Add mksh from CVS 2010/08/24 as system/core/mksh module

Both shells (ash from system/core/sh, and mksh) are built by
default but only the one where $(TARGET_SHELL) is set to is
actually installed (the shell and the mkshrc configuration
file are tagged shell_mksh for this to work).

Signed-off-by: Thorsten Glaser <tg@mirbsd.org>
diff --git a/mksh/src/exec.c b/mksh/src/exec.c
new file mode 100644
index 0000000..391321a
--- /dev/null
+++ b/mksh/src/exec.c
@@ -0,0 +1,1518 @@
+/*	$OpenBSD: exec.c,v 1.49 2009/01/29 23:27:26 jaredy Exp $	*/
+
+/*-
+ * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ *	Thorsten Glaser <tg@mirbsd.org>
+ *
+ * Provided that these terms and disclaimer and all copyright notices
+ * are retained or reproduced in an accompanying document, permission
+ * is granted to deal in this work without restriction, including un-
+ * limited rights to use, publicly perform, distribute, sell, modify,
+ * merge, give away, or sublicence.
+ *
+ * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
+ * the utmost extent permitted by applicable law, neither express nor
+ * implied; without malicious intent or gross negligence. In no event
+ * may a licensor, author or contributor be held liable for indirect,
+ * direct, other damage, loss, or other issues arising in any way out
+ * of dealing in the work, even if advised of the possibility of such
+ * damage or existence of a defect, except proven that it results out
+ * of said person's immediate fault when using the work as intended.
+ */
+
+#include "sh.h"
+
+__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.75 2010/07/17 22:09:34 tg Exp $");
+
+#ifndef MKSH_DEFAULT_EXECSHELL
+#define MKSH_DEFAULT_EXECSHELL	"/bin/sh"
+#endif
+
+static int comexec(struct op *, struct tbl *volatile, const char **,
+    int volatile, volatile int *);
+static void scriptexec(struct op *, const char **) MKSH_A_NORETURN;
+static int call_builtin(struct tbl *, const char **);
+static int iosetup(struct ioword *, struct tbl *);
+static int herein(const char *, int);
+static const char *do_selectargs(const char **, bool);
+static Test_op dbteste_isa(Test_env *, Test_meta);
+static const char *dbteste_getopnd(Test_env *, Test_op, bool);
+static void dbteste_error(Test_env *, int, const char *);
+
+/*
+ * execute command tree
+ */
+int
+execute(struct op *volatile t,
+    volatile int flags,		/* if XEXEC don't fork */
+    volatile int * volatile xerrok)
+{
+	int i;
+	volatile int rv = 0, dummy = 0;
+	int pv[2];
+	const char ** volatile ap;
+	char ** volatile up;
+	const char *s, *cp;
+	struct ioword **iowp;
+	struct tbl *tp = NULL;
+
+	if (t == NULL)
+		return (0);
+
+	/* Caller doesn't care if XERROK should propagate. */
+	if (xerrok == NULL)
+		xerrok = &dummy;
+
+	if ((flags&XFORK) && !(flags&XEXEC) && t->type != TPIPE)
+		/* run in sub-process */
+		return (exchild(t, flags & ~XTIME, xerrok, -1));
+
+	newenv(E_EXEC);
+	if (trap)
+		runtraps(0);
+
+	if (t->type == TCOM) {
+		/* Clear subst_exstat before argument expansion. Used by
+		 * null commands (see comexec() and c_eval()) and by c_set().
+		 */
+		subst_exstat = 0;
+
+		current_lineno = t->lineno;	/* for $LINENO */
+
+		/* POSIX says expand command words first, then redirections,
+		 * and assignments last..
+		 */
+		up = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
+		if (flags & XTIME)
+			/* Allow option parsing (bizarre, but POSIX) */
+			timex_hook(t, &up);
+		ap = (const char **)up;
+		if (Flag(FXTRACE) && ap[0]) {
+			shf_fprintf(shl_out, "%s",
+				substitute(str_val(global("PS4")), 0));
+			for (i = 0; ap[i]; i++)
+				shf_fprintf(shl_out, "%s%c", ap[i],
+				    ap[i + 1] ? ' ' : '\n');
+			shf_flush(shl_out);
+		}
+		if (ap[0])
+			tp = findcom(ap[0], FC_BI|FC_FUNC);
+	}
+	flags &= ~XTIME;
+
+	if (t->ioact != NULL || t->type == TPIPE || t->type == TCOPROC) {
+		e->savefd = alloc(NUFILE * sizeof(short), ATEMP);
+		/* initialise to not redirected */
+		memset(e->savefd, 0, NUFILE * sizeof(short));
+	}
+
+	/* do redirection, to be restored in quitenv() */
+	if (t->ioact != NULL)
+		for (iowp = t->ioact; *iowp != NULL; iowp++) {
+			if (iosetup(*iowp, tp) < 0) {
+				exstat = rv = 1;
+				/* Redirection failures for special commands
+				 * cause (non-interactive) shell to exit.
+				 */
+				if (tp && tp->type == CSHELL &&
+				    (tp->flag & SPEC_BI))
+					errorfz();
+				/* Deal with FERREXIT, quitenv(), etc. */
+				goto Break;
+			}
+		}
+
+	switch (t->type) {
+	case TCOM:
+		rv = comexec(t, tp, (const char **)ap, flags, xerrok);
+		break;
+
+	case TPAREN:
+		rv = execute(t->left, flags | XFORK, xerrok);
+		break;
+
+	case TPIPE:
+		flags |= XFORK;
+		flags &= ~XEXEC;
+		e->savefd[0] = savefd(0);
+		e->savefd[1] = savefd(1);
+		while (t->type == TPIPE) {
+			openpipe(pv);
+			ksh_dup2(pv[1], 1, false); /* stdout of curr */
+			/**
+			 * Let exchild() close pv[0] in child
+			 * (if this isn't done, commands like
+			 *	(: ; cat /etc/termcap) | sleep 1
+			 * will hang forever).
