927 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			927 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
| /*-
 | |
|  * Copyright (c) 1991 The Regents of the University of California.
 | |
|  * All rights reserved.
 | |
|  *
 | |
|  * This code is derived from software contributed to Berkeley by
 | |
|  * Kenneth Almquist.
 | |
|  *
 | |
|  * Redistribution and use in source and binary forms, with or without
 | |
|  * modification, are permitted provided that the following conditions
 | |
|  * are met:
 | |
|  * 1. Redistributions of source code must retain the above copyright
 | |
|  *    notice, this list of conditions and the following disclaimer.
 | |
|  * 2. Redistributions in binary form must reproduce the above copyright
 | |
|  *    notice, this list of conditions and the following disclaimer in the
 | |
|  *    documentation and/or other materials provided with the distribution.
 | |
|  * 3. All advertising materials mentioning features or use of this software
 | |
|  *    must display the following acknowledgement:
 | |
|  *	This product includes software developed by the University of
 | |
|  *	California, Berkeley and its contributors.
 | |
|  * 4. Neither the name of the University nor the names of its contributors
 | |
|  *    may be used to endorse or promote products derived from this software
 | |
|  *    without specific prior written permission.
 | |
|  *
 | |
|  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 | |
|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 | |
|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 | |
|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 | |
|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 | |
|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 | |
|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 | |
|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 | |
|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 | |
|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 | |
|  * SUCH DAMAGE.
 | |
|  */
 | |
| 
 | |
| #ifndef lint
 | |
| static char sccsid[] = "@(#)eval.c	5.3 (Berkeley) 4/12/91";
 | |
| #endif /* not lint */
 | |
| 
 | |
| /*
 | |
|  * Evaluate a command.
 | |
|  */
 | |
| 
 | |
| #include "shell.h"
 | |
| #include "nodes.h"
 | |
| #include "syntax.h"
 | |
| #include "expand.h"
 | |
| #include "parser.h"
 | |
| #include "jobs.h"
 | |
| #include "eval.h"
 | |
| #include "builtins.h"
 | |
| #include "options.h"
 | |
| #include "exec.h"
 | |
| #include "redir.h"
 | |
| #include "input.h"
 | |
| #include "output.h"
 | |
| #include "trap.h"
 | |
| #include "var.h"
 | |
| #include "memalloc.h"
 | |
| #include "error.h"
 | |
| #include "mystring.h"
 | |
| #include <sys/types.h>
 | |
| #include <signal.h>
 | |
| 
 | |
| 
 | |
| /* flags in argument to evaltree */
 | |
| #define EV_EXIT 01		/* exit after evaluating tree */
 | |
| #define EV_TESTED 02		/* exit status is checked; ignore -e flag */
 | |
| #define EV_BACKCMD 04		/* command executing within back quotes */
 | |
| 
 | |
| 
 | |
| /* reasons for skipping commands (see comment on breakcmd routine) */
 | |
| #define SKIPBREAK 1
 | |
| #define SKIPCONT 2
 | |
| #define SKIPFUNC 3
 | |
| 
 | |
| MKINIT int evalskip;		/* set if we are skipping commands */
 | |
| STATIC int skipcount;		/* number of levels to skip */
 | |
| MKINIT int loopnest;		/* current loop nesting level */
 | |
| int funcnest;			/* depth of function calls */
 | |
| 
 | |
| 
 | |
| char *commandname;
 | |
| struct strlist *cmdenviron;
 | |
| int exitstatus;			/* exit status of last command */
 | |
| 
 | |
| 
 | |
| #ifdef __STDC__
 | |
| STATIC void evalloop(union node *);
 | |
| STATIC void evalfor(union node *);
 | |
| STATIC void evalcase(union node *, int);
 | |
| STATIC void evalsubshell(union node *, int);
 | |
| STATIC void expredir(union node *);
 | |
| STATIC void evalpipe(union node *);
 | |
| STATIC void evalcommand(union node *, int, struct backcmd *);
 | |
| STATIC void prehash(union node *);
 | |
| #else
 | |
| STATIC void evalloop();
 | |
| STATIC void evalfor();
 | |
| STATIC void evalcase();
 | |
| STATIC void evalsubshell();
 | |
| STATIC void expredir();
 | |
| STATIC void evalpipe();
 | |
| STATIC void evalcommand();
 | |
| STATIC void prehash();
 | |
| #endif
 | |
| 
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * Called to reset things after an exception.
