1 /* $NetBSD: exec.c,v 1.32 2001/02/04 19:52:06 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 1.32 2001/02/04 19:52:06 christos Exp $"); 45 #endif 46 #endif /* not lint */ 47 48 #include <sys/types.h> 49 #include <sys/stat.h> 50 #include <unistd.h> 51 #include <fcntl.h> 52 #include <errno.h> 53 #include <stdlib.h> 54 55 /* 56 * When commands are first encountered, they are entered in a hash table. 57 * This ensures that a full path search will not have to be done for them 58 * on each invocation. 59 * 60 * We should investigate converting to a linear search, even though that 61 * would make the command name "hash" a misnomer. 62 */ 63 64 #include "shell.h" 65 #include "main.h" 66 #include "nodes.h" 67 #include "parser.h" 68 #include "redir.h" 69 #include "eval.h" 70 #include "exec.h" 71 #include "builtins.h" 72 #include "var.h" 73 #include "options.h" 74 #include "input.h" 75 #include "output.h" 76 #include "syntax.h" 77 #include "memalloc.h" 78 #include "error.h" 79 #include "init.h" 80 #include "mystring.h" 81 #include "show.h" 82 #include "jobs.h" 83 #include "alias.h" 84 85 86 #define CMDTABLESIZE 31 /* should be prime */ 87 #define ARB 1 /* actual size determined at run time */ 88 89 90 91 struct tblentry { 92 struct tblentry *next; /* next entry in hash chain */ 93 union param param; /* definition of builtin function */ 94 short cmdtype; /* index identifying command */ 95 char rehash; /* if set, cd done since entry created */ 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 __P((char *, char **, char **)); 106 STATIC void execinterp __P((char **, char **)); 107 STATIC void printentry __P((struct tblentry *, int)); 108 STATIC void clearcmdentry __P((int)); 109 STATIC struct tblentry *cmdlookup __P((char *, int)); 110 STATIC void delete_cmd_entry __P((void)); 111 112 113 extern char *const parsekwd[]; 114 115 /* 116 * Exec a program. Never returns. If you change this routine, you may 117 * have to change the find_command routine as well. 118 */ 119 120 void 121 shellexec(argv, envp, path, idx) 122 char **argv, **envp; 123 const char *path; 124 int idx; 125 { 126 char *cmdname; 127 int e; 128 129 if (strchr(argv[0], '/') != NULL) { 130 tryexec(argv[0], argv, envp); 131 e = errno; 132 } else { 133 e = ENOENT; 134 while ((cmdname = padvance(&path, argv[0])) != NULL) { 135 if (--idx < 0 && pathopt == NULL) { 136 tryexec(cmdname, argv, envp); 137 if (errno != ENOENT && errno != ENOTDIR) 138 e = errno; 139 } 140 stunalloc(cmdname); 141 } 142 } 143 144 /* Map to POSIX errors */ 145 switch (e) { 146 case EACCES: 147 exerrno = 126; 148 break; 149 case ENOENT: 150 exerrno = 127; 151 break; 152 default: 153 exerrno = 2; 154 break; 155 } 156 exerror(EXEXEC, "%s: %s", argv[0], errmsg(e, E_EXEC)); 157 /* NOTREACHED */ 158 } 159 160 161 STATIC void 162 tryexec(cmd, argv, envp) 163 char *cmd; 164 char **argv; 165 char **envp; 166 { 167 int e; 168 #ifndef BSD 169 char *p; 170 #endif 171 172 #ifdef SYSV 173 do { 174 execve(cmd, argv, envp); 175 } while (errno == EINTR); 176 #else 177 execve(cmd, argv, envp); 178 #endif 179 e = errno; 180 if (e == ENOEXEC) { 181 initshellproc(); 182 