1 /* $NetBSD: exec.c,v 1.59 2024/07/12 07:30:30 kre Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)exec.c 8.4 (Berkeley) 6/8/95"; 39 #else 40 __RCSID("$NetBSD: exec.c,v 1.59 2024/07/12 07:30:30 kre Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 #include <sys/types.h> 45 #include <sys/stat.h> 46 #include <sys/wait.h> 47 #include <unistd.h> 48 #include <fcntl.h> 49 #include <errno.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 53 /* 54 * When commands are first encountered, they are entered in a hash table. 55 * This ensures that a full path search will not have to be done for them 56 * on each invocation. 57 * 58 * We should investigate converting to a linear search, even though that 59 * would make the command name "hash" a misnomer. 60 */ 61 62 #include "shell.h" 63 #include "main.h" 64 #include "nodes.h" 65 #include "parser.h" 66 #include "redir.h" 67 #include "eval.h" 68 #include "exec.h" 69 #include "builtins.h" 70 #include "var.h" 71 #include "options.h" 72 #include "input.h" 73 #include "output.h" 74 #include "syntax.h" 75 #include "memalloc.h" 76 #include "error.h" 77 #include "init.h" 78 #include "mystring.h" 79 #include "show.h" 80 #include "jobs.h" 81 #include "alias.h" 82 83 84 #define CMDTABLESIZE 31 /* should be prime */ 85 #define ARB 1 /* actual size determined at run time */ 86 87 88 89 struct tblentry { 90 struct tblentry *next; /* next entry in hash chain */ 91 union param param; /* definition of builtin function */ 92 short cmdtype; /* index identifying command */ 93 char rehash; /* if set, cd done since entry created */ 94 char fn_ln1; /* for functions, LINENO from 1 */ 95 int lineno; /* for functions abs LINENO of definition */ 96 char cmdname[ARB]; /* name of command */ 97 }; 98 99 100 STATIC struct tblentry *cmdtable[CMDTABLESIZE]; 101 STATIC int builtinloc = -1; /* index in path of %builtin, or -1 */ 102 int exerrno = 0; /* Last exec error */ 103 104 105 STATIC void tryexec(char *, char **, char **, int); 106 STATIC void printentry(struct tblentry *, int); 107 STATIC void addcmdentry(char *, struct cmdentry *); 108 STATIC void clearcmdentry(int); 109 STATIC struct tblentry *cmdlookup(const char *, int); 110 STATIC void delete_cmd_entry(void); 111 112 #ifndef BSD 113 STATIC void execinterp(char **, char **); 114 #endif 115 116 117 extern const char *const parsekwd[]; 118 119 /* 120 * Exec a program. Never returns. If you change this routine, you may 121 * have to change the find_command routine as well. 122 */ 123 124 void 125 shellexec(char **argv, char **envp, const char *path, int idx, int vforked) 126 { 127 char *cmdname; 128 int e, action; 129 struct stat statb; 130 131 action = E_EXEC; 132 133 if (strchr(argv[0], '/') != NULL) { 134 tryexec(argv[0], argv, envp, vforked); 135 e = errno; 136 if (e == EACCES && stat(argv[0], &statb) == -1) 137 action = E_OPEN; 138 } else { 139 e = ENOENT; 140 while ((cmdname = padvance(&path, argv[0], 1)) != NULL) { 141 if (--idx < 0 && pathopt == NULL) { 142 /* 143 * tryexec() does not return if it works. 144 */ 145 tryexec(cmdname, argv, envp, vforked); 146 /* 147 * If do not already have a meaningful error 148 * from earlier in the PATH, examine this one 149 * if it is a simple "not found", just keep 150 * searching. 