 | |
|  */
 | |
| 
 | |
| #ifdef mkinit
 | |
| INCLUDE "eval.h"
 | |
| 
 | |
| RESET {
 | |
| 	evalskip = 0;
 | |
| 	loopnest = 0;
 | |
| 	funcnest = 0;
 | |
| }
 | |
| 
 | |
| SHELLPROC {
 | |
| 	exitstatus = 0;
 | |
| }
 | |
| #endif
 | |
| 
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * The eval commmand.
 | |
|  */
 | |
| 
 | |
| evalcmd(argc, argv)  
 | |
| 	char **argv; 
 | |
| {
 | |
|         char *p;
 | |
|         char *concat;
 | |
|         char **ap;
 | |
| 
 | |
|         if (argc > 1) {
 | |
|                 p = argv[1];
 | |
|                 if (argc > 2) {
 | |
|                         STARTSTACKSTR(concat);
 | |
|                         ap = argv + 2;
 | |
|                         for (;;) {
 | |
|                                 while (*p)
 | |
|                                         STPUTC(*p++, concat);
 | |
|                                 if ((p = *ap++) == NULL)
 | |
|                                         break;
 | |
|                                 STPUTC(' ', concat);
 | |
|                         }
 | |
|                         STPUTC('\0', concat);
 | |
|                         p = grabstackstr(concat);
 | |
|                 }
 | |
|                 evalstring(p);
 | |
|         }
 | |
|         return exitstatus;
 | |
| }
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * Execute a command or commands contained in a string.
 | |
|  */
 | |
| 
 | |
| void
 | |
| evalstring(s)
 | |
| 	char *s;
 | |
| 	{
 | |
| 	union node *n;
 | |
| 	struct stackmark smark;
 | |
| 
 | |
| 	setstackmark(&smark);
 | |
| 	setinputstring(s, 1);
 | |
| 	while ((n = parsecmd(0)) != NEOF) {
 | |
| 		evaltree(n, 0);
 | |
| 		popstackmark(&smark);
 | |
| 	}
 | |
| 	popfile();
 | |
| 	popstackmark(&smark);
 | |
| }
 | |
| 
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * Evaluate a parse tree.  The value is left in the global variable
 | |
|  * exitstatus.
 | |
|  */
 | |
| 
 | |
| void
 | |
| evaltree(n, flags)
 | |
| 	union node *n;
 | |
| 	{
 | |
| 	if (n == NULL) {
 | |
| 		TRACE(("evaltree(NULL) called\n"));
 | |
| 		return;
 | |
| 	}
 | |
| 	TRACE(("evaltree(0x%x: %d) called\n", (int)n, n->type));
 | |
| 	switch (n->type) {
 | |
| 	case NSEMI:
 | |
| 		evaltree(n->nbinary.ch1, 0);
 | |
| 		if (evalskip)
 | |
| 			goto out;
 | |
| 		evaltree(n->nbinary.ch2, flags);
 | |
| 		break;
 | |
| 	case NAND:
 | |
| 		evaltree(n->nbinary.ch1, EV_TESTED);
 | |
| 		if (evalskip || exitstatus != 0)
 | |
| 			goto out;
 | |
| 		evaltree(n->nbinary.ch2, flags);
 | |
| 		break;
 | |
| 	case NOR:
 | |
| 		evaltree(n->nbinary.ch1, EV_TESTED);
 | |
| 		if (evalskip || exitstatus == 0)
 | |
| 			goto out;
 | |
| 		evaltree(n->nbinary.ch2, flags);
 | |
| 		break;
 | |
| 	case NREDIR:
 | |
| 		expredir(n->nredir.redirect);
 | |