setinputfile(cmd, 0); 183 commandname = arg0 = savestr(argv[0]); 184 #ifndef BSD 185 pgetc(); pungetc(); /* fill up input buffer */ 186 p = parsenextc; 187 if (parsenleft > 2 && p[0] == '#' && p[1] == '!') { 188 argv[0] = cmd; 189 execinterp(argv, envp); 190 } 191 #endif 192 setparam(argv + 1); 193 exraise(EXSHELLPROC); 194 } 195 errno = e; 196 } 197 198 199 #ifndef BSD 200 /* 201 * Execute an interpreter introduced by "#!", for systems where this 202 * feature has not been built into the kernel. If the interpreter is 203 * the shell, return (effectively ignoring the "#!"). If the execution 204 * of the interpreter fails, exit. 205 * 206 * This code peeks inside the input buffer in order to avoid actually 207 * reading any input. It would benefit from a rewrite. 208 */ 209 210 #define NEWARGS 5 211 212 STATIC void 213 execinterp(argv, envp) 214 char **argv, **envp; 215 { 216 int n; 217 char *inp; 218 char *outp; 219 char c; 220 char *p; 221 char **ap; 222 char *newargs[NEWARGS]; 223 int i; 224 char **ap2; 225 char **new; 226 227 n = parsenleft - 2; 228 inp = parsenextc + 2; 229 ap = newargs; 230 for (;;) { 231 while (--n >= 0 && (*inp == ' ' || *inp == '\t')) 232 inp++; 233 if (n < 0) 234 goto bad; 235 if ((c = *inp++) == '\n') 236 break; 237 if (ap == &newargs[NEWARGS]) 238 bad: error("Bad #! line"); 239 STARTSTACKSTR(outp); 240 do { 241 STPUTC(c, outp); 242 } while (--n >= 0 && (c = *inp++) != ' ' && c != '\t' && c != '\n'); 243 STPUTC('\0', outp); 244 n++, inp--; 245 *ap++ = grabstackstr(outp); 246 } 247 if (ap == newargs + 1) { /* if no args, maybe no exec is needed */ 248 p = newargs[0]; 249 for (;;) { 250 if (equal(p, "sh") || equal(p, "ash")) { 251 return; 252 } 253 while (*p != '/') { 254 if (*p == '\0') 255 goto break2; 256 p++; 257 } 258 p++; 259 } 260 break2:; 261 } 262 i = (char *)ap - (char *)newargs; /* size in bytes */ 263 if (i == 0) 264 error("Bad #! line"); 265 for (ap2 = argv ; *ap2++ != NULL ; ); 266 new = ckmalloc(i + ((char *)ap2 - (char *)argv)); 267 ap = newargs, ap2 = new; 268 while ((i -= sizeof (char **)) >= 0) 269 *ap2++ = *ap++; 270 ap = argv; 271 while (*ap2++ = *ap++); 272 shellexec(new, envp, pathval(), 0); 273 /* NOTREACHED */ 274 } 275 #endif 276 277 278 279 /* 280 * Do a path search. The variable path (passed by reference) should be 281 * set to the start of the path before the first call; padvance will update 282 * this value as it proceeds. Successive calls to padvance will return 283 * the possible path expansions in sequence. If an option (indicated by 284 * a percent sign) appears in the path entry then the global variable 285 * pathopt will be set to point to it; otherwise pathopt will be set to 286 * NULL. 287 */ 288 289 const char *pathopt; 290 291 char * 292 padvance(path, name) 293 const char **path; 294 const char *name; 295 { 296 const char *p; 297 char *q; 298 const char *start; 299 int len; 300 301 if (*path == NULL) 302 return NULL; 303 start = *path; 304 for (p = start ; *p && *p != ':' && *p != '%' ; p++); 305 len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */ 306 while (stackblocksize() < len) 307 growstackblock(); 308 q = stackblock(); 