exec.c revision 218323
1757Sdg/*- 299703Sjulian * Copyright (c) 1991, 1993 3757Sdg * The Regents of the University of California. All rights reserved. 4174395Sjkoshy * 5757Sdg * This code is derived from software contributed to Berkeley by 6757Sdg * Kenneth Almquist. 7174395Sjkoshy * 8174395Sjkoshy * Redistribution and use in source and binary forms, with or without 9174395Sjkoshy * modification, are permitted provided that the following conditions 10757Sdg * are met: 11757Sdg * 1. Redistributions of source code must retain the above copyright 12757Sdg * notice, this list of conditions and the following disclaimer. 13757Sdg * 2. Redistributions in binary form must reproduce the above copyright 14757Sdg * notice, this list of conditions and the following disclaimer in the 15757Sdg * documentation and/or other materials provided with the distribution. 16757Sdg * 4. Neither the name of the University nor the names of its contributors 17757Sdg * may be used to endorse or promote products derived from this software 18757Sdg * without specific prior written permission. 19757Sdg * 20757Sdg * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21757Sdg * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22757Sdg * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23757Sdg * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24757Sdg * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25757Sdg * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26757Sdg * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27757Sdg * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28757Sdg * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29757Sdg * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30757Sdg * SUCH DAMAGE. 31757Sdg */ 32757Sdg 33757Sdg#ifndef lint 3450477Speter#if 0 35757Sdgstatic char sccsid[] = "@(#)exec.c 8.4 (Berkeley) 6/8/95"; 36757Sdg#endif 37129742Sbde#endif /* not lint */ 38232744Sjhb#include <sys/cdefs.h> 39174395Sjkoshy__FBSDID("$FreeBSD: head/bin/sh/exec.c 218323 2011-02-05 14:01:46Z jilles $"); 40179277Sjb 4171257Speter#include <sys/types.h> 4230265Speter#include <sys/stat.h> 4328921Sfsmp#include <unistd.h> 4430786Sbde#include <fcntl.h> 4530786Sbde#include <errno.h> 46757Sdg#include <paths.h> 4730786Sbde#include <stdlib.h> 4830786Sbde 49757Sdg/* 50179304Sattilio * When commands are first encountered, they are entered in a hash table. 51757Sdg * This ensures that a full path search will not have to be done for them 52179277Sjb * on each invocation. 53179277Sjb * 54179277Sjb * We should investigate converting to a linear search, even though that 55179277Sjb * would make the command name "hash" a misnomer. 56179277Sjb */ 57251988Skib 58179277Sjb#include "shell.h" 59179277Sjb#include "main.h" 60179277Sjb#include "nodes.h" 61179277Sjb#include "parser.h" 62179277Sjb#include "redir.h" 63251988Skib#include "eval.h" 64179277Sjb#include "exec.h" 65179277Sjb#include "builtins.h" 66179277Sjb#include "var.h" 67757Sdg#include "options.h" 68174395Sjkoshy#include "input.h" 69174395Sjkoshy#include "output.h" 70174395Sjkoshy#include "syntax.h" 71757Sdg#include "memalloc.h" 72757Sdg#include "error.h" 73757Sdg#include "init.h" 74757Sdg#include "mystring.h" 7558717Sdillon#include "show.h" 7658717Sdillon#include "jobs.h" 7758717Sdillon#include "alias.h" 78251988Skib 