| 		redirect(n->nredir.redirect, REDIR_PUSH);
 | |
| 		evaltree(n->nredir.n, flags);
 | |
| 		popredir();
 | |
| 		break;
 | |
| 	case NSUBSHELL:
 | |
| 		evalsubshell(n, flags);
 | |
| 		break;
 | |
| 	case NBACKGND:
 | |
| 		evalsubshell(n, flags);
 | |
| 		break;
 | |
| 	case NIF: {
 | |
| 		int status = 0; 
 | |
| 
 | |
| 		evaltree(n->nif.test, EV_TESTED);
 | |
| 		if (evalskip)
 | |
| 			goto out;
 | |
| 		if (exitstatus == 0) {
 | |
| 			evaltree(n->nif.ifpart, flags);
 | |
| 			status = exitstatus;
 | |
| 		} else if (n->nif.elsepart) {
 | |
| 			evaltree(n->nif.elsepart, flags);
 | |
| 			status = exitstatus;
 | |
| 		}
 | |
| 		exitstatus = status;
 | |
| 		break;
 | |
| 	}
 | |
| 	case NWHILE:
 | |
| 	case NUNTIL:
 | |
| 		evalloop(n);
 | |
| 		break;
 | |
| 	case NFOR:
 | |
| 		evalfor(n);
 | |
| 		break;
 | |
| 	case NCASE:
 | |
| 		evalcase(n, flags);
 | |
| 		break;
 | |
| 	case NDEFUN:
 | |
| 		defun(n->narg.text, n->narg.next);
 | |
| 		exitstatus = 0;
 | |
| 		break;
 | |
| 	case NPIPE:
 | |
| 		evalpipe(n);
 | |
| 		break;
 | |
| 	case NCMD:
 | |
| 		evalcommand(n, flags, (struct backcmd *)NULL);
 | |
| 		break;
 | |
| 	default:
 | |
| 		out1fmt("Node type = %d\n", n->type);
 | |
| 		flushout(&output);
 | |
| 		break;
 | |
| 	}
 | |
| out:
 | |
| 	if (pendingsigs)
 | |
| 		dotrap();
 | |
| 	if ((flags & EV_EXIT) || (eflag == 1 && exitstatus && !(flags & EV_TESTED)))
 | |
| 		exitshell(exitstatus);
 | |
| }
 | |
| 
 | |
| 
 | |
| STATIC void
 | |
| evalloop(n)
 | |
| 	union node *n;
 | |
| 	{
 | |
| 	int status;
 | |
| 
 | |
| 	loopnest++;
 | |
| 	status = 0;
 | |
| 	for (;;) {
 | |
| 		evaltree(n->nbinary.ch1, EV_TESTED);
 | |
| 		if (evalskip) {
 | |
| skipping:	  if (evalskip == SKIPCONT && --skipcount <= 0) {
 | |
| 				evalskip = 0;
 | |
| 				continue;
 | |
| 			}
 | |
| 			if (evalskip == SKIPBREAK && --skipcount <= 0)
 | |
| 				evalskip = 0;
 | |
| 			break;
 | |
| 		}
 | |
| 		if (n->type == NWHILE) {
 | |
| 			if (exitstatus != 0)
 | |
| 				break;
 | |
| 		} else {
 | |
| 			if (exitstatus == 0)
 | |
| 				break;
 | |
| 		}
 | |
| 		evaltree(n->nbinary.ch2, 0);
 | |
| 		status = exitstatus;
 | |
| 		if (evalskip)
 | |
| 			goto skipping;
 | |
| 	}
 | |
| 	loopnest--;
 | |
| 	exitstatus = status;
 | |
| }
 | |
| 
 | |
| 
 | |
| 
 | |
| STATIC void
 | |
| evalfor(n)
 | |
| 	union node *n;
 | |
| 	{
 | |
| 	struct arglist arglist;
 | |
| 	union node *argp;
 | |
| 	struct strlist *sp;
 | |
| 	struct stackmark smark;
 | |
| 
 | |
| 	setstackmark(&smark);
 | |
| 	arglist.lastp = &arglist.list;
 | |
| 	for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
 | |
| 		expandarg(argp, &arglist, 1);
 | |
| 		if (evalskip)
 | |
| 			goto out;
 | |
| 	}
 | |
| 	*arglist.lastp = NULL;
 | |
| 
 | |
| 	exitstatus = 0;
 | |
| 	loopnest++;
