initial import of NetBSD tree

1 files changed, 1008 insertions, 0 deletions

diff --git a/bin/sh/eval.c b/bin/sh/eval.c
new file mode 100644
index 00000000000..a6aafd38b65
--- /dev/null
+++ b/bin/sh/eval.c
@@ -0,0 +1,1008 @@
+/*	$NetBSD: eval.c,v 1.27 1995/09/11 17:05:41 christos Exp $	*/
+
+/*-
+ * Copyright (c) 1993
+ *	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
+#if 0
+static char sccsid[] = "@(#)eval.c	8.9 (Berkeley) 6/8/95";
+#else
+static char sccsid[] = "$NetBSD: eval.c,v 1.27 1995/09/11 17:05:41 christos Exp $";
+#endif
+#endif /* not lint */
+
+#include <signal.h>
+#include <unistd.h>
+
+/*
+ * 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 "show.h"
+#include "mystring.h"
+#ifndef NO_HISTORY
+#include "myhistedit.h"
+#endif
+
+
+/* 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 */
+
+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 */
+int oexitstatus;		/* saved exit status */
+
+
+STATIC void evalloop __P((union node *));
+STATIC void evalfor __P((union node *));
+STATIC void evalcase __P((union node *, int));
+STATIC void evalsubshell __P((union node *, int));
+STATIC void expredir __P((union node *));
+STATIC void evalpipe __P((union node *));
+STATIC void evalcommand __P((union node *, int, struct backcmd *));
+STATIC void prehash __P((union node *));
+
+
+/*
+ * 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.
+ */
+
+int
+evalcmd(argc, argv)  
+	int argc;
+	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;
+	int flags;
+{
+	if (n == NULL) {
+		TRACE(("evaltree(NULL) called\n"));
+		exitstatus = 0;
+		goto out;
+	}
+#ifndef NO_HISTORY
+	displayhist = 1;	/* show history substitutions done with fc */
+#endif
+	TRACE(("evaltree(0x%lx: %d) called\n", (long)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; 
+
+		evaltree(n->nif.test, EV_TESTED);
+		status = exitstatus;
+		exitstatus = 0;
+		if (evalskip)
+			goto out;
+		if (status == 0)
+			evaltree(n->nif.ifpart, flags);
+		else if (n->nif.elsepart)
+			evaltree(n->nif.elsepart, flags);
+		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 NNOT:
+		evaltree(n->nnot.com, EV_TESTED);
+		exitstatus = !exitstatus;
+		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 && 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) {
+		oexitstatus = exitstatus;
+		expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
+		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;
+	int flags;
+{
+	union node *cp;
+	union node *patp;
+	struct arglist arglist;
+	struct stackmark smark;
+
+	setstackmark(&smark);
+	arglist.lastp = &arglist.list;
+	oexitstatus = exitstatus;
+	expandarg(n->ncase.expr, &arglist, EXP_TILDE);
+	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;
+	int flags;
+{
+	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) {
+		struct arglist fn;
+		fn.lastp = &fn.list;
+		oexitstatus = exitstatus;
+		switch (redir->type) {
+		case NFROM:
+		case NTO:
+		case NAPPEND:
+			expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
+			redir->nfile.expfname = fn.list->text;
+			break;
+		case NFROMFD:
+		case NTOFD:
+			if (redir->ndup.vname) {
+				expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE);
+				fixredir(redir, fn.list->text, 1);
+			}
+			break;
+		}
+	}
+}
+
+
+
+/*
+ * 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%lx) called\n", (long)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) {
+		exitstatus = 0;
+		goto out;
+	}
+	if (n->type == NCMD) {
+		exitstatus = oexitstatus;
+		evalcommand(n, EV_BACKCMD, result);
+	} else {
+		exitstatus = 0;
+		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;
+	}
+out:
+	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;
+	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;
+	}
+	else {
+		/* Do what ksh does; skip the rest of the file */
+		evalskip = SKIPFILE;
+		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;
+}