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.
 | 
						|
 */
 | 
						|
 | 
						|
STATIC void
 | 
						|
evalcommand(cmd, flags, backcmd)
 | 
						|
	union node *cmd;
 | 
						|
	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;
 | 
						|
	register char *p;
 | 
						|
	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;
 | 
						|
 | 
						|
	/* First expand the arguments. */
 | 
						|
	TRACE(("evalcommand(0x%x, %d) called\n", (int)cmd, flags));
 | 
						|
	setstackmark(&smark);
 | 
						|
	arglist.lastp = &arglist.list;
 | 
						|
	varlist.lastp = &varlist.list;
 | 
						|
	varflag = 1;
 | 
						|
	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
 | 
						|
		p = argp->narg.text;
 | 
						|
		if (varflag && is_name(*p)) {
 | 
						|
			do {
 | 
						|
				p++;
 | 
						|
			} while (is_in_name(*p));
 | 
						|
			if (*p == '=') {
 | 
						|
				expandarg(argp, &varlist, 0);
 | 
						|
				continue;
 | 
						|
			}
 | 
						|
		}
 | 
						|
		expandarg(argp, &arglist, 1);
 | 
						|
		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)
 | 
						|
		*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 == 1) {
 | 
						|
		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 {
 | 
						|
		find_command(argv[0], &cmdentry, 1);
 | 
						|
		if (cmdentry.cmdtype == CMDUNKNOWN) {	/* command not found */
 | 
						|
			exitstatus = 2;
 | 
						|
			flushout(&errout);
 | 
						|
			popstackmark(&smark);
 | 
						|
			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 = 2;
 | 
						|
					flushout(&errout);
 | 
						|
					popstackmark(&smark);
 | 
						|
					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
 | 
						|
					       || 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);
 | 
						|
		if (varlist.list) {
 | 
						|
			p = stalloc(strlen(pathval()) + 1);
 | 
						|
			scopy(pathval(), p);
 | 
						|
		} else {
 | 
						|
			p = pathval();
 | 
						|
		}
 | 
						|
		for (sp = varlist.list ; sp ; sp = sp->next)
 | 
						|
			setvareq(sp->text, VEXPORT|VSTACK);
 | 
						|
		envp = environment();
 | 
						|
		shellexec(argv, envp, p, 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 && goodname(n->ncmd.args->narg.text))
 | 
						|
		find_command(n->ncmd.args->narg.text, &entry, 0);
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
 * 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.
 | 
						|
 */
 | 
						|
 | 
						|
bltincmd(argc, argv)  char **argv; {
 | 
						|
	listsetvar(cmdenviron);
 | 
						|
	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.
 | 
						|
 */
 | 
						|
 | 
						|
breakcmd(argc, argv)  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.
 | 
						|
 */
 | 
						|
 | 
						|
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;
 | 
						|
}
 |