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      1 /*	$OpenBSD: exec.c,v 1.49 2009/01/29 23:27:26 jaredy Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
      5  *	Thorsten Glaser <tg (at) mirbsd.org>
      6  *
      7  * Provided that these terms and disclaimer and all copyright notices
      8  * are retained or reproduced in an accompanying document, permission
      9  * is granted to deal in this work without restriction, including un-
     10  * limited rights to use, publicly perform, distribute, sell, modify,
     11  * merge, give away, or sublicence.
     12  *
     13  * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
     14  * the utmost extent permitted by applicable law, neither express nor
     15  * implied; without malicious intent or gross negligence. In no event
     16  * may a licensor, author or contributor be held liable for indirect,
     17  * direct, other damage, loss, or other issues arising in any way out
     18  * of dealing in the work, even if advised of the possibility of such
     19  * damage or existence of a defect, except proven that it results out
     20  * of said person's immediate fault when using the work as intended.
     21  */
     22 
     23 #include "sh.h"
     24 
     25 __RCSID("$MirOS: src/bin/mksh/exec.c,v 1.75 2010/07/17 22:09:34 tg Exp $");
     26 
     27 #ifndef MKSH_DEFAULT_EXECSHELL
     28 #define MKSH_DEFAULT_EXECSHELL	"/bin/sh"
     29 #endif
     30 
     31 static int comexec(struct op *, struct tbl *volatile, const char **,
     32     int volatile, volatile int *);
     33 static void scriptexec(struct op *, const char **) MKSH_A_NORETURN;
     34 static int call_builtin(struct tbl *, const char **);
     35 static int iosetup(struct ioword *, struct tbl *);
     36 static int herein(const char *, int);
     37 static const char *do_selectargs(const char **, bool);
     38 static Test_op dbteste_isa(Test_env *, Test_meta);
     39 static const char *dbteste_getopnd(Test_env *, Test_op, bool);
     40 static void dbteste_error(Test_env *, int, const char *);
     41 
     42 /*
     43  * execute command tree
     44  */
     45 int
     46 execute(struct op *volatile t,
     47     volatile int flags,		/* if XEXEC don't fork */
     48     volatile int * volatile xerrok)
     49 {
     50 	int i;
     51 	volatile int rv = 0, dummy = 0;
     52 	int pv[2];
     53 	const char ** volatile ap;
     54 	char ** volatile up;
     55 	const char *s, *cp;
     56 	struct ioword **iowp;
     57 	struct tbl *tp = NULL;
     58 
     59 	if (t == NULL)
     60 		return (0);
     61 
     62 	/* Caller doesn't care if XERROK should propagate. */
     63 	if (xerrok == NULL)
     64 		xerrok = &dummy;
     65 
     66 	if ((flags&XFORK) && !(flags&XEXEC) && t->type != TPIPE)
     67 		/* run in sub-process */
     68 		return (exchild(t, flags & ~XTIME, xerrok, -1));
     69 
     70 	newenv(E_EXEC);
     71 	if (trap)
     72 		runtraps(0);
     73 
     74 	if (t->type == TCOM) {
     75 		/* Clear subst_exstat before argument expansion. Used by
     76 		 * null commands (see comexec() and c_eval()) and by c_set().
     77 		 */
     78 		subst_exstat = 0;
     79 
     80 		current_lineno = t->lineno;	/* for $LINENO */
     81 
     82 		/* POSIX says expand command words first, then redirections,
     83 		 * and assignments last..
     84 		 */
     85 		up = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
     86 		if (flags & XTIME)
     87 			/* Allow option parsing (bizarre, but POSIX) */
     88 			timex_hook(t, &up);
     89 		ap = (const char **)up;
     90 		if (Flag(FXTRACE) && ap[0]) {
     91 			shf_fprintf(shl_out, "%s",
     92 				substitute(str_val(global("PS4")), 0));
     93 			for (i = 0; ap[i]; i++)
     94 				shf_fprintf(shl_out, "%s%c", ap[i],
     95 				    ap[i + 1] ? ' ' : '\n');
     96 			shf_flush(shl_out);
     97 		}
     98 		if (ap[0])
     99 			tp = findcom(ap[0], FC_BI|FC_FUNC);
    100 	}
    101 	flags &= ~XTIME;
    102 
    103 	if (t->ioact != NULL || t->type == TPIPE || t->type == TCOPROC) {
    104 		e->savefd = alloc(NUFILE * sizeof(short), ATEMP);
    105 		/* initialise to not redirected */
    106 		memset(e->savefd, 0, NUFILE * sizeof(short));
    107 	}
    108 
    109 	/* do redirection, to be restored in quitenv() */
    110 	if (t->ioact != NULL)
    111 		for (iowp = t->ioact; *iowp != NULL; iowp++) {
    112 			if (iosetup(*iowp, tp) < 0) {
    113 				exstat = rv = 1;
    114 				/* Redirection failures for special commands
    115 				 * cause (non-interactive) shell to exit.
    116 				 */
    117 				if (tp && tp->type == CSHELL &&
    118 				    (tp->flag & SPEC_BI))
    119 					errorfz();
    120 				/* Deal with FERREXIT, quitenv(), etc. */
    121 				goto Break;
    122 			}
    123 		}
    124 
    125 	switch (t->type) {
    126 	case TCOM:
    127 		rv = comexec(t, tp, (const char **)ap, flags, xerrok);
    128 		break;
    129 
    130 	case TPAREN:
    131 		rv = execute(t->left, flags | XFORK, xerrok);
    132 		break;
    133 
    134 	case TPIPE:
    135 		flags |= XFORK;
    136 		flags &= ~XEXEC;
    137 		e->savefd[0] = savefd(0);
    138 		e->savefd[1] = savefd(1);
    139 		while (t->type == TPIPE) {
    140 			openpipe(pv);
    141 			ksh_dup2(pv[1], 1, false); /* stdout of curr */
    142 			/**
    143 			 * Let exchild() close pv[0] in child
    144 			 * (if this isn't done, commands like
    145 			 *	(: ; cat /etc/termcap) | sleep 1
    146 			 * will hang forever).