151 */ 152 if (e == ENOENT && 153 errno != ENOENT && errno != ENOTDIR) { 154 /* 155 * If the error is from permission 156 * denied on the path search (a call 157 * to stat() also fails) ignore it 158 * (just continue with the search) 159 * If it is EACCESS and the file exists 160 * (the stat succeeds) that means no 161 * 'x' perm on the file itself, which 162 * is a meaningful error, this will be 163 * the one reported if no later PATH 164 * element actually succeeds. 165 */ 166 if (errno == EACCES) { 167 if (stat(cmdname, &statb) != -1) 168 e = EACCES; 169 } else { 170 /* 171 * any other error we will 172 * remember as the significant 173 * error 174 */ 175 e = errno; 176 } 177 } 178 } 179 stunalloc(cmdname); 180 } 181 } 182 183 /* Map to POSIX errors */ 184 switch (e) { 185 case EACCES: /* particularly this (unless no search perm) */ 186 if (action == E_OPEN) { 187 /* 188 * this is an EACCES from namei 189 * ie: no permission to search the path given 190 * rather than an EACCESS from exec 191 * ie: no 'x' bit on the file to be executed 192 */ 193 exerrno = 127; 194 break; 195 } 196 /* FALLTHROUGH */ 197 case EINVAL: /* also explicitly these */ 198 case ENOEXEC: 199 default: /* and anything else */ 200 exerrno = 126; 201 break; 202 203 case ENOENT: /* these are the "pathname lookup failed" errors */ 204 case ELOOP: 205 case ENOTDIR: 206 case ENAMETOOLONG: 207 exerrno = 127; 208 break; 209 } 210 CTRACE(DBG_ERRS|DBG_CMDS|DBG_EVAL, 211 ("shellexec failed for %s, errno %d, vforked %d, suppressint %d\n", 212 argv[0], e, vforked, suppressint)); 213 exerror(EXEXEC, "%s: %s", argv[0], errmsg(e, action)); 214 /* NOTREACHED */ 215 } 216 217 218 STATIC void 219 tryexec(char *cmd, char **argv, char **envp, int vforked) 220 { 221 int e; 222 #ifndef BSD 223 char *p; 224 #endif 225 226 #ifdef SYSV 227 do { 228 execve(cmd, argv, envp); 229 } while (errno == EINTR); 230 #else 231 execve(cmd, argv, envp); 232 #endif 233 e = errno; 234 if (e == ENOEXEC) { 235 if (vforked) { 236 /* We are currently vfork(2)ed, so raise an 237 * exception, and evalcommand will try again 238 * with a normal fork(2). 239 */ 240 exraise(EXSHELLPROC); 241 } 242 #ifdef DEBUG 243 VTRACE(DBG_CMDS, ("execve(cmd=%s) returned ENOEXEC\n", cmd)); 244 #endif 245 initshellproc(); 246 setinputfile(cmd, 0); 247 commandname = arg0 = savestr(argv[0]); 248 #ifndef BSD 249 pgetc(); pungetc(); /* fill up input buffer */ 250 p = parsenextc; 251 if (parsenleft > 2 && p[0] == '#' && p[1] == '!') { 252 argv[0] = cmd; 253 execinterp(argv, envp); 254 } 255 #endif 256 setparam(argv + 1); 257 exraise(EXSHELLPROC); 258 } 259 errno = e; 260 } 261 262 263 #ifndef BSD 264 /* 265 * Execute an interpreter introduced by "#!", for systems where this 266 * feature has not been built into the kernel. If the interpreter is 267 * the shell, return (effectively ignoring the "#!"). If the execution 268 * of the interpreter fails, exit. 269 * 270 * This code peeks inside the input buffer in order to avoid actually 271 * reading any input. It would benefit from a rewrite. 272 */ 273 274 #define NEWARGS 5 275 276 STATIC void 277 execinterp(char **argv, char **envp) 278 { 279 int n; 280 char *inp; 281 char *outp; 282 char c; 283 char *p; 284 char **ap; 285 char *newargs[NEWARGS]; 286 int i; 287 char **ap2; 288 char **new; 289 290 n = parsenleft - 2; 291 inp = parsenextc + 2; 292 ap = newargs; 293 for (;;) { 294 while (--n >= 0 && (*inp == ' ' || *inp == '\t')) 295 inp++; 296 if (n < 0) 297 goto bad; 298 if ((c = *inp++) == '\n') 299 break; 300 if (ap == &newargs[NEWARGS]) 301 bad: error("Bad #! line"); 302 STARTSTACKSTR(outp); 303 do { 304 STPUTC(c, outp); 305 } while (--n >= 0 && (c = *inp++) != ' ' && c != '\t' && c != '\n'); 