1130b656e5
This will make a number of things easier in the future, as well as (finally!) avoiding the Id-smashing problem which has plagued developers for so long. Boy, I'm glad we're not using sup anymore. This update would have been insane otherwise.
844 lines
17 KiB
C
844 lines
17 KiB
C
/*-
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Kenneth Almquist.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef lint
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static char const sccsid[] = "@(#)exec.c 8.4 (Berkeley) 6/8/95";
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#endif /* not lint */
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <stdlib.h>
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/*
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* When commands are first encountered, they are entered in a hash table.
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* This ensures that a full path search will not have to be done for them
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* on each invocation.
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*
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* We should investigate converting to a linear search, even though that
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* would make the command name "hash" a misnomer.
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*/
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#include "shell.h"
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#include "main.h"
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#include "nodes.h"
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#include "parser.h"
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#include "redir.h"
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#include "eval.h"
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#include "exec.h"
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#include "builtins.h"
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#include "var.h"
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#include "options.h"
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#include "input.h"
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#include "output.h"
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#include "syntax.h"
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#include "memalloc.h"
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#include "error.h"
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#include "init.h"
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#include "mystring.h"
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#include "show.h"
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#include "jobs.h"
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#define CMDTABLESIZE 31 /* should be prime */
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#define ARB 1 /* actual size determined at run time */
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struct tblentry {
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struct tblentry *next; /* next entry in hash chain */
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union param param; /* definition of builtin function */
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short cmdtype; /* index identifying command */
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char rehash; /* if set, cd done since entry created */
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char cmdname[ARB]; /* name of command */
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};
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STATIC struct tblentry *cmdtable[CMDTABLESIZE];
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STATIC int builtinloc = -1; /* index in path of %builtin, or -1 */
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int exerrno = 0; /* Last exec error */
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|
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STATIC void tryexec __P((char *, char **, char **));
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#ifndef BSD
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STATIC void execinterp __P((char **, char **));
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#endif
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STATIC void printentry __P((struct tblentry *, int));
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STATIC void clearcmdentry __P((int));
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STATIC struct tblentry *cmdlookup __P((char *, int));
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STATIC void delete_cmd_entry __P((void));
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/*
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* Exec a program. Never returns. If you change this routine, you may
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* have to change the find_command routine as well.
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*/
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void
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shellexec(argv, envp, path, index)
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char **argv, **envp;
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char *path;
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int index;
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{
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char *cmdname;
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int e;
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if (strchr(argv[0], '/') != NULL) {
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tryexec(argv[0], argv, envp);
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e = errno;
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} else {
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e = ENOENT;
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while ((cmdname = padvance(&path, argv[0])) != NULL) {
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if (--index < 0 && pathopt == NULL) {
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tryexec(cmdname, argv, envp);
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if (errno != ENOENT && errno != ENOTDIR)
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e = errno;
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}
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stunalloc(cmdname);
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}
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}
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/* Map to POSIX errors */
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switch (e) {
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case EACCES:
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exerrno = 126;
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break;
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case ENOENT:
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exerrno = 127;
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break;
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default:
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exerrno = 2;
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break;
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}
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exerror(EXEXEC, "%s: %s", argv[0], errmsg(e, E_EXEC));
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}
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STATIC void
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tryexec(cmd, argv, envp)
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char *cmd;
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char **argv;
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char **envp;
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{
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int e;
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#ifndef BSD
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char *p;
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#endif
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#ifdef SYSV
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do {
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execve(cmd, argv, envp);
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} while (errno == EINTR);
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#else
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execve(cmd, argv, envp);
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#endif
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e = errno;
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if (e == ENOEXEC) {
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initshellproc();
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setinputfile(cmd, 0);
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commandname = arg0 = savestr(argv[0]);
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#ifndef BSD
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pgetc(); pungetc(); /* fill up input buffer */
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p = parsenextc;
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if (parsenleft > 2 && p[0] == '#' && p[1] == '!') {
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argv[0] = cmd;
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execinterp(argv, envp);
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}
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#endif
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setparam(argv + 1);
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exraise(EXSHELLPROC);
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/*NOTREACHED*/
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}
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errno = e;
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}
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#ifndef BSD
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/*
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* Execute an interpreter introduced by "#!", for systems where this
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* feature has not been built into the kernel. If the interpreter is
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* the shell, return (effectively ignoring the "#!"). If the execution
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* of the interpreter fails, exit.
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*
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* This code peeks inside the input buffer in order to avoid actually
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* reading any input. It would benefit from a rewrite.
