1009 lines
21 KiB
C
1009 lines
21 KiB
C
/* $NetBSD: eval.c,v 1.26 1995/06/09 01:53:44 christos Exp $ */
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/*-
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* Copyright (c) 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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#ifndef lint
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#if 0
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static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95";
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#else
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static char sccsid[] = "$NetBSD: eval.c,v 1.26 1995/06/09 01:53:44 christos Exp $";
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#endif
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#endif /* not lint */
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#include <signal.h>
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#include <unistd.h>
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/*
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* Evaluate a command.
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*/
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#include "shell.h"
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#include "nodes.h"
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#include "syntax.h"
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#include "expand.h"
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#include "parser.h"
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#include "jobs.h"
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#include "eval.h"
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#include "builtins.h"
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#include "options.h"
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#include "exec.h"
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#include "redir.h"
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#include "input.h"
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#include "output.h"
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#include "trap.h"
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#include "var.h"
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#include "memalloc.h"
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#include "error.h"
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#include "show.h"
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#include "mystring.h"
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#ifndef NO_HISTORY
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#include "myhistedit.h"
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#endif
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/* flags in argument to evaltree */
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#define EV_EXIT 01 /* exit after evaluating tree */
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#define EV_TESTED 02 /* exit status is checked; ignore -e flag */
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#define EV_BACKCMD 04 /* command executing within back quotes */
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/* reasons for skipping commands (see comment on breakcmd routine) */
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#define SKIPBREAK 1
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#define SKIPCONT 2
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#define SKIPFUNC 3
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MKINIT int evalskip; /* set if we are skipping commands */
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STATIC int skipcount; /* number of levels to skip */
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MKINIT int loopnest; /* current loop nesting level */
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int funcnest; /* depth of function calls */
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char *commandname;
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struct strlist *cmdenviron;
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int exitstatus; /* exit status of last command */
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int oexitstatus; /* saved exit status */
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STATIC void evalloop __P((union node *));
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STATIC void evalfor __P((union node *));
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STATIC void evalcase __P((union node *, int));
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STATIC void evalsubshell __P((union node *, int));
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STATIC void expredir __P((union node *));
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STATIC void evalpipe __P((union node *));
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STATIC void evalcommand __P((union node *, int, struct backcmd *));
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STATIC void prehash __P((union node *));
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/*
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* Called to reset things after an exception.
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*/
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#ifdef mkinit
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INCLUDE "eval.h"
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RESET {
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evalskip = 0;
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loopnest = 0;
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funcnest = 0;
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}
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SHELLPROC {
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exitstatus = 0;
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}
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#endif
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/*
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* The eval commmand.
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*/
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int
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evalcmd(argc, argv)
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int argc;
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char **argv;
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{
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char *p;
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char *concat;
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char **ap;
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if (argc > 1) {
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p = argv[1];
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if (argc > 2) {
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STARTSTACKSTR(concat);
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ap = argv + 2;
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for (;;) {
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while (*p)
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STPUTC(*p++, concat);
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if ((p = *ap++) == NULL)
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break;
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STPUTC(' ', concat);
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}
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STPUTC('\0', concat);
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p = grabstackstr(concat);
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}
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evalstring(p);
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}
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return exitstatus;
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}
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/*
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* Execute a command or commands contained in a string.
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*/
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void
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evalstring(s)
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char *s;
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{
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union node *n;
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struct stackmark smark;
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setstackmark(&smark);
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setinputstring(s, 1);
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while ((n = parsecmd(0)) != NEOF) {
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evaltree(n, 0);
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popstackmark(&smark);
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}
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popfile();
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popstackmark(&smark);
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}
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/*
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* Evaluate a parse tree. The value is left in the global variable
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* exitstatus.