79251988Skib 8058717Sdillon#define CMDTABLESIZE 31 /* should be prime */ 8158717Sdillon#define ARB 1 /* actual size determined at run time */ 8258717Sdillon 8358717Sdillon 84251988Skib 85251988Skibstruct tblentry { 86251988Skib struct tblentry *next; /* next entry in hash chain */ 8758717Sdillon union param param; /* definition of builtin function */ 88251988Skib int special; /* flag for special builtin commands */ 89251988Skib short cmdtype; /* index identifying command */ 90251988Skib char rehash; /* if set, cd done since entry created */ 9158717Sdillon char cmdname[ARB]; /* name of command */ 9258717Sdillon}; 93251988Skib 9458717Sdillon 9558717Sdillonstatic struct tblentry *cmdtable[CMDTABLESIZE]; 9658717Sdillonint exerrno = 0; /* Last exec error */ 971321Sdg 981321Sdg 991321Sdgstatic void tryexec(char *, char **, char **); 1001321Sdgstatic void printentry(struct tblentry *, int); 1011321Sdgstatic struct tblentry *cmdlookup(const char *, int); 102153135Sjhbstatic void delete_cmd_entry(void); 103153135Sjhb 104757Sdg 105757Sdg 106757Sdg/* 10781583Sbde * Exec a program. Never returns. If you change this routine, you may 108147950Sjkoshy * have to change the find_command routine as well. 109147950Sjkoshy * 110757Sdg * The argv array may be changed and element argv[-1] should be writable. 11181583Sbde */ 112211924Srpaulo 113211924Srpaulovoid 114757Sdgshellexec(char **argv, char **envp, const char *path, int idx) 115757Sdg{ 116757Sdg char *cmdname; 117757Sdg int e; 118179292Sbz 119179292Sbz if (strchr(argv[0], '/') != NULL) { 120179292Sbz tryexec(argv[0], argv, envp); 121179292Sbz e = errno; 122757Sdg } else { 123757Sdg e = ENOENT; 124757Sdg while ((cmdname = padvance(&path, argv[0])) != NULL) { 125757Sdg if (--idx < 0 && pathopt == NULL) { 126757Sdg tryexec(cmdname, argv, envp); 127757Sdg if (errno != ENOENT && errno != ENOTDIR) 128757Sdg e = errno; 129757Sdg if (e == ENOEXEC) 130757Sdg break; 131757Sdg } 132757Sdg stunalloc(cmdname); 133757Sdg } 134757Sdg } 135757Sdg 13617521Sdg /* Map to POSIX errors */ 13717521Sdg if (e == ENOENT || e == ENOTDIR) { 138757Sdg exerrno = 127; 139757Sdg exerror(EXEXEC, "%s: not found", argv[0]); 140757Sdg } else { 141757Sdg exerrno = 126; 1425603Sbde exerror(EXEXEC, "%s: %s", argv[0], strerror(e)); 1435603Sbde } 14479609Speter} 14579609Speter 146139448Sjhb 14758717Sdillonstatic void 148251988Skibtryexec(char *cmd, char **argv, char **envp) 149251988Skib{ 150251988Skib int e, in; 151251988Skib ssize_t n; 152251988Skib char buf[256]; 153251988Skib 154157453Sjkoshy execve(cmd, argv, envp); 15558717Sdillon e = errno; 156757Sdg if (e == ENOEXEC) { 15773011Sjake INTOFF; 15873011Sjake in = open(cmd, O_RDONLY | O_NONBLOCK); 15973011Sjake if (in != -1) { 160757Sdg n = pread(in, buf, sizeof buf, 0); 161290668Sjhb close(in); 162290668Sjhb if (n > 0 && memchr(buf, '\0', n) != NULL) { 163290668Sjhb errno = ENOEXEC; 164290668Sjhb return; 165290668Sjhb } 166290668Sjhb } 1675603Sbde *argv = cmd; 168153135Sjhb *--argv = _PATH_BSHELL; 169209483Skib execve(_PATH_BSHELL, argv, envp); 170129620Sbde } 171757Sdg errno = e; 172165302Skmacy} 17373011Sjake 174165302Skmacy/* 175251988Skib * Do a path search. The variable path (passed by reference) should be 176757Sdg * set to the start of the path before the first call; padvance will update 17773011Sjake * this value