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*/
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#define NEWARGS 5
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STATIC void
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execinterp(argv, envp)
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char **argv, **envp;
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{
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int n;
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char *inp;
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char *outp;
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char c;
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char *p;
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char **ap;
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char *newargs[NEWARGS];
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int i;
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char **ap2;
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char **new;
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n = parsenleft - 2;
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inp = parsenextc + 2;
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ap = newargs;
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for (;;) {
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while (--n >= 0 && (*inp == ' ' || *inp == '\t'))
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inp++;
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if (n < 0)
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goto bad;
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if ((c = *inp++) == '\n')
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break;
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if (ap == &newargs[NEWARGS])
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bad: error("Bad #! line");
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STARTSTACKSTR(outp);
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do {
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STPUTC(c, outp);
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} while (--n >= 0 && (c = *inp++) != ' ' && c != '\t' && c != '\n');
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STPUTC('\0', outp);
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n++, inp--;
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*ap++ = grabstackstr(outp);
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}
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if (ap == newargs + 1) { /* if no args, maybe no exec is needed */
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p = newargs[0];
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for (;;) {
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if (equal(p, "sh") || equal(p, "ash")) {
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return;
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}
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while (*p != '/') {
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if (*p == '\0')
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goto break2;
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p++;
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}
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p++;
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}
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break2:;
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}
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i = (char *)ap - (char *)newargs; /* size in bytes */
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if (i == 0)
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error("Bad #! line");
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for (ap2 = argv ; *ap2++ != NULL ; );
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new = ckmalloc(i + ((char *)ap2 - (char *)argv));
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ap = newargs, ap2 = new;
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while ((i -= sizeof (char **)) >= 0)
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*ap2++ = *ap++;
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ap = argv;
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while (*ap2++ = *ap++);
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shellexec(new, envp, pathval(), 0);
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}
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#endif
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/*
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* Do a path search. The variable path (passed by reference) should be
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* set to the start of the path before the first call; padvance will update
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* this value as it proceeds. Successive calls to padvance will return
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* the possible path expansions in sequence. If an option (indicated by
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* a percent sign) appears in the path entry then the global variable
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* pathopt will be set to point to it; otherwise pathopt will be set to
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* NULL.
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*/
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char *pathopt;
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char *
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padvance(path, name)
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char **path;
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char *name;
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{
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register char *p, *q;
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char *start;
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int len;
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if (*path == NULL)
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return NULL;
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start = *path;
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for (p = start ; *p && *p != ':' && *p != '%' ; p++);
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len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */
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while (stackblocksize() < len)
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growstackblock();
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q = stackblock();
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if (p != start) {
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memcpy(q, start, p - start);
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q += p - start;
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*q++ = '/';
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}
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strcpy(q, name);
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pathopt = NULL;
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if (*p == '%') {
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pathopt = ++p;
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while (*p && *p != ':') p++;
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}
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if (*p == ':')
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*path = p + 1;
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else
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*path = NULL;
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return stalloc(len);
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}
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/*** Command hashing code ***/
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int
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hashcmd(argc, argv)
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int argc;
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char **argv;
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{
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struct tblentry **pp;
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struct tblentry *cmdp;
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int c;
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int verbose;
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struct cmdentry entry;
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char *name;
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verbose = 0;
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while ((c = nextopt("rv")) != '\0') {
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if (c == 'r') {
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clearcmdentry(0);
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} else if (c == 'v') {
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verbose++;
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}
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}
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if (*argptr == NULL) {
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for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
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for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
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printentry(cmdp, verbose);
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}
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}
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return 0;
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}
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while ((name = *argptr) != NULL) {
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if ((cmdp = cmdlookup(name, 0)) != NULL
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&& (cmdp->cmdtype == CMDNORMAL
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|| (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
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delete_cmd_entry();
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find_command(name, &entry, 1, pathval());
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if (verbose) {
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if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */
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cmdp = cmdlookup(name, 0);
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printentry(cmdp, verbose);
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}
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flushall();
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}
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argptr++;
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}
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return 0;
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}
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|
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STATIC void
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printentry(cmdp, verbose)
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struct tblentry *cmdp;
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int verbose;
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{
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int index;
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char *path;
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char *name;
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if (cmdp->cmdtype == CMDNORMAL) {
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index = cmdp->param.index;
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path = pathval();
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do {
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name = padvance(&path, cmdp->cmdname);
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stunalloc(name);
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} while (--index >= 0);
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out1str(name);
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} else if (cmdp->cmdtype == CMDBUILTIN) {
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out1fmt("builtin %s", cmdp->cmdname);
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} else if (cmdp->cmdtype == CMDFUNCTION) {
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out1fmt("function %s", cmdp->cmdname);
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if (verbose) {
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INTOFF;
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name = commandtext(cmdp->param.func);
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out1c(' ');
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out1str(name);
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ckfree(name);
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INTON;
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}
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#ifdef DEBUG
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} else {
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error("internal error: cmdtype %d", cmdp->cmdtype);
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#endif
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}
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if (cmdp->rehash)
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out1c('*');
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out1c('\n');
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}
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|
|
|
|
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/*
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* Resolve a command name. If you change this routine, you may have to
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* change the shellexec routine as well.
