var.c revision 200956
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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#ifndef lint 34#if 0 35static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95"; 36#endif 37#endif /* not lint */ 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: head/bin/sh/var.c 200956 2009-12-24 18:41:14Z jilles $"); 40 41#include <unistd.h> 42#include <stdlib.h> 43#include <paths.h> 44 45/* 46 * Shell variables. 47 */ 48 49#include <locale.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 73struct varinit { 74 struct var *var; 75 int flags; 76 char *text; 77 void (*func)(const char *); 78}; 79 80 81#ifndef NO_HISTORY 82struct var vhistsize; 83#endif 84struct var vifs; 85struct var vmail; 86struct var vmpath; 87struct var vpath; 88struct var vppid; 89struct var vps1; 90struct var vps2; 91struct var vps4; 92struct var vvers; 93STATIC struct var voptind; 94 95STATIC 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, "PATH=" _PATH_DEFPATH, 107 changepath }, 108 { &vppid, VSTRFIXED|VTEXTFIXED|VUNSET, "PPID=", 109 NULL }, 110 /* 111 * vps1 depends on uid 112 */ 113 { &vps2, VSTRFIXED|VTEXTFIXED, "PS2=> ", 114 NULL }, 115 { &vps4, VSTRFIXED|VTEXTFIXED, "PS4=+ ", 116 NULL }, 117 { &voptind, VSTRFIXED|VTEXTFIXED, "OPTIND=1", 118 getoptsreset }, 119 { NULL, 0, NULL, 120 NULL } 121}; 122 123STATIC struct var *vartab[VTABSIZE]; 124 125STATIC struct var **hashvar(const char *); 126STATIC int varequal(const char *, const char *); 127STATIC int localevar(const char *); 128 129/* 130 * Initialize the variable symbol tables and import the environment. 131 */ 132 133#ifdef mkinit 134INCLUDE "var.h" 135INIT { 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 154void 155initvar(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 192int 193setvarsafe(const char *name, const char *val, int flags) 194{ 195 struct jmploc jmploc; 196 struct jmploc *const savehandler = handler; 197 int err = 0; 198 int inton; 199 200 inton = is_int_on(); 201 if (setjmp(jmploc.loc)) 202 err = 1; 203 else { 204 handler = &jmploc; 205 setvar(name, val, flags); 206 } 207 handler = savehandler; 208 SETINTON(inton); 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 217void 218setvar(const char *name, const char *val, int flags) 219{ 220 const char *p; 221 int len; 222 int namelen; 223 char *nameeq; 224 int isbad; 225 226 isbad = 0; 227 p = name; 228 if (! is_name(*p)) 229 isbad = 1; 230 p++; 231 for (;;) { 232 if (! is_in_name(*p)) { 233 if (*p == '\0' || *p == '=') 234 break; 235 isbad = 1; 236 } 237 p++; 238 } 239 namelen = p - name; 240 if (isbad) 241 error("%.*s: bad variable name", namelen, name); 242 len = namelen + 2; /* 2 is space for '=' and '\0' */ 243 if (val == NULL) { 244 flags |= VUNSET; 245 } else { 246 len += strlen(val); 247 } 248 nameeq = ckmalloc(len); 249 memcpy(nameeq, name, namelen); 250 nameeq[namelen] = '='; 251 if (val) 252 scopy(val, nameeq + namelen + 1); 253 else 254 nameeq[namelen + 1] = '\0'; 255 setvareq(nameeq, flags); 256} 257 258STATIC int 259localevar(const char *s) 260{ 261 static char *lnames[7] = { 262 "ALL", "COLLATE", "CTYPE", "MONETARY", 263 "NUMERIC", "TIME", NULL 264 }; 265 char **ss; 266 267 if (*s != 'L') 268 return 0; 269 if (varequal(s + 1, "ANG")) 270 return 1; 271 if (strncmp(s + 1, "C_", 2) != 0) 272 return 0; 273 for (ss = lnames; *ss ; ss++) 274 if (varequal(s + 3, *ss)) 275 return 1; 276 return 0; 277} 278 279 280/* 281 * Sets/unsets an environment variable from a pointer that may actually be a 282 * pointer into environ where the string should not be manipulated. 