309 if (p != start) { 310 memcpy(q, start, p - start); 311 q += p - start; 312 *q++ = '/'; 313 } 314 strcpy(q, name); 315 pathopt = NULL; 316 if (*p == '%') { 317 pathopt = ++p; 318 while (*p && *p != ':') p++; 319 } 320 if (*p == ':') 321 *path = p + 1; 322 else 323 *path = NULL; 324 return stalloc(len); 325 } 326 327 328 329 /*** Command hashing code ***/ 330 331 332 int 333 hashcmd(argc, argv) 334 int argc; 335 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(cmdp, verbose) 381 struct tblentry *cmdp; 382 int verbose; 383 { 384 int idx; 385 const char *path; 386 char *name; 387 388 if (cmdp->cmdtype == CMDNORMAL) { 389 idx = cmdp->param.index; 390 path = pathval(); 391 do { 392 name = padvance(&path, cmdp->cmdname); 393 stunalloc(name); 394 } while (--idx >= 0); 395 out1str(name); 396 } else if (cmdp->cmdtype == CMDBUILTIN) { 397 out1fmt("builtin %s", cmdp->cmdname); 398 } else if (cmdp->cmdtype == CMDFUNCTION) { 399 out1fmt("function %s", cmdp->cmdname); 400 if (verbose) { 401 INTOFF; 402 name = commandtext(cmdp->param.func); 403 out1c(' '); 404 out1str(name); 405 ckfree(name); 406 INTON; 407 } 408 #ifdef DEBUG 409 } else { 410 error("internal error: cmdtype %d", cmdp->cmdtype); 411 #endif 412 } 413 if (cmdp->rehash) 414 out1c('*'); 415 out1c('\n'); 416 } 417 418 419 420 /* 421 * Resolve a command name. If you change this routine, you may have to 422 * change the shellexec routine as well. 423 */ 424 425 void 426 find_command(name, entry, act, path) 427 char *name; 428 struct cmdentry *entry; 429 int act; 430 const char *path; 431 { 432 struct tblentry *cmdp; 433 int idx; 434 int prev; 435 char *fullname; 436 struct stat statb; 437 int e; 438 int i; 439 440 /* If name contains a slash, don't use the hash table */ 441 if (strchr(name, '/') != NULL) { 442 if (act & DO_ABS) { 443 while (stat(name, &statb) < 0) { 444 #ifdef SYSV 445 if (errno == EINTR) 446 continue; 447 #endif 448 if (errno != ENOENT && errno != ENOTDIR) 449 e = errno; 450 entry->cmdtype = CMDUNKNOWN; 451 entry->u.index = -1; 452 return; 453 } 454 entry->cmdtype = CMDNORMAL; 455 entry->u.index = -1; 456 return; 457 } 458 entry->cmdtype = CMDNORMAL; 459 entry->u.index = 0; 460 return; 461 } 462 463 /* If name is in the table, and not invalidated by cd, we're done */ 464 if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->rehash == 0) 465 goto success; 466 467 /* If %builtin not in path, check for builtin next */ 468 if (builtinloc < 0 && (i = find_builtin(name)) >= 0) { 469 INTOFF; 470 cmdp = cmdlookup(name, 1); 471 cmdp->cmdtype = CMDBUILTIN; 472 cmdp->param.index = i; 473 INTON; 474 goto success; 475 } 476 477 /* We have to search path. */ 478 prev = -1; /* where to start */ 479 if (cmdp) { /* doing a rehash */ 480 if (cmdp->cmdtype == CMDBUILTIN) 481 prev = builtinloc; 482 else 483 prev = cmdp->param.index; 484 } 485 486 e = ENOENT; 487 idx = -1; 488 loop: 489 while ((fullname = padvance(&path, name)) != NULL) { 490 stunalloc(fullname); 491 idx++; 492 if (pathopt) { 493 if (prefix("builtin", pathopt)) { 494 if ((i = find_builtin(name)) < 0) 495 goto loop; 496 INTOFF; 497 cmdp = cmdlookup(name, 1); 498 cmdp->cmdtype = CMDBUILTIN; 499 cmdp->param.index = i; 500 INTON; 501 goto success; 502 } else if (prefix("func", pathopt)) { 503 /* handled below */ 504 } else { 505 goto loop; /* ignore unimplemented options */ 506 } 507 } 508 /* if rehash, don't redo absolute path names */ 509 if (fullname[0] == '/' && idx <= prev) { 510 if (idx < prev) 511 goto loop; 512 TRACE(("searchexec \"%s\": no change\n", name)); 513 goto success; 514 } 515 while (stat(fullname, &statb) < 0) { 516 #ifdef SYSV 517 if (errno == EINTR) 518 continue; 519 #endif 520 if (errno != ENOENT && errno != ENOTDIR) 521 e = errno; 522 goto loop; 523 } 524 e = EACCES; /* if we fail, this will be the error */ 525 if (!S_ISREG(statb.st_mode)) 526 goto loop; 527 if (pathopt) { /* this is a %func directory */ 528 stalloc(strlen(fullname) + 1); 529 readcmdfile(fullname); 530 if ((cmdp = cmdlookup(name, 0)) == NULL || cmdp->cmdtype != CMDFUNCTION) 531 error("%s not defined in %s", name, fullname); 532 stunalloc(fullname); 533 goto success; 534 } 535 #ifdef notdef 536 if (statb.st_uid == geteuid()) { 537 if ((statb.st_mode & 0100) == 0) 538 goto loop; 539 } else if (statb.st_gid == getegid()) { 540 if ((statb.st_mode & 010) == 0) 541 goto loop; 542 } else { 543 if ((statb.st_mode & 01) == 0) 544 goto loop; 545 } 546 #endif 547 TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname)); 548 INTOFF; 549 cmdp = cmdlookup(name, 1); 550 cmdp->cmdtype = CMDNORMAL; 551 cmdp->param.index = idx; 552 INTON; 553 goto success; 554 } 555 556 /* We failed. If there was an entry for this command, delete it */ 557 if (cmdp) 558 delete_cmd_entry(); 559 if (act & DO_ERR) 560 outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC)); 561 entry->cmdtype = CMDUNKNOWN; 562 return; 563 564 success: 565 cmdp->rehash = 0; 566 entry->cmdtype = cmdp->cmdtype; 567 entry->u = cmdp->param; 568 } 569 570 571 572 /* 573 * Search the table of builtin commands. 574 */ 575 576 int 577 find_builtin(name) 578 char *name; 579 { 580 const struct builtincmd *bp; 581 582 for (bp = builtincmd ; bp->name ; bp++) { 583 if (*bp->name == *name && equal(bp->name, name)) 584 return bp->code; 585 } 586 return -1; 587 } 588 589 590 591 /* 592 * Called when a cd is done. Marks all commands so the next time they 593 * are executed they will be rehashed. 594 */ 595 596 void 597 hashcd() { 598 struct tblentry **pp; 599 struct tblentry *cmdp; 600 601 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) { 602 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 603 if (cmdp->cmdtype == CMDNORMAL 604 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)) 605 cmdp->rehash = 1; 606 } 607 } 608 } 609 610 611 612 /* 613 * Called before PATH is changed. The argument is the new value of PATH; 614 * pathval() still returns the old value at this point. Called with 615 * interrupts off. 616 */ 617 618 void 619 changepath(newval) 620 const char *newval; 621 { 622 const char *old, *new; 623 int idx; 624 int firstchange; 625 int bltin; 626 627 old = pathval(); 628 new = newval; 629 firstchange = 9999; /* assume no change */ 630 idx = 0; 631 bltin = -1; 632 for (;;) { 633 if (*old != *new) { 634 firstchange = idx; 635 if ((*old == '\0' && *new == ':') 636 || (*old == ':' && *new == '\0')) 637 firstchange++; 638 old = new; /* ignore subsequent differences */ 639 } 640 if (*new == '\0') 641 break; 642 if (*new == '%' && bltin < 0 && prefix("builtin", new + 1)) 643 bltin = idx; 644 if (*new == ':') { 645 idx++; 646 } 647 new++, old++; 648 } 649 if (builtinloc < 0 && bltin >= 0) 650 builtinloc = bltin; /* zap builtins */ 651 if (builtinloc >= 0 && bltin < 0) 652 firstchange = 0; 653 clearcmdentry(firstchange); 654 builtinloc = bltin; 655 } 656 657 658 /* 659 * Clear out command entries. The argument specifies the first entry in 660 * PATH which has changed. 661 */ 662 663 STATIC void 664 clearcmdentry(firstchange) 665 int firstchange; 666 { 667 struct tblentry **tblp; 668 struct tblentry **pp; 669 struct tblentry *cmdp; 670 671 INTOFF; 672 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) { 673 pp = tblp; 674 while ((cmdp = *pp) != NULL) { 675 if ((cmdp->cmdtype == CMDNORMAL && 676 cmdp->param.index >= firstchange) 677 || (cmdp->cmdtype == CMDBUILTIN && 678 builtinloc >= firstchange)) { 679 *pp = cmdp->next; 680 ckfree(cmdp); 681 } else { 682 pp = &cmdp->next; 683 } 684 } 685 } 686 INTON; 687 } 688 689 690 /* 691 * Delete all functions. 692 */ 693 694 #ifdef mkinit 695 MKINIT void deletefuncs __P((void)); 696 697 SHELLPROC { 698 deletefuncs(); 699 } 700 #endif 701 702 void 703 deletefuncs() { 704 struct tblentry **tblp; 705 struct tblentry **pp; 706 struct tblentry *cmdp; 707 708 INTOFF; 709 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) { 710 pp = tblp; 711 while ((cmdp = *pp) != NULL) { 712 if (cmdp->cmdtype == CMDFUNCTION) { 713 *pp = cmdp->next; 714 freefunc(cmdp->param.func); 715 ckfree(cmdp); 716 } else { 717 pp = &cmdp->next; 718 } 719 } 720 } 721 INTON; 722 } 723 724 725 726 /* 727 * Locate a command in the command hash table. If "add" is nonzero, 728 * add the command to the table if it is not already present. The 729 * variable "lastcmdentry" is set to point to the address of the link 730 * pointing to the entry, so that delete_cmd_entry can delete the 731 * entry. 732 */ 733 734 struct tblentry **lastcmdentry; 735 736 737 STATIC struct tblentry * 738 cmdlookup(name, add) 739 char *name; 740 int add; 741 { 742 int hashval; 743 char *p; 744 struct tblentry *cmdp; 745 struct tblentry **pp; 746 747 p = name; 748 hashval = *p << 4; 749 while (*p) 750 hashval += *p++; 751 hashval &= 0x7FFF; 752 pp = &cmdtable[hashval % CMDTABLESIZE]; 753 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 754 if (equal(cmdp->cmdname, name)) 755 break; 756 pp = &cmdp->next; 757 } 758 if (add && cmdp == NULL) { 759 INTOFF; 760 cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB 761 + strlen(name) + 1); 762 cmdp->next = NULL; 763 cmdp->cmdtype = CMDUNKNOWN; 764 cmdp->rehash = 0; 765 strcpy(cmdp->cmdname, name); 766 INTON; 767 } 768 lastcmdentry = pp; 769 return cmdp; 770 } 771 772 /* 773 * Delete the command entry returned on the last lookup. 