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*/
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void
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find_command(name, entry, printerr, path)
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char *name;
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struct cmdentry *entry;
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int printerr;
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char *path;
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{
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struct tblentry *cmdp;
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int index;
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int prev;
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char *fullname;
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struct stat statb;
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int e;
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int i;
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|
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/* If name contains a slash, don't use the hash table */
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if (strchr(name, '/') != NULL) {
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entry->cmdtype = CMDNORMAL;
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entry->u.index = 0;
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return;
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}
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|
|
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/* If name is in the table, and not invalidated by cd, we're done */
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if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->rehash == 0)
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goto success;
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|
|
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/* If %builtin not in path, check for builtin next */
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if (builtinloc < 0 && (i = find_builtin(name)) >= 0) {
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INTOFF;
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cmdp = cmdlookup(name, 1);
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cmdp->cmdtype = CMDBUILTIN;
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cmdp->param.index = i;
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INTON;
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goto success;
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}
|
|
|
|
/* We have to search path. */
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|
prev = -1; /* where to start */
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|
if (cmdp) { /* doing a rehash */
|
|
if (cmdp->cmdtype == CMDBUILTIN)
|
|
prev = builtinloc;
|
|
else
|
|
prev = cmdp->param.index;
|
|
}
|
|
|
|
e = ENOENT;
|
|
index = -1;
|
|
loop:
|
|
while ((fullname = padvance(&path, name)) != NULL) {
|
|
stunalloc(fullname);
|
|
index++;
|
|
if (pathopt) {
|
|
if (prefix("builtin", pathopt)) {
|
|
if ((i = find_builtin(name)) < 0)
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|
goto loop;
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|
INTOFF;
|
|
cmdp = cmdlookup(name, 1);
|
|
cmdp->cmdtype = CMDBUILTIN;
|
|
cmdp->param.index = i;
|
|
INTON;
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|
goto success;
|
|
} else if (prefix("func", pathopt)) {
|
|
/* handled below */
|
|
} else {
|
|
goto loop; /* ignore unimplemented options */
|
|
}
|
|
}
|
|
/* if rehash, don't redo absolute path names */
|
|
if (fullname[0] == '/' && index <= prev) {
|
|
if (index < prev)
|
|
goto loop;
|
|
TRACE(("searchexec \"%s\": no change\n", name));
|
|
goto success;
|
|
}
|
|
while (stat(fullname, &statb) < 0) {
|
|
#ifdef SYSV
|
|
if (errno == EINTR)
|
|
continue;
|
|
#endif
|
|
if (errno != ENOENT && errno != ENOTDIR)
|
|
e = errno;
|
|
goto loop;
|
|
}
|
|
e = EACCES; /* if we fail, this will be the error */
|
|
if (!S_ISREG(statb.st_mode))
|
|
goto loop;
|
|
if (pathopt) { /* this is a %func directory */
|
|
stalloc(strlen(fullname) + 1);
|
|
readcmdfile(fullname);
|
|
if ((cmdp = cmdlookup(name, 0)) == NULL || cmdp->cmdtype != CMDFUNCTION)
|
|
error("%s not defined in %s", name, fullname);
|
|
stunalloc(fullname);
|
|
goto success;
|
|
}
|
|
#ifdef notdef
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|
if (statb.st_uid == geteuid()) {
|
|
if ((statb.st_mode & 0100) == 0)
|
|
goto loop;
|
|
} else if (statb.st_gid == getegid()) {
|
|
if ((statb.st_mode & 010) == 0)
|
|
goto loop;
|
|
} else {
|
|
if ((statb.st_mode & 01) == 0)
|
|
goto loop;
|
|
}
|
|
#endif
|
|
TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
|
|
INTOFF;
|
|
cmdp = cmdlookup(name, 1);
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|
cmdp->cmdtype = CMDNORMAL;
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|
cmdp->param.index = index;
|
|
INTON;
|
|
goto success;
|
|
}
|
|
|
|
/* We failed. If there was an entry for this command, delete it */
|
|
if (cmdp)
|
|
delete_cmd_entry();
|
|
if (printerr)
|
|
outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC));
|
|
entry->cmdtype = CMDUNKNOWN;
|
|
return;
|
|
|
|
success:
|
|
cmdp->rehash = 0;
|
|
entry->cmdtype = cmdp->cmdtype;
|
|
entry->u = cmdp->param;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Search the table of builtin commands.
