exec.c revision 196483
1156136Sdavidxu/*- 2156136Sdavidxu * Copyright (c) 1991, 1993 3156136Sdavidxu * The Regents of the University of California. All rights reserved. 4156136Sdavidxu * 5156136Sdavidxu * This code is derived from software contributed to Berkeley by 6156136Sdavidxu * Kenneth Almquist. 7156136Sdavidxu * 8156136Sdavidxu * Redistribution and use in source and binary forms, with or without 9156136Sdavidxu * modification, are permitted provided that the following conditions 10156136Sdavidxu * are met: 11156136Sdavidxu * 1. Redistributions of source code must retain the above copyright 12156136Sdavidxu * notice, this list of conditions and the following disclaimer. 13156136Sdavidxu * 2. Redistributions in binary form must reproduce the above copyright 14156136Sdavidxu * notice, this list of conditions and the following disclaimer in the 15156136Sdavidxu * documentation and/or other materials provided with the distribution. 16156136Sdavidxu * 4. Neither the name of the University nor the names of its contributors 17156136Sdavidxu * may be used to endorse or promote products derived from this software 18156136Sdavidxu * without specific prior written permission. 19156136Sdavidxu * 20156136Sdavidxu * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21156136Sdavidxu * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22156136Sdavidxu * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23156136Sdavidxu * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24156136Sdavidxu * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25156136Sdavidxu * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26156136Sdavidxu * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27156136Sdavidxu * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28156136Sdavidxu * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29156136Sdavidxu * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30156136Sdavidxu * SUCH DAMAGE. 31156136Sdavidxu */ 32156136Sdavidxu 33156136Sdavidxu#ifndef lint 34156136Sdavidxu#if 0 35156267Sdavidxustatic char sccsid[] = "@(#)exec.c 8.4 (Berkeley) 6/8/95"; 36156136Sdavidxu#endif 37156136Sdavidxu#endif /* not lint */ 38156136Sdavidxu#include <sys/cdefs.h> 39156136Sdavidxu__FBSDID("$FreeBSD: head/bin/sh/exec.c 196483 2009-08-23 21:09:46Z jilles $"); 40156136Sdavidxu 41156136Sdavidxu#include <sys/types.h> 42156136Sdavidxu#include <sys/stat.h> 43156136Sdavidxu#include <unistd.h> 44156136Sdavidxu#include <fcntl.h> 45156136Sdavidxu#include <errno.h> 46156136Sdavidxu#include <stdlib.h> 47156136Sdavidxu 48156136Sdavidxu/* 49156136Sdavidxu * When commands are first encountered, they are entered in a hash table. 50156267Sdavidxu * This ensures that a full path search will not have to be done for them 51156136Sdavidxu * on each invocation. 52156136Sdavidxu * 53156383Sdavidxu * We should investigate converting to a linear search, even though that 54156136Sdavidxu * would make the command name "hash" a misnomer. 