auto import from //depot/cupcake/@135843
diff --git a/sh/exec.c b/sh/exec.c
new file mode 100644
index 0000000..fe3613f
--- /dev/null
+++ b/sh/exec.c
@@ -0,0 +1,1063 @@
+/*	$NetBSD: exec.c,v 1.37 2003/08/07 09:05:31 agc Exp $	*/
+
+/*-
+ * Copyright (c) 1991, 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. 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.
+ */
+
+#include <sys/cdefs.h>
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#)exec.c	8.4 (Berkeley) 6/8/95";
+#else
+__RCSID("$NetBSD: exec.c,v 1.37 2003/08/07 09:05:31 agc Exp $");
+#endif
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/*
+ * When commands are first encountered, they are entered in a hash table.
+ * This ensures that a full path search will not have to be done for them
+ * on each invocation.
+ *
+ * We should investigate converting to a linear search, even though that
+ * would make the command name "hash" a misnomer.
+ */
+
+#include "shell.h"
+#include "main.h"
+#include "nodes.h"
+#include "parser.h"
+#include "redir.h"
+#include "eval.h"
+#include "exec.h"
+#include "builtins.h"
+#include "var.h"
+#include "options.h"
+#include "input.h"
+#include "output.h"
+#include "syntax.h"
+#include "memalloc.h"
+#include "error.h"
+#include "init.h"
+#include "mystring.h"
+#include "show.h"
+#include "jobs.h"
+#include "alias.h"
+
+
+#define CMDTABLESIZE 31		/* should be prime */
+#define ARB 1			/* actual size determined at run time */
+
+
+
+struct tblentry {
+	struct tblentry *next;	/* next entry in hash chain */
+	union param param;	/* definition of builtin function */
+	short cmdtype;		/* index identifying command */
+	char rehash;		/* if set, cd done since entry created */
+	char cmdname[ARB];	/* name of command */
+};
+
+
+STATIC struct tblentry *cmdtable[CMDTABLESIZE];
+STATIC int builtinloc = -1;		/* index in path of %builtin, or -1 */
+int exerrno = 0;			/* Last exec error */
+
+
+STATIC void tryexec(char *, char **, char **, int);
+STATIC void execinterp(char **, char **);
+STATIC void printentry(struct tblentry *, int);
+STATIC void clearcmdentry(int);
+STATIC struct tblentry *cmdlookup(const char *, int);
+STATIC void delete_cmd_entry(void);
+
+
+extern char *const parsekwd[];
+
+/*
+ * Exec a program.  Never returns.  If you change this routine, you may
+ * have to change the find_command routine as well.
+ */
+
+void
+shellexec(char **argv, char **envp, const char *path, int idx, int vforked)
+{
+	char *cmdname;
+	int e;
+
+	if (strchr(argv[0], '/') != NULL) {
+		tryexec(argv[0], argv, envp, vforked);
+		e = errno;
+	} else {
+		e = ENOENT;
+		while ((cmdname = padvance(&path, argv[0])) != NULL) {
+			if (--idx < 0 && pathopt == NULL) {
+				tryexec(cmdname, argv, envp, vforked);
+				if (errno != ENOENT && errno != ENOTDIR)
+					e = errno;
+			}
+			stunalloc(cmdname);
+		}
+	}
+
+	/* Map to POSIX errors */
+	switch (e) {
+	case EACCES:
+		exerrno = 126;
+		break;
+	case ENOENT:
+		exerrno = 127;
+		break;
+	default:
+		exerrno = 2;
+		break;
+	}
+	TRACE(("shellexec failed for %s, errno %d, vforked %d, suppressint %d\n",
+		argv[0], e, vforked, suppressint ));
+	exerror(EXEXEC, "%s: %s", argv[0], errmsg(e, E_EXEC));
+	/* NOTREACHED */
+}
+
+
+STATIC void
+tryexec(char *cmd, char **argv, char **envp, int vforked)
+{
+	int e;
+#ifndef BSD
+	char *p;
+#endif
+
+#ifdef SYSV
+	do {
+		execve(cmd, argv, envp);
+	} while (errno == EINTR);
+#else
+	execve(cmd, argv, envp);
+#endif
+	e = errno;
+	if (e == ENOEXEC) {
+		if (vforked) {
+			/* We are currently vfork(2)ed, so raise an
+			 * exception, and evalcommand will try again
+			 * with a normal fork(2).