+			 */
+			exchild(t->left, flags | XPIPEO | XCCLOSE,
+			    NULL, pv[0]);
+			ksh_dup2(pv[0], 0, false); /* stdin of next */
+			closepipe(pv);
+			flags |= XPIPEI;
+			t = t->right;
+		}
+		restfd(1, e->savefd[1]); /* stdout of last */
+		e->savefd[1] = 0; /* no need to re-restore this */
+		/* Let exchild() close 0 in parent, after fork, before wait */
+		i = exchild(t, flags | XPCLOSE, xerrok, 0);
+		if (!(flags&XBGND) && !(flags&XXCOM))
+			rv = i;
+		break;
+
+	case TLIST:
+		while (t->type == TLIST) {
+			execute(t->left, flags & XERROK, NULL);
+			t = t->right;
+		}
+		rv = execute(t, flags & XERROK, xerrok);
+		break;
+
+	case TCOPROC: {
+		sigset_t omask;
+
+		/* Block sigchild as we are using things changed in the
+		 * signal handler
+		 */
+		sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
+		e->type = E_ERRH;
+		i = sigsetjmp(e->jbuf, 0);
+		if (i) {
+			sigprocmask(SIG_SETMASK, &omask, NULL);
+			quitenv(NULL);
+			unwind(i);
+			/* NOTREACHED */
+		}
+		/* Already have a (live) co-process? */
+		if (coproc.job && coproc.write >= 0)
+			errorf("coprocess already exists");
+
+		/* Can we re-use the existing co-process pipe? */
+		coproc_cleanup(true);
+
+		/* do this before opening pipes, in case these fail */
+		e->savefd[0] = savefd(0);
+		e->savefd[1] = savefd(1);
+
+		openpipe(pv);
+		if (pv[0] != 0) {
+			ksh_dup2(pv[0], 0, false);
+			close(pv[0]);
+		}
+		coproc.write = pv[1];
+		coproc.job = NULL;
+
+		if (coproc.readw >= 0)
+			ksh_dup2(coproc.readw, 1, false);
+		else {
+			openpipe(pv);
+			coproc.read = pv[0];
+			ksh_dup2(pv[1], 1, false);
+			coproc.readw = pv[1];	 /* closed before first read */
+			coproc.njobs = 0;
+			/* create new coprocess id */
+			++coproc.id;
+		}
+		sigprocmask(SIG_SETMASK, &omask, NULL);
+		e->type = E_EXEC; /* no more need for error handler */
+
+		/* exchild() closes coproc.* in child after fork,
+		 * will also increment coproc.njobs when the
+		 * job is actually created.
+		 */
+		flags &= ~XEXEC;
+		exchild(t->left, flags | XBGND | XFORK | XCOPROC | XCCLOSE,
+		    NULL, coproc.readw);
+		break;
+	}
+
+	case TASYNC:
+		/* XXX non-optimal, I think - "(foo &)", forks for (),
+		 * forks again for async... parent should optimise
+		 * this to "foo &"...
+		 */
+		rv = execute(t->left, (flags&~XEXEC)|XBGND|XFORK, xerrok);
+		break;
+
+	case TOR:
+	case TAND:
+		rv = execute(t->left, XERROK, xerrok);
+		if ((rv == 0) == (t->type == TAND))
+			rv = execute(t->right, XERROK, xerrok);
+		flags |= XERROK;
+		if (xerrok)
+			*xerrok = 1;
+		break;
+
+	case TBANG:
+		rv = !execute(t->right, XERROK, xerrok);
+		flags |= XERROK;
+		if (xerrok)
+			*xerrok = 1;
+		break;
+
+	case TDBRACKET: {
+		Test_env te;
+
+		te.flags = TEF_DBRACKET;
+		te.pos.wp = t->args;
+		te.isa = dbteste_isa;
+		te.getopnd = dbteste_getopnd;
+		te.eval = test_eval;
+		te.error = dbteste_error;
+
+		rv = test_parse(&te);
+		break;
+	}
+
+	case TFOR:
+	case TSELECT: {
+		volatile bool is_first = true;
+		ap = (t->vars == NULL) ? e->loc->argv + 1 :
+		    (const char **)eval((const char **)t->vars,
+		    DOBLANK | DOGLOB | DOTILDE);
+		e->type = E_LOOP;
+		while (1) {
+			i = sigsetjmp(e->jbuf, 0);
+			if (!i)
+				break;
+			if ((e->flags&EF_BRKCONT_PASS) ||
+			    (i != LBREAK && i != LCONTIN)) {
+				quitenv(NULL);
+				unwind(i);
+			} else if (i == LBREAK) {
+				rv = 0;
+				goto Break;
+			}
+		}
+		rv = 0; /* in case of a continue */
+		if (t->type == TFOR) {
+			while (*ap != NULL) {
+				setstr(global(t->str), *ap++, KSH_UNWIND_ERROR);
+				rv = execute(t->left, flags & XERROK, xerrok);
+			}
+		} else { /* TSELECT */
+			for (;;) {
+				if (!(cp = do_selectargs(ap, is_first))) {
+					rv = 1;
+					break;
+				}
+				is_first = false;
+				setstr(global(t->str), cp, KSH_UNWIND_ERROR);
+				execute(t->left, flags & XERROK, xerrok);
+			}
+		}
+		break;
+	}
+
+	case TWHILE:
+	case TUNTIL:
+		e->type = E_LOOP;
+		while (1) {
+			i = sigsetjmp(e->jbuf, 0);
+			if (!i)
+				break;
+			if ((e->flags&EF_BRKCONT_PASS) ||
+			    (i != LBREAK && i != LCONTIN)) {
+				quitenv(NULL);
+				unwind(i);
+			} else if (i == LBREAK) {
+				rv = 0;
+				goto Break;
+			}
+		}
+		rv = 0; /* in case of a continue */
+		while ((execute(t->left, XERROK, NULL) == 0) ==
+		    (t->type == TWHILE))
+			rv = execute(t->right, flags & XERROK, xerrok);
+		break;
+
+	case TIF:
+	case TELIF:
+		if (t->right == NULL)
+			break;	/* should be error */
+		rv = execute(t->left, XERROK, NULL) == 0 ?
+		    execute(t->right->left, flags & XERROK, xerrok) :
+		    execute(t->right->right, flags & XERROK, xerrok);
+		break;
+
+	case TCASE:
+		cp = evalstr(t->str, DOTILDE);
+		for (t = t->left; t != NULL && t->type == TPAT; t = t->right)
+		    for (ap = (const char **)t->vars; *ap; ap++)
+			if ((s = evalstr(*ap, DOTILDE|DOPAT)) &&
+			    gmatchx(cp, s, false))
+				goto Found;
+		break;
+ Found:
+		rv = execute(t->left, flags & XERROK, xerrok);
+		break;
+
+	case TBRACE:
+		rv = execute(t->left, flags & XERROK, xerrok);
+		break;
+
+	case TFUNCT:
+		rv = define(t->str, t);
+		break;
+
+	case TTIME:
+		/* Clear XEXEC so nested execute() call doesn't exit
+		 * (allows "ls -l | time grep foo").