306 STPUTC('\0', outp); 307 n++, inp--; 308 *ap++ = grabstackstr(outp); 309 } 310 if (ap == newargs + 1) { /* if no args, maybe no exec is needed */ 311 p = newargs[0]; 312 for (;;) { 313 if (equal(p, "sh") || equal(p, "ash")) { 314 return; 315 } 316 while (*p != '/') { 317 if (*p == '\0') 318 goto break2; 319 p++; 320 } 321 p++; 322 } 323 break2:; 324 } 325 i = (char *)ap - (char *)newargs; /* size in bytes */ 326 if (i == 0) 327 error("Bad #! line"); 328 for (ap2 = argv ; *ap2++ != NULL ; ); 329 new = ckmalloc(i + ((char *)ap2 - (char *)argv)); 330 ap = newargs, ap2 = new; 331 while ((i -= sizeof (char **)) >= 0) 332 *ap2++ = *ap++; 333 ap = argv; 334 while (*ap2++ = *ap++); 335 shellexec(new, envp, pathval(), 0); 336 /* NOTREACHED */ 337 } 338 #endif 339 340 341 342 /* 343 * Do a path search. The variable path (passed by reference) should be 344 * set to the start of the path before the first call; padvance will update 345 * this value as it proceeds. Successive calls to padvance will return 346 * the possible path expansions in sequence. If an option (indicated by 347 * a percent sign) appears in the path entry then the global variable 348 * pathopt will be set to point to it; otherwise pathopt will be set to 349 * NULL. 350 */ 351 352 const char *pathopt; 353 354 char * 355 padvance(const char **path, const char *name, int magic_percent) 356 { 357 const char *p; 358 char *q; 359 const char *start; 360 int len; 361 362 if (*path == NULL) 363 return NULL; 364 if (magic_percent) 365 magic_percent = '%'; 366 367 start = *path; 368 for (p = start ; *p && *p != ':' && *p != magic_percent ; p++) 369 ; 370 len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */ 371 while (stackblocksize() < len) 372 growstackblock(); 373 q = stackblock(); 374 if (p != start) { 375 memcpy(q, start, p - start); 376 q += p - start; 377 if (q[-1] != '/') 378 *q++ = '/'; 379 } 380 strcpy(q, name); 381 pathopt = NULL; 382 if (*p == magic_percent) { 383 pathopt = ++p; 384 while (*p && *p != ':') 385 p++; 386 } 387 if (*p == ':') 388 *path = p + 1; 389 else 390 *path = NULL; 391 return grabstackstr(q + strlen(name) + 1); 392 } 393 394 395 /*** Command hashing code ***/ 396 397 398 int 399 hashcmd(int argc, char **argv) 400 { 401 struct tblentry **pp; 402 struct tblentry *cmdp; 403 int c; 404 struct cmdentry entry; 405 char *name; 406 int allopt=0, bopt=0, fopt=0, ropt=0, sopt=0, uopt=0, verbose=0; 407 int errs=1, emsg=DO_ERR; 408 int status = 0; 409 410 while ((c = nextopt("bcefqrsuv")) != '\0') 411 switch (c) { 412 case 'b': bopt = 1; break; 413 case 'c': uopt = 1; break; /* c == u */ 414 case 'e': errs = 0; break; 415 case 'f': fopt = 1; break; 416 case 'q': emsg = 0; break; 417 case 'r': ropt = 1; break; 418 case 's': sopt = 1; break; 419 case 'u': uopt = 1; break; 420 case 'v': verbose = 1; break; 421 } 422 423 if (!errs) 424 emsg ^= DO_ERR; 425 426 if (ropt) 427 clearcmdentry(0); 428 429 if (bopt == 0 && fopt == 0 && sopt == 0 && uopt == 0) 430 allopt = bopt = fopt = sopt = uopt = 1; 431 432 if (*argptr == NULL) { 433 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) { 434 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 435 switch (cmdp->cmdtype) { 436 case CMDNORMAL: 437 if (!uopt) 438 continue; 439 break; 440 case CMDBUILTIN: 441 if (!bopt) 442 continue; 443 break; 444 case CMDSPLBLTIN: 445 if (!sopt) 446 continue; 447 break; 448 case CMDFUNCTION: 449 if (!fopt) 450 continue; 451 break; 452 default: /* never happens */ 453 