55156136Sdavidxu */ 56156267Sdavidxu 57156267Sdavidxu#include "shell.h" 58156383Sdavidxu#include "main.h" 59156136Sdavidxu#include "nodes.h" 60156267Sdavidxu#include "parser.h" 61156136Sdavidxu#include "redir.h" 62156383Sdavidxu#include "eval.h" 63156383Sdavidxu#include "exec.h" 64156383Sdavidxu#include "builtins.h" 65156383Sdavidxu#include "var.h" 66156383Sdavidxu#include "options.h" 67156383Sdavidxu#include "input.h" 68156383Sdavidxu#include "output.h" 69156136Sdavidxu#include "syntax.h" 70157242Sdeischen#include "memalloc.h" 71156136Sdavidxu#include "error.h" 72156383Sdavidxu#include "init.h" 73156383Sdavidxu#include "mystring.h" 74156136Sdavidxu#include "show.h" 75156383Sdavidxu#include "jobs.h" 76156383Sdavidxu#include "alias.h" 77156383Sdavidxu 78156383Sdavidxu 79156136Sdavidxu#define CMDTABLESIZE 31 /* should be prime */ 80156383Sdavidxu#define ARB 1 /* actual size determined at run time */ 81156383Sdavidxu 82156136Sdavidxu 83156383Sdavidxu 84156383Sdavidxustruct tblentry { 85156383Sdavidxu struct tblentry *next; /* next entry in hash chain */ 86156383Sdavidxu union param param; /* definition of builtin function */ 87156383Sdavidxu int special; /* flag for special builtin commands */ 88156383Sdavidxu short cmdtype; /* index identifying command */ 89156383Sdavidxu char rehash; /* if set, cd done since entry created */ 90156383Sdavidxu char cmdname[ARB]; /* name of command */ 91156383Sdavidxu}; 92156383Sdavidxu 93156383Sdavidxu 94156383SdavidxuSTATIC struct tblentry *cmdtable[CMDTABLESIZE]; 95156383SdavidxuSTATIC int builtinloc = -1; /* index in path of %builtin, or -1 */ 96156383Sdavidxuint exerrno = 0; /* Last exec error */ 97156383Sdavidxu 98156383Sdavidxu 99156383SdavidxuSTATIC void tryexec(char *, char **, char **); 100156136SdavidxuSTATIC void printentry(struct tblentry *, int); 101156136SdavidxuSTATIC struct tblentry *cmdlookup(char *, int); 102156136SdavidxuSTATIC void delete_cmd_entry(void); 103156136Sdavidxu 104156136Sdavidxu 105157242Sdeischen 106156136Sdavidxu/* 107156136Sdavidxu * Exec a program. Never returns. If you change this routine, you may 108156136Sdavidxu * have to change the find_command routine as well. 109156136Sdavidxu */ 110156136Sdavidxu 111156267Sdavidxuvoid 112156383Sdavidxushellexec(char **argv, char **envp, char *path, int index) 113156136Sdavidxu{ 114156136Sdavidxu char *cmdname; 115156383Sdavidxu int e; 116156383Sdavidxu 117156136Sdavidxu if (strchr(argv[0], '/') != NULL) { 118156383Sdavidxu tryexec(argv[0], argv, envp); 119156383Sdavidxu e = errno; 120156383Sdavidxu } else { 121156136Sdavidxu e = ENOENT; 122156136Sdavidxu while ((cmdname = padvance(&path, argv[0])) != NULL) { 123156136Sdavidxu if (--index < 0 && pathopt == NULL) { 124156383Sdavidxu tryexec(cmdname, argv, envp); 125156267Sdavidxu if (errno != ENOENT && errno != ENOTDIR) 126156267Sdavidxu e = errno; 127156383Sdavidxu } 128156267Sdavidxu stunalloc(cmdname); 129156267Sdavidxu } 130156267Sdavidxu } 131156267Sdavidxu 132156267Sdavidxu /* Map to POSIX errors */ 133156267Sdavidxu switch (e) { 134156383Sdavidxu case EACCES: 135156383Sdavidxu exerrno = 126; 136156267Sdavidxu break; 137156383Sdavidxu case ENOENT: 138156136Sdavidxu exerrno = 127; 139156267Sdavidxu break; 140156136Sdavidxu default: 141156383Sdavidxu exerrno = 2; 142156136Sdavidxu break; 143156136Sdavidxu } 144156136Sdavidxu if (e == ENOENT || e == ENOTDIR) 145156136Sdavidxu exerror(EXEXEC, "%s: not found", argv[0]); 146156136Sdavidxu exerror(EXEXEC, "%s: %s", argv[0], strerror(e)); 147156136Sdavidxu} 148156136Sdavidxu 149156136Sdavidxu 