+		 */
+		rv = timex(t, flags & ~XEXEC, xerrok);
+		break;
+
+	case TEXEC:		/* an eval'd TCOM */
+		s = t->args[0];
+		up = makenv();
+		restoresigs();
+		cleanup_proc_env();
+		{
+			union mksh_ccphack cargs;
+
+			cargs.ro = t->args;
+			execve(t->str, cargs.rw, up);
+			rv = errno;
+		}
+		if (rv == ENOEXEC)
+			scriptexec(t, (const char **)up);
+		else
+			errorf("%s: %s", s, strerror(rv));
+	}
+ Break:
+	exstat = rv;
+
+	quitenv(NULL);		/* restores IO */
+	if ((flags&XEXEC))
+		unwind(LEXIT);	/* exit child */
+	if (rv != 0 && !(flags & XERROK) &&
+	    (xerrok == NULL || !*xerrok)) {
+		trapsig(SIGERR_);
+		if (Flag(FERREXIT))
+			unwind(LERROR);
+	}
+	return (rv);
+}
+
+/*
+ * execute simple command
+ */
+
+static int
+comexec(struct op *t, struct tbl *volatile tp, const char **ap,
+    volatile int flags, volatile int *xerrok)
+{
+	int i;
+	volatile int rv = 0;
+	const char *cp;
+	const char **lastp;
+	static struct op texec; /* Must be static (XXX but why?) */
+	int type_flags;
+	int keepasn_ok;
+	int fcflags = FC_BI|FC_FUNC|FC_PATH;
+	bool bourne_function_call = false;
+	struct block *l_expand, *l_assign;
+
+	/* snag the last argument for $_ XXX not the same as AT&T ksh,
+	 * which only seems to set $_ after a newline (but not in
+	 * functions/dot scripts, but in interactive and script) -
+	 * perhaps save last arg here and set it in shell()?.
+	 */
+	if (Flag(FTALKING) && *(lastp = ap)) {
+		while (*++lastp)
+			;
+		/* setstr() can't fail here */
+		setstr(typeset("_", LOCAL, 0, INTEGER, 0), *--lastp,
+		    KSH_RETURN_ERROR);
+	}
+
+	/* Deal with the shell builtins builtin, exec and command since
+	 * they can be followed by other commands. This must be done before
+	 * we know if we should create a local block which must be done
+	 * before we can do a path search (in case the assignments change
+	 * PATH).
+	 * Odd cases:
+	 *	FOO=bar exec >/dev/null		FOO is kept but not exported
+	 *	FOO=bar exec foobar		FOO is exported
+	 *	FOO=bar command exec >/dev/null	FOO is neither kept nor exported
+	 *	FOO=bar command			FOO is neither kept nor exported
+	 *	PATH=... foobar			use new PATH in foobar search
+	 */
+	keepasn_ok = 1;
+	while (tp && tp->type == CSHELL) {
+		fcflags = FC_BI|FC_FUNC|FC_PATH;/* undo effects of command */
+		if (tp->val.f == c_builtin) {
+			if ((cp = *++ap) == NULL) {
+				tp = NULL;
+				break;
+			}
+			tp = findcom(cp, FC_BI);
+			if (tp == NULL)
+				errorf("builtin: %s: not a builtin", cp);
+			continue;
+		} else if (tp->val.f == c_exec) {
+			if (ap[1] == NULL)
+				break;
+			ap++;
+			flags |= XEXEC;
+		} else if (tp->val.f == c_command) {
+			int optc, saw_p = 0;
+
+			/* Ugly dealing with options in two places (here and
+			 * in c_command(), but such is life)
+			 */
+			ksh_getopt_reset(&builtin_opt, 0);
+			while ((optc = ksh_getopt(ap, &builtin_opt, ":p")) == 'p')
+				saw_p = 1;
+			if (optc != EOF)
+				break;	/* command -vV or something */
+			/* don't look for functions */
+			fcflags = FC_BI|FC_PATH;
+			if (saw_p) {
+				if (Flag(FRESTRICTED)) {
+					warningf(true,
+					    "command -p: restricted");
+					rv = 1;
+					goto Leave;
+				}
+				fcflags |= FC_DEFPATH;
+			}
+			ap += builtin_opt.optind;
+			/* POSIX says special builtins lose their status
+			 * if accessed using command.
+			 */
+			keepasn_ok = 0;
+			if (!ap[0]) {
+				/* ensure command with no args exits with 0 */
+				subst_exstat = 0;
+				break;
+			}
+		} else
+			break;
+		tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
+	}
+	l_expand = e->loc;
+	if (keepasn_ok && (!ap[0] || (tp && (tp->flag & KEEPASN))))
+		type_flags = 0;
+	else {
+		/* create new variable/function block */
+		newblock();
+		/* ksh functions don't keep assignments, POSIX functions do. */
+		if (keepasn_ok && tp && tp->type == CFUNC &&
+		    !(tp->flag & FKSH)) {
+			bourne_function_call = true;
+			type_flags = EXPORT;
+		} else
+			type_flags = LOCAL|LOCAL_COPY|EXPORT;
+	}
+	l_assign = e->loc;
+	if (Flag(FEXPORT))
+		type_flags |= EXPORT;
+	for (i = 0; t->vars[i]; i++) {
+		/* do NOT lookup in the new var/fn block just created */
+		e->loc = l_expand;
+		cp = evalstr(t->vars[i], DOASNTILDE);
+		e->loc = l_assign;
+		/* but assign in there as usual */
+
+		if (Flag(FXTRACE)) {
+			if (i == 0)
+				shf_fprintf(shl_out, "%s",
+					substitute(str_val(global("PS4")), 0));
+			shf_fprintf(shl_out, "%s%c", cp,
+			    t->vars[i + 1] ? ' ' : '\n');
+			if (!t->vars[i + 1])
+				shf_flush(shl_out);
+		}
+		typeset(cp, type_flags, 0, 0, 0);
+		if (bourne_function_call && !(type_flags & EXPORT))
+			typeset(cp, LOCAL|LOCAL_COPY|EXPORT, 0, 0, 0);
+	}
+
+	if ((cp = *ap) == NULL) {
+		rv = subst_exstat;
+		goto Leave;
+	} else if (!tp) {
+		if (Flag(FRESTRICTED) && vstrchr(cp, '/')) {
+			warningf(true, "%s: restricted", cp);
+			rv = 1;
+			goto Leave;
+		}
+		tp = findcom(cp, fcflags);
+	}
+
+	switch (tp->type) {
+	case CSHELL:			/* shell built-in */
+		rv = call_builtin(tp, (const char **)ap);
+		break;
+
+	case CFUNC: {			/* function call */
+		volatile unsigned char old_xflag;
+		volatile Tflag old_inuse;
+		const char *volatile old_kshname;
+
+		if (!(tp->flag & ISSET)) {
+			struct tbl *ftp;
+
+			if (!tp->u.fpath) {
+				if (tp->u2.errno_) {
+					warningf(true,
+					    "%s: can't find function "
+					    "definition file - %s",
+					    cp, strerror(tp->u2.errno_));
+					rv = 126;
+				} else {
+					warningf(true,
+					    "%s: can't find function "
+					    "definition file", cp);
+					rv = 127;
+				}
+				break;
+			}
+			if (include(tp->u.fpath, 0, NULL, 0) < 0) {
+				rv = errno;
+				warningf(true,
+				    "%s: can't open function definition file %s - %s",
+				    cp, tp->u.fpath, strerror(rv));
+				rv = 127;
+				break;
+			}
+			if (!(ftp = findfunc(cp, hash(cp), false)) ||
+			    !(ftp->flag & ISSET)) {
+				warningf(true,
+				    "%s: function not defined by %s",
+				    cp, tp->u.fpath);
+				rv = 127;
+				break;
+			}
+			tp = ftp;
+		}
+
+		/* ksh functions set $0 to function name, POSIX functions leave
+		 * $0 unchanged.