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*/
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void
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evaltree(n, flags)
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union node *n;
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int flags;
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{
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if (n == NULL) {
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TRACE(("evaltree(NULL) called\n"));
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exitstatus = 0;
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goto out;
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}
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#ifndef NO_HISTORY
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displayhist = 1; /* show history substitutions done with fc */
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#endif
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TRACE(("evaltree(0x%lx: %d) called\n", (long)n, n->type));
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switch (n->type) {
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case NSEMI:
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evaltree(n->nbinary.ch1, 0);
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if (evalskip)
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goto out;
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evaltree(n->nbinary.ch2, flags);
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break;
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case NAND:
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evaltree(n->nbinary.ch1, EV_TESTED);
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if (evalskip || exitstatus != 0)
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goto out;
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evaltree(n->nbinary.ch2, flags);
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break;
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case NOR:
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evaltree(n->nbinary.ch1, EV_TESTED);
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if (evalskip || exitstatus == 0)
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goto out;
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evaltree(n->nbinary.ch2, flags);
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break;
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case NREDIR:
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expredir(n->nredir.redirect);
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redirect(n->nredir.redirect, REDIR_PUSH);
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evaltree(n->nredir.n, flags);
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popredir();
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break;
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case NSUBSHELL:
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evalsubshell(n, flags);
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break;
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case NBACKGND:
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evalsubshell(n, flags);
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break;
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case NIF: {
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int status;
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evaltree(n->nif.test, EV_TESTED);
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status = exitstatus;
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exitstatus = 0;
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if (evalskip)
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goto out;
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if (status == 0)
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evaltree(n->nif.ifpart, flags);
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else if (n->nif.elsepart)
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evaltree(n->nif.elsepart, flags);
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break;
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}
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case NWHILE:
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case NUNTIL:
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evalloop(n);
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break;
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case NFOR:
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evalfor(n);
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break;
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case NCASE:
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evalcase(n, flags);
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break;
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case NDEFUN:
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defun(n->narg.text, n->narg.next);
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exitstatus = 0;
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break;
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case NNOT:
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evaltree(n->nnot.com, EV_TESTED);
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exitstatus = !exitstatus;
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break;
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case NPIPE:
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evalpipe(n);
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break;
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case NCMD:
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evalcommand(n, flags, (struct backcmd *)NULL);
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break;
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default:
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out1fmt("Node type = %d\n", n->type);
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flushout(&output);
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break;
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}
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out:
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if (pendingsigs)
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dotrap();
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if ((flags & EV_EXIT) || (eflag && exitstatus && !(flags & EV_TESTED)))
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exitshell(exitstatus);
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}
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STATIC void
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evalloop(n)
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union node *n;
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{
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int status;
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loopnest++;
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status = 0;
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for (;;) {
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evaltree(n->nbinary.ch1, EV_TESTED);
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if (evalskip) {
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skipping: if (evalskip == SKIPCONT && --skipcount <= 0) {
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evalskip = 0;
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continue;
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}
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if (evalskip == SKIPBREAK && --skipcount <= 0)
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evalskip = 0;
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break;
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}
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if (n->type == NWHILE) {
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if (exitstatus != 0)
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break;
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} else {
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if (exitstatus == 0)
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break;
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}
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evaltree(n->nbinary.ch2, 0);
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status = exitstatus;
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if (evalskip)
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goto skipping;
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}
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loopnest--;
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exitstatus = status;
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}
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STATIC void
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evalfor(n)
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union node *n;
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{
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struct arglist arglist;
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union node *argp;
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struct strlist *sp;
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struct stackmark smark;
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setstackmark(&smark);
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arglist.lastp = &arglist.list;
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for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
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oexitstatus = exitstatus;
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expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
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if (evalskip)
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goto out;
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}
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*arglist.lastp = NULL;
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exitstatus = 0;
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loopnest++;
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for (sp = arglist.list ; sp ; sp = sp->next) {
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setvar(n->nfor.var, sp->text, 0);
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evaltree(n->nfor.body, 0);
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if (evalskip) {
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if (evalskip == SKIPCONT && --skipcount <= 0) {
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evalskip = 0;
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continue;
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}
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if (evalskip == SKIPBREAK && --skipcount <= 0)
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evalskip = 0;
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break;
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}
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}
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loopnest--;
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out:
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popstackmark(&smark);
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}
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STATIC void
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evalcase(n, flags)
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union node *n;
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int flags;
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{
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union node *cp;
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union node *patp;
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struct arglist arglist;
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struct stackmark smark;
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setstackmark(&smark);
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arglist.lastp = &arglist.list;
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oexitstatus = exitstatus;
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expandarg(n->ncase.expr, &arglist, EXP_TILDE);
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for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) {
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for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
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if (casematch(patp, arglist.list->text)) {
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if (evalskip == 0) {
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evaltree(cp->nclist.body, flags);
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}
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goto out;
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}
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}
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}
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out:
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popstackmark(&smark);
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}
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/*
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* Kick off a subshell to evaluate a tree.