    147 			 */
    148 			exchild(t->left, flags | XPIPEO | XCCLOSE,
    149 			    NULL, pv[0]);
    150 			ksh_dup2(pv[0], 0, false); /* stdin of next */
    151 			closepipe(pv);
    152 			flags |= XPIPEI;
    153 			t = t->right;
    154 		}
    155 		restfd(1, e->savefd[1]); /* stdout of last */
    156 		e->savefd[1] = 0; /* no need to re-restore this */
    157 		/* Let exchild() close 0 in parent, after fork, before wait */
    158 		i = exchild(t, flags | XPCLOSE, xerrok, 0);
    159 		if (!(flags&XBGND) && !(flags&XXCOM))
    160 			rv = i;
    161 		break;
    162 
    163 	case TLIST:
    164 		while (t->type == TLIST) {
    165 			execute(t->left, flags & XERROK, NULL);
    166 			t = t->right;
    167 		}
    168 		rv = execute(t, flags & XERROK, xerrok);
    169 		break;
    170 
    171 	case TCOPROC: {
    172 		sigset_t omask;
    173 
    174 		/* Block sigchild as we are using things changed in the
    175 		 * signal handler
    176 		 */
    177 		sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
    178 		e->type = E_ERRH;
    179 		i = sigsetjmp(e->jbuf, 0);
    180 		if (i) {
    181 			sigprocmask(SIG_SETMASK, &omask, NULL);
    182 			quitenv(NULL);
    183 			unwind(i);
    184 			/* NOTREACHED */
    185 		}
    186 		/* Already have a (live) co-process? */
    187 		if (coproc.job && coproc.write >= 0)
    188 			errorf("coprocess already exists");
    189 
    190 		/* Can we re-use the existing co-process pipe? */
    191 		coproc_cleanup(true);
    192 
    193 		/* do this before opening pipes, in case these fail */
    194 		e->savefd[0] = savefd(0);
    195 		e->savefd[1] = savefd(1);
    196 
    197 		openpipe(pv);
    198 		if (pv[0] != 0) {
    199 			ksh_dup2(pv[0], 0, false);
    200 			close(pv[0]);
    201 		}
    202 		coproc.write = pv[1];
    203 		coproc.job = NULL;
    204 
    205 		if (coproc.readw >= 0)
    206 			ksh_dup2(coproc.readw, 1, false);
    207 		else {
    208 			openpipe(pv);
    209 			coproc.read = pv[0];
    210 			ksh_dup2(pv[1], 1, false);
    211 			coproc.readw = pv[1];	 /* closed before first read */
    212 			coproc.njobs = 0;
    213 			/* create new coprocess id */
    214 			++coproc.id;
    215 		}
    216 		sigprocmask(SIG_SETMASK, &omask, NULL);
    217 		e->type = E_EXEC; /* no more need for error handler */
    218 
    219 		/* exchild() closes coproc.* in child after fork,
    220 		 * will also increment coproc.njobs when the
    221 		 * job is actually created.
    222 		 */
    223 		flags &= ~XEXEC;
    224 		exchild(t->left, flags | XBGND | XFORK | XCOPROC | XCCLOSE,
    225 		    NULL, coproc.readw);
    226 		break;
    227 	}
    228 
    229 	case TASYNC:
    230 		/* XXX non-optimal, I think - "(foo &)", forks for (),
    231 		 * forks again for async... parent should optimise
    232 		 * this to "foo &"...
    233 		 */
    234 		rv = execute(t->left, (flags&~XEXEC)|XBGND|XFORK, xerrok);
    235 		break;
    236 
    237 	case TOR:
    238 	case TAND:
    239 		rv = execute(t->left, XERROK, xerrok);
    240 		if ((rv == 0) == (t->type == TAND))
    241 			rv = execute(t->right, XERROK, xerrok);
    242 		flags |= XERROK;
    243 		if (xerrok)
    244 			*xerrok = 1;
    245 		break;
    246 
    247 	case TBANG:
    248 		rv = !execute(t->right, XERROK, xerrok);
    249 		flags |= XERROK;
    250 		if (xerrok)
    251 			*xerrok = 1;
    252 		break;
    253 
    254 	case TDBRACKET: {
    255 		Test_env te;
    256 
    257 		te.flags = TEF_DBRACKET;
    258 		te.pos.wp = t->args;
    259 		te.isa = dbteste_isa;
    260 		te.getopnd = dbteste_getopnd;
    261 		te.eval = test_eval;
    262 		te.error = dbteste_error;
    263 
    264 		rv = test_parse(&te);
    265 		break;
    266 	}
    267 
    268 	case TFOR:
    269 	case TSELECT: {
    270 		volatile bool is_first = true;
    271 		ap = (t->vars == NULL) ? e->loc->argv + 1 :
    272 		    (const char **)eval((const char **)t->vars,
    273 		    DOBLANK | DOGLOB | DOTILDE);
    274 		e->type = E_LOOP;
    275 		while (1) {
    276 			i = sigsetjmp(e->jbuf, 0);
    277 			if (!i)
    278 				break;
    279 			if ((e->flags&EF_BRKCONT_PASS) ||
    280 			    (i != LBREAK && i != LCONTIN)) {
    281 				quitenv(NULL);
    282 				unwind(i);
    283 			} else if (i == LBREAK) {
    284 				rv = 0;
    285 				goto Break;
    286 			}
    287 		}
    288 		rv = 0; /* in case of a continue */
    289 		if (t->type == TFOR) {
    290 			while (*ap != NULL) {
    291 				setstr(global(t->str), *ap++, KSH_UNWIND_ERROR);
    292 				rv = execute(t->left, flags & XERROK, xerrok);
    293 			}
    294 		} else { /* TSELECT */
    295 			for (;;) {
    296 				if (!(cp = do_selectargs(ap, is_first))) {
    297 					rv = 1;
    298 					break;
    299 				}
    300 				is_first = false;
    301 				setstr(global(t->str), cp, KSH_UNWIND_ERROR);
    302 				execute(t->left, flags & XERROK, xerrok);
    303 			}
    304 		}
    305 		break;
    306 	}
    307 
    308 	case TWHILE:
    309 	case TUNTIL:
    310 		e->type = E_LOOP;
    311 		while (1) {
    312 			i = sigsetjmp(e->jbuf, 0);
    313 			if (!i)
    314 				break;
    315 			if ((e->flags&EF_BRKCONT_PASS) ||
    316 			    (i != LBREAK && i != LCONTIN)) {
    317 				quitenv(NULL);
    318 				unwind(i);
    319 			} else if (i == LBREAK) {
    320 				rv = 0;
    321 				goto Break;
    322 			}
    323 		}
    324 		rv = 0; /* in case of a continue */
    325 		while ((execute(t->left, XERROK, NULL) == 0) ==
    326 		    (t->type == TWHILE))
    327 			rv = execute(t->right, flags & XERROK, xerrok);
    328 		break;
    329 
    330 	case TIF:
    331 	case TELIF:
    332 		if (t->right == NULL)
    333 			break;	/* should be error */
    334 		rv = execute(t->left, XERROK, NULL) == 0 ?
    335 		    execute(t->right->left, flags & XERROK, xerrok) :
    336 		    execute(t->right->right, flags & XERROK, xerrok);
    337 		break;
    338 
    339 	case TCASE:
    340 		cp = evalstr(t->str, DOTILDE);
    341 		for (t = t->left; t != NULL && t->type == TPAT; t = t->right)
    342 		    for (ap = (const char **)t->vars; *ap; ap++)
    343 			if ((s = evalstr(*ap, DOTILDE|DOPAT)) &&
    344 			    gmatchx(cp, s, false))
    345 				goto Found;
    346 		break;
    347  Found:
    348 		rv = execute(t->left, flags & XERROK, xerrok);
    349 		break;
    350 
    351 	case TBRACE:
    352 		rv = execute(t->left, flags & XERROK, xerrok);
    353 		break;
    354 
    355 	case TFUNCT:
    356 		rv = define(t->str, t);
    357 		break;
    358 
    359 	case TTIME:
    360 		/* Clear XEXEC so nested execute() call doesn't exit
    361 		 * (allows "ls -l | time grep foo").