+			 */
+			exraise(EXSHELLPROC);
+		}
+		initshellproc();
+		setinputfile(cmd, 0);
+		commandname = arg0 = savestr(argv[0]);
+#if !defined(BSD) && !defined(__linux__)
+		pgetc(); pungetc();		/* fill up input buffer */
+		p = parsenextc;
+		if (parsenleft > 2 && p[0] == '#' && p[1] == '!') {
+			argv[0] = cmd;
+			execinterp(argv, envp);
+		}
+#endif
+		setparam(argv + 1);
+		exraise(EXSHELLPROC);
+	}
+	errno = e;
+}
+
+
+#if !defined(BSD) && !defined(__linux__)
+/*
+ * Execute an interpreter introduced by "#!", for systems where this
+ * feature has not been built into the kernel.  If the interpreter is
+ * the shell, return (effectively ignoring the "#!").  If the execution
+ * of the interpreter fails, exit.
+ *
+ * This code peeks inside the input buffer in order to avoid actually
+ * reading any input.  It would benefit from a rewrite.
+ */
+
+#define NEWARGS 5
+
+STATIC void
+execinterp(char **argv, char **envp)
+{
+	int n;
+	char *inp;
+	char *outp;
+	char c;
+	char *p;
+	char **ap;
+	char *newargs[NEWARGS];
+	int i;
+	char **ap2;
+	char **new;
+
+	n = parsenleft - 2;
+	inp = parsenextc + 2;
+	ap = newargs;
+	for (;;) {
+		while (--n >= 0 && (*inp == ' ' || *inp == '\t'))
+			inp++;
+		if (n < 0)
+			goto bad;
+		if ((c = *inp++) == '\n')
+			break;
+		if (ap == &newargs[NEWARGS])
+bad:		  error("Bad #! line");
+		STARTSTACKSTR(outp);
+		do {
+			STPUTC(c, outp);
+		} while (--n >= 0 && (c = *inp++) != ' ' && c != '\t' && c != '\n');
+		STPUTC('\0', outp);
+		n++, inp--;
+		*ap++ = grabstackstr(outp);
+	}
+	if (ap == newargs + 1) {	/* if no args, maybe no exec is needed */
+		p = newargs[0];
+		for (;;) {
+			if (equal(p, "sh") || equal(p, "ash")) {
+				return;
+			}
+			while (*p != '/') {
+				if (*p == '\0')
+					goto break2;
+				p++;
+			}
+			p++;
+		}
+break2:;
+	}
+	i = (char *)ap - (char *)newargs;		/* size in bytes */
+	if (i == 0)
+		error("Bad #! line");
+	for (ap2 = argv ; *ap2++ != NULL ; );
+	new = ckmalloc(i + ((char *)ap2 - (char *)argv));
+	ap = newargs, ap2 = new;
+	while ((i -= sizeof (char **)) >= 0)
+		*ap2++ = *ap++;
+	ap = argv;
+	while (*ap2++ = *ap++);
+	shellexec(new, envp, pathval(), 0);
+	/* NOTREACHED */
+}
+#endif
+
+
+
+/*
+ * Do a path search.  The variable path (passed by reference) should be
+ * set to the start of the path before the first call; padvance will update
+ * this value as it proceeds.  Successive calls to padvance will return
+ * the possible path expansions in sequence.  If an option (indicated by
+ * a percent sign) appears in the path entry then the global variable
+ * pathopt will be set to point to it; otherwise pathopt will be set to
+ * NULL.