 | |
| 	for (sp = arglist.list ; sp ; sp = sp->next) {
 | |
| 		setvar(n->nfor.var, sp->text, 0);
 | |
| 		evaltree(n->nfor.body, 0);
 | |
| 		if (evalskip) {
 | |
| 			if (evalskip == SKIPCONT && --skipcount <= 0) {
 | |
| 				evalskip = 0;
 | |
| 				continue;
 | |
| 			}
 | |
| 			if (evalskip == SKIPBREAK && --skipcount <= 0)
 | |
| 				evalskip = 0;
 | |
| 			break;
 | |
| 		}
 | |
| 	}
 | |
| 	loopnest--;
 | |
| out:
 | |
| 	popstackmark(&smark);
 | |
| }
 | |
| 
 | |
| 
 | |
| 
 | |
| STATIC void
 | |
| evalcase(n, flags)
 | |
| 	union node *n;
 | |
| 	{
 | |
| 	union node *cp;
 | |
| 	union node *patp;
 | |
| 	struct arglist arglist;
 | |
| 	struct stackmark smark;
 | |
| 
 | |
| 	setstackmark(&smark);
 | |
| 	arglist.lastp = &arglist.list;
 | |
| 	expandarg(n->ncase.expr, &arglist, 0);
 | |
| 	for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) {
 | |
| 		for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
 | |
| 			if (casematch(patp, arglist.list->text)) {
 | |
| 				if (evalskip == 0) {
 | |
| 					evaltree(cp->nclist.body, flags);
 | |
| 				}
 | |
| 				goto out;
 | |
| 			}
 | |
| 		}
 | |
| 	}
 | |
| out:
 | |
| 	popstackmark(&smark);
 | |
| }
 | |
| 
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * Kick off a subshell to evaluate a tree.
 | |
|  */
 | |
| 
 | |
| STATIC void
 | |
| evalsubshell(n, flags)
 | |
| 	union node *n;
 | |
| 	{
 | |
| 	struct job *jp;
 | |
| 	int backgnd = (n->type == NBACKGND);
 | |
| 
 | |
| 	expredir(n->nredir.redirect);
 | |
| 	jp = makejob(n, 1);
 | |
| 	if (forkshell(jp, n, backgnd) == 0) {
 | |
| 		if (backgnd)
 | |
| 			flags &=~ EV_TESTED;
 | |
| 		redirect(n->nredir.redirect, 0);
 | |
| 		evaltree(n->nredir.n, flags | EV_EXIT);	/* never returns */
 | |
| 	}
 | |
| 	if (! backgnd) {
 | |
| 		INTOFF;
 | |
| 		exitstatus = waitforjob(jp);
 | |
| 		INTON;
 | |
| 	}
 | |
| }
 | |
| 
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * Compute the names of the files in a redirection list.
 | |
|  */
 | |
| 
 | |
| STATIC void
 | |
| expredir(n)
 | |
| 	union node *n;
 | |
| 	{
 | |
| 	register union node *redir;
 | |
| 
 | |
| 	for (redir = n ; redir ; redir = redir->nfile.next) {
 | |
| 		if (redir->type == NFROM
 | |
| 		 || redir->type == NTO
 | |
| 		 || redir->type == NAPPEND) {
 | |
| 			struct arglist fn;
 | |
| 			fn.lastp = &fn.list;
 | |
| 			expandarg(redir->nfile.fname, &fn, 0);
 | |
| 			redir->nfile.expfname = fn.list->text;
 | |
| 		}
 | |
| 	}
 | |
| }
 | |
| 
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * Evaluate a pipeline.  All the processes in the pipeline are children
 | |
|  * of the process creating the pipeline.  (This differs from some versions
 | |
|  * of the shell, which make the last process in a pipeline the parent
 | |
|  * of all the rest.)