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*/
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STATIC void
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evalsubshell(n, flags)
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union node *n;
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int flags;
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{
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struct job *jp;
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int backgnd = (n->type == NBACKGND);
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expredir(n->nredir.redirect);
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jp = makejob(n, 1);
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if (forkshell(jp, n, backgnd) == 0) {
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if (backgnd)
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flags &=~ EV_TESTED;
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redirect(n->nredir.redirect, 0);
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evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */
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}
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if (! backgnd) {
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INTOFF;
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exitstatus = waitforjob(jp);
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INTON;
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}
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}
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/*
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* Compute the names of the files in a redirection list.
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*/
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STATIC void
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expredir(n)
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union node *n;
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{
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register union node *redir;
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for (redir = n ; redir ; redir = redir->nfile.next) {
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struct arglist fn;
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fn.lastp = &fn.list;
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oexitstatus = exitstatus;
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switch (redir->type) {
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case NFROM:
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case NTO:
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case NAPPEND:
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expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
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redir->nfile.expfname = fn.list->text;
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break;
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case NFROMFD:
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case NTOFD:
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if (redir->ndup.vname) {
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expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE);
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fixredir(redir, fn.list->text, 1);
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}
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break;
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}
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}
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}
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|
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/*
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* Evaluate a pipeline. All the processes in the pipeline are children
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* of the process creating the pipeline. (This differs from some versions
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* of the shell, which make the last process in a pipeline the parent
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* of all the rest.)
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*/
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|
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STATIC void
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evalpipe(n)
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union node *n;
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{
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struct job *jp;
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struct nodelist *lp;
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int pipelen;
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int prevfd;
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int pip[2];
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|
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TRACE(("evalpipe(0x%lx) called\n", (long)n));
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pipelen = 0;
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for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
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pipelen++;
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INTOFF;
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jp = makejob(n, pipelen);
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prevfd = -1;
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for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
|
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prehash(lp->n);
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pip[1] = -1;
|
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if (lp->next) {
|
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if (pipe(pip) < 0) {
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close(prevfd);
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error("Pipe call failed");
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}
|
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}
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if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
|
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INTON;
|
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if (prevfd > 0) {
|
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close(0);
|
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copyfd(prevfd, 0);
|
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close(prevfd);
|
|
}
|
|
if (pip[1] >= 0) {
|
|
close(pip[0]);
|
|
if (pip[1] != 1) {
|
|
close(1);
|
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copyfd(pip[1], 1);
|
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close(pip[1]);
|
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}
|
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}
|
|
evaltree(lp->n, EV_EXIT);
|
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}
|
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if (prevfd >= 0)
|
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close(prevfd);
|
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prevfd = pip[0];
|
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close(pip[1]);
|
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}
|
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INTON;
|
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if (n->npipe.backgnd == 0) {
|
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INTOFF;
|
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exitstatus = waitforjob(jp);
|
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TRACE(("evalpipe: job done exit status %d\n", exitstatus));
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INTON;
|
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}
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Execute a command inside back quotes. If it's a builtin command, we
|
|
* want to save its output in a block obtained from malloc. Otherwise
|
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* we fork off a subprocess and get the output of the command via a pipe.