+ */
+
+const char *pathopt;
+
+char *
+padvance(const char **path, const char *name)
+{
+	const char *p;
+	char *q;
+	const char *start;
+	int len;
+
+	if (*path == NULL)
+		return NULL;
+	start = *path;
+	for (p = start ; *p && *p != ':' && *p != '%' ; p++);
+	len = p - start + strlen(name) + 2;	/* "2" is for '/' and '\0' */
+	while (stackblocksize() < len)
+		growstackblock();
+	q = stackblock();
+	if (p != start) {
+		memcpy(q, start, p - start);
+		q += p - start;
+		*q++ = '/';
+	}
+	strcpy(q, name);
+	pathopt = NULL;
+	if (*p == '%') {
+		pathopt = ++p;
+		while (*p && *p != ':')  p++;
+	}
+	if (*p == ':')
+		*path = p + 1;
+	else
+		*path = NULL;
+	return stalloc(len);
+}
+
+
+
+/*** Command hashing code ***/
+
+
+int
+hashcmd(int argc, char **argv)
+{
+	struct tblentry **pp;
+	struct tblentry *cmdp;
+	int c;
+	int verbose;
+	struct cmdentry entry;
+	char *name;
+
+	verbose = 0;
+	while ((c = nextopt("rv")) != '\0') {
+		if (c == 'r') {
+			clearcmdentry(0);
+		} else if (c == 'v') {
+			verbose++;
+		}
+	}
+	if (*argptr == NULL) {
+		for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
+			for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+				if (verbose || cmdp->cmdtype == CMDNORMAL)
+					printentry(cmdp, verbose);
+			}
+		}
+		return 0;
+	}
+	while ((name = *argptr) != NULL) {
+		if ((cmdp = cmdlookup(name, 0)) != NULL
+		 && (cmdp->cmdtype == CMDNORMAL
+		     || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
+			delete_cmd_entry();
+		find_command(name, &entry, DO_ERR, pathval());
+		if (verbose) {
+			if (entry.cmdtype != CMDUNKNOWN) {	/* if no error msg */
+				cmdp = cmdlookup(name, 0);
+				printentry(cmdp, verbose);
+			}
+			flushall();
+		}
+		argptr++;
+	}
+	return 0;
+}
+
+
+STATIC void
+printentry(struct tblentry *cmdp, int verbose)
+{
+	int idx;
+	const char *path;
+	char *name;
+
+	switch (cmdp->cmdtype) {
+	case CMDNORMAL:
+		idx = cmdp->param.index;
+		path = pathval();
+		do {
+			name = padvance(&path, cmdp->cmdname);
+			stunalloc(name);
+		} while (--idx >= 0);
+		out1str(name);
+		break;
+	case CMDSPLBLTIN:
+		out1fmt("special builtin %s", cmdp->cmdname);
+		break;
+	case CMDBUILTIN:
+		out1fmt("builtin %s", cmdp->cmdname);
+		break;
+	case CMDFUNCTION:
+		out1fmt("function %s", cmdp->cmdname);
+		if (verbose) {
+			struct procstat ps;
+			INTOFF;
+			commandtext(&ps, cmdp->param.func);
+			INTON;
+			out1str("() { ");
+			out1str(ps.cmd);
+			out1str("; }");
+		}
+		break;
+	default:
+		error("internal error: %s cmdtype %d", cmdp->cmdname, cmdp->cmdtype);
+	}
+	if (cmdp->rehash)
+		out1c('*');
+	out1c('\n');
+}
+
+
+
+/*
+ * Resolve a command name.  If you change this routine, you may have to
+ * change the shellexec routine as well.