    362 		 */
    363 		rv = timex(t, flags & ~XEXEC, xerrok);
    364 		break;
    365 
    366 	case TEXEC:		/* an eval'd TCOM */
    367 		s = t->args[0];
    368 		up = makenv();
    369 		restoresigs();
    370 		cleanup_proc_env();
    371 		{
    372 			union mksh_ccphack cargs;
    373 
    374 			cargs.ro = t->args;
    375 			execve(t->str, cargs.rw, up);
    376 			rv = errno;
    377 		}
    378 		if (rv == ENOEXEC)
    379 			scriptexec(t, (const char **)up);
    380 		else
    381 			errorf("%s: %s", s, strerror(rv));
    382 	}
    383  Break:
    384 	exstat = rv;
    385 
    386 	quitenv(NULL);		/* restores IO */
    387 	if ((flags&XEXEC))
    388 		unwind(LEXIT);	/* exit child */
    389 	if (rv != 0 && !(flags & XERROK) &&
    390 	    (xerrok == NULL || !*xerrok)) {
    391 		trapsig(SIGERR_);
    392 		if (Flag(FERREXIT))
    393 			unwind(LERROR);
    394 	}
    395 	return (rv);
    396 }
    397 
    398 /*
    399  * execute simple command
    400  */
    401 
    402 static int
    403 comexec(struct op *t, struct tbl *volatile tp, const char **ap,
    404     volatile int flags, volatile int *xerrok)
    405 {
    406 	int i;
    407 	volatile int rv = 0;
    408 	const char *cp;
    409 	const char **lastp;
    410 	static struct op texec; /* Must be static (XXX but why?) */
    411 	int type_flags;
    412 	int keepasn_ok;
    413 	int fcflags = FC_BI|FC_FUNC|FC_PATH;
    414 	bool bourne_function_call = false;
    415 	struct block *l_expand, *l_assign;
    416 
    417 	/* snag the last argument for $_ XXX not the same as AT&T ksh,
    418 	 * which only seems to set $_ after a newline (but not in
    419 	 * functions/dot scripts, but in interactive and script) -
    420 	 * perhaps save last arg here and set it in shell()?.
    421 	 */
    422 	if (Flag(FTALKING) && *(lastp = ap)) {
    423 		while (*++lastp)
    424 			;
    425 		/* setstr() can't fail here */
    426 		setstr(typeset("_", LOCAL, 0, INTEGER, 0), *--lastp,
    427 		    KSH_RETURN_ERROR);
    428 	}
    429 
    430 	/* Deal with the shell builtins builtin, exec and command since
    431 	 * they can be followed by other commands. This must be done before
    432 	 * we know if we should create a local block which must be done
    433 	 * before we can do a path search (in case the assignments change
    434 	 * PATH).
    435 	 * Odd cases:
    436 	 *	FOO=bar exec >/dev/null		FOO is kept but not exported
    437 	 *	FOO=bar exec foobar		FOO is exported
    438 	 *	FOO=bar command exec >/dev/null	FOO is neither kept nor exported
    439 	 *	FOO=bar command			FOO is neither kept nor exported
    440 	 *	PATH=... foobar			use new PATH in foobar search
    441 	 */
    442 	keepasn_ok = 1;
    443 	while (tp && tp->type == CSHELL) {
    444 		fcflags = FC_BI|FC_FUNC|FC_PATH;/* undo effects of command */
    445 		if (tp->val.f == c_builtin) {
    446 			if ((cp = *++ap) == NULL) {
    447 				tp = NULL;
    448 				break;
    449 			}
    450 			tp = findcom(cp, FC_BI);
    451 			if (tp == NULL)
    452 				errorf("builtin: %s: not a builtin", cp);
    453 			continue;
    454 		} else if (tp->val.f == c_exec) {
    455 			if (ap[1] == NULL)
    456 				break;
    457 			ap++;
    458 			flags |= XEXEC;
    459 		} else if (tp->val.f == c_command) {
    460 			int optc, saw_p = 0;
    461 
    462 			/* Ugly dealing with options in two places (here and
    463 			 * in c_command(), but such is life)
    464 			 */
    465 			ksh_getopt_reset(&builtin_opt, 0);
    466 			while ((optc = ksh_getopt(ap, &builtin_opt, ":p")) == 'p')
    467 				saw_p = 1;
    468 			if (optc != EOF)
    469 				break;	/* command -vV or something */
    470 			/* don't look for functions */
    471 			fcflags = FC_BI|FC_PATH;
    472 			if (saw_p) {
    473 				if (Flag(FRESTRICTED)) {
    474 					warningf(true,
    475 					    "command -p: restricted");
    476 					rv = 1;
    477 					goto Leave;
    478 				}
    479 				fcflags |= FC_DEFPATH;
    480 			}
    481 			ap += builtin_opt.optind;
    482 			/* POSIX says special builtins lose their status
    483 			 * if accessed using command.
    484 			 */
    485 			keepasn_ok = 0;
    486 			if (!ap[0]) {
    487 				/* ensure command with no args exits with 0 */
    488 				subst_exstat = 0;
    489 				break;
    490 			}
    491 		} else
    492 			break;
    493 		tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
    494 	}
    495 	l_expand = e->loc;
    496 	if (keepasn_ok && (!ap[0] || (tp && (tp->flag & KEEPASN))))
    497 		type_flags = 0;
    498 	else {
    499 		/* create new variable/function block */
    500 		newblock();
    501 		/* ksh functions don't keep assignments, POSIX functions do. */
    502 		if (keepasn_ok && tp && tp->type == CFUNC &&
    503 		    !(tp->flag & FKSH)) {
    504 			bourne_function_call = true;
    505 			type_flags = EXPORT;
    506 		} else
    507 			type_flags = LOCAL|LOCAL_COPY|EXPORT;
    508 	}
    509 	l_assign = e->loc;
    510 	if (Flag(FEXPORT))
    511 		type_flags |= EXPORT;
    512 	for (i = 0; t->vars[i]; i++) {
    513 		/* do NOT lookup in the new var/fn block just created */
    514 		e->loc = l_expand;
    515 		cp = evalstr(t->vars[i], DOASNTILDE);
    516 		e->loc = l_assign;
    517 		/* but assign in there as usual */
    518 
    519 		if (Flag(FXTRACE)) {
    520 			if (i == 0)
    521 				shf_fprintf(shl_out, "%s",
    522 					substitute(str_val(global("PS4")), 0));
    523 			shf_fprintf(shl_out, "%s%c", cp,
    524 			    t->vars[i + 1] ? ' ' : '\n');
    525 			if (!t->vars[i + 1])
    526 				shf_flush(shl_out);
    527 		}
    528 		typeset(cp, type_flags, 0, 0, 0);
    529 		if (bourne_function_call && !(type_flags & EXPORT))
    530 			typeset(cp, LOCAL|LOCAL_COPY|EXPORT, 0, 0, 0);
    531 	}
    532 
    533 	if ((cp = *ap) == NULL) {
    534 		rv = subst_exstat;
    535 		goto Leave;
    536 	} else if (!tp) {
    537 		if (Flag(FRESTRICTED) && vstrchr(cp, '/')) {
    538 			warningf(true, "%s: restricted", cp);
    539 			rv = 1;
    540 			goto Leave;
    541 		}
    542 		tp = findcom(cp, fcflags);
    543 	}
    544 
    545 	switch (tp->type) {
    546 	case CSHELL:			/* shell built-in */
    547 		rv = call_builtin(tp, (const char **)ap);
    548 		break;
    549 
    550 	case CFUNC: {			/* function call */
    551 		volatile unsigned char old_xflag;
    552 		volatile Tflag old_inuse;
    553 		const char *volatile old_kshname;
    554 
    555 		if (!(tp->flag & ISSET)) {
    556 			struct tbl *ftp;
    557 
    558 			if (!tp->u.fpath) {
    559 				if (tp->u2.errno_) {
    560 					warningf(true,
    561 					    "%s: can't find function "
    562 					    "definition file - %s",
    563 					    cp, strerror(tp->u2.errno_));
    564 					rv = 126;
    565 				} else {
    566 					warningf(true,
    567 					    "%s: can't find function "
    568 					    "definition file", cp);
    569 					rv = 127;
    570 				}
    571 				break;
    572 			}
    573 			if (include(tp->u.fpath, 0, NULL, 0) < 0) {
    574 				rv = errno;
    575 				warningf(true,
    576 				    "%s: can't open function definition file %s - %s",
    577 				    cp, tp->u.fpath, strerror(rv));
    578 				rv = 127;
    579 				break;
    580 			}
    581 			if (!(ftp = findfunc(cp, hash(cp), false)) ||
    582 			    !(ftp->flag & ISSET)) {
    583 				warningf(true,
    584 				    "%s: function not defined by %s",
    585 				    cp, tp->u.fpath);
    586 				rv = 127;
    587 				break;
    588 			}
    589 			tp = ftp;
    590 		}
    591 
    592 		/* ksh functions set $0 to function name, POSIX functions leave
    593 		 * $0 unchanged.