+		 */
+		old_kshname = kshname;
+		if (tp->flag & FKSH)
+			kshname = ap[0];
+		else
+			ap[0] = kshname;
+		e->loc->argv = ap;
+		for (i = 0; *ap++ != NULL; i++)
+			;
+		e->loc->argc = i - 1;
+		/* ksh-style functions handle getopts sanely,
+		 * Bourne/POSIX functions are insane...
+		 */
+		if (tp->flag & FKSH) {
+			e->loc->flags |= BF_DOGETOPTS;
+			e->loc->getopts_state = user_opt;
+			getopts_reset(1);
+		}
+
+		old_xflag = Flag(FXTRACE);
+		Flag(FXTRACE) = tp->flag & TRACE ? 1 : 0;
+
+		old_inuse = tp->flag & FINUSE;
+		tp->flag |= FINUSE;
+
+		e->type = E_FUNC;
+		i = sigsetjmp(e->jbuf, 0);
+		if (i == 0) {
+			/* seems odd to pass XERROK here, but AT&T ksh does */
+			exstat = execute(tp->val.t, flags & XERROK, xerrok);
+			i = LRETURN;
+		}
+		kshname = old_kshname;
+		Flag(FXTRACE) = old_xflag;
+		tp->flag = (tp->flag & ~FINUSE) | old_inuse;
+		/* Were we deleted while executing? If so, free the execution
+		 * tree. todo: Unfortunately, the table entry is never re-used
+		 * until the lookup table is expanded.
+		 */
+		if ((tp->flag & (FDELETE|FINUSE)) == FDELETE) {
+			if (tp->flag & ALLOC) {
+				tp->flag &= ~ALLOC;
+				tfree(tp->val.t, tp->areap);
+			}
+			tp->flag = 0;
+		}
+		switch (i) {
+		case LRETURN:
+		case LERROR:
+			rv = exstat;
+			break;
+		case LINTR:
+		case LEXIT:
+		case LLEAVE:
+		case LSHELL:
+			quitenv(NULL);
+			unwind(i);
+			/* NOTREACHED */
+		default:
+			quitenv(NULL);
+			internal_errorf("CFUNC %d", i);
+		}
+		break;
+	}
+
+	case CEXEC:		/* executable command */
+	case CTALIAS:		/* tracked alias */
+		if (!(tp->flag&ISSET)) {
+			/* errno_ will be set if the named command was found
+			 * but could not be executed (permissions, no execute
+			 * bit, directory, etc). Print out a (hopefully)
+			 * useful error message and set the exit status to 126.
+			 */
+			if (tp->u2.errno_) {
+				warningf(true, "%s: cannot execute - %s", cp,
+				    strerror(tp->u2.errno_));
+				rv = 126;	/* POSIX */
+			} else {
+				warningf(true, "%s: not found", cp);
+				rv = 127;
+			}
+			break;
+		}
+
+		/* set $_ to programme's full path */
+		/* setstr() can't fail here */
+		setstr(typeset("_", LOCAL|EXPORT, 0, INTEGER, 0),
+		    tp->val.s, KSH_RETURN_ERROR);
+
+		if (flags&XEXEC) {
+			j_exit();
+			if (!(flags&XBGND)
+#ifndef MKSH_UNEMPLOYED
+			    || Flag(FMONITOR)
+#endif
+			    ) {
+				setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
+				setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
+			}
+		}
+
+		/* to fork we set up a TEXEC node and call execute */
+		texec.type = TEXEC;
+		texec.left = t;	/* for tprint */
+		texec.str = tp->val.s;
+		texec.args = ap;
+		rv = exchild(&texec, flags, xerrok, -1);
+		break;
+	}
+ Leave:
+	if (flags & XEXEC) {
+		exstat = rv;
+		unwind(LLEAVE);
+	}
+	return (rv);
+}
+
+static void
+scriptexec(struct op *tp, const char **ap)
+{
+	const char *sh;
+#ifndef MKSH_SMALL
+	unsigned char *cp;
+	char buf[64];		/* 64 == MAXINTERP in MirBSD <sys/param.h> */
+	int fd;
+#endif
+	union mksh_ccphack args, cap;
+
+	sh = str_val(global("EXECSHELL"));
+	if (sh && *sh)
+		sh = search(sh, path, X_OK, NULL);
+	if (!sh || !*sh)
+		sh = MKSH_DEFAULT_EXECSHELL;
+
+	*tp->args-- = tp->str;
+
+#ifndef MKSH_SMALL
+	if ((fd = open(tp->str, O_RDONLY)) >= 0) {
+		/* read first MAXINTERP octets from file */
+		if (read(fd, buf, sizeof(buf)) <= 0)
+			/* read error -> no good */
+			buf[0] = '\0';
+		close(fd);
+		/* scan for newline (or CR) or NUL _before_ end of buffer */
+		cp = (unsigned char *)buf;
+		while ((char *)cp < (buf + sizeof(buf)))
+			if (*cp == '\0' || *cp == '\n' || *cp == '\r') {
+				*cp = '\0';
+				break;
+			} else
+				++cp;
+		/* if the shebang line is longer than MAXINTERP, bail out */
+		if ((char *)cp >= (buf + sizeof(buf)))
+			goto noshebang;
+		/* skip UTF-8 Byte Order Mark, if present */
+		cp = (unsigned char *)buf;
+		if ((cp[0] == 0xEF) && (cp[1] == 0xBB) && (cp[2] == 0xBF))
+			cp += 3;
+		/* bail out if read error (above) or no shebang */
+		if ((cp[0] != '#') || (cp[1] != '!'))