as it proceeds. Successive calls to padvance will return 178757Sdg * the possible path expansions in sequence. If an option (indicated by 1791321Sdg * a percent sign) appears in the path entry then the global variable 18073011Sjake * pathopt will be set to point to it; otherwise pathopt will be set to 181757Sdg * NULL. 182757Sdg */ 183179277Sjb 184179277Sjbconst char *pathopt; 185179292Sbz 186179277Sjbchar * 187179277Sjbpadvance(const char **path, const char *name) 188322755Skib{ 189322755Skib const char *p, *start; 190322755Skib char *q; 191322755Skib int len; 192322755Skib 193322755Skib if (*path == NULL) 194179277Sjb return NULL; 195179277Sjb start = *path; 196322755Skib for (p = start; *p && *p != ':' && *p != '%'; p++) 197322755Skib ; /* nothing */ 198322755Skib len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */ 199322755Skib STARTSTACKSTR(q); 200322755Skib CHECKSTRSPACE(len, q); 201179277Sjb if (p != start) { 202322755Skib memcpy(q, start, p - start); 203322755Skib q += p - start; 204251988Skib *q++ = '/'; 205179277Sjb } 206179277Sjb strcpy(q, name); 207179277Sjb pathopt = NULL; 208179277Sjb if (*p == '%') { 209322755Skib pathopt = ++p; 210322755Skib while (*p && *p != ':') p++; 211179277Sjb } 212179277Sjb if (*p == ':') 213179277Sjb *path = p + 1; 214179277Sjb else 215179277Sjb *path = NULL; 216179277Sjb return stalloc(len); 217179277Sjb} 218179277Sjb 219179277Sjb 220179277Sjb 221179277Sjb/*** Command hashing code ***/ 222179277Sjb 223179277Sjb 224179277Sjbint 225179277Sjbhashcmd(int argc __unused, char **argv __unused) 226179277Sjb{ 227179292Sbz struct tblentry **pp; 228179277Sjb struct tblentry *cmdp; 229179277Sjb int c; 230251988Skib int verbose; 231251988Skib struct cmdentry entry; 23258717Sdillon char *name; 23310609Sdg 23410609Sdg verbose = 0; 23510609Sdg while ((c = nextopt("rv")) != '\0') { 23610609Sdg if (c == 'r') { 23710609Sdg clearcmdentry(0); 23810609Sdg } else if (c == 'v') { 23910609Sdg verbose++; 240757Sdg } 241757Sdg } 24273001Sjake if (*argptr == NULL) { 24373001Sjake for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) { 24473001Sjake for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 24573001Sjake if (cmdp->cmdtype == CMDNORMAL) 246302983Skib printentry(cmdp, verbose); 247100781Speter } 248290668Sjhb } 249290668Sjhb return 0; 250290668Sjhb } 251290668Sjhb while ((name = *argptr) != NULL) { 252290668Sjhb if ((cmdp = cmdlookup(name, 0)) != NULL 253290668Sjhb && cmdp->cmdtype == CMDNORMAL) 254153135Sjhb delete_cmd_entry(); 255209483Skib find_command(name, &entry, DO_ERR, pathval()); 256129620Sbde if (verbose) { 257165302Skmacy if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */ 258100781Speter cmdp = cmdlookup(name, 0); 259165302Skmacy if (cmdp != NULL) 260100781Speter printentry(cmdp, verbose); 261100781Speter else 262757Sdg outfmt(out2, "%s: not found\n", name); 263757Sdg } 264251988Skib flushall(); 265251988Skib } 266251988Skib argptr++; 26758717Sdillon } 268251988Skib return 0; 269251988Skib} 270251988Skib 2716380Ssos 2726380Ssosstatic void 27314331Speterprintentry(struct tblentry *cmdp, int verbose) 27473001Sjake{ 275302983Skib int idx; 2766380Ssos const char *path; 277290668Sjhb char *name; 278290668Sjhb 279290668Sjhb if (cmdp->cmdtype == CMDNORMAL) { 280290668Sjhb idx = cmdp->param.index; 281290668Sjhb path = pathval(); 282290668Sjhb do { 283153135Sjhb name = padvance(&path, cmdp->cmdname); 284209483Skib stunalloc(name); 285129620Sbde } while (--idx >= 0); 286165302Skmacy out1str(name); 28773011Sjake } else if (cmdp->cmdtype == CMDBUILTIN) { 288165302Skmacy out1fmt("builtin %s", cmdp->cmdname); 28958717Sdillon } else if (cmdp->cmdtype == CMDFUNCTION) { 29073011Sjake out1fmt("function %s", cmdp->cmdname); 2916380Ssos if (verbose) { 29224691Speter INTOFF; 29371604Sjhb name = commandtext(getfuncnode(cmdp->param.func)); 29428043Sfsmp out1c(' '); 29571522Sjhb out1str(name); 29673011Sjake ckfree(name); 29771604Sjhb INTON; 29824691Speter } 29928641Sfsmp#ifdef DEBUG 30024691Speter } else { 30173011Sjake error("internal error: cmdtype %d", cmdp->cmdtype); 30224691Speter#endif 30324691Speter } 30473011Sjake if (cmdp->rehash) 30524691Speter out1c('*'); 30628641Sfsmp out1c('\n'); 3076380Ssos} 308129742Sbde 309129742Sbde 310129742Sbde 311129742Sbde/* 312129742Sbde * Resolve a command name. If you change this routine, you may have to 313129742Sbde * change the shellexec routine as well. 314129742Sbde */ 31534840Sjlemon 31634840Sjlemonvoid 31799703Sjulianfind_command(const char *name, struct cmdentry *entry, int act, 318129742Sbde const char *path) 319129742Sbde{ 320129742Sbde struct tblentry *cmdp, loc_cmd; 321129742Sbde int idx; 32299703Sjulian int prev; 323232744Sjhb char *fullname; 324204309Sattilio struct stat statb; 325232744Sjhb int e; 326129742Sbde int i; 327232744Sjhb int spec; 328129742Sbde 329129742Sbde /* If name contains a slash, don't use the hash table */ 330129742Sbde if (strchr(name, '/') != NULL) { 331129742Sbde entry->cmdtype = CMDNORMAL; 332232744Sjhb entry->u.index = 0; 333129742Sbde return; 334232744Sjhb } 335129742Sbde 336129742Sbde /* If name is in the table, and not invalidated by cd, we're done */ 337129742Sbde if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->rehash == 0) { 338129742Sbde if (cmdp->cmdtype == CMDFUNCTION && act & DO_NOFUNC) 339129742Sbde cmdp = NULL; 340129742Sbde else 341129742Sbde goto success; 342129742Sbde } 343129742Sbde 344129742Sbde /* Check for builtin next */ 345129742Sbde if ((i = find_builtin(name, &spec)) >= 0) { 346129742Sbde INTOFF; 3473156Sbde cmdp = cmdlookup(name, 1); 34899703Sjulian if (cmdp->cmdtype == CMDFUNCTION) 34999703Sjulian cmdp = &loc_cmd; 35099703Sjulian cmdp->cmdtype = CMDBUILTIN; 3513156Sbde cmdp->param.index = i; 3523156Sbde cmdp->special = spec; 3533156Sbde INTON; 35499703Sjulian goto success; 355302041Ssephe } 35699703Sjulian 357129624Sbde /* We have to search path. */ 35899703Sjulian prev = -1; /* where to start */ 35999703Sjulian if (cmdp) { /* doing a rehash */ 360174395Sjkoshy if (cmdp->cmdtype == CMDBUILTIN) 361174395Sjkoshy prev = -1; 36299703Sjulian else 363174395Sjkoshy prev = cmdp->param.index; 364174395Sjkoshy } 365174395Sjkoshy 366174395Sjkoshy e = ENOENT; 367174395Sjkoshy idx = -1; 368174395Sjkoshyloop: 369174395Sjkoshy while ((fullname = padvance(&path, name)) != NULL) { 370174395Sjkoshy stunalloc(fullname); 371174395Sjkoshy idx++; 372251988Skib if (pathopt) { 373174395Sjkoshy if (prefix("func", pathopt)) { 374251988Skib /* handled below */ 37599703Sjulian } else { 376106542Sdavidxu goto loop; /* ignore unimplemented options */ 377251988Skib } 378251988Skib } 379251988Skib /* if rehash, don't