774 */ 775 776 STATIC void 777 delete_cmd_entry() { 778 struct tblentry *cmdp; 779 780 INTOFF; 781 cmdp = *lastcmdentry; 782 *lastcmdentry = cmdp->next; 783 ckfree(cmdp); 784 INTON; 785 } 786 787 788 789 #ifdef notdef 790 void 791 getcmdentry(name, entry) 792 char *name; 793 struct cmdentry *entry; 794 { 795 struct tblentry *cmdp = cmdlookup(name, 0); 796 797 if (cmdp) { 798 entry->u = cmdp->param; 799 entry->cmdtype = cmdp->cmdtype; 800 } else { 801 entry->cmdtype = CMDUNKNOWN; 802 entry->u.index = 0; 803 } 804 } 805 #endif 806 807 808 /* 809 * Add a new command entry, replacing any existing command entry for 810 * the same name. 811 */ 812 813 void 814 addcmdentry(name, entry) 815 char *name; 816 struct cmdentry *entry; 817 { 818 struct tblentry *cmdp; 819 820 INTOFF; 821 cmdp = cmdlookup(name, 1); 822 if (cmdp->cmdtype == CMDFUNCTION) { 823 freefunc(cmdp->param.func); 824 } 825 cmdp->cmdtype = entry->cmdtype; 826 cmdp->param = entry->u; 827 INTON; 828 } 829 830 831 /* 832 * Define a shell function. 833 */ 834 835 void 836 defun(name, func) 837 char *name; 838 union node *func; 839 { 840 struct cmdentry entry; 841 842 INTOFF; 843 entry.cmdtype = CMDFUNCTION; 844 entry.u.func = copyfunc(func); 845 addcmdentry(name, &entry); 846 INTON; 847 } 848 849 850 /* 851 * Delete a function if it exists. 852 */ 853 854 int 855 unsetfunc(name) 856 char *name; 857 { 858 struct tblentry *cmdp; 859 860 if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->cmdtype == CMDFUNCTION) { 861 freefunc(cmdp->param.func); 862 delete_cmd_entry(); 863 return (0); 864 } 865 return (1); 866 } 867 868 /* 869 * Locate and print what a word is... 870 */ 871 872 int 873 typecmd(argc, argv) 874 int argc; 875 char **argv; 876 { 877 struct cmdentry entry; 878 struct tblentry *cmdp; 879 char * const *pp; 880 struct alias *ap; 881 int i; 882 int err = 0; 883 884 for (i = 1; i < argc; i++) { 885 out1str(argv[i]); 886 /* First look at the keywords */ 887 for (pp = parsekwd; *pp; pp++) 888 if (**pp == *argv[i] && equal(*pp, argv[i])) 889 break; 890 891 if (*pp) { 892 out1str(" is a shell keyword\n"); 893 continue; 894 } 895 896 /* Then look at the aliases */ 897 if ((ap = lookupalias(argv[i], 1)) != NULL) { 898 out1fmt(" is an alias for %s\n", ap->val); 899 continue; 900 } 901 902 /* Then check if it is a tracked alias */ 903 if ((cmdp = cmdlookup(argv[i], 0)) != NULL) { 904 entry.cmdtype = cmdp->cmdtype; 905 entry.u = cmdp->param; 906 } 907 else { 908 /* Finally use brute force */ 909 find_command(argv[i], &entry, DO_ABS, pathval()); 910 } 911 912 switch (entry.cmdtype) { 913 case CMDNORMAL: { 914 if (strchr(argv[i], '/') == NULL) { 915 const char *path = pathval(); 916 char *name; 917 int j = entry.u.index; 918 do { 919 name = padvance(&path, argv[i]); 920 stunalloc(name); 921 } while (--j >= 0); 922 out1fmt(" is%s %s\n", 923 cmdp ? " a tracked alias for" : "", name); 924 } else { 925 if (access(argv[i], X_OK) == 0) 926 out1fmt(" is %s\n", argv[i]); 927 else 928 out1fmt(": %s\n", strerror(errno)); 929 } 930 break; 931 } 932 case CMDFUNCTION: 933 out1str(" is a shell function\n"); 934 break; 935 936 case CMDBUILTIN: 937 out1str(" is a shell builtin\n"); 938 break; 939 940 default: 941 out1str(": not found\n"); 942 err |= 127; 943 break; 944 } 945 } 946 return err; 947 } 948