+			goto noshebang;
+		cp += 2;
+		/* skip whitespace before shell name */
+		while (*cp == ' ' || *cp == '\t')
+			++cp;
+		/* just whitespace on the line? */
+		if (*cp == '\0')
+			goto noshebang;
+		/* no, we actually found an interpreter name */
+		sh = (char *)cp;
+		/* look for end of shell/interpreter name */
+		while (*cp != ' ' && *cp != '\t' && *cp != '\0')
+			++cp;
+		/* any arguments? */
+		if (*cp) {
+			*cp++ = '\0';
+			/* skip spaces before arguments */
+			while (*cp == ' ' || *cp == '\t')
+				++cp;
+			/* pass it all in ONE argument (historic reasons) */
+			if (*cp)
+				*tp->args-- = (char *)cp;
+		}
+ noshebang:
+		fd = buf[0] << 8 | buf[1];
+		if ((fd == /* OMAGIC */ 0407) ||
+		    (fd == /* NMAGIC */ 0410) ||
+		    (fd == /* ZMAGIC */ 0413) ||
+		    (fd == /* QMAGIC */ 0314) ||
+		    (fd == /* ECOFF_I386 */ 0x4C01) ||
+		    (fd == /* ECOFF_M68K */ 0x0150 || fd == 0x5001) ||
+		    (fd == /* ECOFF_SH */   0x0500 || fd == 0x0005) ||
+		    (fd == 0x7F45 && buf[2] == 'L' && buf[3] == 'F') ||
+		    (fd == /* "MZ" */ 0x4D5A) ||
+		    (fd == /* gzip */ 0x1F8B))
+			errorf("%s: not executable: magic %04X", tp->str, fd);
+	}
+#endif
+	args.ro = tp->args;
+	*args.ro = sh;
+
+	cap.ro = ap;
+	execve(args.rw[0], args.rw, cap.rw);
+
+	/* report both the programme that was run and the bogus interpreter */
+	errorf("%s: %s: %s", tp->str, sh, strerror(errno));
+}
+
+int
+shcomexec(const char **wp)
+{
+	struct tbl *tp;
+
+	tp = ktsearch(&builtins, *wp, hash(*wp));
+	if (tp == NULL)
+		internal_errorf("shcomexec: %s", *wp);
+	return (call_builtin(tp, wp));
+}
+
+/*
+ * Search function tables for a function. If create set, a table entry
+ * is created if none is found.
+ */
+struct tbl *
+findfunc(const char *name, uint32_t h, bool create)
+{
+	struct block *l;
+	struct tbl *tp = NULL;
+
+	for (l = e->loc; l; l = l->next) {
+		tp = ktsearch(&l->funs, name, h);
+		if (tp)
+			break;
+		if (!l->next && create) {
+			tp = ktenter(&l->funs, name, h);
+			tp->flag = DEFINED;
+			tp->type = CFUNC;
+			tp->val.t = NULL;
+			break;
+		}
+	}
+	return (tp);
+}
+
+/*
+ * define function. Returns 1 if function is being undefined (t == 0) and
+ * function did not exist, returns 0 otherwise.
+ */
+int
+define(const char *name, struct op *t)
+{
+	struct tbl *tp;
+	bool was_set = false;
+
+	while (1) {
+		tp = findfunc(name, hash(name), true);
+
+		if (tp->flag & ISSET)
+			was_set = true;
+		/* If this function is currently being executed, we zap this
+		 * table entry so findfunc() won't see it
+		 */
+		if (tp->flag & FINUSE) {
+			tp->name[0] = '\0';
+			tp->flag &= ~DEFINED; /* ensure it won't be found */
+			tp->flag |= FDELETE;
+		} else
+			break;
+	}
+
+	if (tp->flag & ALLOC) {
+		tp->flag &= ~(ISSET|ALLOC);
+		tfree(tp->val.t, tp->areap);
+	}
+
+	if (t == NULL) {		/* undefine */
+		ktdelete(tp);
+		return (was_set ? 0 : 1);
+	}
+
+	tp->val.t = tcopy(t->left, tp->areap);
+	tp->flag |= (ISSET|ALLOC);
+	if (t->u.ksh_func)
+		tp->flag |= FKSH;
+
+	return (0);
+}
+
+/*
+ * add builtin
+ */
+void
+builtin(const char *name, int (*func) (const char **))
+{
+	struct tbl *tp;
+	Tflag flag;
+
+	/* see if any flags should be set for this builtin */
+	for (flag = 0; ; name++) {
+		if (*name == '=')	/* command does variable assignment */
+			flag |= KEEPASN;
+		else if (*name == '*')	/* POSIX special builtin */
+			flag |= SPEC_BI;
+		else if (*name == '+')	/* POSIX regular builtin */
+			flag |= REG_BI;
+		else
+			break;
+	}
+
+	tp = ktenter(&builtins, name, hash(name));
+	tp->flag = DEFINED | flag;
+	tp->type = CSHELL;
+	tp->val.f = func;
+}
+
+/*
+ * find command
+ * either function, hashed command, or built-in (in that order)
+ */
+struct tbl *
+findcom(const char *name, int flags)
+{
+	static struct tbl temp;
+	uint32_t h = hash(name);
+	struct tbl *tp = NULL, *tbi;
+	unsigned char insert = Flag(FTRACKALL);	/* insert if not found */
+	char *fpath;			/* for function autoloading */
+	union mksh_cchack npath;
+
+	if (vstrchr(name, '/')) {
+		insert = 0;
+		/* prevent FPATH search below */
+		flags &= ~FC_FUNC;
+		goto Search;
+	}
+	tbi = (flags & FC_BI) ? ktsearch(&builtins, name, h) : NULL;
+	/* POSIX says special builtins first, then functions, then
+	 * POSIX regular builtins, then search path...
