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      1 /*	$OpenBSD: main.c,v 1.51 2012/09/10 01:25:30 tedu Exp $	*/
      2 /*	$OpenBSD: tty.c,v 1.9 2006/03/14 22:08:01 deraadt Exp $	*/
      3 /*	$OpenBSD: io.c,v 1.22 2006/03/17 16:30:13 millert Exp $	*/
      4 /*	$OpenBSD: table.c,v 1.15 2012/02/19 07:52:30 otto Exp $	*/
      5 
      6 /*-
      7  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
      8  *		 2011, 2012, 2013
      9  *	Thorsten Glaser <tg (at) mirbsd.org>
     10  *
     11  * Provided that these terms and disclaimer and all copyright notices
     12  * are retained or reproduced in an accompanying document, permission
     13  * is granted to deal in this work without restriction, including un-
     14  * limited rights to use, publicly perform, distribute, sell, modify,
     15  * merge, give away, or sublicence.
     16  *
     17  * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
     18  * the utmost extent permitted by applicable law, neither express nor
     19  * implied; without malicious intent or gross negligence. In no event
     20  * may a licensor, author or contributor be held liable for indirect,
     21  * direct, other damage, loss, or other issues arising in any way out
     22  * of dealing in the work, even if advised of the possibility of such
     23  * damage or existence of a defect, except proven that it results out
     24  * of said person's immediate fault when using the work as intended.
     25  */
     26 
     27 #define EXTERN
     28 #include "sh.h"
     29 
     30 #if HAVE_LANGINFO_CODESET
     31 #include <langinfo.h>
     32 #endif
     33 #if HAVE_SETLOCALE_CTYPE
     34 #include <locale.h>
     35 #endif
     36 
     37 __RCSID("$MirOS: src/bin/mksh/main.c,v 1.260 2013/02/10 21:42:16 tg Exp $");
     38 
     39 extern char **environ;
     40 
     41 #ifndef MKSHRC_PATH
     42 #define MKSHRC_PATH	"~/.mkshrc"
     43 #endif
     44 
     45 #ifndef MKSH_DEFAULT_TMPDIR
     46 #define MKSH_DEFAULT_TMPDIR	"/tmp"
     47 #endif
     48 
     49 static uint8_t isuc(const char *);
     50 static int main_init(int, const char *[], Source **, struct block **);
     51 void chvt_reinit(void);
     52 static void reclaim(void);
     53 static void remove_temps(struct temp *);
     54 static mksh_uari_t rndsetup(void);
     55 #ifdef SIGWINCH
     56 static void x_sigwinch(int);
     57 #endif
     58 
     59 static const char initifs[] = "IFS= \t\n";
     60 
     61 static const char initsubs[] =
     62     "${PS2=> } ${PS3=#? } ${PS4=+ } ${SECONDS=0} ${TMOUT=0} ${EPOCHREALTIME=}";
     63 
     64 static const char *initcoms[] = {
     65 	Ttypeset, "-r", initvsn, NULL,
     66 	Ttypeset, "-x", "HOME", "PATH", "RANDOM", "SHELL", NULL,
     67 	Ttypeset, "-i10", "COLUMNS", "LINES", "SECONDS", "TMOUT", NULL,
     68 	Talias,
     69 	"integer=typeset -i",
     70 	Tlocal_typeset,
     71 	/* not "alias -t --": hash -r needs to work */
     72 	"hash=alias -t",
     73 	"type=whence -v",
     74 #if !defined(ANDROID) && !defined(MKSH_UNEMPLOYED)
     75 	/* not in Android for political reasons */
     76 	/* not in ARGE mksh due to no job control */
     77 	"stop=kill -STOP",
     78 	"suspend=kill -STOP $$",
     79 #endif
     80 	"autoload=typeset -fu",
     81 	"functions=typeset -f",
     82 	"history=fc -l",
     83 	"nameref=typeset -n",
     84 	"nohup=nohup ",
     85 	Tr_fc_e_dash,
     86 	"source=PATH=$PATH:. command .",
     87 	"login=exec login",
     88 	NULL,
     89 	 /* this is what AT&T ksh seems to track, with the addition of emacs */
     90 	Talias, "-tU",
     91 	"cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
     92 	"make", "mv", "pr", "rm", "sed", "sh", "vi", "who", NULL,
     93 	NULL
     94 };
     95 
     96 static const char *restr_com[] = {
     97 	Ttypeset, "-r", "PATH", "ENV", "SHELL", NULL
     98 };
     99 
    100 static bool initio_done;
    101 
    102 /* top-level parsing and execution environment */
    103 static struct env env;
    104 struct env *e = &env;
    105 
    106 static mksh_uari_t