    594 		 */
    595 		old_kshname = kshname;
    596 		if (tp->flag & FKSH)
    597 			kshname = ap[0];
    598 		else
    599 			ap[0] = kshname;
    600 		e->loc->argv = ap;
    601 		for (i = 0; *ap++ != NULL; i++)
    602 			;
    603 		e->loc->argc = i - 1;
    604 		/* ksh-style functions handle getopts sanely,
    605 		 * Bourne/POSIX functions are insane...
    606 		 */
    607 		if (tp->flag & FKSH) {
    608 			e->loc->flags |= BF_DOGETOPTS;
    609 			e->loc->getopts_state = user_opt;
    610 			getopts_reset(1);
    611 		}
    612 
    613 		old_xflag = Flag(FXTRACE);
    614 		Flag(FXTRACE) = tp->flag & TRACE ? 1 : 0;
    615 
    616 		old_inuse = tp->flag & FINUSE;
    617 		tp->flag |= FINUSE;
    618 
    619 		e->type = E_FUNC;
    620 		i = sigsetjmp(e->jbuf, 0);
    621 		if (i == 0) {
    622 			/* seems odd to pass XERROK here, but AT&T ksh does */
    623 			exstat = execute(tp->val.t, flags & XERROK, xerrok);
    624 			i = LRETURN;
    625 		}
    626 		kshname = old_kshname;
    627 		Flag(FXTRACE) = old_xflag;
    628 		tp->flag = (tp->flag & ~FINUSE) | old_inuse;
    629 		/* Were we deleted while executing? If so, free the execution
    630 		 * tree. todo: Unfortunately, the table entry is never re-used
    631 		 * until the lookup table is expanded.
    632 		 */
    633 		if ((tp->flag & (FDELETE|FINUSE)) == FDELETE) {
    634 			if (tp->flag & ALLOC) {
    635 				tp->flag &= ~ALLOC;
    636 				tfree(tp->val.t, tp->areap);
    637 			}
    638 			tp->flag = 0;
    639 		}
    640 		switch (i) {
    641 		case LRETURN:
    642 		case LERROR:
    643 			rv = exstat;
    644 			break;
    645 		case LINTR:
    646 		case LEXIT:
    647 		case LLEAVE:
    648 		case LSHELL:
    649 			quitenv(NULL);
    650 			unwind(i);
    651 			/* NOTREACHED */
    652 		default:
    653 			quitenv(NULL);
    654 			internal_errorf("CFUNC %d", i);
    655 		}
    656 		break;
    657 	}
    658 
    659 	case CEXEC:		/* executable command */
    660 	case CTALIAS:		/* tracked alias */
    661 		if (!(tp->flag&ISSET)) {
    662 			/* errno_ will be set if the named command was found
    663 			 * but could not be executed (permissions, no execute
    664 			 * bit, directory, etc). Print out a (hopefully)
    665 			 * useful error message and set the exit status to 126.
    666 			 */
    667 			if (tp->u2.errno_) {
    668 				warningf(true, "%s: cannot execute - %s", cp,
    669 				    strerror(tp->u2.errno_));
    670 				rv = 126;	/* POSIX */
    671 			} else {
    672 				warningf(true, "%s: not found", cp);
    673 				rv = 127;
    674 			}
    675 			break;
    676 		}
    677 
    678 		/* set $_ to programme's full path */
    679 		/* setstr() can't fail here */
    680 		setstr(typeset("_", LOCAL|EXPORT, 0, INTEGER, 0),
    681 		    tp->val.s, KSH_RETURN_ERROR);
    682 
    683 		if (flags&XEXEC) {
    684 			j_exit();
    685 			if (!(flags&XBGND)
    686 #ifndef MKSH_UNEMPLOYED
    687 			    || Flag(FMONITOR)
    688 #endif
    689 			    ) {
    690 				setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
    691 				setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
    692 			}
    693 		}
    694 
    695 		/* to fork we set up a TEXEC node and call execute */
    696 		texec.type = TEXEC;
    697 		texec.left = t;	/* for tprint */
    698 		texec.str = tp->val.s;
    699 		texec.args = ap;
    700 		rv = exchild(&texec, flags, xerrok, -1);
    701 		break;
    702 	}
    703  Leave:
    704 	if (flags & XEXEC) {
    705 		exstat = rv;
    706 		unwind(LLEAVE);
    707 	}
    708 	return (rv);
    709 }
    710 
    711 static void
    712 scriptexec(struct op *tp, const char **ap)
    713 {
    714 	const char *sh;
    715 #ifndef MKSH_SMALL
    716 	unsigned char *cp;
    717 	char buf[64];		/* 64 == MAXINTERP in MirBSD <sys/param.h> */
    718 	int fd;
    719 #endif
    720 	union mksh_ccphack args, cap;
    721 
    722 	sh = str_val(global("EXECSHELL"));
    723 	if (sh && *sh)
    724 		sh = search(sh, path, X_OK, NULL);
    725 	if (!sh || !*sh)
    726 		sh = MKSH_DEFAULT_EXECSHELL;
    727 
    728 	*tp->args-- = tp->str;
    729 
    730 #ifndef MKSH_SMALL
    731 	if ((fd = open(tp->str, O_RDONLY)) >= 0) {
    732 		/* read first MAXINTERP octets from file */
    733 		if (read(fd, buf, sizeof(buf)) <= 0)
    734 			/* read error -> no good */
    735 			buf[0] = '\0';
    736 		close(fd);
    737 		/* scan for newline (or CR) or NUL _before_ end of buffer */
    738 		cp = (unsigned char *)buf;
    739 		while ((char *)cp < (buf + sizeof(buf)))
    740 			if (*cp == '\0' || *cp == '\n' || *cp == '\r') {
    741 				*cp = '\0';
    742 				break;
    743 			} else
    744 				++cp;
    745 		/* if the shebang line is longer than MAXINTERP, bail out */
    746 		if ((char *)cp >= (buf + sizeof(buf)))
    747 			goto noshebang;
    748 		/* skip UTF-8 Byte Order Mark, if present */
    749 		cp = (unsigned char *)buf;
    750 		if ((cp[0] == 0xEF) && (cp[1] == 0xBB) && (cp[2] == 0xBF))
    751 			cp += 3;
    752 		/* bail out if read error (above) or no shebang */
    753 		if ((cp[0] != '#') || (cp[1] != '!'))