150156136SdavidxuSTATIC void 151156267Sdavidxutryexec(char *cmd, char **argv, char **envp) 152156136Sdavidxu{ 153156136Sdavidxu int e; 154156267Sdavidxu 155156136Sdavidxu execve(cmd, argv, envp); 156156136Sdavidxu e = errno; 157156136Sdavidxu if (e == ENOEXEC) { 158156136Sdavidxu initshellproc(); 159156267Sdavidxu setinputfile(cmd, 0); 160156136Sdavidxu commandname = arg0 = savestr(argv[0]); 161156136Sdavidxu setparam(argv + 1); 162156136Sdavidxu exraise(EXSHELLPROC); 163156136Sdavidxu /*NOTREACHED*/ 164156267Sdavidxu } 165156136Sdavidxu errno = e; 166156136Sdavidxu} 167156267Sdavidxu 168156267Sdavidxu/* 169156267Sdavidxu * Do a path search. The variable path (passed by reference) should be 170156267Sdavidxu * set to the start of the path before the first call; padvance will update 171156267Sdavidxu * this value as it proceeds. Successive calls to padvance will return 172156267Sdavidxu * the possible path expansions in sequence. If an option (indicated by 173156267Sdavidxu * a percent sign) appears in the path entry then the global variable 174156136Sdavidxu * pathopt will be set to point to it; otherwise pathopt will be set to 175156136Sdavidxu * NULL. 176156136Sdavidxu */ 177156383Sdavidxu 178156136Sdavidxuchar *pathopt; 179156136Sdavidxu 180156383Sdavidxuchar * 181156136Sdavidxupadvance(char **path, char *name) 182156136Sdavidxu{ 183156383Sdavidxu char *p, *q; 184156136Sdavidxu char *start; 185156136Sdavidxu int len; 186156383Sdavidxu 187156136Sdavidxu if (*path == NULL) 188156136Sdavidxu return NULL; 189156136Sdavidxu start = *path; 190156267Sdavidxu for (p = start; *p && *p != ':' && *p != '%'; p++) 191156383Sdavidxu ; /* nothing */ 192156136Sdavidxu len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */ 193156136Sdavidxu while (stackblocksize() < len) 194156136Sdavidxu growstackblock(); 195156136Sdavidxu q = stackblock(); 196156136Sdavidxu if (p != start) { 197156136Sdavidxu memcpy(q, start, p - start); 198156383Sdavidxu q += p - start; 199156383Sdavidxu *q++ = '/'; 200156383Sdavidxu } 201156383Sdavidxu strcpy(q, name); 202156383Sdavidxu pathopt = NULL; 203156383Sdavidxu if (*p == '%') { 204156383Sdavidxu pathopt = ++p; 205156383Sdavidxu while (*p && *p != ':') p++; 206156383Sdavidxu } 207156383Sdavidxu if (*p == ':') 208156383Sdavidxu *path = p + 1; 209156383Sdavidxu else 210156383Sdavidxu *path = NULL; 211156383Sdavidxu return stalloc(len); 212156383Sdavidxu} 213156383Sdavidxu 214156383Sdavidxu 215156383Sdavidxu 216156383Sdavidxu/*** Command hashing code ***/ 217156136Sdavidxu 218156136Sdavidxu 219156136Sdavidxuint 220156136Sdavidxuhashcmd(int argc __unused, char **argv __unused) 221156136Sdavidxu{ 222156136Sdavidxu struct tblentry **pp; 223156136Sdavidxu struct tblentry *cmdp; 224156136Sdavidxu int c; 225156136Sdavidxu int verbose; 226156136Sdavidxu struct cmdentry entry; 227156383Sdavidxu char *name; 228156136Sdavidxu 229156136Sdavidxu verbose = 0; 230156136Sdavidxu while ((c = nextopt("rv")) != '\0') { 231156383Sdavidxu if (c == 'r') { 232156136Sdavidxu clearcmdentry(0); 233156136Sdavidxu } else if (c == 'v') { 234156136Sdavidxu verbose++; 235156136Sdavidxu } 236156136Sdavidxu } 237156136Sdavidxu if (*argptr == NULL) { 238156136Sdavidxu for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) { 