, 113 { &voptind, VSTRFIXED|VTEXTFIXED, "OPTIND=1", 114 getoptsreset }, 115 { NULL, 0, NULL, 116 NULL } 117 }; 118 119 STATIC struct var *vartab[VTABSIZE]; 120 121 STATIC struct var **hashvar(const char *); 122 STATIC int varequal(const char *, const char *); 123 STATIC int localevar(const char *); 124 125 /* 126 * Initialize the variable symbol tables and import the environment. 127 */ 128 129 #ifdef mkinit 130 INCLUDE "var.h" 131 INIT { 132 char **envp; 133 extern char **environ; 134 135 initvar(); 136 for (envp = environ ; *envp ; envp++) { 137 if (strchr(*envp, '=')) { 138 setvareq(*envp, VEXPORT|VTEXTFIXED); 139 } 140 } 141 } 142 #endif 143 144 145 /* 146 * This routine initializes the builtin variables. It is called when the 147 * shell is initialized and again when a shell procedure is spawned. 148 */ 149 150 void 151 initvar(void) 152 { 153 char ppid[20]; 154 const struct varinit *ip; 155 struct var *vp; 156 struct var **vpp; 157 158 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { 159 if ((vp->flags & VEXPORT) == 0) { 160 vpp = hashvar(ip->text); 161 vp->next = *vpp; 162 *vpp = vp; 163 vp->text = ip->text; 164 vp->flags = ip->flags; 165 vp->func = ip->func; 166 } 167 } 168 /* 169 * PS1 depends on uid 170 */ 171 if ((vps1.flags & VEXPORT) == 0) { 172 vpp = hashvar("PS1="); 173 vps1.next = *vpp; 174 *vpp = &vps1; 175 vps1.text = geteuid() ? "PS1=$ " : "PS1=# "; 176 vps1.flags = VSTRFIXED|VTEXTFIXED; 177 } 178 if ((vppid.flags & VEXPORT) == 0) { 179 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid()); 180 setvarsafe("PPID", ppid, 0); 181 } 182 } 183 184 /* 185 * Safe version of setvar, returns 1 on success 0 on failure. 186 */ 187 188 int 189 setvarsafe(const char *name, const char *val, int flags) 190 { 191 struct jmploc jmploc; 192 struct jmploc *volatile savehandler = handler; 193 int err = 0; 194 #if __GNUC__ 195 /* Avoid longjmp clobbering */ 196 (void) &err; 197 #endif 198 199 if (setjmp(jmploc.loc)) 200 err = 1; 201 else { 202 handler = &jmploc; 203 setvar(name, val, flags); 204 } 205 handler = savehandler; 206 return err; 207 } 208 209 /* 210 * Set the value of a variable. The flags argument is tored with the 211 * flags of the variable. If val is NULL, the variable is unset. 212 */ 213 214 void 215 setvar(const char *name, const char *val, int flags) 216 { 217 const char *cp; 218 char *p; 219 int len; 220 int namelen; 221 char *nameeq; 222 int isbad; 223 224 isbad = 0; 225 cp = name; 226 if (!is_name(*cp)) 227 isbad = 1; 228 cp++; 229 for (;;) { 230 if (!is_in_name(*cp)) { 231 if (*cp == '\0' || *cp == '=') 232 break; 233 isbad = 1; 234 } 235 cp++; 236 } 237 namelen = cp - name; 238 if (isbad) 239 error("%.*s: bad variable name", namelen, name); 240 len = namelen + 2; /* 2 is space for '=' and '\0' */ 241 if (val == NULL) { 242 flags |= VUNSET; 243 } else { 244 len += strlen(val); 245 } 246 p = nameeq = ckmalloc(len); 247 cp = name; 248 while (--namelen >= 0) 249 *p++ = *cp++; 250 *p++ = '='; 251 *p = '\0'; 252 if (val) 253 scopy(val, p); 254 setvareq(nameeq, flags); 255 } 256 257 STATIC int 258 localevar(const char *s) 259 { 260 static const char * const lnames[7] = { 261 "ALL", "COLLATE", "CTYPE", "MONETARY", 262 "NUMERIC", "TIME", NULL 263 }; 264 const char * const *ss; 265 266 if (*s != 'L') 267 return 0; 268 if (varequal(s + 1, "ANG")) 269 return 1; 270 if (strncmp(s + 1, "C_", 2) != 0) 271 return 0; 272 for (ss = lnames; *ss ; ss++) 273 if (varequal(s + 3, *ss)) 274 return 1; 275 return 0; 276 } 277 278 /* 279 * Same as setvar except that the variable and value are passed in 280 * the first argument as name=value. Since the first argument will 281 * be actually stored in the table, it should not be a string that 282 * will go away. 283 */ 284 285 void 286 setvareq(char *s, int flags) 287 { 288 struct var *vp, **vpp; 289 int len; 290 291 if (aflag) 292 flags |= VEXPORT; 293 vpp = hashvar(s); 294 for (vp = *vpp ; vp ; vp = vp->next) { 295 if (varequal(s, vp->text)) { 296 if (vp->flags & VREADONLY) { 297 len = strchr(s, '=') - s; 298 error("%.