    754 			goto noshebang;
    755 		cp += 2;
    756 		/* skip whitespace before shell name */
    757 		while (*cp == ' ' || *cp == '\t')
    758 			++cp;
    759 		/* just whitespace on the line? */
    760 		if (*cp == '\0')
    761 			goto noshebang;
    762 		/* no, we actually found an interpreter name */
    763 		sh = (char *)cp;
    764 		/* look for end of shell/interpreter name */
    765 		while (*cp != ' ' && *cp != '\t' && *cp != '\0')
    766 			++cp;
    767 		/* any arguments? */
    768 		if (*cp) {
    769 			*cp++ = '\0';
    770 			/* skip spaces before arguments */
    771 			while (*cp == ' ' || *cp == '\t')
    772 				++cp;
    773 			/* pass it all in ONE argument (historic reasons) */
    774 			if (*cp)
    775 				*tp->args-- = (char *)cp;
    776 		}
    777  noshebang:
    778 		fd = buf[0] << 8 | buf[1];
    779 		if ((fd == /* OMAGIC */ 0407) ||
    780 		    (fd == /* NMAGIC */ 0410) ||
    781 		    (fd == /* ZMAGIC */ 0413) ||
    782 		    (fd == /* QMAGIC */ 0314) ||
    783 		    (fd == /* ECOFF_I386 */ 0x4C01) ||
    784 		    (fd == /* ECOFF_M68K */ 0x0150 || fd == 0x5001) ||
    785 		    (fd == /* ECOFF_SH */   0x0500 || fd == 0x0005) ||
    786 		    (fd == 0x7F45 && buf[2] == 'L' && buf[3] == 'F') ||
    787 		    (fd == /* "MZ" */ 0x4D5A) ||
    788 		    (fd == /* gzip */ 0x1F8B))
    789 			errorf("%s: not executable: magic %04X", tp->str, fd);
    790 	}
    791 #endif
    792 	args.ro = tp->args;
    793 	*args.ro = sh;
    794 
    795 	cap.ro = ap;
    796 	execve(args.rw[0], args.rw, cap.rw);
    797 
    798 	/* report both the programme that was run and the bogus interpreter */
    799 	errorf("%s: %s: %s", tp->str, sh, strerror(errno));
    800 }
    801 
    802 int
    803 shcomexec(const char **wp)
    804 {
    805 	struct tbl *tp;
    806 
    807 	tp = ktsearch(&builtins, *wp, hash(*wp));
    808 	if (tp == NULL)
    809 		internal_errorf("shcomexec: %s", *wp);
    810 	return (call_builtin(tp, wp));
    811 }
    812 
    813 /*
    814  * Search function tables for a function. If create set, a table entry
    815  * is created if none is found.
    816  */
    817 struct tbl *
    818 findfunc(const char *name, uint32_t h, bool create)
    819 {
    820 	struct block *l;
    821 	struct tbl *tp = NULL;
    822 
    823 	for (l = e->loc; l; l = l->next) {
    824 		tp = ktsearch(&l->funs, name, h);
    825 		if (tp)
    826 			break;
    827 		if (!l->next && create) {
    828 			tp = ktenter(&l->funs, name, h);
    829 			tp->flag = DEFINED;
    830 			tp->type = CFUNC;
    831 			tp->val.t = NULL;
    832 			break;
    833 		}
    834 	}
    835 	return (tp);
    836 }
    837 
    838 /*
    839  * define function. Returns 1 if function is being undefined (t == 0) and
    840  * function did not exist, returns 0 otherwise.
    841  */
    842 int
    843 define(const char *name, struct op *t)
    844 {
    845 	struct tbl *tp;
    846 	bool was_set = false;
    847 
    848 	while (1) {
    849 		tp = findfunc(name, hash(name), true);
    850 
    851 		if (tp->flag & ISSET)
    852 			was_set = true;
    853 		/* If this function is currently being executed, we zap this
    854 		 * table entry so findfunc() won't see it
    855 		 */
    856 		if (tp->flag & FINUSE) {
    857 			tp->name[0] = '\0';
    858 			tp->flag &= ~DEFINED; /* ensure it won't be found */
    859 			tp->flag |= FDELETE;
    860 		} else
    861 			break;
    862 	}
    863 
    864 	if (tp->flag & ALLOC) {
    865 		tp->flag &= ~(ISSET|ALLOC);
    866 		tfree(tp->val.t, tp->areap);
    867 	}
    868 
    869 	if (t == NULL) {		/* undefine */
    870 		ktdelete(tp);
    871 		return (was_set ? 0 : 1);
    872 	}
    873 
    874 	tp->val.t = tcopy(t->left, tp->areap);
    875 	tp->flag |= (ISSET|ALLOC);
    876 	if (t->u.ksh_func)
    877 		tp->flag |= FKSH;
    878 
    879 	return (0);
    880 }
    881 
    882 /*
    883  * add builtin
    884  */
    885 void
    886 builtin(const char *name, int (*func) (const char **))
    887 {
    888 	struct tbl *tp;
    889 	Tflag flag;
    890 
    891 	/* see if any flags should be set for this builtin */
    892 	for (flag = 0; ; name++) {
    893 		if (*name == '=')	/* command does variable assignment */
    894 			flag |= KEEPASN;
    895 		else if (*name == '*')	/* POSIX special builtin */
    896 			flag |= SPEC_BI;
    897 		else if (*name == '+')	/* POSIX regular builtin */
    898 			flag |= REG_BI;
    899 		else
    900 			break;
    901 	}
    902 
    903 	tp = ktenter(&builtins, name, hash(name));
    904 	tp->flag = DEFINED | flag;
    905 	tp->type = CSHELL;
    906 	tp->val.f = func;
    907 }
    908 
    909 /*
    910  * find command
    911  * either function, hashed command, or built-in (in that order)
    912  */
    913 struct tbl *
    914 findcom(const char *name, int flags)
    915 {
    916 	static struct tbl temp;
    917 	uint32_t h = hash(name);
    918 	struct tbl *tp = NULL, *tbi;
    919 	unsigned char insert = Flag(FTRACKALL);	/* insert if not found */
    920 	char *fpath;			/* for function autoloading */
    921 	union mksh_cchack npath;
    922 
    923 	if (vstrchr(name, '/')) {
    924 		insert = 0;
    925 		/* prevent FPATH search below */
    926 		flags &= ~FC_FUNC;
    927 		goto Search;
    928 	}
    929 	tbi = (flags & FC_BI) ? ktsearch(&builtins, name, h) : NULL;
    930 	/* POSIX says special builtins first, then functions, then
    931 	 * POSIX regular builtins, then search path...