+ */
+
+void
+find_command(char *name, struct cmdentry *entry, int act, const char *path)
+{
+	struct tblentry *cmdp, loc_cmd;
+	int idx;
+	int prev;
+	char *fullname;
+	struct stat statb;
+	int e;
+	int (*bltin)(int,char **);
+
+	/* If name contains a slash, don't use PATH or hash table */
+	if (strchr(name, '/') != NULL) {
+		if (act & DO_ABS) {
+			while (stat(name, &statb) < 0) {
+#ifdef SYSV
+				if (errno == EINTR)
+					continue;
+#endif
+				if (errno != ENOENT && errno != ENOTDIR)
+					e = errno;
+				entry->cmdtype = CMDUNKNOWN;
+				entry->u.index = -1;
+				return;
+			}
+			entry->cmdtype = CMDNORMAL;
+			entry->u.index = -1;
+			return;
+		}
+		entry->cmdtype = CMDNORMAL;
+		entry->u.index = 0;
+		return;
+	}
+
+	if (path != pathval())
+		act |= DO_ALTPATH;
+
+	if (act & DO_ALTPATH && strstr(path, "%builtin") != NULL)
+		act |= DO_ALTBLTIN;
+
+	/* If name is in the table, check answer will be ok */
+	if ((cmdp = cmdlookup(name, 0)) != NULL) {
+		do {
+			switch (cmdp->cmdtype) {
+			case CMDNORMAL:
+				if (act & DO_ALTPATH) {
+					cmdp = NULL;
+					continue;
+				}
+				break;
+			case CMDFUNCTION:
+				if (act & DO_NOFUNC) {
+					cmdp = NULL;
+					continue;
+				}
+				break;
+			case CMDBUILTIN:
+				if ((act & DO_ALTBLTIN) || builtinloc >= 0) {
+					cmdp = NULL;
+					continue;
+				}
+				break;
+			}
+			/* if not invalidated by cd, we're done */
+			if (cmdp->rehash == 0)
+				goto success;
+		} while (0);
+	}
+
+	/* If %builtin not in path, check for builtin next */
+	if ((act & DO_ALTPATH ? !(act & DO_ALTBLTIN) : builtinloc < 0) &&
+	    (bltin = find_builtin(name)) != 0)
+		goto builtin_success;
+
+	/* We have to search path. */
+	prev = -1;		/* where to start */
+	if (cmdp) {		/* doing a rehash */
+		if (cmdp->cmdtype == CMDBUILTIN)
+			prev = builtinloc;
+		else
+			prev = cmdp->param.index;
+	}
+
+	e = ENOENT;
+	idx = -1;
+loop:
+	while ((fullname = padvance(&path, name)) != NULL) {
+		stunalloc(fullname);
+		idx++;
+		if (pathopt) {
+			if (prefix("builtin", pathopt)) {
+				if ((bltin = find_builtin(name)) == 0)
+					goto loop;
+				goto builtin_success;
+			} else if (prefix("func", pathopt)) {
+				/* handled below */
+			} else {
+				/* ignore unimplemented options */
+				goto loop;
+			}
+		}
+		/* if rehash, don't redo absolute path names */
+		if (fullname[0] == '/' && idx <= prev) {
+			if (idx < prev)
+				goto loop;
+			TRACE(("searchexec \"%s\": no change\n", name));
+			goto success;
+		}
+		while (stat(fullname, &statb) < 0) {
+#ifdef SYSV
+			if (errno == EINTR)
+				continue;
+#endif
+			if (errno != ENOENT && errno != ENOTDIR)
+				e = errno;
+			goto loop;
+		}
+		e = EACCES;	/* if we fail, this will be the error */
+		if (!S_ISREG(statb.st_mode))
+			goto loop;
+		if (pathopt) {		/* this is a %func directory */
+			if (act & DO_NOFUNC)
+				goto loop;
+			stalloc(strlen(fullname) + 1);
+			readcmdfile(fullname);
+			if ((cmdp = cmdlookup(name, 0)) == NULL ||
+			    cmdp->cmdtype != CMDFUNCTION)
+				error("%s not defined in %s", name, fullname);
+			stunalloc(fullname);
+			goto success;
+		}
+#ifdef notdef
+		/* XXX this code stops root executing stuff, and is buggy
+		   if you need a group from the group list. */
+		if (statb.st_uid == geteuid()) {
+			if ((statb.st_mode & 0100) == 0)
+				goto loop;
+		} else if (statb.st_gid == getegid()) {
+			if ((statb.st_mode & 010) == 0)
+				goto loop;
+		} else {
+			if ((statb.st_mode & 01) == 0)
+				goto loop;
+		}
+#endif
+		TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
+		INTOFF;
+		if (act & DO_ALTPATH) {
+			stalloc(strlen(fullname) + 1);
+			cmdp = &loc_cmd;
+		} else
+			cmdp = cmdlookup(name, 1);
+		cmdp->cmdtype = CMDNORMAL;
+		cmdp->param.index = idx;
+		INTON;
+		goto success;
+	}
+
+	/* We failed.  If there was an entry for this command, delete it */
+	if (cmdp)
+		delete_cmd_entry();
+	if (act & DO_ERR)
+		outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC));
+	entry->cmdtype = CMDUNKNOWN;
+	return;
+
+builtin_success:
+	INTOFF;
+	if (act & DO_ALTPATH)
+		cmdp = &loc_cmd;
+	else
+		cmdp = cmdlookup(name, 1);
+	if (cmdp->cmdtype == CMDFUNCTION)
+		/* DO_NOFUNC must have been set */
+		cmdp = &loc_cmd;
+	cmdp->cmdtype = CMDBUILTIN;
+	cmdp->param.bltin = bltin;
+	INTON;
+success:
+	cmdp->rehash = 0;
+	entry->cmdtype = cmdp->cmdtype;
+	entry->u = cmdp->param;
+}
+
+
+
+/*
+ * Search the table of builtin commands.