|
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* Should be called with interrupts off.
|
|
*/
|
|
|
|
void
|
|
evalbackcmd(n, result)
|
|
union node *n;
|
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struct backcmd *result;
|
|
{
|
|
int pip[2];
|
|
struct job *jp;
|
|
struct stackmark smark; /* unnecessary */
|
|
|
|
setstackmark(&smark);
|
|
result->fd = -1;
|
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result->buf = NULL;
|
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result->nleft = 0;
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result->jp = NULL;
|
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if (n == NULL) {
|
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exitstatus = 0;
|
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goto out;
|
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}
|
|
if (n->type == NCMD) {
|
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exitstatus = oexitstatus;
|
|
evalcommand(n, EV_BACKCMD, result);
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|
} else {
|
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exitstatus = 0;
|
|
if (pipe(pip) < 0)
|
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error("Pipe call failed");
|
|
jp = makejob(n, 1);
|
|
if (forkshell(jp, n, FORK_NOJOB) == 0) {
|
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FORCEINTON;
|
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close(pip[0]);
|
|
if (pip[1] != 1) {
|
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close(1);
|
|
copyfd(pip[1], 1);
|
|
close(pip[1]);
|
|
}
|
|
evaltree(n, EV_EXIT);
|
|
}
|
|
close(pip[1]);
|
|
result->fd = pip[0];
|
|
result->jp = jp;
|
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}
|
|
out:
|
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popstackmark(&smark);
|
|
TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
|
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result->fd, result->buf, result->nleft, result->jp));
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Execute a simple command.
|
|
*/
|
|
|
|
STATIC void
|
|
evalcommand(cmd, flags, backcmd)
|
|
union node *cmd;
|
|
int flags;
|
|
struct backcmd *backcmd;
|
|
{
|
|
struct stackmark smark;
|
|
union node *argp;
|
|
struct arglist arglist;
|
|
struct arglist varlist;
|
|
char **argv;
|
|
int argc;
|
|
char **envp;
|
|
int varflag;
|
|
struct strlist *sp;
|
|
int mode;
|
|
int pip[2];
|
|
struct cmdentry cmdentry;
|
|
struct job *jp;
|
|
struct jmploc jmploc;
|
|
struct jmploc *volatile savehandler;
|
|
char *volatile savecmdname;
|
|
volatile struct shparam saveparam;
|
|
struct localvar *volatile savelocalvars;
|
|
volatile int e;
|
|
char *lastarg;
|
|
#if __GNUC__
|
|
/* Avoid longjmp clobbering */
|
|
(void) &argv;
|
|
(void) &argc;
|
|
(void) &lastarg;
|
|
(void) &flags;
|
|
#endif
|
|
|
|
/* First expand the arguments. */
|
|
TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
|
|
setstackmark(&smark);
|
|
arglist.lastp = &arglist.list;
|
|
varlist.lastp = &varlist.list;
|
|
varflag = 1;
|
|
oexitstatus = exitstatus;
|
|
exitstatus = 0;
|
|
for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
|
|
char *p = argp->narg.text;
|
|
if (varflag && is_name(*p)) {