239156383Sdavidxu for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 240156136Sdavidxu if (cmdp->cmdtype == CMDNORMAL) 241156136Sdavidxu printentry(cmdp, verbose); 242156136Sdavidxu } 243156136Sdavidxu } 244156136Sdavidxu return 0; 245156136Sdavidxu } 246156136Sdavidxu while ((name = *argptr) != NULL) { 247156136Sdavidxu if ((cmdp = cmdlookup(name, 0)) != NULL 248156136Sdavidxu && (cmdp->cmdtype == CMDNORMAL 249156136Sdavidxu || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))) 250156136Sdavidxu delete_cmd_entry(); 251156136Sdavidxu find_command(name, &entry, 1, pathval()); 252156136Sdavidxu if (verbose) { 253156136Sdavidxu if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */ 254156136Sdavidxu cmdp = cmdlookup(name, 0); 255156136Sdavidxu if (cmdp != NULL) 256156136Sdavidxu printentry(cmdp, verbose); 257156136Sdavidxu else 258156136Sdavidxu outfmt(&errout, "%s: not found\n", name); 259156136Sdavidxu } 260156136Sdavidxu flushall(); 261156136Sdavidxu } 262156136Sdavidxu argptr++; 263156136Sdavidxu } 264156136Sdavidxu return 0; 265156136Sdavidxu} 266156136Sdavidxu 267156136Sdavidxu 268156136SdavidxuSTATIC void 269156136Sdavidxuprintentry(struct tblentry *cmdp, int verbose) 270156136Sdavidxu{ 271156136Sdavidxu int index; 272156136Sdavidxu char *path; 273156136Sdavidxu char *name; 274156136Sdavidxu 275156136Sdavidxu if (cmdp->cmdtype == CMDNORMAL) { 276156136Sdavidxu index = cmdp->param.index; 277156136Sdavidxu path = pathval(); 278156136Sdavidxu do { 279156136Sdavidxu name = padvance(&path, cmdp->cmdname); 280156136Sdavidxu stunalloc(name); 281156267Sdavidxu } while (--index >= 0); 282156383Sdavidxu out1str(name); 283156136Sdavidxu } else if (cmdp->cmdtype == CMDBUILTIN) { 284156136Sdavidxu out1fmt("builtin %s", cmdp->cmdname); 285156383Sdavidxu } else if (cmdp->cmdtype == CMDFUNCTION) { 286156136Sdavidxu out1fmt("function %s", cmdp->cmdname); 287156136Sdavidxu if (verbose) { 288156136Sdavidxu INTOFF; 289156136Sdavidxu name = commandtext(&cmdp->param.func->n); 290156383Sdavidxu out1c(' '); 291156136Sdavidxu out1str(name); 292156136Sdavidxu ckfree(name); 293156136Sdavidxu INTON; 294156136Sdavidxu } 295156136Sdavidxu#ifdef DEBUG 296156136Sdavidxu } else { 297156136Sdavidxu error("internal error: cmdtype %d", cmdp->cmdtype); 298156136Sdavidxu#endif 299156136Sdavidxu } 300156136Sdavidxu if (cmdp->rehash) 301156136Sdavidxu out1c('*'); 302156136Sdavidxu out1c('\n'); 303156136Sdavidxu} 304156383Sdavidxu 305156383Sdavidxu 306156136Sdavidxu 307156383Sdavidxu/* 308156529Sdavidxu * Resolve a command name. If you change this routine, you may have to 309156136Sdavidxu * change the shellexec routine as well. 310156136Sdavidxu */ 311156383Sdavidxu 312156383Sdavidxuvoid 313156267Sdavidxufind_command(char *name, struct cmdentry *entry, int printerr, char *path) 314156383Sdavidxu{ 315156383Sdavidxu struct tblentry *cmdp; 316156267Sdavidxu int index; 317156267Sdavidxu int prev; 318156136Sdavidxu char *fullname; 319156136Sdavidxu struct stat statb; 320156267Sdavidxu int e; 321156267Sdavidxu int i; 322156383Sdavidxu int spec; 323156383Sdavidxu 324156383Sdavidxu /* If name contains a slash, don't use the hash table */ 325156383Sdavidxu if (strchr(name, '/') != NULL) { 326156383Sdavidxu entry->cmdtype = CMDNORMAL; 