    107 rndsetup(void)
    108 {
    109 	register uint32_t h;
    110 	struct {
    111 		ALLOC_ITEM alloc_INT;
    112 		void *dataptr, *stkptr, *mallocptr;
    113 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
    114 		sigjmp_buf jbuf;
    115 #endif
    116 		struct timeval tv;
    117 	} *bufptr;
    118 	char *cp;
    119 
    120 	cp = alloc(sizeof(*bufptr) - ALLOC_SIZE, APERM);
    121 #ifdef DEBUG
    122 	/* clear the allocated space, for valgrind */
    123 	memset(cp, 0, sizeof(*bufptr) - ALLOC_SIZE);
    124 #endif
    125 	/* undo what alloc() did to the malloc result address */
    126 	bufptr = (void *)(cp - ALLOC_SIZE);
    127 	/* PIE or something similar provides us with deltas here */
    128 	bufptr->dataptr = &rndsetupstate;
    129 	/* ASLR in at least Windows, Linux, some BSDs */
    130 	bufptr->stkptr = &bufptr;
    131 	/* randomised malloc in BSD (and possibly others) */
    132 	bufptr->mallocptr = bufptr;
    133 #if defined(__GLIBC__) && (__GLIBC__ >= 2)
    134 	/* glibc pointer guard */
    135 	sigsetjmp(bufptr->jbuf, 1);
    136 #endif
    137 	/* introduce variation (and yes, second arg MBZ for portability) */
    138 	mksh_TIME(bufptr->tv);
    139 
    140 	NZATInit(h);
    141 	/* variation through pid, ppid, and the works */
    142 	NZATUpdateMem(h, &rndsetupstate, sizeof(rndsetupstate));
    143 	/* some variation, some possibly entropy, depending on OE */
    144 	NZATUpdateMem(h, bufptr, sizeof(*bufptr));
    145 	NZAATFinish(h);
    146 
    147 	afree(cp, APERM);
    148 	return ((mksh_uari_t)h);
    149 }
    150 
    151 void
    152 chvt_reinit(void)
    153 {
    154 	kshpid = procpid = getpid();
    155 	ksheuid = geteuid();
    156 	kshpgrp = getpgrp();
    157 	kshppid = getppid();
    158 }
    159 
    160 static const char *empty_argv[] = {
    161 	"mksh", NULL
    162 };
    163 
    164 static uint8_t
    165 isuc(const char *cx) {
    166 	char *cp, *x;
    167 	uint8_t rv = 0;
    168 
    169 	if (!cx || !*cx)
    170 		return (0);
    171 
    172 	/* uppercase a string duplicate */
    173 	strdupx(x, cx, ATEMP);
    174 	cp = x;
    175 	while ((*cp = ksh_toupper(*cp)))
    176 		++cp;
    177 
    178 	/* check for UTF-8 */
    179 	if (strstr(x, "UTF-8") || strstr(x, "UTF8"))
    180 		rv = 1;
    181 
    182 	/* free copy and out */
    183 	afree(x, ATEMP);
    184 	return (rv);
    185 }
    186 
    187 static int
    188 main_init(int argc, const char *argv[], Source **sp, struct block **lp)
    189 {
    190 	int argi, i;
    191 	Source *s = NULL;
    192 	struct block *l;
    193 	unsigned char restricted, errexit, utf_flag;
    194 	char *cp;
    195 	const char *ccp, **wp;
    196 	struct tbl *vp;
    197 	struct stat s_stdin;
    198 #if !defined(_PATH_DEFPATH) && defined(_CS_PATH)
    199 	ssize_t k;
    200 #endif
    201 
    202 	/* do things like getpgrp() et al. */
    203 	chvt_reinit();
    204 
    205 	/* make sure argv[] is sane */
    206 	if (!*argv) {
    207 		argv = empty_argv;
    208 		argc = 1;
    209 	}
    210 	kshname = argv[0];
    211 
    212 	/* initialise permanent Area */
    213 	ainit(&aperm);
    214 
    215 	/* set up base environment */
    216 	env.type = E_NONE;
    217 	ainit(&env.area);
    218 	/* set up global l->vars and l->funs */
    219 	newblock();
    220 
    221 	/* Do this first so output routines (eg, errorf, shellf) can work */
    222 	initio();
    223 
    224 	/* determine the basename (without '-' or path) of the executable */
    225 	ccp = kshname;
    226 	goto begin_parse_kshname;
    227 	while ((i = ccp[argi++])) {
    228 		if (i == '/') {
    229 			ccp += argi;
    230  begin_parse_kshname:
    231 			argi = 0;
    232 			if (*ccp == '-')
    233 				++ccp;
    234 		}
    235 	}
    236 	if (!*ccp)
    237 		ccp = empty_argv[0];
    238 
    239 	/* define built-in commands and see if we were called as one */
    240 	ktinit(APERM, &builtins,
    241 	    /* currently up to 50 builtins: 75% of 128 = 2^7 */
    242 	    7);