|
|
*/
|
|
|
|
int
|
|
find_builtin(name)
|
|
char *name;
|
|
{
|
|
register const struct builtincmd *bp;
|
|
|
|
for (bp = builtincmd ; bp->name ; bp++) {
|
|
if (*bp->name == *name && equal(bp->name, name))
|
|
return bp->code;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Called when a cd is done. Marks all commands so the next time they
|
|
* are executed they will be rehashed.
|
|
*/
|
|
|
|
void
|
|
hashcd() {
|
|
struct tblentry **pp;
|
|
struct tblentry *cmdp;
|
|
|
|
for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
|
|
for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
|
|
if (cmdp->cmdtype == CMDNORMAL
|
|
|| (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))
|
|
cmdp->rehash = 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Called before PATH is changed. The argument is the new value of PATH;
|
|
* pathval() still returns the old value at this point. Called with
|
|
* interrupts off.
|
|
*/
|
|
|
|
void
|
|
changepath(newval)
|
|
const char *newval;
|
|
{
|
|
const char *old, *new;
|
|
int index;
|
|
int firstchange;
|
|
int bltin;
|
|
|
|
old = pathval();
|
|
new = newval;
|
|
firstchange = 9999; /* assume no change */
|
|
index = 0;
|
|
bltin = -1;
|
|
for (;;) {
|
|
if (*old != *new) {
|
|
firstchange = index;
|
|
if ((*old == '\0' && *new == ':')
|
|
|| (*old == ':' && *new == '\0'))
|
|
firstchange++;
|
|
old = new; /* ignore subsequent differences */
|
|
}
|
|
if (*new == '\0')
|
|
break;
|
|
if (*new == '%' && bltin < 0 && prefix("builtin", new + 1))
|
|
bltin = index;
|
|
if (*new == ':') {
|
|
index++;
|
|
}
|
|
new++, old++;
|
|
}
|
|
if (builtinloc < 0 && bltin >= 0)
|
|
builtinloc = bltin; /* zap builtins */
|
|
if (builtinloc >= 0 && bltin < 0)
|
|
firstchange = 0;
|
|
clearcmdentry(firstchange);
|
|
builtinloc = bltin;
|
|
}
|
|
|
|
|
|
/*
|
|
* Clear out command entries. The argument specifies the first entry in
|
|
* PATH which has changed.
|
|
*/
|
|
|
|
STATIC void
|
|
clearcmdentry(firstchange)
|
|
int firstchange;
|
|
{
|
|
struct tblentry **tblp;
|
|
struct tblentry **pp;
|
|
struct tblentry *cmdp;
|
|
|
|
INTOFF;
|
|
for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
|
|
pp = tblp;
|
|
while ((cmdp = *pp) != NULL) {
|
|
if ((cmdp->cmdtype == CMDNORMAL &&
|
|
cmdp->param.index >= firstchange)
|
|
|| (cmdp->cmdtype == CMDBUILTIN &&
|
|
builtinloc >= firstchange)) {
|
|
*pp = cmdp->next;
|
|
ckfree(cmdp);
|
|
} else {
|
|
pp = &cmdp->next;
|
|
}
|
|
}
|
|
}
|
|
INTON;
|
|
}
|
|
|
|
|
|
/*
|
|
* Delete all functions.