327156383Sdavidxu entry->u.index = 0; 328156383Sdavidxu return; 329156529Sdavidxu } 330156529Sdavidxu 331156529Sdavidxu /* If name is in the table, and not invalidated by cd, we're done */ 332156529Sdavidxu if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->rehash == 0) 333156529Sdavidxu goto success; 334156529Sdavidxu 335156529Sdavidxu /* If %builtin not in path, check for builtin next */ 336157242Sdeischen if (builtinloc < 0 && (i = find_builtin(name, &spec)) >= 0) { 337156383Sdavidxu INTOFF; 338156529Sdavidxu cmdp = cmdlookup(name, 1); 339156383Sdavidxu cmdp->cmdtype = CMDBUILTIN; 340156136Sdavidxu cmdp->param.index = i; 341156383Sdavidxu cmdp->special = spec; 342156383Sdavidxu INTON; 343156383Sdavidxu goto success; 344156136Sdavidxu } 345156136Sdavidxu 346156136Sdavidxu /* We have to search path. */ 347156136Sdavidxu prev = -1; /* where to start */ 348156136Sdavidxu if (cmdp) { /* doing a rehash */ 349156136Sdavidxu if (cmdp->cmdtype == CMDBUILTIN) 350156383Sdavidxu prev = builtinloc; 351156383Sdavidxu else 352156136Sdavidxu prev = cmdp->param.index; 353156136Sdavidxu } 354156383Sdavidxu 355156136Sdavidxu e = ENOENT; 356156136Sdavidxu index = -1; 357156136Sdavidxuloop: 358156383Sdavidxu while ((fullname = padvance(&path, name)) != NULL) { 359156383Sdavidxu stunalloc(fullname); 360156136Sdavidxu index++; 361156136Sdavidxu if (pathopt) { 362156136Sdavidxu if (prefix("builtin", pathopt)) { 363156136Sdavidxu if ((i = find_builtin(name, &spec)) < 0) 364156383Sdavidxu goto loop; 365156383Sdavidxu INTOFF; 366156136Sdavidxu cmdp = cmdlookup(name, 1); 367156136Sdavidxu cmdp->cmdtype = CMDBUILTIN; 368156383Sdavidxu cmdp->param.index = i; 369156136Sdavidxu cmdp->special = spec; 370156136Sdavidxu INTON; 371156383Sdavidxu goto success; 372156267Sdavidxu } else if (prefix("func", pathopt)) { 373156136Sdavidxu /* handled below */ 374156136Sdavidxu } else { 375156136Sdavidxu goto loop; /* ignore unimplemented options */ 376156383Sdavidxu } 377156383Sdavidxu } 378156383Sdavidxu /* if rehash, don't redo absolute path names */ 379156136Sdavidxu if (fullname[0] == '/' && index <= prev) { 380156136Sdavidxu if (index < prev) 381156383Sdavidxu goto loop; 382156136Sdavidxu TRACE(("searchexec \"%s\": no change\n", name)); 383156267Sdavidxu goto success; 384156383Sdavidxu } 385156383Sdavidxu if (stat(fullname, &statb) < 0) { 386156267Sdavidxu if (errno != ENOENT && errno != ENOTDIR) 387156383Sdavidxu e = errno; 388156383Sdavidxu goto loop; 389156267Sdavidxu } 390156267Sdavidxu e = EACCES; /* if we fail, this will be the error */ 391156267Sdavidxu if (!S_ISREG(statb.st_mode)) 392156383Sdavidxu goto loop; 393156383Sdavidxu if (pathopt) { /* this is a %func directory */ 394156383Sdavidxu stalloc(strlen(fullname) + 1); 395156136Sdavidxu readcmdfile(fullname); 396156383Sdavidxu if ((cmdp = cmdlookup(name, 0)) == NULL || cmdp->cmdtype != CMDFUNCTION) 397156383Sdavidxu error("%s not defined in %s", name, fullname); 398156136Sdavidxu stunalloc(fullname); 399156136Sdavidxu goto success; 400156383Sdavidxu } 401156192Sdavidxu#ifdef notdef 402156383Sdavidxu if (statb.st_uid == geteuid()) { 403156192Sdavidxu if ((statb.st_mode & 0100) == 0) 404156383Sdavidxu goto loop; 405156383Sdavidxu } else if (statb.st_gid == getegid()) { 406156383Sdavidxu