*s: is read only", len, s); 299 } 300 INTOFF; 301 302 if (vp->func && (flags & VNOFUNC) == 0) 303 (*vp->func)(strchr(s, '=') + 1); 304 305 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) 306 ckfree(vp->text); 307 308 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET); 309 vp->flags |= flags; 310 vp->text = s; 311 312 /* 313 * We could roll this to a function, to handle it as 314 * a regular variable function callback, but why bother? 315 */ 316 if (vp == &vmpath || (vp == &vmail && ! mpathset())) 317 chkmail(1); 318 if ((vp->flags & VEXPORT) && localevar(s)) { 319 if (putenv(s) != 0) 320 error("putenv: cannot set %s", s); 321 setlocale(LC_ALL, ""); 322 } 323 INTON; 324 return; 325 } 326 } 327 /* not found */ 328 vp = ckmalloc(sizeof (*vp)); 329 vp->flags = flags; 330 vp->text = s; 331 vp->next = *vpp; 332 vp->func = NULL; 333 INTOFF; 334 *vpp = vp; 335 if ((vp->flags & VEXPORT) && localevar(s)) { 336 if (putenv(s) != 0) 337 error("putenv: cannot set %s", s); 338 setlocale(LC_ALL, ""); 339 } 340 INTON; 341 } 342 343 344 345 /* 346 * Process a linked list of variable assignments. 347 */ 348 349 void 350 listsetvar(struct strlist *list) 351 { 352 struct strlist *lp; 353 354 INTOFF; 355 for (lp = list ; lp ; lp = lp->next) { 356 setvareq(savestr(lp->text), 0); 357 } 358 INTON; 359 } 360 361 362 363 /* 364 * Find the value of a variable. Returns NULL if not set. 365 */ 366 367 char * 368 lookupvar(const char *name) 369 { 370 struct var *v; 371 372 for (v = *hashvar(name) ; v ; v = v->next) { 373 if (varequal(v->text, name)) { 374 if (v->flags & VUNSET) 375 return NULL; 376 return strchr(v->text, '=') + 1; 377 } 378 } 379 return NULL; 380 } 381 382 383 384 /* 385 * Search the environment of a builtin command. If the second argument 386 * is nonzero, return the value of a variable even if it hasn't been 387 * exported. 388 */ 389 390 char * 391 bltinlookup(const char *name, int doall) 392 { 393 struct strlist *sp; 394 struct var *v; 395 396 for (sp = cmdenviron ; sp ; sp = sp->next) { 397 if (varequal(sp->text, name)) 398 return strchr(sp->text, '=') + 1; 399 } 400 for (v = *hashvar(name) ; v ; v = v->next) { 401 if (varequal(v->text, name)) { 402 if ((v->flags & VUNSET) 403 || (!doall && (v->flags & VEXPORT) == 0)) 404 return NULL; 405 return strchr(v->text, '=') + 1; 406 } 407 } 408 return NULL; 409 } 410 411 412 413 /* 414 * Generate a list of exported variables. This routine is used to construct 415 * the third argument to execve when executing a program. 416 */ 417 418 char ** 419 environment(void) 420 { 421 int nenv; 422 struct var **vpp; 423 struct var *vp; 424 char **env, **ep; 425 426 nenv = 0; 427 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 428 for (vp = *vpp ; vp ; vp = vp->next) 429 if (vp->flags & VEXPORT) 430 nenv++; 431 } 432 ep = env = stalloc((nenv + 1) * sizeof *env); 433 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 434 for (vp = *vpp ; vp ; vp = vp->next) 435 if (vp->flags & VEXPORT) 436 *ep++ = vp->text; 437 } 438 *ep = NULL; 439 return env; 440 } 441 442 443 /* 444 * Called when a shell procedure is invoked to clear out nonexported 445 * variables. It is also necessary to reallocate variables of with 446 * VSTACK set since these are currently allocated on the stack. 