|
|
*/
|
|
|
|
#ifdef mkinit
|
|
MKINIT void deletefuncs();
|
|
|
|
SHELLPROC {
|
|
deletefuncs();
|
|
}
|
|
#endif
|
|
|
|
void
|
|
deletefuncs() {
|
|
struct tblentry **tblp;
|
|
struct tblentry **pp;
|
|
struct tblentry *cmdp;
|
|
|
|
INTOFF;
|
|
for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
|
|
pp = tblp;
|
|
while ((cmdp = *pp) != NULL) {
|
|
if (cmdp->cmdtype == CMDFUNCTION) {
|
|
*pp = cmdp->next;
|
|
freefunc(cmdp->param.func);
|
|
ckfree(cmdp);
|
|
} else {
|
|
pp = &cmdp->next;
|
|
}
|
|
}
|
|
}
|
|
INTON;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Locate a command in the command hash table. If "add" is nonzero,
|
|
* add the command to the table if it is not already present. The
|
|
* variable "lastcmdentry" is set to point to the address of the link
|
|
* pointing to the entry, so that delete_cmd_entry can delete the
|
|
* entry.
|
|
*/
|
|
|
|
struct tblentry **lastcmdentry;
|
|
|
|
|
|
STATIC struct tblentry *
|
|
cmdlookup(name, add)
|
|
char *name;
|
|
int add;
|
|
{
|
|
int hashval;
|
|
register char *p;
|
|
struct tblentry *cmdp;
|
|
struct tblentry **pp;
|
|
|
|
p = name;
|
|
hashval = *p << 4;
|
|
while (*p)
|
|
hashval += *p++;
|
|
hashval &= 0x7FFF;
|
|
pp = &cmdtable[hashval % CMDTABLESIZE];
|
|
for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
|
|
if (equal(cmdp->cmdname, name))
|
|
break;
|
|
pp = &cmdp->next;
|
|
}
|
|
if (add && cmdp == NULL) {
|
|
INTOFF;
|
|
cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
|
|
+ strlen(name) + 1);
|
|
cmdp->next = NULL;
|
|
cmdp->cmdtype = CMDUNKNOWN;
|
|
cmdp->rehash = 0;
|
|
strcpy(cmdp->cmdname, name);
|
|
INTON;
|
|
}
|
|
lastcmdentry = pp;
|
|
return cmdp;
|
|
}
|
|
|
|
/*
|
|
* Delete the command entry returned on the last lookup.
|
|
*/
|
|
|
|
STATIC void
|
|
delete_cmd_entry() {
|
|
struct tblentry *cmdp;
|
|
|
|
INTOFF;
|
|
cmdp = *lastcmdentry;
|
|
*lastcmdentry = cmdp->next;
|
|
ckfree(cmdp);
|
|
INTON;
|
|
}
|
|
|
|
|
|
|
|
#ifdef notdef
|
|
void
|
|
getcmdentry(name, entry)
|
|
char *name;
|
|
struct cmdentry *entry;
|
|
{
|
|
struct tblentry *cmdp = cmdlookup(name, 0);
|
|
|
|
if (cmdp) {
|
|
entry->u = cmdp->param;
|
|
entry->cmdtype = cmdp->cmdtype;
|
|
} else {
|
|
entry->cmdtype = CMDUNKNOWN;
|
|
entry->u.index = 0;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
|
|
/*
|
|
* Add a new command entry, replacing any existing command entry for
|
|
* the same name.
|
|
*/
|
|
|
|
void
|
|
addcmdentry(name, entry)
|
|
char *name;
|
|
struct cmdentry *entry;
|
|
{
|
|
struct tblentry *cmdp;
|
|
|
|
INTOFF;
|
|
cmdp = cmdlookup(name, 1);
|
|
if (cmdp->cmdtype == CMDFUNCTION) {
|
|
freefunc(cmdp->param.func);
|
|
}
|
|
cmdp->cmdtype = entry->cmdtype;
|
|
cmdp->param = entry->u;
|
|
INTON;
|
|
}
|
|
|
|
|
|
/*
|
|
* Define a shell function.
|
|
*/
|
|
|
|
void
|
|
defun(name, func)
|
|
char *name;
|
|
union node *func;
|
|
{
|
|
struct cmdentry entry;
|
|
|
|
INTOFF;
|
|
entry.cmdtype = CMDFUNCTION;
|
|
entry.u.func = copyfunc(func);
|
|
addcmdentry(name, &entry);
|
|
INTON;
|
|
}
|
|
|
|
|
|
/*
|
|
* Delete a function if it exists.
|
|
*/
|
|
|
|
int
|
|
unsetfunc(name)
|
|
char *name;
|
|
{
|
|
struct tblentry *cmdp;
|
|
|
|
if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->cmdtype == CMDFUNCTION) {
|
|
freefunc(cmdp->param.func);
|
|
delete_cmd_entry();
|
|
return (0);
|
|
}
|
|
return (1);
|
|
}
|