if ((statb.st_mode & 010) == 0) 407156383Sdavidxu goto loop; 408156383Sdavidxu } else { 409156383Sdavidxu if ((statb.st_mode & 01) == 0) 410156383Sdavidxu goto loop; 411156383Sdavidxu } 412156267Sdavidxu#endif 413157242Sdeischen TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname)); 414156383Sdavidxu INTOFF; 415156383Sdavidxu cmdp = cmdlookup(name, 1); 416156383Sdavidxu cmdp->cmdtype = CMDNORMAL; 417156383Sdavidxu cmdp->param.index = index; 418156267Sdavidxu INTON; 419156267Sdavidxu goto success; 420156383Sdavidxu } 421156383Sdavidxu 422156383Sdavidxu /* We failed. If there was an entry for this command, delete it */ 423156267Sdavidxu if (cmdp) 424156383Sdavidxu delete_cmd_entry(); 425156267Sdavidxu if (printerr) { 426156383Sdavidxu if (e == ENOENT || e == ENOTDIR) 427156383Sdavidxu outfmt(out2, "%s: not found\n", name); 428156267Sdavidxu else 429156267Sdavidxu outfmt(out2, "%s: %s\n", name, strerror(e)); 430156267Sdavidxu } 431156383Sdavidxu entry->cmdtype = CMDUNKNOWN; 432156267Sdavidxu return; 433156267Sdavidxu 434156267Sdavidxusuccess: 435156383Sdavidxu cmdp->rehash = 0; 436156267Sdavidxu entry->cmdtype = cmdp->cmdtype; 437156267Sdavidxu entry->u = cmdp->param; 438156383Sdavidxu entry->special = cmdp->special; 439156267Sdavidxu} 440156383Sdavidxu 441156267Sdavidxu 442156383Sdavidxu 443156383Sdavidxu/* 444156383Sdavidxu * Search the table of builtin commands. 445156267Sdavidxu */ 446156267Sdavidxu 447156267Sdavidxuint 448156267Sdavidxufind_builtin(char *name, int *special) 449156383Sdavidxu{ 450156267Sdavidxu const struct builtincmd *bp; 451156267Sdavidxu 452156267Sdavidxu for (bp = builtincmd ; bp->name ; bp++) { 453156383Sdavidxu if (*bp->name == *name && equal(bp->name, name)) { 454156267Sdavidxu *special = bp->special; 455156267Sdavidxu return bp->code; 456156383Sdavidxu } 457156383Sdavidxu } 458156383Sdavidxu return -1; 459156383Sdavidxu} 460156267Sdavidxu 461156267Sdavidxu 462156383Sdavidxu 463156383Sdavidxu/* 464156267Sdavidxu * Called when a cd is done. Marks all commands so the next time they 465156267Sdavidxu * are executed they will be rehashed. 466 */ 467 468void 469hashcd(void) 470{ 471 struct tblentry **pp; 472 struct tblentry *cmdp; 473 474 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) { 475 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 476 if (cmdp->cmdtype == CMDNORMAL 477 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)) 478 cmdp->rehash = 1; 479 } 480 } 481} 482 483 484 485/* 486 * Called before PATH is changed. The argument is the new value of PATH; 487 * pathval() still returns the old value at this point. Called with 488 * interrupts off. 489 */ 490 491void 492changepath(const char *newval) 493{ 494 const char *old, *new; 495 int index; 496 int firstchange; 497 int bltin; 498 499 old = pathval(); 500 new = newval; 501 firstchange = 9999; /* assume no change */ 502 index = 0; 503 bltin = -1; 504 for (;;) { 505 if (*old != *new) { 506 firstchange = index; 507 if ((*old == '\0' && *new == ':') 508 || (*old == ':' && *new == '\0')) 509 firstchange++; 510 old = new; /* ignore subsequent differences */ 511 } 512 if (*new == '\0') 513 break; 514 if (*new == '%' && bltin < 0 && prefix("builtin", new + 1)) 515 bltin = index; 516 if (*new == ':') { 517 index++; 518 } 519 new++, old++; 520 } 521 if (builtinloc < 0 && bltin >= 0) 522 builtinloc = bltin; /* zap builtins */ 523 if (builtinloc >= 0 && bltin < 0) 524 firstchange = 0; 525 clearcmdentry(firstchange); 526 builtinloc = bltin; 527} 528 529 530/* 531 * Clear out command entries. The argument specifies the first entry in 532 * PATH which has changed. 