continue; 454 } 455 if (!allopt || verbose || 456 cmdp->cmdtype == CMDNORMAL) 457 printentry(cmdp, verbose); 458 } 459 } 460 flushout(out1); 461 if (io_err(out1)) { 462 out2str("hash: I/O error writing to standard output\n"); 463 return 1; 464 } 465 return 0; 466 } 467 468 while ((name = *argptr++) != NULL) { 469 if ((cmdp = cmdlookup(name, 0)) != NULL) { 470 switch (cmdp->cmdtype) { 471 case CMDNORMAL: 472 if (!uopt) 473 continue; 474 delete_cmd_entry(); 475 break; 476 case CMDBUILTIN: 477 if (!bopt) 478 continue; 479 if (builtinloc >= 0) 480 delete_cmd_entry(); 481 break; 482 case CMDSPLBLTIN: 483 if (!sopt) 484 continue; 485 break; 486 case CMDFUNCTION: 487 if (!fopt) 488 continue; 489 break; 490 } 491 } 492 find_command(name, &entry, emsg, pathval()); 493 if (errs && entry.cmdtype == CMDUNKNOWN) 494 status = 1; 495 if (verbose) { 496 if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */ 497 cmdp = cmdlookup(name, 0); 498 if (cmdp != NULL) 499 printentry(cmdp, verbose); 500 } 501 flushall(); 502 } 503 } 504 return status; 505 } 506 507 STATIC void 508 printentry(struct tblentry *cmdp, int verbose) 509 { 510 int idx; 511 const char *path; 512 char *name; 513 514 switch (cmdp->cmdtype) { 515 case CMDNORMAL: 516 idx = cmdp->param.index; 517 path = pathval(); 518 do { 519 name = padvance(&path, cmdp->cmdname, 1); 520 stunalloc(name); 521 } while (--idx >= 0); 522 if (verbose) 523 out1fmt("Command from PATH[%d]: ", 524 cmdp->param.index); 525 out1str(name); 526 break; 527 case CMDSPLBLTIN: 528 if (verbose) 529 out1str("special "); 530 /* FALLTHROUGH */ 531 case CMDBUILTIN: 532 if (verbose) 533 out1str("builtin "); 534 out1fmt("%s", cmdp->cmdname); 535 break; 536 case CMDFUNCTION: 537 if (verbose) 538 out1str("function "); 539 out1fmt("%s", cmdp->cmdname); 540 if (verbose) { 541 struct procstat ps; 542 543 INTOFF; 544 commandtext(&ps, getfuncnode(cmdp->param.func)); 545 INTON; 546 out1str("() { "); 547 out1str(ps.cmd); 548 out1str("; }"); 549 } 550 break; 551 default: 552 error("internal error: %s cmdtype %d", 553 cmdp->cmdname, cmdp->cmdtype); 554 } 555 if (cmdp->rehash) 556 out1c('*'); 557 out1c('\n'); 558 } 559 560 561 562 /* 563 * Resolve a command name. If you change this routine, you may have to 564 * change the shellexec routine as well. 565 */ 566 567 void 568 find_command(char *name, struct cmdentry *entry, int act, const char *path) 569 { 570 struct tblentry *cmdp, loc_cmd; 571 int idx; 572 int prev; 573 char *fullname; 574 struct stat statb; 575 int e; 576 int (*bltin)(int,char **); 577 578 /* If name contains a slash, don't use PATH or hash table */ 579 if (strchr(name, '/') != NULL) { 580 if (act & DO_ABS) { 581 while (stat(name, &statb) < 0) { 582 #ifdef SYSV 583 if (errno == EINTR) 584 continue; 585 #endif 586 if (errno != ENOENT && errno != ENOTDIR) 587 e = errno; 588 entry->cmdtype = CMDUNKNOWN; 589 entry->u.index = -1; 590 return; 591 } 592 entry->cmdtype = CMDNORMAL; 593 entry->u.index = -1; 594 return; 595 } 596 entry->cmdtype = CMDNORMAL; 597 entry->u.index = 0; 598 return; 599 } 600 601 if (path != pathval()) 602 act |= DO_ALTPATH; 603 604 if (act & DO_ALTPATH && strstr(path, "%builtin") != NULL) 605 act |= DO_ALTBLTIN; 606 607 /* If name is in the table, check answer will be ok */ 608 if ((cmdp = cmdlookup(name, 0)) != NULL) { 609 switch (cmdp->cmdtype) { 610 case CMDNORMAL: 611 if (act & DO_ALTPATH) 612 cmdp = NULL; 613 break; 614 case CMDFUNCTION: 615 if (act & DO_NOFUNC) 616 cmdp = NULL; 617 break; 618 case CMDBUILTIN: 619 if ((act & DO_ALTBLTIN) || builtinloc >= 0) 620 cmdp = NULL; 621 break; 622 } 623 /* if not invalidated by cd, we're done */ 624 if (cmdp != NULL && cmdp->rehash == 0) 625 goto success; 626 } 627 628 /* If %builtin not in path, check for builtin next */ 629 if ((act & DO_ALTPATH ? !