1 /* $NetBSD: exec.c,v 1.34 2002/11/24 22:35:39 christos 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)exec.c 8.4 (Berkeley) 6/8/95"; 43 #else 44 __RCSID("$NetBSD: exec.c,v 1.34 2002/11/24 22:35:39 christos Exp $"); 45 #endif 46 #endif /* not lint */ 47 48 #include <sys/types.h> 49 #include <sys/stat.h> 50 #include <sys/wait.h> 51 #include <unistd.h> 52 #include <fcntl.h> 53 #include <errno.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 57 /* 58 * When commands are first encountered, they are entered in a hash table. 59 * This ensures that a full path search will not have to be done for them 60 * on each invocation. 61 * 62 * We should investigate converting to a linear search, even though that 63 * would make the command name "hash" a misnomer. 64 */ 65 66 #include "shell.h" 67 #include "main.h" 68 #include "nodes.h" 69 #include "parser.h" 70 #include "redir.h" 71 #include "eval.h" 72 #include "exec.h" 73 #include "builtins.h" 74 #include "var.h" 75 #include "options.h" 76 #include "input.h" 77 #include "output.h" 78 #include "syntax.h" 79 #include "memalloc.h" 80 #include "error.h" 81 #include "init.h" 82 #include "mystring.h" 83 #include "show.h" 84 #include "jobs.h" 85 #include "alias.h" 86 87 88 #define CMDTABLESIZE 31 /* should be prime */ 89 #define ARB 1 /* actual size determined at run time */ 90 91 92 93 struct tblentry { 94 struct tblentry *next; /* next entry in hash chain */ 95 union param param; /* definition of builtin function */ 96 short cmdtype; /* index identifying command */ 97 char rehash; /* if set, cd done since entry created */ 98 char cmdname[ARB]; /* name of command */ 99 }; 100 101 102 STATIC struct tblentry *cmdtable[CMDTABLESIZE]; 103 STATIC int builtinloc = -1; /* index in path of %builtin, or -1 */ 104 int exerrno = 0; /* Last exec error */ 105 106 107 STATIC void tryexec(char *, char **, char **, int); 108 STATIC void execinterp(char **, char **); 109 STATIC void printentry(struct tblentry *, int); 110 STATIC void clearcmdentry(int); 111 STATIC struct tblentry *cmdlookup(const char *, int); 112 STATIC void delete_cmd_entry(void); 113 114 115 extern char *const parsekwd[]; 116 117 /* 118 * Exec a program. Never returns. If you change this routine, you may 119 * have to change the find_command routine as well. 120 */ 121 122 void 123 shellexec(char **argv, char **envp, const char *path, int idx, int vforked) 124 { 125 char *cmdname; 126 int e; 127 128 if (strchr(argv[0], '/') != NULL) { 129 tryexec(argv[0], argv, envp, vforked); 130 e = errno; 131 } else { 132 e = ENOENT; 133 while ((cmdname = padvance(&path, argv[0])) != NULL) { 134 if (--idx < 0 && pathopt == NULL) { 135 tryexec(cmdname, argv, envp, vforked); 136 if (errno != ENOENT && errno != ENOTDIR) 137 e = errno; 138 } 139 stunalloc(cmdname); 140 } 141 } 142 143 /* Map to POSIX errors */ 144 switch (e) { 145 case EACCES: 146 exerrno = 126; 147 break; 148 case ENOENT: 149 exerrno = 127; 150 break; 151 default: 152 exerrno = 2; 153 break; 154 } 155 TRACE(("shellexec failed for %s, errno %d, vforked %d, suppressint %d\n", 156 argv[0], e, vforked, suppressint )); 157 exerror(EXEXEC, "%s: %s", argv[0], errmsg(e, E_EXEC)); 158 /* NOTREACHED */ 159 } 160 161 162 STATIC void 163 tryexec(char *cmd, char **argv, char **envp, int vforked) 164 { 165 int e; 166 #ifndef BSD 167 char *p; 168 #endif 169 170 #ifdef SYSV 171 do { 172 execve(cmd, argv, envp); 173 } while (errno == EINTR); 174 #else 175 execve(cmd, argv, envp); 176 #endif 177 e = errno; 178 if (e == ENOEXEC) { 179 if (vforked) { 180 /* We are currently vfork(2)ed, so raise an 181 * exception, and evalcommand will try again 182 * with a normal fork(2). 