447 */ 448 449 #ifdef mkinit 450 MKINIT void shprocvar(void); 451 452 SHELLPROC { 453 shprocvar(); 454 } 455 #endif 456 457 void 458 shprocvar(void) 459 { 460 struct var **vpp; 461 struct var *vp, **prev; 462 463 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 464 for (prev = vpp ; (vp = *prev) != NULL ; ) { 465 if ((vp->flags & VEXPORT) == 0) { 466 *prev = vp->next; 467 if ((vp->flags & VTEXTFIXED) == 0) 468 ckfree(vp->text); 469 if ((vp->flags & VSTRFIXED) == 0) 470 ckfree(vp); 471 } else { 472 if (vp->flags & VSTACK) { 473 vp->text = savestr(vp->text); 474 vp->flags &=~ VSTACK; 475 } 476 prev = &vp->next; 477 } 478 } 479 } 480 initvar(); 481 } 482 483 484 485 /* 486 * Command to list all variables which are set. Currently this command 487 * is invoked from the set command when the set command is called without 488 * any variables. 489 */ 490 491 int 492 showvarscmd(int argc __unused, char **argv __unused) 493 { 494 struct var **vpp; 495 struct var *vp; 496 const char *s; 497 498 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 499 for (vp = *vpp ; vp ; vp = vp->next) { 500 if (vp->flags & VUNSET) 501 continue; 502 for (s = vp->text; *s != '='; s++) 503 out1c(*s); 504 out1c('='); 505 out1qstr(s + 1); 506 out1c('\n'); 507 } 508 } 509 return 0; 510 } 511 512 513 514 /* 515 * The export and readonly commands. 516 */ 517 518 int 519 exportcmd(int argc, char **argv) 520 { 521 struct var **vpp; 522 struct var *vp; 523 char *name; 524 char *p; 525 char *cmdname; 526 int ch, values; 527 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 528 529 cmdname = argv[0]; 530 optreset = optind = 1; 531 opterr = 0; 532 values = 0; 533 while ((ch = getopt(argc, argv, "p")) != -1) { 534 switch (ch) { 535 case 'p': 536 values = 1; 537 break; 538 case '?': 539 default: 540 error("unknown option: -%c", optopt); 541 } 542 } 543 argc -= optind; 544 argv += optind; 545 546 listsetvar(cmdenviron); 547 if (argc != 0) { 548 while ((name = *argptr++) != NULL) { 549 if ((p = strchr(name, '=')) != NULL) { 550 p++; 551 } else { 552 vpp = hashvar(name); 553 for (vp = *vpp ; vp ; vp = vp->next) { 554 if (varequal(vp->text, name)) { 555 556 vp->flags |= flag; 557 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 558 if (putenv(vp->text) != 0) 559 error("putenv: cannot set %s", vp->text); 560 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 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(const 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 return (0); 767 } 768 769 770 771 /* 772 * Find the appropriate entry in the hash table from the name. 773 */ 774 775 STATIC struct var ** 776 hashvar(const char *p) 777 { 778 unsigned int hashval; 779 780 hashval = ((unsigned char) *p) << 4; 781 while (*p && *p != '=') 782 hashval += (unsigned char) *p++; 783 return &vartab[hashval % VTABSIZE]; 784 } 785 786 787 788 /* 789 * Returns true if the two strings specify the same varable. The first 790 * variable name is terminated by '='; the second may be terminated by 791 * either '=' or '\0'. 792 */ 793 794 STATIC int 795 varequal(const char *p, const char *q) 796 { 797 while (*p == *q++) { 798 if (*p++ == '=') 799 return 1; 800 } 801 if (*p == '=' && *(q - 1) == '\0') 802 return 1; 803 return 0; 804 } 805