+	 */
+	if ((flags & FC_SPECBI) && tbi && (tbi->flag & SPEC_BI))
+		tp = tbi;
+	if (!tp && (flags & FC_FUNC)) {
+		tp = findfunc(name, h, false);
+		if (tp && !(tp->flag & ISSET)) {
+			if ((fpath = str_val(global("FPATH"))) == null) {
+				tp->u.fpath = NULL;
+				tp->u2.errno_ = 0;
+			} else
+				tp->u.fpath = search(name, fpath, R_OK,
+				    &tp->u2.errno_);
+		}
+	}
+	if (!tp && (flags & FC_REGBI) && tbi && (tbi->flag & REG_BI))
+		tp = tbi;
+	if (!tp && (flags & FC_UNREGBI) && tbi)
+		tp = tbi;
+	if (!tp && (flags & FC_PATH) && !(flags & FC_DEFPATH)) {
+		tp = ktsearch(&taliases, name, h);
+		if (tp && (tp->flag & ISSET) && access(tp->val.s, X_OK) != 0) {
+			if (tp->flag & ALLOC) {
+				tp->flag &= ~ALLOC;
+				afree(tp->val.s, APERM);
+			}
+			tp->flag &= ~ISSET;
+		}
+	}
+
+ Search:
+	if ((!tp || (tp->type == CTALIAS && !(tp->flag&ISSET))) &&
+	    (flags & FC_PATH)) {
+		if (!tp) {
+			if (insert && !(flags & FC_DEFPATH)) {
+				tp = ktenter(&taliases, name, h);
+				tp->type = CTALIAS;
+			} else {
+				tp = &temp;
+				tp->type = CEXEC;
+			}
+			tp->flag = DEFINED;	/* make ~ISSET */
+		}
+		npath.ro = search(name, flags & FC_DEFPATH ? def_path : path,
+		    X_OK, &tp->u2.errno_);
+		if (npath.ro) {
+			strdupx(tp->val.s, npath.ro, APERM);
+			if (npath.ro != name)
+				afree(npath.rw, ATEMP);
+			tp->flag |= ISSET|ALLOC;
+		} else if ((flags & FC_FUNC) &&
+		    (fpath = str_val(global("FPATH"))) != null &&
+		    (npath.ro = search(name, fpath, R_OK,
+		    &tp->u2.errno_)) != NULL) {
+			/* An undocumented feature of AT&T ksh is that it
+			 * searches FPATH if a command is not found, even
+			 * if the command hasn't been set up as an autoloaded
+			 * function (ie, no typeset -uf).
+			 */
+			tp = &temp;
+			tp->type = CFUNC;
+			tp->flag = DEFINED; /* make ~ISSET */
+			tp->u.fpath = npath.ro;
+		}
+	}
+	return (tp);
+}
+
+/*
+ * flush executable commands with relative paths
+ */
+void
+flushcom(int all)	/* just relative or all */
+{
+	struct tbl *tp;
+	struct tstate ts;
+
+	for (ktwalk(&ts, &taliases); (tp = ktnext(&ts)) != NULL; )
+		if ((tp->flag&ISSET) && (all || tp->val.s[0] != '/')) {
+			if (tp->flag&ALLOC) {
+				tp->flag &= ~(ALLOC|ISSET);
+				afree(tp->val.s, APERM);
+			}
+			tp->flag &= ~ISSET;
+		}
+}
+
+/* Check if path is something we want to find. Returns -1 for failure. */
+int
+search_access(const char *lpath, int mode,
+    int *errnop)	/* set if candidate found, but not suitable */
+{
+	int ret, err = 0;
+	struct stat statb;
+
+	if (stat(lpath, &statb) < 0)
+		return (-1);
+	ret = access(lpath, mode);
+	if (ret < 0)
+		err = errno; /* File exists, but we can't access it */
+	else if (mode == X_OK && (!S_ISREG(statb.st_mode) ||
+	    !(statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)))) {
+		/* This 'cause access() says root can execute everything */
+		ret = -1;
+		err = S_ISDIR(statb.st_mode) ? EISDIR : EACCES;
+	}
+	if (err && errnop && !*errnop)
+		*errnop = err;
+	return (ret);
+}
+
+/*
+ * search for command with PATH
+ */
+const char *
+search(const char *name, const char *lpath,
+    int mode,		/* R_OK or X_OK */
+    int *errnop)	/* set if candidate found, but not suitable */
+{
+	const char *sp, *p;
+	char *xp;
+	XString xs;
+	int namelen;
+
+	if (errnop)
+		*errnop = 0;
+	if (vstrchr(name, '/')) {
+		if (search_access(name, mode, errnop) == 0)
+			return (name);
+		return (NULL);
+	}
+
+	namelen = strlen(name) + 1;
+	Xinit(xs, xp, 128, ATEMP);
+
+	sp = lpath;
+	while (sp != NULL) {
+		xp = Xstring(xs, xp);
+		if (!(p = cstrchr(sp, ':')))
+			p = sp + strlen(sp);
+		if (p != sp) {
+			XcheckN(xs, xp, p - sp);
+			memcpy(xp, sp, p - sp);
+			xp += p - sp;
+			*xp++ = '/';
+		}
+		sp = p;
+		XcheckN(xs, xp, namelen);
+		memcpy(xp, name, namelen);
+		if (search_access(Xstring(xs, xp), mode, errnop) == 0)
+			return (Xclose(xs, xp + namelen));
+		if (*sp++ == '\0')
+			sp = NULL;
+	}
+	Xfree(xs, xp);
+	return (NULL);
+}
+
+static int
+call_builtin(struct tbl *tp, const char **wp)
+{
+	int rv;
+
+	builtin_argv0 = wp[0];
+	builtin_flag = tp->flag;
+	shf_reopen(1, SHF_WR, shl_stdout);
+	shl_stdout_ok = 1;
+	ksh_getopt_reset(&builtin_opt, GF_ERROR);
+	rv = (*tp->val.f)(wp);
+	shf_flush(shl_stdout);
+	shl_stdout_ok = 0;
+	builtin_flag = 0;
+	builtin_argv0 = NULL;
+	return (rv);
+}
+
+/*
+ * set up redirection, saving old fds in e->savefd
+ */
+static int
+iosetup(struct ioword *iop, struct tbl *tp)
+{
+	int u = -1;
+	char *cp = iop->name;
+	int iotype = iop->flag & IOTYPE;
+	int do_open = 1, do_close = 0, flags = 0;
+	struct ioword iotmp;
+	struct stat statb;
+
+	if (iotype != IOHERE)
+		cp = evalonestr(cp, DOTILDE|(Flag(FTALKING_I) ? DOGLOB : 0));
+
+	/* Used for tracing and error messages to print expanded cp */
+	iotmp = *iop;
+	iotmp.name = (iotype == IOHERE) ? NULL : cp;
+	iotmp.flag |= IONAMEXP;
+
+	if (Flag(FXTRACE))
+		shellf("%s%s\n",
+		    substitute(str_val(global("PS4")), 0),
+		    snptreef(NULL, 32, "%R", &iotmp));
+
+	switch (iotype) {
+	case IOREAD:
+		flags = O_RDONLY;
+		break;
+
+	case IOCAT:
+		flags = O_WRONLY | O_APPEND | O_CREAT;
+		break;
+
+	case IOWRITE:
+		flags = O_WRONLY | O_CREAT | O_TRUNC;
+		/* The stat() is here to allow redirections to
+		 * things like /dev/null without error.