183 */ 184 exraise(EXSHELLPROC); 185 } 186 initshellproc(); 187 setinputfile(cmd, 0); 188 commandname = arg0 = savestr(argv[0]); 189 #ifndef BSD 190 pgetc(); pungetc(); /* fill up input buffer */ 191 p = parsenextc; 192 if (parsenleft > 2 && p[0] == '#' && p[1] == '!') { 193 argv[0] = cmd; 194 execinterp(argv, envp); 195 } 196 #endif 197 setparam(argv + 1); 198 exraise(EXSHELLPROC); 199 } 200 errno = e; 201 } 202 203 204 #ifndef BSD 205 /* 206 * Execute an interpreter introduced by "#!", for systems where this 207 * feature has not been built into the kernel. If the interpreter is 208 * the shell, return (effectively ignoring the "#!"). If the execution 209 * of the interpreter fails, exit. 210 * 211 * This code peeks inside the input buffer in order to avoid actually 212 * reading any input. It would benefit from a rewrite. 213 */ 214 215 #define NEWARGS 5 216 217 STATIC void 218 execinterp(char **argv, char **envp) 219 { 220 int n; 221 char *inp; 222 char *outp; 223 char c; 224 char *p; 225 char **ap; 226 char *newargs[NEWARGS]; 227 int i; 228 char **ap2; 229 char **new; 230 231 n = parsenleft - 2; 232 inp = parsenextc + 2; 233 ap = newargs; 234 for (;;) { 235 while (--n >= 0 && (*inp == ' ' || *inp == '\t')) 236 inp++; 237 if (n < 0) 238 goto bad; 239 if ((c = *inp++) == '\n') 240 break; 241 if (ap == &newargs[NEWARGS]) 242 bad: error("Bad #! line"); 243 STARTSTACKSTR(outp); 244 do { 245 STPUTC(c, outp); 246 } while (--n >= 0 && (c = *inp++) != ' ' && c != '\t' && c != '\n'); 247 STPUTC('\0', outp); 248 n++, inp--; 249 *ap++ = grabstackstr(outp); 250 } 251 if (ap == newargs + 1) { /* if no args, maybe no exec is needed */ 252 p = newargs[0]; 253 for (;;) { 254 if (equal(p, "sh") || equal(p, "ash")) { 255 return; 256 } 257 while (*p != '/') { 258 if (*p == '\0') 259 goto break2; 260 p++; 261 } 262 p++; 263 } 264 break2:; 265 } 266 i = (char *)ap - (char *)newargs; /* size in bytes */ 267 if (i == 0) 268 error("Bad #! line"); 269 for (ap2 = argv ; *ap2++ != NULL ; ); 270 new = ckmalloc(i + ((char *)ap2 - (char *)argv)); 271 ap = newargs, ap2 = new; 272 while ((i -= sizeof (char **)) >= 0) 273 *ap2++ = *ap++; 274 ap = argv; 275 while (*ap2++ = *ap++); 276 shellexec(new, envp, pathval(), 0); 277 /* NOTREACHED */ 278 } 279 #endif 280 281 282 283 /* 284 * Do a path search. The variable path (passed by reference) should be 285 * set to the start of the path before the first call; padvance will update 286 * this value as it proceeds. Successive calls to padvance will return 287 * the possible path expansions in sequence. If an option (indicated by 288 * a percent sign) appears in the path entry then the global variable 289 * pathopt will be set to point to it; otherwise pathopt will be set to 290 * NULL. 291 */ 292 293 const char *pathopt; 294 295 char * 296 padvance(const char **path, const char *name) 297 { 298 const char *p; 299 char *q; 300 const char *start; 301 int len; 302 303 if (*path == NULL) 304 return NULL; 305 start = *path; 306 for (p = start ; *p && *p != ':' && *p != '%' ; p++); 307 len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */ 308 while (stackblocksize() < len) 309 growstackblock(); 310 q = stackblock(); 311 if (p != start) { 312 memcpy(q, start, p - start); 313 q += p - start; 314 *q++ = '/'; 315 } 316 strcpy(q, name); 317 pathopt = NULL; 318 if (*p == '%') { 319 pathopt = ++p; 320 while (*p && *p != ':') p++; 321 } 322 if (*p == ':') 323 *path = p + 1; 324 else 