283 */ 284static void 285change_env(const char *s, int set) 286{ 287 char *eqp; 288 char *ss; 289 290 ss = savestr(s); 291 if ((eqp = strchr(ss, '=')) != NULL) 292 *eqp = '\0'; 293 if (set && eqp != NULL) 294 (void) setenv(ss, eqp + 1, 1); 295 else 296 (void) unsetenv(ss); 297 ckfree(ss); 298 299 return; 300} 301 302 303/* 304 * Same as setvar except that the variable and value are passed in 305 * the first argument as name=value. Since the first argument will 306 * be actually stored in the table, it should not be a string that 307 * will go away. 308 */ 309 310void 311setvareq(char *s, int flags) 312{ 313 struct var *vp, **vpp; 314 int len; 315 316 if (aflag) 317 flags |= VEXPORT; 318 vpp = hashvar(s); 319 for (vp = *vpp ; vp ; vp = vp->next) { 320 if (varequal(s, vp->text)) { 321 if (vp->flags & VREADONLY) { 322 len = strchr(s, '=') - s; 323 error("%.*s: is read only", len, s); 324 } 325 INTOFF; 326 327 if (vp->func && (flags & VNOFUNC) == 0) 328 (*vp->func)(strchr(s, '=') + 1); 329 330 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) 331 ckfree(vp->text); 332 333 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET); 334 vp->flags |= flags; 335 vp->text = s; 336 337 /* 338 * We could roll this to a function, to handle it as 339 * a regular variable function callback, but why bother? 340 */ 341 if (vp == &vmpath || (vp == &vmail && ! mpathset())) 342 chkmail(1); 343 if ((vp->flags & VEXPORT) && localevar(s)) { 344 change_env(s, 1); 345 (void) setlocale(LC_ALL, ""); 346 } 347 INTON; 348 return; 349 } 350 } 351 /* not found */ 352 vp = ckmalloc(sizeof (*vp)); 353 vp->flags = flags; 354 vp->text = s; 355 vp->next = *vpp; 356 vp->func = NULL; 357 INTOFF; 358 *vpp = vp; 359 if ((vp->flags & VEXPORT) && localevar(s)) { 360 change_env(s, 1); 361 (void) setlocale(LC_ALL, ""); 362 } 363 INTON; 364} 365 366 367 368/* 369 * Process a linked list of variable assignments. 370 */ 371 372void 373listsetvar(struct strlist *list) 374{ 375 struct strlist *lp; 376 377 INTOFF; 378 for (lp = list ; lp ; lp = lp->next) { 379 setvareq(savestr(lp->text), 0); 380 } 381 INTON; 382} 383 384 385 386/* 387 * Find the value of a variable. Returns NULL if not set. 388 */ 389 390char * 391lookupvar(const char *name) 392{ 393 struct var *v; 394 395 for (v = *hashvar(name) ; v ; v = v->next) { 396 if (varequal(v->text, name)) { 397 if (v->flags & VUNSET) 398 return NULL; 399 return strchr(v->text, '=') + 1; 400 } 401 } 402 return NULL; 403} 404 405 406 407/* 408 * Search the environment of a builtin command. If the second argument 409 * is nonzero, return the value of a variable even if it hasn't been 410 * exported. 411 */ 412 413char * 414bltinlookup(const char *name, int doall) 415{ 416 struct strlist *sp; 417 struct var *v; 418 419 for (sp = cmdenviron ; sp ; sp = sp->next) { 420 if (varequal(sp->text, name)) 421 return strchr(sp->text, '=') + 1; 422 } 423 for (v = *hashvar(name) ; v ; v = v->next) { 424 if (varequal(v->text, name)) { 425 if ((v->flags & VUNSET) 426 || (!doall && (v->flags & VEXPORT) == 0)) 427 return NULL; 428 return strchr(v->text, '=') + 1; 429 } 430 } 431 return NULL; 432} 433 434 435 436/* 437 * Generate a list of exported variables. This routine is used to construct 438 * the third argument to execve when executing a program. 439 */ 440 441char ** 442environment(void) 443{ 444 int nenv; 445 struct var **vpp; 446 struct var *vp; 447 char **env, **ep; 448 449 nenv = 0; 450 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 451 for (vp = *vpp ; vp ; vp = vp->next) 452 if (vp->flags & VEXPORT) 453 nenv++; 454 } 455 ep = env = stalloc((nenv + 1) * sizeof *env); 456 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 457 for (vp = *vpp ; vp ; vp = vp->next) 458 if (vp->flags & VEXPORT) 459 *ep++ = vp->text; 460 } 461 *ep = NULL; 462 return env; 463} 464 465 466/* 467 * Called when a shell procedure is invoked to clear out nonexported 468 * variables. It is also necessary to reallocate variables of with 469 * VSTACK set since these are currently allocated on the stack. 