 | |
|  */
 | |
| 
 | |
| STATIC void
 | |
| evalpipe(n)
 | |
| 	union node *n;
 | |
| 	{
 | |
| 	struct job *jp;
 | |
| 	struct nodelist *lp;
 | |
| 	int pipelen;
 | |
| 	int prevfd;
 | |
| 	int pip[2];
 | |
| 
 | |
| 	TRACE(("evalpipe(0x%x) called\n", (int)n));
 | |
| 	pipelen = 0;
 | |
| 	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
 | |
| 		pipelen++;
 | |
| 	INTOFF;
 | |
| 	jp = makejob(n, pipelen);
 | |
| 	prevfd = -1;
 | |
| 	for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
 | |
| 		prehash(lp->n);
 | |
| 		pip[1] = -1;
 | |
| 		if (lp->next) {
 | |
| 			if (pipe(pip) < 0) {
 | |
| 				close(prevfd);
 | |
| 				error("Pipe call failed");
 | |
| 			}
 | |
| 		}
 | |
| 		if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
 | |
| 			INTON;
 | |
| 			if (prevfd > 0) {
 | |
| 				close(0);
 | |
| 				copyfd(prevfd, 0);
 | |
| 				close(prevfd);
 | |
| 			}
 | |
| 			if (pip[1] >= 0) {
 | |
| 				close(pip[0]);
 | |
| 				if (pip[1] != 1) {
 | |
| 					close(1);
 | |
| 					copyfd(pip[1], 1);
 | |
| 					close(pip[1]);
 | |
| 				}
 | |
| 			}
 | |
| 			evaltree(lp->n, EV_EXIT);
 | |
| 		}
 | |
| 		if (prevfd >= 0)
 | |
| 			close(prevfd);
 | |
| 		prevfd = pip[0];
 | |
| 		close(pip[1]);
 | |
| 	}
 | |
| 	INTON;
 | |
| 	if (n->npipe.backgnd == 0) {
 | |
| 		INTOFF;
 | |
| 		exitstatus = waitforjob(jp);
 | |
| 		TRACE(("evalpipe:  job done exit status %d\n", exitstatus));
 | |
| 		INTON;
 | |
| 	}
 | |
| }
 | |
| 
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * 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
 | |
|  * we fork off a subprocess and get the output of the command via a pipe.
 | |
|  * Should be called with interrupts off.
 | |
|  */
 | |
| 
 | |
| void
 | |
| evalbackcmd(n, result)
 | |
| 	union node *n;
 | |
| 	struct backcmd *result;
 | |
| 	{
 | |
| 	int pip[2];
 | |
| 	struct job *jp;
 | |
| 	struct stackmark smark;		/* unnecessary */
 | |
| 
 | |
| 	setstackmark(&smark);
 | |
| 	result->fd = -1;
 | |
| 	result->buf = NULL;
 | |
| 	result->nleft = 0;
 | |
| 	result->jp = NULL;
 | |
| 	if (n == NULL) {
 | |
| 		/* `` */
 | |
| 	} else
 | |
| 	if (n->type == NCMD) {
 | |
| 		evalcommand(n, EV_BACKCMD, result);
 | |
| 	} else {
 | |
| 		if (pipe(pip) < 0)
 | |
| 			error("Pipe call failed");
 | |
| 		jp = makejob(n, 1);
 | |
| 		if (forkshell(jp, n, FORK_NOJOB) == 0) {
 | |
| 			FORCEINTON;
 | |
| 			close(pip[0]);
 | |
| 			if (pip[1] != 1) {
 | |
| 				close(1);
 | |
| 				copyfd(pip[1], 1);
 | |
| 				close(pip[1]);
 | |
| 			}
 | |
| 			evaltree(n, EV_EXIT);
 | |
| 		}
 | |
| 		close(pip[1]);
 | |
| 		result->fd = pip[0];
 | |
| 		result->jp = jp;
 | |
| 	}
 | |
| 	popstackmark(&smark);
 | |
| 	TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
 | |
| 		result->fd, result->buf, result->nleft, result->jp));
 | |
| }
 | |
| 
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * Execute a simple command.