325 *path = NULL; 326 return stalloc(len); 327 } 328 329 330 331 /*** Command hashing code ***/ 332 333 334 int 335 hashcmd(int argc, char **argv) 336 { 337 struct tblentry **pp; 338 struct tblentry *cmdp; 339 int c; 340 int verbose; 341 struct cmdentry entry; 342 char *name; 343 344 verbose = 0; 345 while ((c = nextopt("rv")) != '\0') { 346 if (c == 'r') { 347 clearcmdentry(0); 348 } else if (c == 'v') { 349 verbose++; 350 } 351 } 352 if (*argptr == NULL) { 353 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) { 354 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 355 printentry(cmdp, verbose); 356 } 357 } 358 return 0; 359 } 360 while ((name = *argptr) != NULL) { 361 if ((cmdp = cmdlookup(name, 0)) != NULL 362 && (cmdp->cmdtype == CMDNORMAL 363 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))) 364 delete_cmd_entry(); 365 find_command(name, &entry, DO_ERR, pathval()); 366 if (verbose) { 367 if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */ 368 cmdp = cmdlookup(name, 0); 369 printentry(cmdp, verbose); 370 } 371 flushall(); 372 } 373 argptr++; 374 } 375 return 0; 376 } 377 378 379 STATIC void 380 printentry(struct tblentry *cmdp, int verbose) 381 { 382 int idx; 383 const char *path; 384 char *name; 385 386 switch (cmdp->cmdtype) { 387 case CMDNORMAL: 388 idx = cmdp->param.index; 389 path = pathval(); 390 do { 391 name = padvance(&path, cmdp->cmdname); 392 stunalloc(name); 393 } while (--idx >= 0); 394 out1str(name); 395 break; 396 case CMDSPLBLTIN: 397 out1fmt("special builtin %s", cmdp->cmdname); 398 break; 399 case CMDBUILTIN: 400 out1fmt("builtin %s", cmdp->cmdname); 401 break; 402 case CMDFUNCTION: 403 out1fmt("function %s", cmdp->cmdname); 404 if (verbose) { 405 struct procstat ps; 406 INTOFF; 407 commandtext(&ps, cmdp->param.func); 408 out1c(' '); 409 out1str(ps.cmd); 410 INTON; 411 } 412 break; 413 default: 414 error("internal error: %s cmdtype %d", cmdp->cmdname, cmdp->cmdtype); 415 } 416 if (cmdp->rehash) 417 out1c('*'); 418 out1c('\n'); 419 } 420 421 422 423 /* 424 * Resolve a command name. If you change this routine, you may have to 425 * change the shellexec routine as well. 426 */ 427 428 void 429 find_command(char *name, struct cmdentry *entry, int act, const char *path) 430 { 431 struct tblentry *cmdp; 432 int idx; 433 int prev; 434 char *fullname; 435 struct stat statb; 436 int e; 437 int (*bltin)(int,char **); 438 439 /* If name contains a slash, don't use the hash table */ 440 if (strchr(name, '/') != NULL) { 441 if (act & DO_ABS) { 442 while (stat(name, &statb) < 0) { 443 #ifdef SYSV 444 if (errno == EINTR) 445 continue; 446 #endif 447 if (errno != ENOENT && errno != ENOTDIR) 448 e = errno; 449 entry->cmdtype = CMDUNKNOWN; 450 entry->u.index = -1; 451 return; 452 } 453 entry->cmdtype = CMDNORMAL; 454 entry->u.index = -1; 455 return; 456 } 457 entry->cmdtype = CMDNORMAL; 458 entry->u.index = 0; 459 return; 460 } 461 462 /* If name is in the table, and not invalidated by cd, we're done */ 463 if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->rehash == 0) 464 goto success; 465 466 /* If %builtin not in path, check for builtin next */ 467 if (builtinloc < 0 && (bltin = find_builtin(name)) != 0) { 468 INTOFF; 469 cmdp = cmdlookup(name, 1); 470 cmdp->cmdtype = CMDBUILTIN; 471 cmdp->param.bltin = bltin; 472 INTON; 473 goto success; 474 } 475 476 /* We have to search path. */ 477 prev = -1; /* where to start */ 478 if (cmdp) { /* doing a rehash */ 479 if (cmdp->cmdtype == CMDBUILTIN) 480 prev = builtinloc; 481 else 482 prev = cmdp->param.index; 483 } 