(act & DO_ALTBLTIN) : builtinloc < 0) && 630 (bltin = find_builtin(name)) != 0) 631 goto builtin_success; 632 633 /* We have to search path. */ 634 prev = -1; /* where to start */ 635 if (cmdp) { /* doing a rehash */ 636 if (cmdp->cmdtype == CMDBUILTIN) 637 prev = builtinloc; 638 else 639 prev = cmdp->param.index; 640 } 641 642 e = ENOENT; 643 idx = -1; 644 loop: 645 while ((fullname = padvance(&path, name, 1)) != NULL) { 646 stunalloc(fullname); 647 idx++; 648 if (pathopt) { 649 if (prefix("builtin", pathopt)) { 650 if ((bltin = find_builtin(name)) == 0) 651 goto loop; 652 goto builtin_success; 653 } else if (prefix("func", pathopt)) { 654 /* handled below */ 655 } else { 656 /* ignore unimplemented options */ 657 goto loop; 658 } 659 } 660 /* if rehash, don't redo absolute path names */ 661 if (fullname[0] == '/' && idx <= prev) { 662 if (idx < prev) 663 goto loop; 664 VTRACE(DBG_CMDS, ("searchexec \"%s\": no change\n", 665 name)); 666 goto success; 667 } 668 while (stat(fullname, &statb) < 0) { 669 #ifdef SYSV 670 if (errno == EINTR) 671 continue; 672 #endif 673 if (errno != ENOENT && errno != ENOTDIR) 674 e = errno; 675 goto loop; 676 } 677 e = EACCES; /* if we fail, this will be the error */ 678 if (!S_ISREG(statb.st_mode)) 679 goto loop; 680 if (pathopt) { /* this is a %func directory */ 681 char *endname; 682 683 if (act & DO_NOFUNC) 684 goto loop; 685 endname = fullname + strlen(fullname) + 1; 686 grabstackstr(endname); 687 readcmdfile(fullname); 688 if ((cmdp = cmdlookup(name, 0)) == NULL || 689 cmdp->cmdtype != CMDFUNCTION) 690 error("%s not defined in %s", name, fullname); 691 ungrabstackstr(fullname, endname); 692 goto success; 693 } 694 #ifdef notdef 695 /* XXX this code stops root executing stuff, and is buggy 696 if you need a group from the group list. */ 697 if (statb.st_uid == geteuid()) { 698 if ((statb.st_mode & 0100) == 0) 699 goto loop; 700 } else if (statb.st_gid == getegid()) { 701 if ((statb.st_mode & 010) == 0) 702 goto loop; 703 } else { 704 if ((statb.st_mode & 01) == 0) 705 goto loop; 706 } 707 #endif 708 VTRACE(DBG_CMDS, ("searchexec \"%s\" returns \"%s\"\n", name, 709 fullname)); 710 INTOFF; 711 if (act & DO_ALTPATH) { 712 /* 713 * this should be a grabstackstr() but is not needed: 714 * fullname is no longer needed for anything 715 stalloc(strlen(fullname) + 1); 716 */ 717 cmdp = &loc_cmd; 718 } else 719 cmdp = cmdlookup(name, 1); 720 721 if (cmdp->cmdtype == CMDFUNCTION) 722 cmdp = &loc_cmd; 723 724 cmdp->cmdtype = CMDNORMAL; 725 cmdp->param.index = idx; 726 INTON; 727 goto success; 728 } 729 730 /* We failed. If there was an entry for this command, delete it */ 731 if (cmdp) 732 delete_cmd_entry(); 733 if (act & DO_ERR) 734 outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC)); 735 entry->cmdtype = CMDUNKNOWN; 736 entry->u.index = idx + 1; 737 return; 738 739 builtin_success: 740 INTOFF; 741 if (act & DO_ALTPATH) 742 cmdp = &loc_cmd; 743 else 744 cmdp = cmdlookup(name, 1); 745 if (cmdp->cmdtype == CMDFUNCTION) 746 /* DO_NOFUNC must have been set */ 747 cmdp = &loc_cmd; 748 cmdp->cmdtype = CMDBUILTIN; 749 cmdp->param.bltin = bltin; 750 INTON; 751 success: 752 if (cmdp) { 753 cmdp->rehash = 0; 754 entry->cmdtype = cmdp->cmdtype; 755 entry->lineno = cmdp->lineno; 756 entry->lno_frel = cmdp->fn_ln1; 757 entry->u = cmdp->param; 758 } else { 759 entry->cmdtype = CMDUNKNOWN; 760 entry->u.index = -1; 761 } 762 } 763 764 765 766 /* 767 * Search the table of builtin commands. 