redo absolute path names */ 38099703Sjulian if (fullname[0] == '/' && idx <= prev) { 38199703Sjulian if (idx < prev) 38299746Sjulian goto loop; 38399703Sjulian TRACE(("searchexec \"%s\": no change\n", name)); 38499703Sjulian goto success; 38599703Sjulian } 38699703Sjulian if (stat(fullname, &statb) < 0) { 38799703Sjulian if (errno != ENOENT && errno != ENOTDIR) 388118839Sjhb e = errno; 38999703Sjulian goto loop; 39099703Sjulian } 39199703Sjulian e = EACCES; /* if we fail, this will be the error */ 39299703Sjulian if (!S_ISREG(statb.st_mode)) 393111032Sjulian goto loop; 39499703Sjulian if (pathopt) { /* this is a %func directory */ 39599703Sjulian stalloc(strlen(fullname) + 1); 39699703Sjulian readcmdfile(fullname); 39799703Sjulian if ((cmdp = cmdlookup(name, 0)) == NULL || cmdp->cmdtype != CMDFUNCTION) 39899703Sjulian error("%s not defined in %s", name, fullname); 39999703Sjulian stunalloc(fullname); 40099703Sjulian goto success; 40199703Sjulian } 40299703Sjulian#ifdef notdef 40399703Sjulian if (statb.st_uid == geteuid()) { 40499703Sjulian if ((statb.st_mode & 0100) == 0) 40599703Sjulian goto loop; 40699703Sjulian } else if (statb.st_gid == getegid()) { 40799703Sjulian if ((statb.st_mode & 010) == 0) 40899703Sjulian goto loop; 40999703Sjulian } else { 41099703Sjulian if ((statb.st_mode & 01) == 0) 41199703Sjulian goto loop; 41299703Sjulian } 41399703Sjulian#endif 41499703Sjulian TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname)); 41599703Sjulian INTOFF; 41699703Sjulian cmdp = cmdlookup(name, 1); 41799703Sjulian if (cmdp->cmdtype == CMDFUNCTION) 41899703Sjulian cmdp = &loc_cmd; 41999703Sjulian cmdp->cmdtype = CMDNORMAL; 42099703Sjulian cmdp->param.index = idx; 42199703Sjulian INTON; 42299703Sjulian goto success; 42399703Sjulian } 42499703Sjulian 42599703Sjulian /* We failed. If there was an entry for this command, delete it */ 426251988Skib if (cmdp && cmdp->cmdtype != CMDFUNCTION) 42799703Sjulian delete_cmd_entry(); 42899703Sjulian if (act & DO_ERR) { 42999703Sjulian if (e == ENOENT || e == ENOTDIR) 43099703Sjulian outfmt(out2, "%s: not found\n", name); 43199703Sjulian else 43299703Sjulian outfmt(out2, "%s: %s\n", name, strerror(e)); 43399703Sjulian } 43499703Sjulian entry->cmdtype = CMDUNKNOWN; 43599703Sjulian entry->u.index = 0; 43699703Sjulian return; 43799703Sjulian 438290668Sjhbsuccess: 439290668Sjhb cmdp->rehash = 0; 44099703Sjulian entry->cmdtype = cmdp->cmdtype; 44199703Sjulian entry->u = cmdp->param; 442290668Sjhb entry->special = cmdp->special; 443290668Sjhb} 44499703Sjulian 44599703Sjulian 446290668Sjhb 447290668Sjhb/* 44899703Sjulian * Search the table of builtin commands. 44999703Sjulian */ 450251033Skib 45199703Sjulianint 45299703Sjulianfind_builtin(const char *name, int *special) 45399703Sjulian{ 454174395Sjkoshy const struct builtincmd *bp; 455174395Sjkoshy 456174395Sjkoshy for (bp = builtincmd ; bp->name ; bp++) { 457174395Sjkoshy if (*bp->name == *name && equal(bp->name, name)) { 458174395Sjkoshy *special = bp->special; 459174395Sjkoshy return bp->code; 460174395Sjkoshy } 461174395Sjkoshy } 462174395Sjkoshy return -1; 463174395Sjkoshy} 464174395Sjkoshy 465174395Sjkoshy 466174395Sjkoshy 467174395Sjkoshy/* 468174395Sjkoshy * Called when a cd is done. Marks all commands so the next time they 469174395Sjkoshy * are executed they will be rehashed. 