484 485 e = ENOENT; 486 idx = -1; 487 loop: 488 while ((fullname = padvance(&path, name)) != NULL) { 489 stunalloc(fullname); 490 idx++; 491 if (pathopt) { 492 if (prefix("builtin", pathopt)) { 493 if ((bltin = find_builtin(name)) == 0) 494 goto loop; 495 INTOFF; 496 cmdp = cmdlookup(name, 1); 497 cmdp->cmdtype = CMDBUILTIN; 498 cmdp->param.bltin = bltin; 499 INTON; 500 goto success; 501 } else if (prefix("func", pathopt)) { 502 /* handled below */ 503 } else { 504 goto loop; /* ignore unimplemented options */ 505 } 506 } 507 /* if rehash, don't redo absolute path names */ 508 if (fullname[0] == '/' && idx <= prev) { 509 if (idx < prev) 510 goto loop; 511 TRACE(("searchexec \"%s\": no change\n", name)); 512 goto success; 513 } 514 while (stat(fullname, &statb) < 0) { 515 #ifdef SYSV 516 if (errno == EINTR) 517 continue; 518 #endif 519 if (errno != ENOENT && errno != ENOTDIR) 520 e = errno; 521 goto loop; 522 } 523 e = EACCES; /* if we fail, this will be the error */ 524 if (!S_ISREG(statb.st_mode)) 525 goto loop; 526 if (pathopt) { /* this is a %func directory */ 527 stalloc(strlen(fullname) + 1); 528 readcmdfile(fullname); 529 if ((cmdp = cmdlookup(name, 0)) == NULL || cmdp->cmdtype != CMDFUNCTION) 530 error("%s not defined in %s", name, fullname); 531 stunalloc(fullname); 532 goto success; 533 } 534 #ifdef notdef 535 if (statb.st_uid == geteuid()) { 536 if ((statb.st_mode & 0100) == 0) 537 goto loop; 538 } else if (statb.st_gid == getegid()) { 539 if ((statb.st_mode & 010) == 0) 540 goto loop; 541 } else { 542 if ((statb.st_mode & 01) == 0) 543 goto loop; 544 } 545 #endif 546 TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname)); 547 INTOFF; 548 cmdp = cmdlookup(name, 1); 549 cmdp->cmdtype = CMDNORMAL; 550 cmdp->param.index = idx; 551 INTON; 552 goto success; 553 } 554 555 /* We failed. If there was an entry for this command, delete it */ 556 if (cmdp) 557 delete_cmd_entry(); 558 if (act & DO_ERR) 559 outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC)); 560 entry->cmdtype = CMDUNKNOWN; 561 return; 562 563 success: 564 cmdp->rehash = 0; 565 entry->cmdtype = cmdp->cmdtype; 566 entry->u = cmdp->param; 567 } 568 569 570 571 /* 572 * Search the table of builtin commands. 573 */ 574 575 int 576 (*find_builtin(name))(int, char **) 577 char *name; 578 { 579 const struct builtincmd *bp; 580 581 for (bp = builtincmd ; bp->name ; bp++) { 582 if (*bp->name == *name && equal(bp->name, name)) 583 return bp->builtin; 584 } 585 return 0; 586 } 587 588 int 589 (*find_splbltin(name))(int, char **) 590 char *name; 591 { 592 const struct builtincmd *bp; 593 594 for (bp = splbltincmd ; bp->name ; bp++) { 595 if (*bp->name == *name && equal(bp->name, name)) 596 return bp->builtin; 597 } 598 return 0; 599 } 600 601 /* 602 * At shell startup put special builtins into hash table. 603 * ensures they are executed first (see posix). 604 * We stop functions being added with the same name 605 * (as they are impossible to call) 606 */ 607 608 void 609 hash_special_builtins(void) 610 { 611 const struct builtincmd *bp; 612 struct tblentry *cmdp; 613 614 for (bp = splbltincmd ; bp->name ; bp++) { 615 cmdp = cmdlookup(bp->name, 1); 616 cmdp->cmdtype = CMDSPLBLTIN; 617 cmdp->param.bltin = bp->builtin; 618 } 619 } 620 621 622 623 /* 624 * Called when a cd is done. Marks all commands so the next time they 625 * are executed they will be rehashed. 