533 */ 534 535void 536clearcmdentry(int firstchange) 537{ 538 struct tblentry **tblp; 539 struct tblentry **pp; 540 struct tblentry *cmdp; 541 542 INTOFF; 543 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) { 544 pp = tblp; 545 while ((cmdp = *pp) != NULL) { 546 if ((cmdp->cmdtype == CMDNORMAL && 547 cmdp->param.index >= firstchange) 548 || (cmdp->cmdtype == CMDBUILTIN && 549 builtinloc >= firstchange)) { 550 *pp = cmdp->next; 551 ckfree(cmdp); 552 } else { 553 pp = &cmdp->next; 554 } 555 } 556 } 557 INTON; 558} 559 560 561/* 562 * Delete all functions. 563 */ 564 565#ifdef mkinit 566MKINIT void deletefuncs(void); 567 568SHELLPROC { 569 deletefuncs(); 570} 571#endif 572 573void 574deletefuncs(void) 575{ 576 struct tblentry **tblp; 577 struct tblentry **pp; 578 struct tblentry *cmdp; 579 580 INTOFF; 581 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) { 582 pp = tblp; 583 while ((cmdp = *pp) != NULL) { 584 if (cmdp->cmdtype == CMDFUNCTION) { 585 *pp = cmdp->next; 586 unreffunc(cmdp->param.func); 587 ckfree(cmdp); 588 } else { 589 pp = &cmdp->next; 590 } 591 } 592 } 593 INTON; 594} 595 596 597 598/* 599 * Locate a command in the command hash table. If "add" is nonzero, 600 * add the command to the table if it is not already present. The 601 * variable "lastcmdentry" is set to point to the address of the link 602 * pointing to the entry, so that delete_cmd_entry can delete the 603 * entry. 604 */ 605 606STATIC struct tblentry **lastcmdentry; 607 608 609STATIC struct tblentry * 610cmdlookup(char *name, int add) 611{ 612 int hashval; 613 char *p; 614 struct tblentry *cmdp; 615 struct tblentry **pp; 616 617 p = name; 618 hashval = *p << 4; 619 while (*p) 620 hashval += *p++; 621 hashval &= 0x7FFF; 622 pp = &cmdtable[hashval % CMDTABLESIZE]; 623 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) { 624 if (equal(cmdp->cmdname, name)) 625 break; 626 pp = &cmdp->next; 627 } 628 if (add && cmdp == NULL) { 629 INTOFF; 630 cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB 631 + strlen(name) + 1); 632 cmdp->next = NULL; 633 cmdp->cmdtype = CMDUNKNOWN; 634 cmdp->rehash = 0; 635 strcpy(cmdp->cmdname, name); 636 INTON; 637 } 638 lastcmdentry = pp; 639 return cmdp; 640} 641 642/* 643 * Delete the command entry returned on the last lookup. 644 */ 645 646STATIC void 647delete_cmd_entry(void) 648{ 649 struct tblentry *cmdp; 650 651 INTOFF; 652 cmdp = *lastcmdentry; 653 *lastcmdentry = cmdp->next; 654 ckfree(cmdp); 655 INTON; 656} 657 658 659 660/* 661 * Add a new command entry, replacing any existing command entry for 662 * the same name. 663 */ 664 665void 666addcmdentry(char *name, struct cmdentry *entry) 667{ 668 struct tblentry *cmdp; 669 670 INTOFF; 671 cmdp = cmdlookup(name, 1); 672 if (cmdp->cmdtype == CMDFUNCTION) { 673 unreffunc(cmdp->param.func); 674 } 675 cmdp->cmdtype = entry->cmdtype; 676 cmdp->param = entry->u; 677 INTON; 678} 679 680 681/* 682 * Define a shell function. 