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|  */
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| 
 | |
| STATIC void
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| evalcommand(cmd, flags, backcmd)
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| 	union node *cmd;
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| 	struct backcmd *backcmd;
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| 	{
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| 	struct stackmark smark;
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| 	union node *argp;
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| 	struct arglist arglist;
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| 	struct arglist varlist;
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| 	char **argv;
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| 	int argc;
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| 	char **envp;
 | |
| 	int varflag;
 | |
| 	struct strlist *sp;
 | |
| 	register char *p;
 | |
| 	int mode;
 | |
| 	int pip[2];
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| 	struct cmdentry cmdentry;
 | |
| 	struct job *jp;
 | |
| 	struct jmploc jmploc;
 | |
| 	struct jmploc *volatile savehandler;
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| 	char *volatile savecmdname;
 | |
| 	volatile struct shparam saveparam;
 | |
| 	struct localvar *volatile savelocalvars;
 | |
| 	volatile int e;
 | |
| 	char *lastarg;
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| 
 | |
| 	/* First expand the arguments. */
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| 	TRACE(("evalcommand(0x%x, %d) called\n", (int)cmd, flags));
 | |
| 	setstackmark(&smark);
 | |
| 	arglist.lastp = &arglist.list;
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| 	varlist.lastp = &varlist.list;
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| 	varflag = 1;
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| 	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
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| 		p = argp->narg.text;
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| 		if (varflag && is_name(*p)) {
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| 			do {
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| 				p++;
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| 			} while (is_in_name(*p));
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| 			if (*p == '=') {
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| 				expandarg(argp, &varlist, 0);
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| 				continue;
 | |
| 			}
 | |
| 		}
 | |
| 		expandarg(argp, &arglist, 1);
 | |
| 		varflag = 0;
 | |
| 	}
 | |
| 	*arglist.lastp = NULL;
 | |
| 	*varlist.lastp = NULL;
 | |
| 	expredir(cmd->ncmd.redirect);
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| 	argc = 0;
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| 	for (sp = arglist.list ; sp ; sp = sp->next)
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| 		argc++;
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| 	argv = stalloc(sizeof (char *) * (argc + 1));
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| 	for (sp = arglist.list ; sp ; sp = sp->next)
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| 		*argv++ = sp->text;
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| 	*argv = NULL;
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| 	lastarg = NULL;
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| 	if (iflag && funcnest == 0 && argc > 0)
 | |
| 		lastarg = argv[-1];
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| 	argv -= argc;
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| 
 | |
| 	/* Print the command if xflag is set. */
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| 	if (xflag == 1) {
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| 		outc('+', &errout);
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| 		for (sp = varlist.list ; sp ; sp = sp->next) {
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| 			outc(' ', &errout);
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| 			out2str(sp->text);
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| 		}
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| 		for (sp = arglist.list ; sp ; sp = sp->next) {
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| 			outc(' ', &errout);
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| 			out2str(sp->text);
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| 		}
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| 		outc('\n', &errout);
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| 		flushout(&errout);
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| 	}
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| 
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| 	/* Now locate the command. */
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| 	if (argc == 0) {
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| 		cmdentry.cmdtype = CMDBUILTIN;
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| 		cmdentry.u.index = BLTINCMD;
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| 	} else {
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| 		find_command(argv[0], &cmdentry, 1);
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| 		if (cmdentry.cmdtype == CMDUNKNOWN) {	/* command not found */
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| 			exitstatus = 2;
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| 			flushout(&errout);
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| 			popstackmark(&smark);
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| 			return;
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| 		}
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| 		/* implement the bltin builtin here */
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| 		if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) {
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| 			for (;;) {
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| 				argv++;
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| 				if (--argc == 0)
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| 					break;
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| 				if ((cmdentry.u.index = find_builtin(*argv)) < 0) {
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| 					outfmt(&errout, "%s: not found\n", *argv);
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| 					exitstatus = 2;
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| 					flushout(&errout);
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| 					popstackmark(&smark);
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| 					return;
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| 				}
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| 				if (cmdentry.u.index != BLTINCMD)
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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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| 	/* Fork off a child process if necessary. */
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| 	if (cmd->ncmd.backgnd
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| 	 || cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0
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| 	 || (flags & EV_BACKCMD) != 0
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| 	    && (cmdentry.cmdtype != CMDBUILTIN
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| 		 || cmdentry.u.index == DOTCMD
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| 		 || cmdentry.u.index == EVALCMD)) {
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| 		jp = makejob(cmd, 1);
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| 		mode = cmd->ncmd.backgnd;
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| 		if (flags & EV_BACKCMD) {
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| 			mode = FORK_NOJOB;
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| 			if (pipe(pip) < 0)