626 */ 627 628 void 629 hashcd(void) 630 { 631 struct tblentry **pp; 632 struct tblentry *cmdp; 633 634 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) { 635 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 636 if (cmdp->cmdtype == CMDNORMAL 637 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)) 638 cmdp->rehash = 1; 639 } 640 } 641 } 642 643 644 645 /* 646 * Called before PATH is changed. The argument is the new value of PATH; 647 * pathval() still returns the old value at this point. Called with 648 * interrupts off. 649 */ 650 651 void 652 changepath(const char *newval) 653 { 654 const char *old, *new; 655 int idx; 656 int firstchange; 657 int bltin; 658 659 old = pathval(); 660 new = newval; 661 firstchange = 9999; /* assume no change */ 662 idx = 0; 663 bltin = -1; 664 for (;;) { 665 if (*old != *new) { 666 firstchange = idx; 667 if ((*old == '\0' && *new == ':') 668 || (*old == ':' && *new == '\0')) 669 firstchange++; 670 old = new; /* ignore subsequent differences */ 671 } 672 if (*new == '\0') 673 break; 674 if (*new == '%' && bltin < 0 && prefix("builtin", new + 1)) 675 bltin = idx; 676 if (*new == ':') { 677 idx++; 678 } 679 new++, old++; 680 } 681 if (builtinloc < 0 && bltin >= 0) 682 builtinloc = bltin; /* zap builtins */ 683 if (builtinloc >= 0 && bltin < 0) 684 firstchange = 0; 685 clearcmdentry(firstchange); 686 builtinloc = bltin; 687 } 688 689 690 /* 691 * Clear out command entries. The argument specifies the first entry in 692 * PATH which has changed. 693 */ 694 695 STATIC void 696 clearcmdentry(int firstchange) 697 { 698 struct tblentry **tblp; 699 struct tblentry **pp; 700 struct tblentry *cmdp; 701 702 INTOFF; 703 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) { 704 pp = tblp; 705 while ((cmdp = *pp) != NULL) { 706 if ((cmdp->cmdtype == CMDNORMAL && 707 cmdp->param.index >= firstchange) 708 || (cmdp->cmdtype == CMDBUILTIN && 709 builtinloc >= firstchange)) { 710 *pp = cmdp->next; 711 ckfree(cmdp); 712 } else { 713 pp = &cmdp->next; 714 } 715 } 716 } 717 INTON; 718 } 719 720 721 /* 722 * Delete all functions. 723 */ 724 725 #ifdef mkinit 726 MKINIT void deletefuncs(void); 727 MKINIT void hash_special_builtins(void); 728 729 INIT { 730 hash_special_builtins(); 731 } 732 733 SHELLPROC { 734 deletefuncs(); 735 } 736 #endif 737 738 void 739 deletefuncs(void) 740 { 741 struct tblentry **tblp; 742 struct tblentry **pp; 743 struct tblentry *cmdp; 744 745 INTOFF; 746 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) { 747 pp = tblp; 748 while ((cmdp = *pp) != NULL) { 749 if (cmdp->cmdtype == CMDFUNCTION) { 750 *pp = cmdp->next; 751 freefunc(cmdp->param.func); 752 ckfree(cmdp); 753 } else { 754 pp = &cmdp->next; 755 } 756 } 757 } 758 INTON; 759 } 760 761 762 763 /* 764 * Locate a command in the command hash table. If "add" is nonzero, 765 * add the command to the table if it is not already present. The 766 * variable "lastcmdentry" is set to point to the address of the link 767 * pointing to the entry, so that delete_cmd_entry can delete the 768 * entry. 769 */ 770 771 struct tblentry **lastcmdentry; 772 773 774 STATIC struct tblentry * 775 cmdlookup(const char *name, int add) 776 { 777 int hashval; 778 const char *p; 779 struct tblentry *cmdp; 780 struct tblentry **pp; 781 782 p = name; 783 hashval = *p << 4; 784 while (*p) 785 hashval += *p++; 786 hashval &= 0x7FFF; 787 pp = &cmdtable[hashval % CMDTABLESIZE]; 788 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 789 if (equal(cmdp->cmdname, name)) 790 break; 791 pp = &cmdp->next; 792 } 793 if (add && cmdp == NULL) { 794 INTOFF; 795 cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB 796 + strlen(name) + 1); 797 cmdp->next = NULL; 798 cmdp->cmdtype = CMDUNKNOWN; 799 cmdp->rehash = 0; 800 strcpy(cmdp->cmdname, name); 801 INTON; 802 } 803 lastcmdentry = pp; 804 return cmdp; 805 } 806 807 /* 808 * Delete the command entry returned on the last lookup. 