470174395Sjkoshy */ 471174395Sjkoshy 472174395Sjkoshyvoid 473174395Sjkoshyhashcd(void) 474174395Sjkoshy{ 475174395Sjkoshy struct tblentry **pp; 476174395Sjkoshy struct tblentry *cmdp; 477186037Sjkoshy 478174395Sjkoshy for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) { 479186037Sjkoshy for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 480186037Sjkoshy if (cmdp->cmdtype == CMDNORMAL) 481186037Sjkoshy cmdp->rehash = 1; 482186037Sjkoshy } 483186037Sjkoshy } 484186037Sjkoshy} 485186037Sjkoshy 486174395Sjkoshy 487186037Sjkoshy 488186037Sjkoshy/* 489174395Sjkoshy * Called before PATH is changed. The argument is the new value of PATH; 490174395Sjkoshy * pathval() still returns the old value at this point. Called with 491174395Sjkoshy * interrupts off. 492 */ 493 494void 495changepath(const char *newval) 496{ 497 clearcmdentry(0); 498} 499 500 501/* 502 * Clear out command entries. The argument specifies the first entry in 503 * PATH which has changed. 504 */ 505 506void 507clearcmdentry(int firstchange) 508{ 509 struct tblentry **tblp; 510 struct tblentry **pp; 511 struct tblentry *cmdp; 512 513 INTOFF; 514 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) { 515 pp = tblp; 516 while ((cmdp = *pp) != NULL) { 517 if ((cmdp->cmdtype == CMDNORMAL && 518 cmdp->param.index >= firstchange)) { 519 *pp = cmdp->next; 520 ckfree(cmdp); 521 } else { 522 pp = &cmdp->next; 523 } 524 } 525 } 526 INTON; 527} 528 529 530/* 531 * Locate a command in the command hash table. If "add" is nonzero, 532 * add the command to the table if it is not already present. The 533 * variable "lastcmdentry" is set to point to the address of the link 534 * pointing to the entry, so that delete_cmd_entry can delete the 535 * entry. 536 */ 537 538static struct tblentry **lastcmdentry; 539 540 541static struct tblentry * 542cmdlookup(const char *name, int add) 543{ 544 int hashval; 545 const char *p; 546 struct tblentry *cmdp; 547 struct tblentry **pp; 548 549 p = name; 550 hashval = *p << 4; 551 while (*p) 552 hashval += *p++; 553 hashval &= 0x7FFF; 554 pp = &cmdtable[hashval % CMDTABLESIZE]; 555 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 556 if (equal(cmdp->cmdname, name)) 557 break; 558 pp = &cmdp->next; 559 } 560 if (add && cmdp == NULL) { 561 INTOFF; 562 cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB 563 + strlen(name) + 1); 564 cmdp->next = NULL; 565 cmdp->cmdtype = CMDUNKNOWN; 566 cmdp->rehash = 0; 567 strcpy(cmdp->cmdname, name); 568 INTON; 569 } 570 lastcmdentry = pp; 571 return cmdp; 572} 573 574/* 575 * Delete the command entry returned on the last lookup. 576 */ 577 578static void 579delete_cmd_entry(void) 580{ 581 struct tblentry *cmdp; 582 583 INTOFF; 584 cmdp = *lastcmdentry; 585 *lastcmdentry = cmdp->next; 586 ckfree(cmdp); 587 INTON; 588} 589 590 591 592/* 593 * Add a new command entry, replacing any existing command entry for 594 * the same name. 595 */ 596 597void 598addcmdentry(const char *name, struct cmdentry *entry) 599{ 600 struct tblentry *cmdp; 601 602 INTOFF; 603 cmdp = cmdlookup(name, 1); 604 if (cmdp->cmdtype == CMDFUNCTION) { 605 unreffunc(cmdp->param.func); 606 } 607 cmdp->cmdtype = entry->cmdtype; 608 cmdp->param = entry->u; 609 INTON; 610} 611 612 613/* 614 * Define a shell function. 