683 */ 684 685void 686defun(char *name, union node *func) 687{ 688 struct cmdentry entry; 689 690 INTOFF; 691 entry.cmdtype = CMDFUNCTION; 692 entry.u.func = copyfunc(func); 693 addcmdentry(name, &entry); 694 INTON; 695} 696 697 698/* 699 * Delete a function if it exists. 700 */ 701 702int 703unsetfunc(char *name) 704{ 705 struct tblentry *cmdp; 706 707 if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->cmdtype == CMDFUNCTION) { 708 unreffunc(cmdp->param.func); 709 delete_cmd_entry(); 710 return (0); 711 } 712 return (0); 713} 714 715/* 716 * Shared code for the following builtin commands: 717 * type, command -v, command -V 718 */ 719 720int 721typecmd_impl(int argc, char **argv, int cmd) 722{ 723 struct cmdentry entry; 724 struct tblentry *cmdp; 725 char **pp; 726 struct alias *ap; 727 int i; 728 int error = 0; 729 extern char *const parsekwd[]; 730 731 for (i = 1; i < argc; i++) { 732 /* First look at the keywords */ 733 for (pp = (char **)parsekwd; *pp; pp++) 734 if (**pp == *argv[i] && equal(*pp, argv[i])) 735 break; 736 737 if (*pp) { 738 if (cmd == TYPECMD_SMALLV) 739 out1fmt("%s\n", argv[i]); 740 else 741 out1fmt("%s is a shell keyword\n", argv[i]); 742 continue; 743 } 744 745 /* Then look at the aliases */ 746 if ((ap = lookupalias(argv[i], 1)) != NULL) { 747 if (cmd == TYPECMD_SMALLV) 748 out1fmt("alias %s='%s'\n", argv[i], ap->val); 749 else 750 out1fmt("%s is an alias for %s\n", argv[i], 751 ap->val); 752 continue; 753 } 754 755 /* Then check if it is a tracked alias */ 756 if ((cmdp = cmdlookup(argv[i], 0)) != NULL) { 757 entry.cmdtype = cmdp->cmdtype; 758 entry.u = cmdp->param; 759 entry.special = cmdp->special; 760 } 761 else { 762 /* Finally use brute force */ 763 find_command(argv[i], &entry, 0, pathval()); 764 } 765 766 switch (entry.cmdtype) { 767 case CMDNORMAL: { 768 if (strchr(argv[i], '/') == NULL) { 769 char *path = pathval(), *name; 770 int j = entry.u.index; 771 do { 772 name = padvance(&path, argv[i]); 773 stunalloc(name); 774 } while (--j >= 0); 775 if (cmd == TYPECMD_SMALLV) 776 out1fmt("%s\n", name); 777 else 778 out1fmt("%s is%s %s\n", argv[i], 779 (cmdp && cmd == TYPECMD_TYPE) ? 780 " a tracked alias for" : "", 781 name); 782 } else { 783 if (eaccess(argv[i], X_OK) == 0) { 784 if (cmd == TYPECMD_SMALLV) 785 out1fmt("%s\n", argv[i]); 786 else 787 out1fmt("%s is %s\n", argv[i], 788 argv[i]); 789 } else { 790 if (cmd != TYPECMD_SMALLV) 791 outfmt(out2, "%s: %s\n", 792 argv[i], strerror(errno)); 793 error |= 127; 794 } 795 } 796 break; 797 } 798 case CMDFUNCTION: 799 if (cmd == TYPECMD_SMALLV) 800 out1fmt("%s\n", argv[i]); 801 else 802 out1fmt("%s is a shell function\n", argv[i]); 803 break; 804 805 case CMDBUILTIN: 806 if (cmd == TYPECMD_SMALLV) 807 out1fmt("%s\n", argv[i]); 808 else if (entry.special) 809 out1fmt("%s is a special shell builtin\n", 810 argv[i]); 811 else 812 out1fmt("%s is a shell builtin\n", argv[i]); 813 break; 814 815 default: 816 if (cmd != TYPECMD_SMALLV) 817 outfmt(out2, "%s: not found\n", argv[i]); 818 error |= 127; 819 break; 820 } 821 } 822 return error; 823} 824 825/* 826 * Locate and print what a word is... 827 */ 828 829int 830typecmd(int argc, char **argv) 831{ 832 return typecmd_impl(argc, argv, TYPECMD_TYPE); 833} 834