|
|
do {
|
|
p++;
|
|
} while (is_in_name(*p));
|
|
if (*p == '=') {
|
|
expandarg(argp, &varlist, EXP_VARTILDE);
|
|
continue;
|
|
}
|
|
}
|
|
expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
|
|
varflag = 0;
|
|
}
|
|
*arglist.lastp = NULL;
|
|
*varlist.lastp = NULL;
|
|
expredir(cmd->ncmd.redirect);
|
|
argc = 0;
|
|
for (sp = arglist.list ; sp ; sp = sp->next)
|
|
argc++;
|
|
argv = stalloc(sizeof (char *) * (argc + 1));
|
|
|
|
for (sp = arglist.list ; sp ; sp = sp->next) {
|
|
TRACE(("evalcommand arg: %s\n", sp->text));
|
|
*argv++ = sp->text;
|
|
}
|
|
*argv = NULL;
|
|
lastarg = NULL;
|
|
if (iflag && funcnest == 0 && argc > 0)
|
|
lastarg = argv[-1];
|
|
argv -= argc;
|
|
|
|
/* Print the command if xflag is set. */
|
|
if (xflag) {
|
|
outc('+', &errout);
|
|
for (sp = varlist.list ; sp ; sp = sp->next) {
|
|
outc(' ', &errout);
|
|
out2str(sp->text);
|
|
}
|
|
for (sp = arglist.list ; sp ; sp = sp->next) {
|
|
outc(' ', &errout);
|
|
out2str(sp->text);
|
|
}
|
|
outc('\n', &errout);
|
|
flushout(&errout);
|
|
}
|
|
|
|
/* Now locate the command. */
|
|
if (argc == 0) {
|
|
cmdentry.cmdtype = CMDBUILTIN;
|
|
cmdentry.u.index = BLTINCMD;
|
|
} else {
|
|
static const char PATH[] = "PATH=";
|
|
char *path = pathval();
|
|
|
|
/*
|
|
* Modify the command lookup path, if a PATH= assignment
|
|
* is present
|
|
*/
|
|
for (sp = varlist.list ; sp ; sp = sp->next)
|
|
if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
|
|
path = sp->text + sizeof(PATH) - 1;
|
|
|
|
find_command(argv[0], &cmdentry, 1, path);
|
|
if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */
|
|
exitstatus = 1;
|
|
flushout(&errout);
|
|
return;
|
|
}
|
|
/* implement the bltin builtin here */
|
|
if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) {
|
|
for (;;) {
|
|
argv++;
|
|
if (--argc == 0)
|
|
break;
|
|
if ((cmdentry.u.index = find_builtin(*argv)) < 0) {
|
|
outfmt(&errout, "%s: not found\n", *argv);
|
|
exitstatus = 1;
|
|
flushout(&errout);
|
|
return;
|
|
}
|
|
if (cmdentry.u.index != BLTINCMD)
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Fork off a child process if necessary. */
|
|
if (cmd->ncmd.backgnd
|
|
|| (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0)
|
|
|| ((flags & EV_BACKCMD) != 0
|
|
&& (cmdentry.cmdtype != CMDBUILTIN
|
|
|| cmdentry.u.index == DOTCMD
|
|
|| cmdentry.u.index == EVALCMD))) {
|
|
jp = makejob(cmd, 1);
|
|
mode = cmd->ncmd.backgnd;
|
|
if (flags & EV_BACKCMD) {
|
|
mode = FORK_NOJOB;
|
|
if (pipe(pip) < 0)
|
|
error("Pipe call failed");
|
|
}
|
|
if (forkshell(jp, cmd, mode) != 0)
|
|
goto parent; /* at end of routine */
|
|
if (flags & EV_BACKCMD) {
|
|
FORCEINTON;
|
|
close(pip[0]);
|
|
if (pip[1] != 1) {
|
|
close(1);
|
|
copyfd(pip[1], 1);
|
|
close(pip[1]);
|
|
}
|
|
}
|
|
flags |= EV_EXIT;
|
|
}
|
|
|
|
/* This is the child process if a fork occurred. */
|
|
/* Execute the command. */
|
|
if (cmdentry.cmdtype == CMDFUNCTION) {
|
|
trputs("Shell function: "); trargs(argv);
|
|
redirect(cmd->ncmd.redirect, REDIR_PUSH);
|
|
saveparam = shellparam;
|
|
shellparam.malloc = 0;
|
|
shellparam.nparam = argc - 1;
|
|
shellparam.p = argv + 1;
|
|
shellparam.optnext = NULL;
|
|
INTOFF;
|
|
savelocalvars = localvars;
|
|
localvars = NULL;