768 */ 769 770 int 771 (*find_builtin(char *name))(int, char **) 772 { 773 const struct builtincmd *bp; 774 775 for (bp = builtincmd ; bp->name ; bp++) { 776 if (*bp->name == *name 777 && (*name == '%' || equal(bp->name, name))) 778 return bp->builtin; 779 } 780 return 0; 781 } 782 783 int 784 (*find_splbltin(char *name))(int, char **) 785 { 786 const struct builtincmd *bp; 787 788 for (bp = splbltincmd ; bp->name ; bp++) { 789 if (*bp->name == *name && equal(bp->name, name)) 790 return bp->builtin; 791 } 792 return 0; 793 } 794 795 /* 796 * At shell startup put special builtins into hash table. 797 * ensures they are executed first (see posix). 798 * We stop functions being added with the same name 799 * (as they are impossible to call) 800 */ 801 802 void 803 hash_special_builtins(void) 804 { 805 const struct builtincmd *bp; 806 struct tblentry *cmdp; 807 808 for (bp = splbltincmd ; bp->name ; bp++) { 809 cmdp = cmdlookup(bp->name, 1); 810 cmdp->cmdtype = CMDSPLBLTIN; 811 cmdp->param.bltin = bp->builtin; 812 } 813 } 814 815 816 817 /* 818 * Called when a cd is done. Marks all commands so the next time they 819 * are executed they will be rehashed. 820 */ 821 822 void 823 hashcd(void) 824 { 825 struct tblentry **pp; 826 struct tblentry *cmdp; 827 828 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) { 829 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 830 if (cmdp->cmdtype == CMDNORMAL 831 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)) 832 cmdp->rehash = 1; 833 } 834 } 835 } 836 837 838 839 /* 840 * Fix command hash table when PATH changed. 841 * Called before PATH is changed. The argument is the new value of PATH; 842 * pathval() still returns the old value at this point. 843 * Called with interrupts off. 844 */ 845 846 void 847 changepath(char *newval, int flags __unused) 848 { 849 const char *old, *new; 850 int idx; 851 int firstchange; 852 int bltin; 853 854 old = pathval(); 855 new = newval; 856 firstchange = 9999; /* assume no change */ 857 idx = 0; 858 bltin = -1; 859 for (;;) { 860 if (*old != *new) { 861 firstchange = idx; 862 if ((*old == '\0' && *new == ':') 863 || (*old == ':' && *new == '\0')) 864 firstchange++; 865 old = new; /* ignore subsequent differences */ 866 } 867 if (*new == '\0') 868 break; 869 if (*new == '%' && bltin < 0 && prefix("builtin", new + 1)) 870 bltin = idx; 871 if (*new == ':') { 872 idx++; 873 } 874 new++, old++; 875 } 876 if (builtinloc < 0 && bltin >= 0) 877 builtinloc = bltin; /* zap builtins */ 878 if (builtinloc >= 0 && bltin < 0) 879 firstchange = 0; 880 clearcmdentry(firstchange); 881 builtinloc = bltin; 882 } 883 884 885 /* 886 * Clear out command entries. The argument specifies the first entry in 887 * PATH which has changed. 888 */ 889 890 STATIC void 891 clearcmdentry(int firstchange) 892 { 893 struct tblentry **tblp; 894 struct tblentry **pp; 895 struct tblentry *cmdp; 896 897 INTOFF; 898 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) { 899 pp = tblp; 900 while ((cmdp = *pp) != NULL) { 901 if ((cmdp->cmdtype == CMDNORMAL && 902 cmdp->param.index >= firstchange) 903 || (cmdp->cmdtype == CMDBUILTIN && 904 builtinloc >= firstchange)) { 905 *pp = cmdp->next; 906 ckfree(cmdp); 907 } else { 908 pp = &cmdp->next; 909 } 910 } 911 } 912 INTON; 913 } 914 915 916 /* 917 * Delete all functions. 