809 */ 810 811 STATIC void 812 delete_cmd_entry(void) 813 { 814 struct tblentry *cmdp; 815 816 INTOFF; 817 cmdp = *lastcmdentry; 818 *lastcmdentry = cmdp->next; 819 ckfree(cmdp); 820 INTON; 821 } 822 823 824 825 #ifdef notdef 826 void 827 getcmdentry(char *name, struct cmdentry *entry) 828 { 829 struct tblentry *cmdp = cmdlookup(name, 0); 830 831 if (cmdp) { 832 entry->u = cmdp->param; 833 entry->cmdtype = cmdp->cmdtype; 834 } else { 835 entry->cmdtype = CMDUNKNOWN; 836 entry->u.index = 0; 837 } 838 } 839 #endif 840 841 842 /* 843 * Add a new command entry, replacing any existing command entry for 844 * the same name - except special builtins. 845 */ 846 847 void 848 addcmdentry(char *name, struct cmdentry *entry) 849 { 850 struct tblentry *cmdp; 851 852 INTOFF; 853 cmdp = cmdlookup(name, 1); 854 if (cmdp->cmdtype != CMDSPLBLTIN) { 855 if (cmdp->cmdtype == CMDFUNCTION) { 856 freefunc(cmdp->param.func); 857 } 858 cmdp->cmdtype = entry->cmdtype; 859 cmdp->param = entry->u; 860 } 861 INTON; 862 } 863 864 865 /* 866 * Define a shell function. 867 */ 868 869 void 870 defun(char *name, union node *func) 871 { 872 struct cmdentry entry; 873 874 INTOFF; 875 entry.cmdtype = CMDFUNCTION; 876 entry.u.func = copyfunc(func); 877 addcmdentry(name, &entry); 878 INTON; 879 } 880 881 882 /* 883 * Delete a function if it exists. 884 */ 885 886 int 887 unsetfunc(char *name) 888 { 889 struct tblentry *cmdp; 890 891 if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->cmdtype == CMDFUNCTION) { 892 freefunc(cmdp->param.func); 893 delete_cmd_entry(); 894 return (0); 895 } 896 return (1); 897 } 898 899 /* 900 * Locate and print what a word is... 901 */ 902 903 int 904 typecmd(int argc, char **argv) 905 { 906 struct cmdentry entry; 907 struct tblentry *cmdp; 908 char * const *pp; 909 struct alias *ap; 910 int i; 911 int err = 0; 912 913 for (i = 1; i < argc; i++) { 914 out1str(argv[i]); 915 /* First look at the keywords */ 916 for (pp = parsekwd; *pp; pp++) 917 if (**pp == *argv[i] && equal(*pp, argv[i])) 918 break; 919 920 if (*pp) { 921 out1str(" is a shell keyword\n"); 922 continue; 923 } 924 925 /* Then look at the aliases */ 926 if ((ap = lookupalias(argv[i], 1)) != NULL) { 927 out1fmt(" is an alias for %s\n", ap->val); 928 continue; 929 } 930 931 /* Then check if it is a tracked alias */ 932 if ((cmdp = cmdlookup(argv[i], 0)) != NULL) { 933 entry.cmdtype = cmdp->cmdtype; 934 entry.u = cmdp->param; 935 } 936 else { 937 /* Finally use brute force */ 938 find_command(argv[i], &entry, DO_ABS, pathval()); 939 } 940 941 switch (entry.cmdtype) { 942 case CMDNORMAL: { 943 if (strchr(argv[i], '/') == NULL) { 944 const char *path = pathval(); 945 char *name; 946 int j = entry.u.index; 947 do { 948 name = padvance(&path, argv[i]); 949 stunalloc(name); 950 } while (--j >= 0); 951 out1fmt(" is%s %s\n", 952 cmdp ? " a tracked alias for" : "", name); 953 } else { 954 if (access(argv[i], X_OK) == 0) 955 out1fmt(" is %s\n", argv[i]); 956 else 957 out1fmt(": %s\n", strerror(errno)); 958 } 959 break; 960 } 961 case CMDFUNCTION: 962 out1str(" is a shell function\n"); 963 break; 964 965 case CMDBUILTIN: 966 out1str(" is a shell builtin\n"); 967 break; 968 969 case CMDSPLBLTIN: 970 out1str(" is a special shell builtin\n"); 971 break; 972 973 default: 974 out1str(": not found\n"); 975 err |= 127; 976 break; 977 } 978 } 979 return err; 980 } 981