    932 	 */
    933 	if ((flags & FC_SPECBI) && tbi && (tbi->flag & SPEC_BI))
    934 		tp = tbi;
    935 	if (!tp && (flags & FC_FUNC)) {
    936 		tp = findfunc(name, h, false);
    937 		if (tp && !(tp->flag & ISSET)) {
    938 			if ((fpath = str_val(global("FPATH"))) == null) {
    939 				tp->u.fpath = NULL;
    940 				tp->u2.errno_ = 0;
    941 			} else
    942 				tp->u.fpath = search(name, fpath, R_OK,
    943 				    &tp->u2.errno_);
    944 		}
    945 	}
    946 	if (!tp && (flags & FC_REGBI) && tbi && (tbi->flag & REG_BI))
    947 		tp = tbi;
    948 	if (!tp && (flags & FC_UNREGBI) && tbi)
    949 		tp = tbi;
    950 	if (!tp && (flags & FC_PATH) && !(flags & FC_DEFPATH)) {
    951 		tp = ktsearch(&taliases, name, h);
    952 		if (tp && (tp->flag & ISSET) && access(tp->val.s, X_OK) != 0) {
    953 			if (tp->flag & ALLOC) {
    954 				tp->flag &= ~ALLOC;
    955 				afree(tp->val.s, APERM);
    956 			}
    957 			tp->flag &= ~ISSET;
    958 		}
    959 	}
    960 
    961  Search:
    962 	if ((!tp || (tp->type == CTALIAS && !(tp->flag&ISSET))) &&
    963 	    (flags & FC_PATH)) {
    964 		if (!tp) {
    965 			if (insert && !(flags & FC_DEFPATH)) {
    966 				tp = ktenter(&taliases, name, h);
    967 				tp->type = CTALIAS;
    968 			} else {
    969 				tp = &temp;
    970 				tp->type = CEXEC;
    971 			}
    972 			tp->flag = DEFINED;	/* make ~ISSET */
    973 		}
    974 		npath.ro = search(name, flags & FC_DEFPATH ? def_path : path,
    975 		    X_OK, &tp->u2.errno_);
    976 		if (npath.ro) {
    977 			strdupx(tp->val.s, npath.ro, APERM);
    978 			if (npath.ro != name)
    979 				afree(npath.rw, ATEMP);
    980 			tp->flag |= ISSET|ALLOC;
    981 		} else if ((flags & FC_FUNC) &&
    982 		    (fpath = str_val(global("FPATH"))) != null &&
    983 		    (npath.ro = search(name, fpath, R_OK,
    984 		    &tp->u2.errno_)) != NULL) {
    985 			/* An undocumented feature of AT&T ksh is that it
    986 			 * searches FPATH if a command is not found, even
    987 			 * if the command hasn't been set up as an autoloaded
    988 			 * function (ie, no typeset -uf).
    989 			 */
    990 			tp = &temp;
    991 			tp->type = CFUNC;
    992 			tp->flag = DEFINED; /* make ~ISSET */
    993 			tp->u.fpath = npath.ro;
    994 		}
    995 	}
    996 	return (tp);
    997 }
    998 
    999 /*
   1000  * flush executable commands with relative paths
   1001  */
   1002 void
   1003 flushcom(int all)	/* just relative or all */
   1004 {
   1005 	struct tbl *tp;
   1006 	struct tstate ts;
   1007 
   1008 	for (ktwalk(&ts, &taliases); (tp = ktnext(&ts)) != NULL; )
   1009 		if ((tp->flag&ISSET) && (all || tp->val.s[0] != '/')) {
   1010 			if (tp->flag&ALLOC) {
   1011 				tp->flag &= ~(ALLOC|ISSET);
   1012 				afree(tp->val.s, APERM);
   1013 			}
   1014 			tp->flag &= ~ISSET;
   1015 		}
   1016 }
   1017 
   1018 /* Check if path is something we want to find. Returns -1 for failure. */
   1019 int
   1020 search_access(const char *lpath, int mode,
   1021     int *errnop)	/* set if candidate found, but not suitable */
   1022 {
   1023 	int ret, err = 0;
   1024 	struct stat statb;
   1025 
   1026 	if (stat(lpath, &statb) < 0)
   1027 		return (-1);
   1028 	ret = access(lpath, mode);
   1029 	if (ret < 0)
   1030 		err = errno; /* File exists, but we can't access it */
   1031 	else if (mode == X_OK && (!S_ISREG(statb.st_mode) ||
   1032 	    !(statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)))) {
   1033 		/* This 'cause access() says root can execute everything */
   1034 		ret = -1;
   1035 		err = S_ISDIR(statb.st_mode) ? EISDIR : EACCES;
   1036 	}
   1037 	if (err && errnop && !*errnop)
   1038 		*errnop = err;
   1039 	return (ret);
   1040 }
   1041 
   1042 /*
   1043  * search for command with PATH
   1044  */
   1045 const char *
   1046 search(const char *name, const char *lpath,
   1047     int mode,		/* R_OK or X_OK */
   1048     int *errnop)	/* set if candidate found, but not suitable */
   1049 {
   1050 	const char *sp, *p;
   1051 	char *xp;
   1052 	XString xs;
   1053 	int namelen;
   1054 
   1055 	if (errnop)
   1056 		*errnop = 0;
   1057 	if (vstrchr(name, '/')) {
   1058 		if (search_access(name, mode, errnop) == 0)
   1059 			return (name);
   1060 		return (NULL);
   1061 	}
   1062 
   1063 	namelen = strlen(name) + 1;
   1064 	Xinit(xs, xp, 128, ATEMP);
   1065 
   1066 	sp = lpath;
   1067 	while (sp != NULL) {
   1068 		xp = Xstring(xs, xp);
   1069 		if (!(p = cstrchr(sp, ':')))
   1070 			p = sp + strlen(sp);
   1071 		if (p != sp) {
   1072 			XcheckN(xs, xp, p - sp);
   1073 			memcpy(xp, sp, p - sp);
   1074 			xp += p - sp;
   1075 			*xp++ = '/';
   1076 		}
   1077 		sp = p;
   1078 		XcheckN(xs, xp, namelen);
   1079 		memcpy(xp, name, namelen);
   1080 		if (search_access(Xstring(xs, xp), mode, errnop) == 0)
   1081 			return (Xclose(xs, xp + namelen));
   1082 		if (*sp++ == '\0')
   1083 			sp = NULL;
   1084 	}
   1085 	Xfree(xs, xp);
   1086 	return (NULL);
   1087 }
   1088 
   1089 static int
   1090 call_builtin(struct tbl *tp, const char **wp)
   1091 {
   1092 	int rv;
   1093 
   1094 	builtin_argv0 = wp[0];
   1095 	builtin_flag = tp->flag;
   1096 	shf_reopen(1, SHF_WR, shl_stdout);
   1097 	shl_stdout_ok = 1;
   1098 	ksh_getopt_reset(&builtin_opt, GF_ERROR);
   1099 	rv = (*tp->val.f)(wp);
   1100 	shf_flush(shl_stdout);
   1101 	shl_stdout_ok = 0;
   1102 	builtin_flag = 0;
   1103 	builtin_argv0 = NULL;
   1104 	return (rv);
   1105 }
   1106 
   1107 /*
   1108  * set up redirection, saving old fds in e->savefd
   1109  */
   1110 static int
   1111 iosetup(struct ioword *iop, struct tbl *tp)
   1112 {
   1113 	int u = -1;
   1114 	char *cp = iop->name;
   1115 	int iotype = iop->flag & IOTYPE;
   1116 	int do_open = 1, do_close = 0, flags = 0;
   1117 	struct ioword iotmp;
   1118 	struct stat statb;
   1119 
   1120 	if (iotype != IOHERE)
   1121 		cp = evalonestr(cp, DOTILDE|(Flag(FTALKING_I) ? DOGLOB : 0));
   1122 
   1123 	/* Used for tracing and error messages to print expanded cp */
   1124 	iotmp = *iop;
   1125 	iotmp.name = (iotype == IOHERE) ? NULL : cp;
   1126 	iotmp.flag |= IONAMEXP;
   1127 
   1128 	if (Flag(FXTRACE))
   1129 		shellf("%s%s\n",
   1130 		    substitute(str_val(global("PS4")), 0),
   1131 		    snptreef(NULL, 32, "%R", &iotmp));
   1132 
   1133 	switch (iotype) {
   1134 	case IOREAD:
   1135 		flags = O_RDONLY;
   1136 		break;
   1137 
   1138 	case IOCAT:
   1139 		flags = O_WRONLY | O_APPEND | O_CREAT;
   1140 		break;
   1141 
   1142 	case IOWRITE:
   1143 		flags = O_WRONLY | O_CREAT | O_TRUNC;
   1144 		/* The stat() is here to allow redirections to
   1145 		 * things like /dev/null without error.