470 */ 471 472#ifdef mkinit 473MKINIT void shprocvar(void); 474 475SHELLPROC { 476 shprocvar(); 477} 478#endif 479 480void 481shprocvar(void) 482{ 483 struct var **vpp; 484 struct var *vp, **prev; 485 486 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 487 for (prev = vpp ; (vp = *prev) != NULL ; ) { 488 if ((vp->flags & VEXPORT) == 0) { 489 *prev = vp->next; 490 if ((vp->flags & VTEXTFIXED) == 0) 491 ckfree(vp->text); 492 if ((vp->flags & VSTRFIXED) == 0) 493 ckfree(vp); 494 } else { 495 if (vp->flags & VSTACK) { 496 vp->text = savestr(vp->text); 497 vp->flags &=~ VSTACK; 498 } 499 prev = &vp->next; 500 } 501 } 502 } 503 initvar(); 504} 505 506 507static int 508var_compare(const void *a, const void *b) 509{ 510 const char *const *sa, *const *sb; 511 512 sa = a; 513 sb = b; 514 /* 515 * This compares two var=value strings which creates a different 516 * order from what you would probably expect. POSIX is somewhat 517 * ambiguous on what should be sorted exactly. 518 */ 519 return strcoll(*sa, *sb); 520} 521 522 523/* 524 * Command to list all variables which are set. Currently this command 525 * is invoked from the set command when the set command is called without 526 * any variables. 527 */ 528 529int 530showvarscmd(int argc __unused, char **argv __unused) 531{ 532 struct var **vpp; 533 struct var *vp; 534 const char *s; 535 const char **vars; 536 int i, n; 537 538 /* 539 * POSIX requires us to sort the variables. 540 */ 541 n = 0; 542 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 543 for (vp = *vpp; vp; vp = vp->next) { 544 if (!(vp->flags & VUNSET)) 545 n++; 546 } 547 } 548 549 INTON; 550 vars = ckmalloc(n * sizeof(*vars)); 551 i = 0; 552 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) { 553 for (vp = *vpp; vp; vp = vp->next) { 554 if (!(vp->flags & VUNSET)) 555 vars[i++] = vp->text; 556 } 557 } 558 559 qsort(vars, n, sizeof(*vars), var_compare); 560 for (i = 0; i < n; i++) { 561 for (s = vars[i]; *s != '='; s++) 562 out1c(*s); 563 out1c('='); 564 out1qstr(s + 1); 565 out1c('\n'); 566 } 567 ckfree(vars); 568 INTOFF; 569 570 return 0; 571} 572 573 574 575/* 576 * The export and readonly commands. 577 */ 578 579int 580exportcmd(int argc, char **argv) 581{ 582 struct var **vpp; 583 struct var *vp; 584 char *name; 585 char *p; 586 char *cmdname; 587 int ch, values; 588 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; 589 590 cmdname = argv[0]; 591 optreset = optind = 1; 592 opterr = 0; 593 values = 0; 594 while ((ch = getopt(argc, argv, "p")) != -1) { 595 switch (ch) { 596 case 'p': 597 values = 1; 598 break; 599 case '?': 600 default: 601 error("unknown option: -%c", optopt); 602 } 603 } 604 argc -= optind; 605 argv += optind; 606 607 if (values && argc != 0) 608 error("-p requires no arguments"); 609 if (argc != 0) { 610 while ((name = *argv++) != NULL) { 611 if ((p = strchr(name, '=')) != NULL) { 612 p++; 613 } else { 614 vpp = hashvar(name); 615 for (vp = *vpp ; vp ; vp = vp->next) { 616 if (varequal(vp->text, name)) { 617 618 vp->flags |= flag; 619 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 620 change_env(vp->text, 1); 621 (void) setlocale(LC_ALL, ""); 622 } 623 goto found; 624 } 625 } 626 } 627 setvar(name, p, flag); 628found:; 629 } 630 } else { 631 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { 632 for (vp = *vpp ; vp ; vp = vp->next) { 633 if (vp->flags & flag) { 634 if (values) { 635 out1str(cmdname); 636 out1c(' '); 637 } 638 for (p = vp->text ; *p != '=' ; p++) 639 out1c(*p); 640 if (values && !(vp->flags & VUNSET)) { 641 out1c('='); 642 out1qstr(p + 1); 643 } 644 out1c('\n'); 645 } 646 } 647 } 648 } 649 return 0; 650} 651 652 653/* 654 * The "local" command. 