918 */ 919 920 #ifdef mkinit 921 MKINIT void deletefuncs(void); 922 MKINIT void hash_special_builtins(void); 923 924 INIT { 925 hash_special_builtins(); 926 } 927 928 SHELLPROC { 929 deletefuncs(); 930 } 931 #endif 932 933 void 934 deletefuncs(void) 935 { 936 struct tblentry **tblp; 937 struct tblentry **pp; 938 struct tblentry *cmdp; 939 940 INTOFF; 941 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) { 942 pp = tblp; 943 while ((cmdp = *pp) != NULL) { 944 if (cmdp->cmdtype == CMDFUNCTION) { 945 *pp = cmdp->next; 946 freefunc(cmdp->param.func); 947 ckfree(cmdp); 948 } else { 949 pp = &cmdp->next; 950 } 951 } 952 } 953 INTON; 954 } 955 956 957 958 /* 959 * Locate a command in the command hash table. If "add" is nonzero, 960 * add the command to the table if it is not already present. The 961 * variable "lastcmdentry" is set to point to the address of the link 962 * pointing to the entry, so that delete_cmd_entry can delete the 963 * entry. 964 */ 965 966 struct tblentry **lastcmdentry; 967 968 969 STATIC struct tblentry * 970 cmdlookup(const char *name, int add) 971 { 972 int hashval; 973 const char *p; 974 struct tblentry *cmdp; 975 struct tblentry **pp; 976 977 p = name; 978 hashval = *p << 4; 979 while (*p) 980 hashval += *p++; 981 hashval &= 0x7FFF; 982 pp = &cmdtable[hashval % CMDTABLESIZE]; 983 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 984 if (equal(cmdp->cmdname, name)) 985 break; 986 pp = &cmdp->next; 987 } 988 if (add && cmdp == NULL) { 989 INTOFF; 990 cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB 991 + strlen(name) + 1); 992 cmdp->next = NULL; 993 cmdp->cmdtype = CMDUNKNOWN; 994 cmdp->rehash = 0; 995 strcpy(cmdp->cmdname, name); 996 INTON; 997 } 998 lastcmdentry = pp; 999 return cmdp; 1000 } 1001 1002 /* 1003 * Delete the command entry returned on the last lookup. 1004 */ 1005 1006 STATIC void 1007 delete_cmd_entry(void) 1008 { 1009 struct tblentry *cmdp; 1010 1011 INTOFF; 1012 cmdp = *lastcmdentry; 1013 *lastcmdentry = cmdp->next; 1014 ckfree(cmdp); 1015 INTON; 1016 } 1017 1018 1019 1020 #ifdef notdef 1021 void 1022 getcmdentry(char *name, struct cmdentry *entry) 1023 { 1024 struct tblentry *cmdp = cmdlookup(name, 0); 1025 1026 if (cmdp) { 1027 entry->u = cmdp->param; 1028 entry->cmdtype = cmdp->cmdtype; 1029 } else { 1030 entry->cmdtype = CMDUNKNOWN; 1031 entry->u.index = 0; 1032 } 1033 } 1034 #endif 1035 1036 1037 /* 1038 * Add a new command entry, replacing any existing command entry for 1039 * the same name - except special builtins. 1040 */ 1041 1042 STATIC void 1043 addcmdentry(char *name, struct cmdentry *entry) 1044 { 1045 struct tblentry *cmdp; 1046 1047 INTOFF; 1048 cmdp = cmdlookup(name, 1); 1049 if (cmdp->cmdtype != CMDSPLBLTIN) { 1050 if (cmdp->cmdtype == CMDFUNCTION) 1051 unreffunc(cmdp->param.func); 1052 cmdp->cmdtype = entry->cmdtype; 1053 cmdp->lineno = entry->lineno; 1054 cmdp->fn_ln1 = entry->lno_frel; 1055 cmdp->param = entry->u; 1056 } 1057 INTON; 1058 } 1059 1060 1061 /* 1062 * Define a shell function. 1063 */ 1064 1065 void 1066 defun(char *name, union node *func, int lineno) 1067 { 1068 struct cmdentry entry; 1069 1070 INTOFF; 1071 entry.cmdtype = CMDFUNCTION; 1072 entry.lineno = lineno; 1073 entry.lno_frel = fnline1; 1074 entry.u.func = copyfunc(func); 1075 addcmdentry(name, &entry); 1076 INTON; 1077 } 1078 1079 1080 /* 1081 * Delete a function if it exists. 