+ */
+
+int
+(*find_builtin(name))(int, char **)
+	char *name;
+{
+	const struct builtincmd *bp;
+
+	for (bp = builtincmd ; bp->name ; bp++) {
+		if (*bp->name == *name && equal(bp->name, name))
+			return bp->builtin;
+	}
+	return 0;
+}
+
+int
+(*find_splbltin(name))(int, char **)
+	char *name;
+{
+	const struct builtincmd *bp;
+
+	for (bp = splbltincmd ; bp->name ; bp++) {
+		if (*bp->name == *name && equal(bp->name, name))
+			return bp->builtin;
+	}
+	return 0;
+}
+
+/*
+ * At shell startup put special builtins into hash table.
+ * ensures they are executed first (see posix).
+ * We stop functions being added with the same name
+ * (as they are impossible to call)
+ */
+
+void
+hash_special_builtins(void)
+{
+	const struct builtincmd *bp;
+	struct tblentry *cmdp;
+
+	for (bp = splbltincmd ; bp->name ; bp++) {
+		cmdp = cmdlookup(bp->name, 1);
+		cmdp->cmdtype = CMDSPLBLTIN;
+		cmdp->param.bltin = bp->builtin;
+	}
+}
+
+
+
+/*
+ * Called when a cd is done.  Marks all commands so the next time they
+ * are executed they will be rehashed.
+ */
+
+void
+hashcd(void)
+{
+	struct tblentry **pp;
+	struct tblentry *cmdp;
+
+	for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
+		for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+			if (cmdp->cmdtype == CMDNORMAL
+			 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))
+				cmdp->rehash = 1;
+		}
+	}
+}
+
+
+
+/*
+ * Fix command hash table when PATH changed.
+ * Called before PATH is changed.  The argument is the new value of PATH;
+ * pathval() still returns the old value at this point.
+ * Called with interrupts off.
+ */
+
+void
+changepath(const char *newval)
+{
+	const char *old, *new;
+	int idx;
+	int firstchange;
+	int bltin;
+
+	old = pathval();
+	new = newval;
+	firstchange = 9999;	/* assume no change */
+	idx = 0;
+	bltin = -1;
+	for (;;) {
+		if (*old != *new) {
+			firstchange = idx;
+			if ((*old == '\0' && *new == ':')
+			 || (*old == ':' && *new == '\0'))
+				firstchange++;
+			old = new;	/* ignore subsequent differences */
+		}
+		if (*new == '\0')
+			break;
+		if (*new == '%' && bltin < 0 && prefix("builtin", new + 1))
+			bltin = idx;
+		if (*new == ':') {
+			idx++;
+		}
+		new++, old++;
+	}
+	if (builtinloc < 0 && bltin >= 0)
+		builtinloc = bltin;		/* zap builtins */
+	if (builtinloc >= 0 && bltin < 0)
+		firstchange = 0;
+	clearcmdentry(firstchange);
+	builtinloc = bltin;
+}
+
+
+/*
+ * Clear out command entries.  The argument specifies the first entry in
+ * PATH which has changed.