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| 				error("Pipe call failed");
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| 		}
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| 		if (forkshell(jp, cmd, mode) != 0)
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| 			goto parent;	/* at end of routine */
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| 		if (flags & EV_BACKCMD) {
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| 			FORCEINTON;
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| 			close(pip[0]);
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| 			if (pip[1] != 1) {
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| 				close(1);
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| 				copyfd(pip[1], 1);
 | |
| 				close(pip[1]);
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| 			}
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| 		}
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| 		flags |= EV_EXIT;
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| 	}
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| 
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| 	/* This is the child process if a fork occurred. */
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| 	/* Execute the command. */
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| 	if (cmdentry.cmdtype == CMDFUNCTION) {
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| 		trputs("Shell function:  ");  trargs(argv);
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| 		redirect(cmd->ncmd.redirect, REDIR_PUSH);
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| 		saveparam = shellparam;
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| 		shellparam.malloc = 0;
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| 		shellparam.nparam = argc - 1;
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| 		shellparam.p = argv + 1;
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| 		shellparam.optnext = NULL;
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| 		INTOFF;
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| 		savelocalvars = localvars;
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| 		localvars = NULL;
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| 		INTON;
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| 		if (setjmp(jmploc.loc)) {
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| 			if (exception == EXSHELLPROC)
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| 				freeparam((struct shparam *)&saveparam);
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| 			else {
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| 				freeparam(&shellparam);
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| 				shellparam = saveparam;
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| 			}
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| 			poplocalvars();
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| 			localvars = savelocalvars;
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| 			handler = savehandler;
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| 			longjmp(handler->loc, 1);
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| 		}
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| 		savehandler = handler;
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| 		handler = &jmploc;
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| 		for (sp = varlist.list ; sp ; sp = sp->next)
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| 			mklocal(sp->text);
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| 		funcnest++;
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| 		evaltree(cmdentry.u.func, 0);
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| 		funcnest--;
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| 		INTOFF;
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| 		poplocalvars();
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| 		localvars = savelocalvars;
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| 		freeparam(&shellparam);
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| 		shellparam = saveparam;
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| 		handler = savehandler;
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| 		popredir();
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| 		INTON;
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| 		if (evalskip == SKIPFUNC) {
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| 			evalskip = 0;
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| 			skipcount = 0;
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| 		}
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| 		if (flags & EV_EXIT)
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| 			exitshell(exitstatus);
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| 	} else if (cmdentry.cmdtype == CMDBUILTIN) {
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| 		trputs("builtin command:  ");  trargs(argv);
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| 		mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH;
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| 		if (flags == EV_BACKCMD) {
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| 			memout.nleft = 0;
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| 			memout.nextc = memout.buf;
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| 			memout.bufsize = 64;
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| 			mode |= REDIR_BACKQ;
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| 		}
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| 		redirect(cmd->ncmd.redirect, mode);
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| 		savecmdname = commandname;
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| 		cmdenviron = varlist.list;
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| 		e = -1;
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| 		if (setjmp(jmploc.loc)) {
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| 			e = exception;
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| 			exitstatus = (e == EXINT)? SIGINT+128 : 2;
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| 			goto cmddone;
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| 		}
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| 		savehandler = handler;
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| 		handler = &jmploc;
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| 		commandname = argv[0];
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| 		argptr = argv + 1;
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| 		optptr = NULL;			/* initialize nextopt */
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| 		exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv);
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| 		flushall();
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| cmddone:
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| 		out1 = &output;
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| 		out2 = &errout;
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| 		freestdout();
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| 		if (e != EXSHELLPROC) {
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| 			commandname = savecmdname;
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| 			if (flags & EV_EXIT) {
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| 				exitshell(exitstatus);
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| 			}
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| 		}
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| 		handler = savehandler;
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| 		if (e != -1) {
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| 			if (e != EXERROR || cmdentry.u.index == BLTINCMD
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| 					       || cmdentry.u.index == DOTCMD
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| 					       || cmdentry.u.index == EVALCMD
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| 					       || cmdentry.u.index == EXECCMD)