|
|
INTON;
|
|
if (setjmp(jmploc.loc)) {
|
|
if (exception == EXSHELLPROC)
|
|
freeparam((struct shparam *)&saveparam);
|
|
else {
|
|
freeparam(&shellparam);
|
|
shellparam = saveparam;
|
|
}
|
|
poplocalvars();
|
|
localvars = savelocalvars;
|
|
handler = savehandler;
|
|
longjmp(handler->loc, 1);
|
|
}
|
|
savehandler = handler;
|
|
handler = &jmploc;
|
|
for (sp = varlist.list ; sp ; sp = sp->next)
|
|
mklocal(sp->text);
|
|
funcnest++;
|
|
evaltree(cmdentry.u.func, 0);
|
|
funcnest--;
|
|
INTOFF;
|
|
poplocalvars();
|
|
localvars = savelocalvars;
|
|
freeparam(&shellparam);
|
|
shellparam = saveparam;
|
|
handler = savehandler;
|
|
popredir();
|
|
INTON;
|
|
if (evalskip == SKIPFUNC) {
|
|
evalskip = 0;
|
|
skipcount = 0;
|
|
}
|
|
if (flags & EV_EXIT)
|
|
exitshell(exitstatus);
|
|
} else if (cmdentry.cmdtype == CMDBUILTIN) {
|
|
trputs("builtin command: "); trargs(argv);
|
|
mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH;
|
|
if (flags == EV_BACKCMD) {
|
|
memout.nleft = 0;
|
|
memout.nextc = memout.buf;
|
|
memout.bufsize = 64;
|
|
mode |= REDIR_BACKQ;
|
|
}
|
|
redirect(cmd->ncmd.redirect, mode);
|
|
savecmdname = commandname;
|
|
cmdenviron = varlist.list;
|
|
e = -1;
|
|
if (setjmp(jmploc.loc)) {
|
|
e = exception;
|
|
exitstatus = (e == EXINT)? SIGINT+128 : 2;
|
|
goto cmddone;
|
|
}
|
|
savehandler = handler;
|
|
handler = &jmploc;
|
|
commandname = argv[0];
|
|
argptr = argv + 1;
|
|
optptr = NULL; /* initialize nextopt */
|
|
exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv);
|
|
flushall();
|
|
cmddone:
|
|
out1 = &output;
|
|
out2 = &errout;
|
|
freestdout();
|
|
if (e != EXSHELLPROC) {
|
|
commandname = savecmdname;
|
|
if (flags & EV_EXIT) {
|
|
exitshell(exitstatus);
|
|
}
|
|
}
|
|
handler = savehandler;
|
|
if (e != -1) {
|
|
if (e != EXERROR || cmdentry.u.index == BLTINCMD
|
|
|| cmdentry.u.index == DOTCMD
|
|
|| cmdentry.u.index == EVALCMD
|
|
#ifndef NO_HISTORY
|
|
|| cmdentry.u.index == HISTCMD
|
|
#endif
|
|
|| cmdentry.u.index == EXECCMD)
|
|
exraise(e);
|
|
FORCEINTON;
|
|
}
|
|
if (cmdentry.u.index != EXECCMD)
|
|
popredir();
|
|
if (flags == EV_BACKCMD) {
|
|
backcmd->buf = memout.buf;
|
|
backcmd->nleft = memout.nextc - memout.buf;
|
|
memout.buf = NULL;
|
|
}
|
|
} else {
|
|
trputs("normal command: "); trargs(argv);
|
|
clearredir();
|
|
redirect(cmd->ncmd.redirect, 0);
|
|
for (sp = varlist.list ; sp ; sp = sp->next)
|
|
setvareq(sp->text, VEXPORT|VSTACK);
|
|
envp = environment();
|
|
shellexec(argv, envp, pathval(), cmdentry.u.index);
|
|
/*NOTREACHED*/
|
|
}
|
|
goto out;
|
|
|
|
parent: /* parent process gets here (if we forked) */
|
|
if (mode == 0) { /* argument to fork */
|
|
INTOFF;
|
|
exitstatus = waitforjob(jp);
|
|
INTON;
|
|
} else if (mode == 2) {
|
|
backcmd->fd = pip[0];
|
|
close(pip[1]);
|
|
backcmd->jp = jp;
|
|
}
|
|
|
|
out:
|
|
if (lastarg)
|
|
setvar("_", lastarg, 0);
|
|
popstackmark(&smark);
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Search for a command. This is called before we fork so that the
|
|
* location of the command will be available in the parent as well as
|
|
* the child. The check for "goodname" is an overly conservative
|
|
* check that the name will not be subject to expansion.