655 */ 656 657int 658localcmd(int argc __unused, char **argv __unused) 659{ 660 char *name; 661 662 if (! in_function()) 663 error("Not in a function"); 664 while ((name = *argptr++) != NULL) { 665 mklocal(name); 666 } 667 return 0; 668} 669 670 671/* 672 * Make a variable a local variable. When a variable is made local, it's 673 * value and flags are saved in a localvar structure. The saved values 674 * will be restored when the shell function returns. We handle the name 675 * "-" as a special case. 676 */ 677 678void 679mklocal(char *name) 680{ 681 struct localvar *lvp; 682 struct var **vpp; 683 struct var *vp; 684 685 INTOFF; 686 lvp = ckmalloc(sizeof (struct localvar)); 687 if (name[0] == '-' && name[1] == '\0') { 688 lvp->text = ckmalloc(sizeof optlist); 689 memcpy(lvp->text, optlist, sizeof optlist); 690 vp = NULL; 691 } else { 692 vpp = hashvar(name); 693 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); 694 if (vp == NULL) { 695 if (strchr(name, '=')) 696 setvareq(savestr(name), VSTRFIXED); 697 else 698 setvar(name, NULL, VSTRFIXED); 699 vp = *vpp; /* the new variable */ 700 lvp->text = NULL; 701 lvp->flags = VUNSET; 702 } else { 703 lvp->text = vp->text; 704 lvp->flags = vp->flags; 705 vp->flags |= VSTRFIXED|VTEXTFIXED; 706 if (strchr(name, '=')) 707 setvareq(savestr(name), 0); 708 } 709 } 710 lvp->vp = vp; 711 lvp->next = localvars; 712 localvars = lvp; 713 INTON; 714} 715 716 717/* 718 * Called after a function returns. 719 */ 720 721void 722poplocalvars(void) 723{ 724 struct localvar *lvp; 725 struct var *vp; 726 727 while ((lvp = localvars) != NULL) { 728 localvars = lvp->next; 729 vp = lvp->vp; 730 if (vp == NULL) { /* $- saved */ 731 memcpy(optlist, lvp->text, sizeof optlist); 732 ckfree(lvp->text); 733 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { 734 (void)unsetvar(vp->text); 735 } else { 736 if ((vp->flags & VTEXTFIXED) == 0) 737 ckfree(vp->text); 738 vp->flags = lvp->flags; 739 vp->text = lvp->text; 740 } 741 ckfree(lvp); 742 } 743} 744 745 746int 747setvarcmd(int argc, char **argv) 748{ 749 if (argc <= 2) 750 return unsetcmd(argc, argv); 751 else if (argc == 3) 752 setvar(argv[1], argv[2], 0); 753 else 754 error("List assignment not implemented"); 755 return 0; 756} 757 758 759/* 760 * The unset builtin command. We unset the function before we unset the 761 * variable to allow a function to be unset when there is a readonly variable 762 * with the same name. 763 */ 764 765int 766unsetcmd(int argc __unused, char **argv __unused) 767{ 768 char **ap; 769 int i; 770 int flg_func = 0; 771 int flg_var = 0; 772 int ret = 0; 773 774 while ((i = nextopt("vf")) != '\0') { 775 if (i == 'f') 776 flg_func = 1; 777 else 778 flg_var = 1; 779 } 780 if (flg_func == 0 && flg_var == 0) 781 flg_var = 1; 782 783 for (ap = argptr; *ap ; ap++) { 784 if (flg_func) 785 ret |= unsetfunc(*ap); 786 if (flg_var) 787 ret |= unsetvar(*ap); 788 } 789 return ret; 790} 791 792 793/* 794 * Unset the specified variable. 795 */ 796 797int 798unsetvar(const char *s) 799{ 800 struct var **vpp; 801 struct var *vp; 802 803 vpp = hashvar(s); 804 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { 805 if (varequal(vp->text, s)) { 806 if (vp->flags & VREADONLY) 807 return (1); 808 INTOFF; 809 if (*(strchr(vp->text, '=') + 1) != '\0') 810 setvar(s, nullstr, 0); 811 if ((vp->flags & VEXPORT) && localevar(vp->text)) { 812 change_env(s, 0); 813 setlocale(LC_ALL, ""); 814 } 815 vp->flags &= ~VEXPORT; 816 vp->flags |= VUNSET; 817 if ((vp->flags & VSTRFIXED) == 0) { 818 if ((vp->flags & VTEXTFIXED) == 0) 819 ckfree(vp->text); 820 *vpp = vp->next; 821 ckfree(vp); 822 } 823 INTON; 824 return (0); 825 } 826 } 827 828 return (0); 829} 830 831 832 833/* 834 * Find the appropriate entry in the hash table from the name. 835 */ 836 837STATIC struct var ** 838hashvar(const char *p) 839{ 840 unsigned int hashval; 841 842 hashval = ((unsigned char) *p) << 4; 843 while (*p && *p != '=') 844 hashval += (unsigned char) *p++; 845 return &vartab[hashval % VTABSIZE]; 846} 847 848 849 850/* 851 * Returns true if the two strings specify the same varable. The first 852 * variable name is terminated by '='; the second may be terminated by 853 * either '=' or '\0'. 854 */ 855 856STATIC int 857varequal(const char *p, const char *q) 858{ 859 while (*p == *q++) { 860 if (*p++ == '=') 861 return 1; 862 } 863 if (*p == '=' && *(q - 1) == '\0') 864 return 1; 865 return 0; 866} 867