+		 */
+		if (Flag(FNOCLOBBER) && !(iop->flag & IOCLOB) &&
+		    (stat(cp, &statb) < 0 || S_ISREG(statb.st_mode)))
+			flags |= O_EXCL;
+		break;
+
+	case IORDWR:
+		flags = O_RDWR | O_CREAT;
+		break;
+
+	case IOHERE:
+		do_open = 0;
+		/* herein() returns -2 if error has been printed */
+		u = herein(iop->heredoc, iop->flag & IOEVAL);
+		/* cp may have wrong name */
+		break;
+
+	case IODUP: {
+		const char *emsg;
+
+		do_open = 0;
+		if (*cp == '-' && !cp[1]) {
+			u = 1009;	 /* prevent error return below */
+			do_close = 1;
+		} else if ((u = check_fd(cp,
+		    X_OK | ((iop->flag & IORDUP) ? R_OK : W_OK),
+		    &emsg)) < 0) {
+			warningf(true, "%s: %s",
+			    snptreef(NULL, 32, "%R", &iotmp), emsg);
+			return (-1);
+		}
+		if (u == iop->unit)
+			return (0);		/* "dup from" == "dup to" */
+		break;
+	}
+	}
+
+	if (do_open) {
+		if (Flag(FRESTRICTED) && (flags & O_CREAT)) {
+			warningf(true, "%s: restricted", cp);
+			return (-1);
+		}
+		u = open(cp, flags, 0666);
+	}
+	if (u < 0) {
+		/* herein() may already have printed message */
+		if (u == -1) {
+			u = errno;
+			warningf(true, "cannot %s %s: %s",
+			    iotype == IODUP ? "dup" :
+			    (iotype == IOREAD || iotype == IOHERE) ?
+			    "open" : "create", cp, strerror(u));
+		}
+		return (-1);
+	}
+	/* Do not save if it has already been redirected (i.e. "cat >x >y"). */
+	if (e->savefd[iop->unit] == 0) {
+		/* If these are the same, it means unit was previously closed */
+		if (u == iop->unit)
+			e->savefd[iop->unit] = -1;
+		else
+			/* c_exec() assumes e->savefd[fd] set for any
+			 * redirections. Ask savefd() not to close iop->unit;
+			 * this allows error messages to be seen if iop->unit
+			 * is 2; also means we can't lose the fd (eg, both
+			 * dup2 below and dup2 in restfd() failing).
+			 */
+			e->savefd[iop->unit] = savefd(iop->unit);
+	}
+
+	if (do_close)
+		close(iop->unit);
+	else if (u != iop->unit) {
+		if (ksh_dup2(u, iop->unit, true) < 0) {
+			int ev;
+
+			ev = errno;
+			warningf(true,
+			    "could not finish (dup) redirection %s: %s",
+			    snptreef(NULL, 32, "%R", &iotmp),
+			    strerror(ev));
+			if (iotype != IODUP)
+				close(u);
+			return (-1);
+		}
+		if (iotype != IODUP)
+			close(u);
+		/* Touching any co-process fd in an empty exec
+		 * causes the shell to close its copies
+		 */
+		else if (tp && tp->type == CSHELL && tp->val.f == c_exec) {
+			if (iop->flag & IORDUP)	/* possible exec <&p */
+				coproc_read_close(u);
+			else			/* possible exec >&p */
+				coproc_write_close(u);
+		}
+	}
+	if (u == 2) /* Clear any write errors */
+		shf_reopen(2, SHF_WR, shl_out);
+	return (0);
+}
+
+/*
+ * open here document temp file.
+ * if unquoted here, expand here temp file into second temp file.
+ */
+static int
+herein(const char *content, int sub)
+{
+	volatile int fd = -1;
+	struct source *s, *volatile osource;
+	struct shf *volatile shf;
+	struct temp *h;
+	int i;
+
+	/* ksh -c 'cat << EOF' can cause this... */
+	if (content == NULL) {
+		warningf(true, "here document missing");
+		return (-2); /* special to iosetup(): don't print error */
+	}
+
+	/* Create temp file to hold content (done before newenv so temp
+	 * doesn't get removed too soon).