1082 */ 1083 1084 int 1085 unsetfunc(char *name) 1086 { 1087 struct tblentry *cmdp; 1088 1089 if ((cmdp = cmdlookup(name, 0)) != NULL && 1090 cmdp->cmdtype == CMDFUNCTION) { 1091 unreffunc(cmdp->param.func); 1092 delete_cmd_entry(); 1093 } 1094 return 0; 1095 } 1096 1097 /* 1098 * Locate and print what a word is... 1099 * also used for 'command -[v|V]' 1100 */ 1101 1102 int 1103 typecmd(int argc, char **argv) 1104 { 1105 struct cmdentry entry; 1106 struct tblentry *cmdp; 1107 const char * const *pp; 1108 struct alias *ap; 1109 int err = 0; 1110 char *arg; 1111 int c; 1112 int V_flag = 0; 1113 int v_flag = 0; 1114 int p_flag = 0; 1115 1116 while ((c = nextopt("vVp")) != 0) { 1117 switch (c) { 1118 case 'v': v_flag = 1; break; 1119 case 'V': V_flag = 1; break; 1120 case 'p': p_flag = 1; break; 1121 } 1122 } 1123 1124 if (argv[0][0] != 'c' && v_flag | V_flag | p_flag) 1125 error("usage: %s name...", argv[0]); 1126 1127 if (v_flag && V_flag) 1128 error("-v and -V cannot both be specified"); 1129 1130 if (*argptr == NULL) 1131 error("usage: %s%s name ...", argv[0], 1132 argv[0][0] == 'c' ? " [-p] [-v|-V]" : ""); 1133 1134 while ((arg = *argptr++)) { 1135 if (!v_flag) 1136 out1str(arg); 1137 /* First look at the keywords */ 1138 for (pp = parsekwd; *pp; pp++) 1139 if (**pp == *arg && equal(*pp, arg)) 1140 break; 1141 1142 if (*pp) { 1143 if (v_flag) 1144 out1fmt("%s\n", arg); 1145 else 1146 out1str(" is a shell keyword\n"); 1147 continue; 1148 } 1149 1150 /* Then look at the aliases */ 1151 if ((ap = lookupalias(arg, 1)) != NULL) { 1152 int ml = 0; 1153 1154 if (!v_flag) { 1155 out1str(" is an alias "); 1156 if (strchr(ap->val, '\n')) { 1157 out1str("(multiline)...\n"); 1158 ml = 1; 1159 } else 1160 out1str("for: "); 1161 } 1162 out1fmt("%s\n", ap->val); 1163 if (ml && *argptr != NULL) 1164 out1c('\n'); 1165 continue; 1166 } 1167 1168 /* Then check if it is a tracked alias */ 1169 if (!p_flag && (cmdp = cmdlookup(arg, 0)) != NULL) { 1170 entry.cmdtype = cmdp->cmdtype; 1171 entry.u = cmdp->param; 1172 } else { 1173 cmdp = NULL; 1174 /* Finally use brute force */ 1175 find_command(arg, &entry, DO_ABS, 1176 p_flag ? syspath() + 5 : pathval()); 1177 } 1178 1179 switch (entry.cmdtype) { 1180 case CMDNORMAL: { 1181 if (strchr(arg, '/') == NULL) { 1182 const char *path; 1183 char *name; 1184 int j = entry.u.index; 1185 1186 path = p_flag ? syspath() + 5 : pathval(); 1187 1188 do { 1189 name = padvance(&path, arg, 1); 1190 stunalloc(name); 1191 } while (--j >= 0); 1192 if (!v_flag) 1193 out1fmt(" is%s ", 1194 cmdp ? " a tracked alias for" : ""); 1195 out1fmt("%s\n", name); 1196 } else { 1197 if (access(arg, X_OK) == 0) { 1198 if (!v_flag) 1199 out1fmt(" is "); 1200 out1fmt("%s\n", arg); 1201 } else { 1202 if (!v_flag) 1203 out1fmt(": %s\n", 1204 strerror(errno)); 1205 else 1206 err = 126; 1207 } 1208 } 1209 break; 1210 } 1211 case CMDFUNCTION: 1212 if (!v_flag) 1213 out1str(" is a shell function\n"); 1214 else 1215 out1fmt("%s\n", arg); 1216 break; 1217 1218 case CMDBUILTIN: 1219 if (!v_flag) 1220 out1str(" is a shell builtin\n"); 1221 else 1222 out1fmt("%s\n", arg); 1223 break; 1224 1225 case CMDSPLBLTIN: 1226 if (!v_flag) 1227 out1str(" is a special shell builtin\n"); 1228 else 1229 out1fmt("%s\n", arg); 1230 break; 1231 1232 default: 1233 if (!v_flag) 1234 out1str(": not found\n"); 1235 err = 127; 1236 break; 1237 } 1238 } 1239 return err; 1240 } 1241
Indexes created Sun Sep 21 20:09:37 GMT 2025