|
|
*/
|
|
|
|
STATIC void
|
|
prehash(n)
|
|
union node *n;
|
|
{
|
|
struct cmdentry entry;
|
|
|
|
if (n->type == NCMD && n->ncmd.args)
|
|
if (goodname(n->ncmd.args->narg.text))
|
|
find_command(n->ncmd.args->narg.text, &entry, 0,
|
|
pathval());
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Builtin commands. Builtin commands whose functions are closely
|
|
* tied to evaluation are implemented here.
|
|
*/
|
|
|
|
/*
|
|
* No command given, or a bltin command with no arguments. Set the
|
|
* specified variables.
|
|
*/
|
|
|
|
int
|
|
bltincmd(argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
{
|
|
listsetvar(cmdenviron);
|
|
/*
|
|
* Preserve exitstatus of a previous possible redirection
|
|
* as POSIX mandates
|
|
*/
|
|
return exitstatus;
|
|
}
|
|
|
|
|
|
/*
|
|
* Handle break and continue commands. Break, continue, and return are
|
|
* all handled by setting the evalskip flag. The evaluation routines
|
|
* above all check this flag, and if it is set they start skipping
|
|
* commands rather than executing them. The variable skipcount is
|
|
* the number of loops to break/continue, or the number of function
|
|
* levels to return. (The latter is always 1.) It should probably
|
|
* be an error to break out of more loops than exist, but it isn't
|
|
* in the standard shell so we don't make it one here.
|
|
*/
|
|
|
|
int
|
|
breakcmd(argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
{
|
|
int n;
|
|
|
|
n = 1;
|
|
if (argc > 1)
|
|
n = number(argv[1]);
|
|
if (n > loopnest)
|
|
n = loopnest;
|
|
if (n > 0) {
|
|
evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
|
|
skipcount = n;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* The return command.
|
|
*/
|
|
|
|
int
|
|
returncmd(argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
{
|
|
int ret;
|
|
|
|
ret = exitstatus;
|
|
if (argc > 1)
|
|
ret = number(argv[1]);
|
|
if (funcnest) {
|
|
evalskip = SKIPFUNC;
|
|
skipcount = 1;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
|
|
int
|
|
falsecmd(argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
|
|
int
|
|
truecmd(argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
|
|
int
|
|
execcmd(argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
{
|
|
if (argc > 1) {
|
|
struct strlist *sp;
|
|
|
|
iflag = 0; /* exit on error */
|
|
mflag = 0;
|
|
optschanged();
|
|
for (sp = cmdenviron; sp ; sp = sp->next)
|
|
setvareq(sp->text, VEXPORT|VSTACK);
|
|
shellexec(argv + 1, environment(), pathval(), 0);
|
|
|
|
}
|
|
return 0;
|
|
}
|