+	 */
+	h = maketemp(ATEMP, TT_HEREDOC_EXP, &e->temps);
+	if (!(shf = h->shf) || (fd = open(h->name, O_RDONLY, 0)) < 0) {
+		fd = errno;
+		warningf(true, "can't %s temporary file %s: %s",
+		    !shf ? "create" : "open",
+		    h->name, strerror(fd));
+		if (shf)
+			shf_close(shf);
+		return (-2 /* special to iosetup(): don't print error */);
+	}
+
+	osource = source;
+	newenv(E_ERRH);
+	i = sigsetjmp(e->jbuf, 0);
+	if (i) {
+		source = osource;
+		quitenv(shf);
+		close(fd);
+		return (-2); /* special to iosetup(): don't print error */
+	}
+	if (sub) {
+		/* Do substitutions on the content of heredoc */
+		s = pushs(SSTRING, ATEMP);
+		s->start = s->str = content;
+		source = s;
+		if (yylex(ONEWORD|HEREDOC) != LWORD)
+			internal_errorf("herein: yylex");
+		source = osource;
+		shf_puts(evalstr(yylval.cp, 0), shf);
+	} else
+		shf_puts(content, shf);
+
+	quitenv(NULL);
+
+	if (shf_close(shf) == EOF) {
+		i = errno;
+		close(fd);
+		fd = errno;
+		warningf(true, "error writing %s: %s, %s", h->name,
+		    strerror(i), strerror(fd));
+		return (-2);	/* special to iosetup(): don't print error */
+	}
+
+	return (fd);
+}
+
+/*
+ *	ksh special - the select command processing section
+ *	print the args in column form - assuming that we can
+ */
+static const char *
+do_selectargs(const char **ap, bool print_menu)
+{
+	static const char *read_args[] = {
+		"read", "-r", "REPLY", NULL
+	};
+	char *s;
+	int i, argct;
+
+	for (argct = 0; ap[argct]; argct++)
+		;
+	while (1) {
+		/* Menu is printed if
+		 *	- this is the first time around the select loop
+		 *	- the user enters a blank line
+		 *	- the REPLY parameter is empty
+		 */
+		if (print_menu || !*str_val(global("REPLY")))
+			pr_menu(ap);
+		shellf("%s", str_val(global("PS3")));
+		if (call_builtin(findcom("read", FC_BI), read_args))
+			return (NULL);
+		s = str_val(global("REPLY"));
+		if (*s) {
+			getn(s, &i);
+			return ((i >= 1 && i <= argct) ? ap[i - 1] : null);
+		}
+		print_menu = 1;
+	}
+}
+
+struct select_menu_info {
+	const char * const *args;
+	int num_width;
+};
+
+static char *select_fmt_entry(char *, int, int, const void *);
+
+/* format a single select menu item */
+static char *
+select_fmt_entry(char *buf, int buflen, int i, const void *arg)
+{
+	const struct select_menu_info *smi =
+	    (const struct select_menu_info *)arg;
+
+	shf_snprintf(buf, buflen, "%*d) %s",
+	    smi->num_width, i + 1, smi->args[i]);
+	return (buf);
+}
+
+/*
+ *	print a select style menu
+ */
+int
+pr_menu(const char * const *ap)
+{
+	struct select_menu_info smi;
+	const char * const *pp;
+	int acols = 0, aocts = 0, i, n;
+
+	/*
+	 * width/column calculations were done once and saved, but this
+	 * means select can't be used recursively so we re-calculate
+	 * each time (could save in a structure that is returned, but
+	 * it's probably not worth the bother)
+	 */
+
+	/*
+	 * get dimensions of the list
+	 */
+	for (n = 0, pp = ap; *pp; n++, pp++) {
+		i = strlen(*pp);
+		if (i > aocts)
+			aocts = i;
+		i = utf_mbswidth(*pp);
+		if (i > acols)
+			acols = i;
+	}
+
+	/*
+	 * we will print an index of the form "%d) " in front of
+	 * each entry, so get the maximum width of this
+	 */
+	for (i = n, smi.num_width = 1; i >= 10; i /= 10)
+		smi.num_width++;
+
+	smi.args = ap;
+	print_columns(shl_out, n, select_fmt_entry, (void *)&smi,
+	    smi.num_width + 2 + aocts, smi.num_width + 2 + acols,
+	    true);
+
+	return (n);
+}
+
+/* XXX: horrible kludge to fit within the framework */
+static char *plain_fmt_entry(char *, int, int, const void *);
+
+static char *
+plain_fmt_entry(char *buf, int buflen, int i, const void *arg)
+{
+	shf_snprintf(buf, buflen, "%s", ((const char * const *)arg)[i]);
+	return (buf);
+}
+
+int
+pr_list(char * const *ap)
+{
+	int acols = 0, aocts = 0, i, n;
+	char * const *pp;
+
+	for (n = 0, pp = ap; *pp; n++, pp++) {
+		i = strlen(*pp);
+		if (i > aocts)
+			aocts = i;
+		i = utf_mbswidth(*pp);
+		if (i > acols)
+			acols = i;
+	}
+
+	print_columns(shl_out, n, plain_fmt_entry, (const void *)ap,
+	    aocts, acols, false);
+
+	return (n);
+}
+
+/*
+ *	[[ ... ]] evaluation routines
+ */
+
+/*
+ * Test if the current token is a whatever. Accepts the current token if
+ * it is. Returns 0 if it is not, non-zero if it is (in the case of
+ * TM_UNOP and TM_BINOP, the returned value is a Test_op).
+ */
+static Test_op
+dbteste_isa(Test_env *te, Test_meta meta)
+{
+	Test_op ret = TO_NONOP;
+	int uqword;
+	const char *p;
+
+	if (!*te->pos.wp)
+		return (meta == TM_END ? TO_NONNULL : TO_NONOP);
+
+	/* unquoted word? */
+	for (p = *te->pos.wp; *p == CHAR; p += 2)
+		;
+	uqword = *p == EOS;
+
+	if (meta == TM_UNOP || meta == TM_BINOP) {
+		if (uqword) {
+			char buf[8];	/* longer than the longest operator */
+			char *q = buf;
+			for (p = *te->pos.wp;
+			    *p == CHAR && q < &buf[sizeof(buf) - 1]; p += 2)
+				*q++ = p[1];
+			*q = '\0';
+			ret = test_isop(meta, buf);
+		}
+	} else if (meta == TM_END)
+		ret = TO_NONOP;
+	else
+		ret = (uqword && !strcmp(*te->pos.wp,
+		    dbtest_tokens[(int)meta])) ? TO_NONNULL : TO_NONOP;
+
+	/* Accept the token? */
+	if (ret != TO_NONOP)
+		te->pos.wp++;
+
+	return (ret);
+}
+
+static const char *
+dbteste_getopnd(Test_env *te, Test_op op, bool do_eval)
+{
+	const char *s = *te->pos.wp;
+
+	if (!s)
+		return (NULL);
+
+	te->pos.wp++;
+
+	if (!do_eval)
+		return (null);
+
+	if (op == TO_STEQL || op == TO_STNEQ)
+		s = evalstr(s, DOTILDE | DOPAT);
+	else
+		s = evalstr(s, DOTILDE);
+
+	return (s);
+}
+
+static void
+dbteste_error(Test_env *te, int offset, const char *msg)
+{
+	te->flags |= TEF_ERROR;
+	internal_warningf("dbteste_error: %s (offset %d)", msg, offset);
+}