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| 				exraise(e);
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| 			FORCEINTON;
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| 		}
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| 		if (cmdentry.u.index != EXECCMD)
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| 			popredir();
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| 		if (flags == EV_BACKCMD) {
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| 			backcmd->buf = memout.buf;
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| 			backcmd->nleft = memout.nextc - memout.buf;
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| 			memout.buf = NULL;
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| 		}
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| 	} else {
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| 		trputs("normal command:  ");  trargs(argv);
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| 		clearredir();
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| 		redirect(cmd->ncmd.redirect, 0);
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| 		if (varlist.list) {
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| 			p = stalloc(strlen(pathval()) + 1);
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| 			scopy(pathval(), p);
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| 		} else {
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| 			p = pathval();
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| 		}
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| 		for (sp = varlist.list ; sp ; sp = sp->next)
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| 			setvareq(sp->text, VEXPORT|VSTACK);
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| 		envp = environment();
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| 		shellexec(argv, envp, p, cmdentry.u.index);
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| 		/*NOTREACHED*/
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| 	}
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| 	goto out;
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| 
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| parent:	/* parent process gets here (if we forked) */
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| 	if (mode == 0) {	/* argument to fork */
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| 		INTOFF;
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| 		exitstatus = waitforjob(jp);
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| 		INTON;
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| 	} else if (mode == 2) {
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| 		backcmd->fd = pip[0];
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| 		close(pip[1]);
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| 		backcmd->jp = jp;
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| 	}
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| 
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| out:
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| 	if (lastarg)
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| 		setvar("_", lastarg, 0);
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| 	popstackmark(&smark);
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| }
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| 
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| 
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| 
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| /*
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|  * Search for a command.  This is called before we fork so that the
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|  * location of the command will be available in the parent as well as
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|  * the child.  The check for "goodname" is an overly conservative
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|  * check that the name will not be subject to expansion.
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|  */
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| 
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| STATIC void
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| prehash(n)
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| 	union node *n;
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| 	{
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| 	struct cmdentry entry;
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| 
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| 	if (n->type == NCMD && goodname(n->ncmd.args->narg.text))
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| 		find_command(n->ncmd.args->narg.text, &entry, 0);
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| }
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| 
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| 
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| 
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| /*
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|  * Builtin commands.  Builtin commands whose functions are closely
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|  * tied to evaluation are implemented here.
 | |
|  */
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| 
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| /*
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|  * No command given, or a bltin command with no arguments.  Set the
 | |
|  * specified variables.
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|  */
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| 
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| bltincmd(argc, argv)  char **argv; {
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| 	listsetvar(cmdenviron);
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| 	return exitstatus;
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| }
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| 
 | |
| 
 | |
| /*
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|  * Handle break and continue commands.  Break, continue, and return are
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|  * all handled by setting the evalskip flag.  The evaluation routines
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|  * above all check this flag, and if it is set they start skipping
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|  * commands rather than executing them.  The variable skipcount is
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|  * the number of loops to break/continue, or the number of function
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|  * levels to return.  (The latter is always 1.)  It should probably
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|  * be an error to break out of more loops than exist, but it isn't
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|  * in the standard shell so we don't make it one here.
 | |
|  */
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| 
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| breakcmd(argc, argv)  char **argv; {
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| 	int n;
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| 
 | |
| 	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.
 | |
|  */
 | |
| 
 | |
| returncmd(argc, argv)  char **argv; {
 | |
| 	int ret;
 | |
| 
 | |
| 	ret = exitstatus;
 | |
| 	if (argc > 1)
 | |
| 		ret = number(argv[1]);
 | |
| 	if (funcnest) {
 | |
| 		evalskip = SKIPFUNC;
 | |
| 		skipcount = 1;
 | |
| 	}
 | |
| 	return ret;
 | |
| }
 | |
| 
 | |
| 
 | |
| truecmd(argc, argv)  char **argv; {
 | |
| 	return strcmp(argv[0], "false") == 0 ? 1 : 0;
 | |
| }
 | |
| 
 | |
| 
 | |
| execcmd(argc, argv)  char **argv; {
 | |
| 	if (argc > 1) {
 | |
| 		iflag = 0;		/* exit on error */
 | |
| 		setinteractive(0);
 | |
| #if JOBS
 | |
| 		jflag = 0;
 | |
| 		setjobctl(0);
 | |
| #endif
 | |
| 		shellexec(argv + 1, environment(), pathval(), 0);
 | |
| 
 | |
| 	}
 | |
| 	return 0;
 | |
| }
 | 