+ */
+
+STATIC void
+clearcmdentry(int firstchange)
+{
+	struct tblentry **tblp;
+	struct tblentry **pp;
+	struct tblentry *cmdp;
+
+	INTOFF;
+	for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
+		pp = tblp;
+		while ((cmdp = *pp) != NULL) {
+			if ((cmdp->cmdtype == CMDNORMAL &&
+			     cmdp->param.index >= firstchange)
+			 || (cmdp->cmdtype == CMDBUILTIN &&
+			     builtinloc >= firstchange)) {
+				*pp = cmdp->next;
+				ckfree(cmdp);
+			} else {
+				pp = &cmdp->next;
+			}
+		}
+	}
+	INTON;
+}
+
+
+/*
+ * Delete all functions.
+ */
+
+#ifdef mkinit
+MKINIT void deletefuncs(void);
+MKINIT void hash_special_builtins(void);
+
+INIT {
+	hash_special_builtins();
+}
+
+SHELLPROC {
+	deletefuncs();
+}
+#endif
+
+void
+deletefuncs(void)
+{
+	struct tblentry **tblp;
+	struct tblentry **pp;
+	struct tblentry *cmdp;
+
+	INTOFF;
+	for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
+		pp = tblp;
+		while ((cmdp = *pp) != NULL) {
+			if (cmdp->cmdtype == CMDFUNCTION) {
+				*pp = cmdp->next;
+				freefunc(cmdp->param.func);
+				ckfree(cmdp);
+			} else {
+				pp = &cmdp->next;
+			}
+		}
+	}
+	INTON;
+}
+
+
+
+/*
+ * Locate a command in the command hash table.  If "add" is nonzero,
+ * add the command to the table if it is not already present.  The
+ * variable "lastcmdentry" is set to point to the address of the link
+ * pointing to the entry, so that delete_cmd_entry can delete the
+ * entry.
+ */
+
+struct tblentry **lastcmdentry;
+
+
+STATIC struct tblentry *
+cmdlookup(const char *name, int add)
+{
+	int hashval;
+	const char *p;
+	struct tblentry *cmdp;
+	struct tblentry **pp;
+
+	p = name;
+	hashval = *p << 4;
+	while (*p)
+		hashval += *p++;
+	hashval &= 0x7FFF;
+	pp = &cmdtable[hashval % CMDTABLESIZE];
+	for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
+		if (equal(cmdp->cmdname, name))
+			break;
+		pp = &cmdp->next;
+	}
+	if (add && cmdp == NULL) {
+		INTOFF;
+		cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
+					+ strlen(name) + 1);
+		cmdp->next = NULL;
+		cmdp->cmdtype = CMDUNKNOWN;
+		cmdp->rehash = 0;
+		strcpy(cmdp->cmdname, name);
+		INTON;
+	}
+	lastcmdentry = pp;
+	return cmdp;
+}
+
+/*
+ * Delete the command entry returned on the last lookup.
+ */
+
+STATIC void
+delete_cmd_entry(void)
+{
+	struct tblentry *cmdp;
+
+	INTOFF;
+	cmdp = *lastcmdentry;
+	*lastcmdentry = cmdp->next;
+	ckfree(cmdp);
+	INTON;
+}
+
+
+
+#ifdef notdef
+void
+getcmdentry(char *name, struct cmdentry *entry)
+{
+	struct tblentry *cmdp = cmdlookup(name, 0);
+
+	if (cmdp) {
+		entry->u = cmdp->param;
+		entry->cmdtype = cmdp->cmdtype;
+	} else {
+		entry->cmdtype = CMDUNKNOWN;
+		entry->u.index = 0;
+	}
+}
+#endif
+
+
+/*
+ * Add a new command entry, replacing any existing command entry for
+ * the same name - except special builtins.
+ */
+
+STATIC void
+addcmdentry(char *name, struct cmdentry *entry)
+{
+	struct tblentry *cmdp;
+
+	INTOFF;
+	cmdp = cmdlookup(name, 1);
+	if (cmdp->cmdtype != CMDSPLBLTIN) {
+		if (cmdp->cmdtype == CMDFUNCTION) {
+			freefunc(cmdp->param.func);
+		}
+		cmdp->cmdtype = entry->cmdtype;
+		cmdp->param = entry->u;
+	}
+	INTON;
+}
+
+
+/*
+ * Define a shell function.