   1146 		 */
   1147 		if (Flag(FNOCLOBBER) && !(iop->flag & IOCLOB) &&
   1148 		    (stat(cp, &statb) < 0 || S_ISREG(statb.st_mode)))
   1149 			flags |= O_EXCL;
   1150 		break;
   1151 
   1152 	case IORDWR:
   1153 		flags = O_RDWR | O_CREAT;
   1154 		break;
   1155 
   1156 	case IOHERE:
   1157 		do_open = 0;
   1158 		/* herein() returns -2 if error has been printed */
   1159 		u = herein(iop->heredoc, iop->flag & IOEVAL);
   1160 		/* cp may have wrong name */
   1161 		break;
   1162 
   1163 	case IODUP: {
   1164 		const char *emsg;
   1165 
   1166 		do_open = 0;
   1167 		if (*cp == '-' && !cp[1]) {
   1168 			u = 1009;	 /* prevent error return below */
   1169 			do_close = 1;
   1170 		} else if ((u = check_fd(cp,
   1171 		    X_OK | ((iop->flag & IORDUP) ? R_OK : W_OK),
   1172 		    &emsg)) < 0) {
   1173 			warningf(true, "%s: %s",
   1174 			    snptreef(NULL, 32, "%R", &iotmp), emsg);
   1175 			return (-1);
   1176 		}
   1177 		if (u == iop->unit)
   1178 			return (0);		/* "dup from" == "dup to" */
   1179 		break;
   1180 	}
   1181 	}
   1182 
   1183 	if (do_open) {
   1184 		if (Flag(FRESTRICTED) && (flags & O_CREAT)) {
   1185 			warningf(true, "%s: restricted", cp);
   1186 			return (-1);
   1187 		}
   1188 		u = open(cp, flags, 0666);
   1189 	}
   1190 	if (u < 0) {
   1191 		/* herein() may already have printed message */
   1192 		if (u == -1) {
   1193 			u = errno;
   1194 			warningf(true, "cannot %s %s: %s",
   1195 			    iotype == IODUP ? "dup" :
   1196 			    (iotype == IOREAD || iotype == IOHERE) ?
   1197 			    "open" : "create", cp, strerror(u));
   1198 		}
   1199 		return (-1);
   1200 	}
   1201 	/* Do not save if it has already been redirected (i.e. "cat >x >y"). */
   1202 	if (e->savefd[iop->unit] == 0) {
   1203 		/* If these are the same, it means unit was previously closed */
   1204 		if (u == iop->unit)
   1205 			e->savefd[iop->unit] = -1;
   1206 		else
   1207 			/* c_exec() assumes e->savefd[fd] set for any
   1208 			 * redirections. Ask savefd() not to close iop->unit;
   1209 			 * this allows error messages to be seen if iop->unit
   1210 			 * is 2; also means we can't lose the fd (eg, both
   1211 			 * dup2 below and dup2 in restfd() failing).
   1212 			 */
   1213 			e->savefd[iop->unit] = savefd(iop->unit);
   1214 	}
   1215 
   1216 	if (do_close)
   1217 		close(iop->unit);
   1218 	else if (u != iop->unit) {
   1219 		if (ksh_dup2(u, iop->unit, true) < 0) {
   1220 			int ev;
   1221 
   1222 			ev = errno;
   1223 			warningf(true,
   1224 			    "could not finish (dup) redirection %s: %s",
   1225 			    snptreef(NULL, 32, "%R", &iotmp),
   1226 			    strerror(ev));
   1227 			if (iotype != IODUP)
   1228 				close(u);
   1229 			return (-1);
   1230 		}
   1231 		if (iotype != IODUP)
   1232 			close(u);
   1233 		/* Touching any co-process fd in an empty exec
   1234 		 * causes the shell to close its copies
   1235 		 */
   1236 		else if (tp && tp->type == CSHELL && tp->val.f == c_exec) {
   1237 			if (iop->flag & IORDUP)	/* possible exec <&p */
   1238 				coproc_read_close(u);
   1239 			else			/* possible exec >&p */
   1240 				coproc_write_close(u);
   1241 		}
   1242 	}
   1243 	if (u == 2) /* Clear any write errors */
   1244 		shf_reopen(2, SHF_WR, shl_out);
   1245 	return (0);
   1246 }
   1247 
   1248 /*
   1249  * open here document temp file.
   1250  * if unquoted here, expand here temp file into second temp file.
   1251  */
   1252 static int
   1253 herein(const char *content, int sub)
   1254 {
   1255 	volatile int fd = -1;
   1256 	struct source *s, *volatile osource;
   1257 	struct shf *volatile shf;
   1258 	struct temp *h;
   1259 	int i;
   1260 
   1261 	/* ksh -c 'cat << EOF' can cause this... */
   1262 	if (content == NULL) {
   1263 		warningf(true, "here document missing");
   1264 		return (-2); /* special to iosetup(): don't print error */
   1265 	}
   1266 
   1267 	/* Create temp file to hold content (done before newenv so temp
   1268 	 * doesn't get removed too soon).