615 */ 616 617void 618defun(const char *name, union node *func) 619{ 620 struct cmdentry entry; 621 622 INTOFF; 623 entry.cmdtype = CMDFUNCTION; 624 entry.u.func = copyfunc(func); 625 addcmdentry(name, &entry); 626 INTON; 627} 628 629 630/* 631 * Delete a function if it exists. 632 */ 633 634int 635unsetfunc(const char *name) 636{ 637 struct tblentry *cmdp; 638 639 if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->cmdtype == CMDFUNCTION) { 640 unreffunc(cmdp->param.func); 641 delete_cmd_entry(); 642 return (0); 643 } 644 return (0); 645} 646 647/* 648 * Shared code for the following builtin commands: 649 * type, command -v, command -V 650 */ 651 652int 653typecmd_impl(int argc, char **argv, int cmd, const char *path) 654{ 655 struct cmdentry entry; 656 struct tblentry *cmdp; 657 const char *const *pp; 658 struct alias *ap; 659 int i; 660 int error1 = 0; 661 662 if (path != pathval()) 663 clearcmdentry(0); 664 665 for (i = 1; i < argc; i++) { 666 /* First look at the keywords */ 667 for (pp = parsekwd; *pp; pp++) 668 if (**pp == *argv[i] && equal(*pp, argv[i])) 669 break; 670 671 if (*pp) { 672 if (cmd == TYPECMD_SMALLV) 673 out1fmt("%s\n", argv[i]); 674 else 675 out1fmt("%s is a shell keyword\n", argv[i]); 676 continue; 677 } 678 679 /* Then look at the aliases */ 680 if ((ap = lookupalias(argv[i], 1)) != NULL) { 681 if (cmd == TYPECMD_SMALLV) 682 out1fmt("alias %s='%s'\n", argv[i], ap->val); 683 else 684 out1fmt("%s is an alias for %s\n", argv[i], 685 ap->val); 686 continue; 687 } 688 689 /* Then check if it is a tracked alias */ 690 if ((cmdp = cmdlookup(argv[i], 0)) != NULL) { 691 entry.cmdtype = cmdp->cmdtype; 692 entry.u = cmdp->param; 693 entry.special = cmdp->special; 694 } 695 else { 696 /* Finally use brute force */ 697 find_command(argv[i], &entry, 0, path); 698 } 699 700 switch (entry.cmdtype) { 701 case CMDNORMAL: { 702 if (strchr(argv[i], '/') == NULL) { 703 const char *path2 = path; 704 char *name; 705 int j = entry.u.index; 706 do { 707 name = padvance(&path2, argv[i]); 708 stunalloc(name); 709 } while (--j >= 0); 710 if (cmd == TYPECMD_SMALLV) 711 out1fmt("%s\n", name); 712 else 713 out1fmt("%s is%s %s\n", argv[i], 714 (cmdp && cmd == TYPECMD_TYPE) ? 715 " a tracked alias for" : "", 716 name); 717 } else { 718 if (eaccess(argv[i], X_OK) == 0) { 719 if (cmd == TYPECMD_SMALLV) 720 out1fmt("%s\n", argv[i]); 721 else 722 out1fmt("%s is %s\n", argv[i], 723 argv[i]); 724 } else { 725 if (cmd != TYPECMD_SMALLV) 726 outfmt(out2, "%s: %s\n", 727 argv[i], strerror(errno)); 728 error1 |= 127; 729 } 730 } 731 break; 732 } 733 case CMDFUNCTION: 734 if (cmd == TYPECMD_SMALLV) 735 out1fmt("%s\n", argv[i]); 736 else 737 out1fmt("%s is a shell function\n", argv[i]); 738 break; 739 740 case CMDBUILTIN: 741 if (cmd == TYPECMD_SMALLV) 742 out1fmt("%s\n", argv[i]); 743 else if (entry.special) 744 out1fmt("%s is a special shell builtin\n", 745 argv[i]); 746 else 747 out1fmt("%s is a shell builtin\n", argv[i]); 748 break; 749 750 default: 751 if (cmd != TYPECMD_SMALLV) 752 outfmt(out2, "%s: not found\n", argv[i]); 753 error1 |= 127; 754 break; 755 } 756 } 757 758 if (path != pathval()) 759 clearcmdentry(0); 760 761 return error1; 762} 763 764/* 765 * Locate and print what a word is... 766 */ 767 768int 769typecmd(int argc, char **argv) 770{ 771 return typecmd_impl(argc, argv, TYPECMD_TYPE, bltinlookup("PATH", 1)); 772} 773