+ */
+
+void
+defun(char *name, union node *func)
+{
+	struct cmdentry entry;
+
+	INTOFF;
+	entry.cmdtype = CMDFUNCTION;
+	entry.u.func = copyfunc(func);
+	addcmdentry(name, &entry);
+	INTON;
+}
+
+
+/*
+ * Delete a function if it exists.
+ */
+
+int
+unsetfunc(char *name)
+{
+	struct tblentry *cmdp;
+
+	if ((cmdp = cmdlookup(name, 0)) != NULL &&
+	    cmdp->cmdtype == CMDFUNCTION) {
+		freefunc(cmdp->param.func);
+		delete_cmd_entry();
+		return (0);
+	}
+	return (1);
+}
+
+/*
+ * Locate and print what a word is...
+ * also used for 'command -[v|V]'
+ */
+
+int
+typecmd(int argc, char **argv)
+{
+	struct cmdentry entry;
+	struct tblentry *cmdp;
+	char * const *pp;
+	struct alias *ap;
+	int err = 0;
+	char *arg;
+	int c;
+	int V_flag = 0;
+	int v_flag = 0;
+	int p_flag = 0;
+
+	while ((c = nextopt("vVp")) != 0) {
+		switch (c) {
+		case 'v': v_flag = 1; break;
+		case 'V': V_flag = 1; break;
+		case 'p': p_flag = 1; break;
+		}
+	}
+
+	if (p_flag && (v_flag || V_flag))
+		error("cannot specify -p with -v or -V");
+
+	while ((arg = *argptr++)) {
+		if (!v_flag)
+			out1str(arg);
+		/* First look at the keywords */
+		for (pp = parsekwd; *pp; pp++)
+			if (**pp == *arg && equal(*pp, arg))
+				break;
+
+		if (*pp) {
+			if (v_flag)
+				err = 1;
+			else
+				out1str(" is a shell keyword\n");
+			continue;
+		}
+
+		/* Then look at the aliases */
+		if ((ap = lookupalias(arg, 1)) != NULL) {
+			if (!v_flag)
+				out1fmt(" is an alias for \n");
+			out1fmt("%s\n", ap->val);
+			continue;
+		}
+
+		/* Then check if it is a tracked alias */
+		if ((cmdp = cmdlookup(arg, 0)) != NULL) {
+			entry.cmdtype = cmdp->cmdtype;
+			entry.u = cmdp->param;
+		} else {
+			/* Finally use brute force */
+			find_command(arg, &entry, DO_ABS, pathval());
+		}
+
+		switch (entry.cmdtype) {
+		case CMDNORMAL: {
+			if (strchr(arg, '/') == NULL) {
+				const char *path = pathval();
+				char *name;
+				int j = entry.u.index;
+				do {
+					name = padvance(&path, arg);
+					stunalloc(name);
+				} while (--j >= 0);
+				if (!v_flag)
+					out1fmt(" is%s ",
+					    cmdp ? " a tracked alias for" : "");
+				out1fmt("%s\n", name);
+			} else {
+				if (access(arg, X_OK) == 0) {
+					if (!v_flag)
+						out1fmt(" is ");
+					out1fmt("%s\n", arg);
+				} else {
+					if (!v_flag)
+						out1fmt(": %s\n",
+						    strerror(errno));
+					else
+						err = 126;
+				}
+			}
+ 			break;
+		}
+		case CMDFUNCTION:
+			if (!v_flag)
+				out1str(" is a shell function\n");
+			else
+				out1fmt("%s\n", arg);
+			break;
+
+		case CMDBUILTIN:
+			if (!v_flag)
+				out1str(" is a shell builtin\n");
+			else
+				out1fmt("%s\n", arg);
+			break;
+
+		case CMDSPLBLTIN:
+			if (!v_flag)
+				out1str(" is a special shell builtin\n");
+			else
+				out1fmt("%s\n", arg);
+			break;
+
+		default:
+			if (!v_flag)
+				out1str(": not found\n");
+			err = 127;
+			break;
+		}
+	}
+	return err;
+}