   1269 	 */
   1270 	h = maketemp(ATEMP, TT_HEREDOC_EXP, &e->temps);
   1271 	if (!(shf = h->shf) || (fd = open(h->name, O_RDONLY, 0)) < 0) {
   1272 		fd = errno;
   1273 		warningf(true, "can't %s temporary file %s: %s",
   1274 		    !shf ? "create" : "open",
   1275 		    h->name, strerror(fd));
   1276 		if (shf)
   1277 			shf_close(shf);
   1278 		return (-2 /* special to iosetup(): don't print error */);
   1279 	}
   1280 
   1281 	osource = source;
   1282 	newenv(E_ERRH);
   1283 	i = sigsetjmp(e->jbuf, 0);
   1284 	if (i) {
   1285 		source = osource;
   1286 		quitenv(shf);
   1287 		close(fd);
   1288 		return (-2); /* special to iosetup(): don't print error */
   1289 	}
   1290 	if (sub) {
   1291 		/* Do substitutions on the content of heredoc */
   1292 		s = pushs(SSTRING, ATEMP);
   1293 		s->start = s->str = content;
   1294 		source = s;
   1295 		if (yylex(ONEWORD|HEREDOC) != LWORD)
   1296 			internal_errorf("herein: yylex");
   1297 		source = osource;
   1298 		shf_puts(evalstr(yylval.cp, 0), shf);
   1299 	} else
   1300 		shf_puts(content, shf);
   1301 
   1302 	quitenv(NULL);
   1303 
   1304 	if (shf_close(shf) == EOF) {
   1305 		i = errno;
   1306 		close(fd);
   1307 		fd = errno;
   1308 		warningf(true, "error writing %s: %s, %s", h->name,
   1309 		    strerror(i), strerror(fd));
   1310 		return (-2);	/* special to iosetup(): don't print error */
   1311 	}
   1312 
   1313 	return (fd);
   1314 }
   1315 
   1316 /*
   1317  *	ksh special - the select command processing section
   1318  *	print the args in column form - assuming that we can
   1319  */
   1320 static const char *
   1321 do_selectargs(const char **ap, bool print_menu)
   1322 {
   1323 	static const char *read_args[] = {
   1324 		"read", "-r", "REPLY", NULL
   1325 	};
   1326 	char *s;
   1327 	int i, argct;
   1328 
   1329 	for (argct = 0; ap[argct]; argct++)
   1330 		;
   1331 	while (1) {
   1332 		/* Menu is printed if
   1333 		 *	- this is the first time around the select loop
   1334 		 *	- the user enters a blank line
   1335 		 *	- the REPLY parameter is empty
   1336 		 */
   1337 		if (print_menu || !*str_val(global("REPLY")))
   1338 			pr_menu(ap);
   1339 		shellf("%s", str_val(global("PS3")));
   1340 		if (call_builtin(findcom("read", FC_BI), read_args))
   1341 			return (NULL);
   1342 		s = str_val(global("REPLY"));
   1343 		if (*s) {
   1344 			getn(s, &i);
   1345 			return ((i >= 1 && i <= argct) ? ap[i - 1] : null);
   1346 		}
   1347 		print_menu = 1;
   1348 	}
   1349 }
   1350 
   1351 struct select_menu_info {
   1352 	const char * const *args;
   1353 	int num_width;
   1354 };
   1355 
   1356 static char *select_fmt_entry(char *, int, int, const void *);
   1357 
   1358 /* format a single select menu item */
   1359 static char *
   1360 select_fmt_entry(char *buf, int buflen, int i, const void *arg)
   1361 {
   1362 	const struct select_menu_info *smi =
   1363 	    (const struct select_menu_info *)arg;
   1364 
   1365 	shf_snprintf(buf, buflen, "%*d) %s",
   1366 	    smi->num_width, i + 1, smi->args[i]);
   1367 	return (buf);
   1368 }
   1369 
   1370 /*
   1371  *	print a select style menu
   1372  */
   1373 int
   1374 pr_menu(const char * const *ap)
   1375 {
   1376 	struct select_menu_info smi;
   1377 	const char * const *pp;
   1378 	int acols = 0, aocts = 0, i, n;
   1379 
   1380 	/*
   1381 	 * width/column calculations were done once and saved, but this
   1382 	 * means select can't be used recursively so we re-calculate
   1383 	 * each time (could save in a structure that is returned, but
   1384 	 * it's probably not worth the bother)
   1385 	 */
   1386 
   1387 	/*
   1388 	 * get dimensions of the list
   1389 	 */
   1390 	for (n = 0, pp = ap; *pp; n++, pp++) {
   1391 		i = strlen(*pp);
   1392 		if (i > aocts)
   1393 			aocts = i;
   1394 		i = utf_mbswidth(*pp);
   1395 		if (i > acols)
   1396 			acols = i;
   1397 	}
   1398 
   1399 	/*
   1400 	 * we will print an index of the form "%d) " in front of
   1401 	 * each entry, so get the maximum width of this
   1402 	 */
   1403 	for (i = n, smi.num_width = 1; i >= 10; i /= 10)
   1404 		smi.num_width++;
   1405 
   1406 	smi.args = ap;
   1407 	print_columns(shl_out, n, select_fmt_entry, (void *)&smi,
   1408 	    smi.num_width + 2 + aocts, smi.num_width + 2 + acols,
   1409 	    true);
   1410 
   1411 	return (n);
   1412 }
   1413 
   1414 /* XXX: horrible kludge to fit within the framework */
   1415 static char *plain_fmt_entry(char *, int, int, const void *);
   1416 
   1417 static char *
   1418 plain_fmt_entry(char *buf, int buflen, int i, const void *arg)
   1419 {
   1420 	shf_snprintf(buf, buflen, "%s", ((const char * const *)arg)[i]);
   1421 	return (buf);
   1422 }
   1423 
   1424 int
   1425 pr_list(char * const *ap)
   1426 {
   1427 	int acols = 0, aocts = 0, i, n;
   1428 	char * const *pp;
   1429 
   1430 	for (n = 0, pp = ap; *pp; n++, pp++) {
   1431 		i = strlen(*pp);
   1432 		if (i > aocts)
   1433 			aocts = i;
   1434 		i = utf_mbswidth(*pp);
   1435 		if (i > acols)
   1436 			acols = i;
   1437 	}
   1438 
   1439 	print_columns(shl_out, n, plain_fmt_entry, (const void *)ap,
   1440 	    aocts, acols, false);
   1441 
   1442 	return (n);
   1443 }
   1444 
   1445 /*
   1446  *	[[ ... ]] evaluation routines
   1447  */
   1448 
   1449 /*
   1450  * Test if the current token is a whatever. Accepts the current token if
   1451  * it is. Returns 0 if it is not, non-zero if it is (in the case of
   1452  * TM_UNOP and TM_BINOP, the returned value is a Test_op).
   1453  */
   1454 static Test_op
   1455 dbteste_isa(Test_env *te, Test_meta meta)
   1456 {
   1457 	Test_op ret = TO_NONOP;
   1458 	int uqword;
   1459 	const char *p;
   1460 
   1461 	if (!*te->pos.wp)
   1462 		return (meta == TM_END ? TO_NONNULL : TO_NONOP);
   1463 
   1464 	/* unquoted word? */
   1465 	for (p = *te->pos.wp; *p == CHAR; p += 2)
   1466 		;
   1467 	uqword = *p == EOS;
   1468 
   1469 	if (meta == TM_UNOP || meta == TM_BINOP) {
   1470 		if (uqword) {
   1471 			char buf[8];	/* longer than the longest operator */
   1472 			char *q = buf;
   1473 			for (p = *te->pos.wp;
   1474 			    *p == CHAR && q < &buf[sizeof(buf) - 1]; p += 2)
   1475 				*q++ = p[1];
   1476 			*q = '\0';
   1477 			ret = test_isop(meta, buf);
   1478 		}
   1479 	} else if (meta == TM_END)
   1480 		ret = TO_NONOP;
   1481 	else
   1482 		ret = (uqword && !strcmp(*te->pos.wp,
   1483 		    dbtest_tokens[(int)meta])) ? TO_NONNULL : TO_NONOP;
   1484 
   1485 	/* Accept the token? */
   1486 	if (ret != TO_NONOP)
   1487 		te->pos.wp++;
   1488 
   1489 	return (ret);
   1490 }
   1491 
   1492 static const char *
   1493 dbteste_getopnd(Test_env *te, Test_op op, bool do_eval)
   1494 {
   1495 	const char *s = *te->pos.wp;
   1496 
   1497 	if (!s)
   1498 		return (NULL);
   1499 
   1500 	te->pos.wp++;
   1501 
   1502 	if (!do_eval)
   1503 		return (null);
   1504 
   1505 	if (op == TO_STEQL || op == TO_STNEQ)
   1506 		s = evalstr(s, DOTILDE | DOPAT);
   1507 	else
   1508 		s = evalstr(s, DOTILDE);
   1509 
   1510 	return (s);
   1511 }
   1512 
   1513 static void
   1514 dbteste_error(Test_env *te, int offset, const char *msg)
   1515 {
   1516 	te->flags |= TEF_ERROR;
   1517 	internal_warningf("dbteste_error: %s (offset %d)", msg, offset);
   1518 }
   1519