    243 	for (i = 0; mkshbuiltins[i].name != NULL; i++)
    244 		if (!strcmp(ccp, builtin(mkshbuiltins[i].name,
    245 		    mkshbuiltins[i].func)))
    246 			Flag(FAS_BUILTIN) = 1;
    247 
    248 	if (!Flag(FAS_BUILTIN)) {
    249 		/* check for -T option early */
    250 		argi = parse_args(argv, OF_FIRSTTIME, NULL);
    251 		if (argi < 0)
    252 			return (1);
    253 
    254 #ifdef MKSH_BINSHREDUCED
    255 		/* set FSH if we're called as -sh or /bin/sh or so */
    256 		if (!strcmp(ccp, "sh"))
    257 			change_flag(FSH, OF_FIRSTTIME, true);
    258 #endif
    259 	}
    260 
    261 	initvar();
    262 
    263 	initctypes();
    264 
    265 	inittraps();
    266 
    267 	coproc_init();
    268 
    269 	/* set up variable and command dictionaries */
    270 	ktinit(APERM, &taliases, 0);
    271 	ktinit(APERM, &aliases, 0);
    272 #ifndef MKSH_NOPWNAM
    273 	ktinit(APERM, &homedirs, 0);
    274 #endif
    275 
    276 	/* define shell keywords */
    277 	initkeywords();
    278 
    279 	init_histvec();
    280 
    281 	/* initialise tty size before importing environment */
    282 	change_winsz();
    283 
    284 #ifdef _PATH_DEFPATH
    285 	def_path = _PATH_DEFPATH;
    286 #else
    287 #ifdef _CS_PATH
    288 	if ((k = confstr(_CS_PATH, NULL, 0)) > 0 &&
    289 	    confstr(_CS_PATH, cp = alloc(k + 1, APERM), k + 1) == k + 1)
    290 		def_path = cp;
    291 	else
    292 #endif
    293 		/*
    294 		 * this is uniform across all OSes unless it
    295 		 * breaks somewhere; don't try to optimise,
    296 		 * e.g. add stuff for Interix or remove /usr
    297 		 * for HURD, because e.g. Debian GNU/HURD is
    298 		 * "keeping a regular /usr"; this is supposed
    299 		 * to be a sane 'basic' default PATH
    300 		 */
    301 		def_path = "/bin:/usr/bin:/sbin:/usr/sbin";
    302 #endif
    303 
    304 	/*
    305 	 * Set PATH to def_path (will set the path global variable).
    306 	 * (import of environment below will probably change this setting).
    307 	 */
    308 	vp = global("PATH");
    309 	/* setstr can't fail here */
    310 	setstr(vp, def_path, KSH_RETURN_ERROR);
    311 
    312 	/*
    313 	 * Turn on nohup by default for now - will change to off
    314 	 * by default once people are aware of its existence
    315 	 * (AT&T ksh does not have a nohup option - it always sends
    316 	 * the hup).
    317 	 */
    318 	Flag(FNOHUP) = 1;
    319 
    320 	/*
    321 	 * Turn on brace expansion by default. AT&T kshs that have
    322 	 * alternation always have it on.
    323 	 */
    324 	Flag(FBRACEEXPAND) = 1;
    325 
    326 #ifndef MKSH_NO_CMDLINE_EDITING
    327 	/*
    328 	 * Set edit mode to emacs by default, may be overridden
    329 	 * by the environment or the user. Also, we want tab completion
    330 	 * on in vi by default.
    331 	 */
    332 	change_flag(FEMACS, OF_SPECIAL, true);
    333 #if !MKSH_S_NOVI
    334 	Flag(FVITABCOMPLETE) = 1;
    335 #endif
    336 #endif
    337 
    338 	/* import environment */
    339 	if (environ != NULL)
    340 		for (wp = (const char **)environ; *wp != NULL; wp++)
    341 			typeset(*wp, IMPORT | EXPORT, 0, 0, 0);
    342 
    343 	/* for security */
    344 	typeset(initifs, 0, 0, 0, 0);
    345 
    346 	/* assign default shell variable values */
    347 	substitute(initsubs, 0);
    348 
    349 	/* Figure out the current working directory and set $PWD */
    350 	vp = global("PWD");
    351 	cp = str_val(vp);
    352 	/* Try to use existing $PWD if it is valid */
    353 	set_current_wd((cp[0] == '/' && test_eval(NULL, TO_FILEQ, cp, ".",
    354 	    true)) ? cp : NULL);
    355 	if (current_wd[0])
    356 		simplify_path(current_wd);
    357 	/* Only set pwd if we know where we are or if it had a bogus value */
    358 	if (current_wd[0] || *cp)
    359 		/* setstr can't fail here */
    360 		setstr(vp, current_wd, KSH_RETURN_ERROR);
    361 
    362 	for (wp = initcoms; *wp != NULL; wp++) {
    363 		shcomexec(wp);
    364 		while (*wp != NULL)
    365 			wp++;
    366 	}
    367 	setint_n(global("OPTIND"), 1, 10);
    368 
    369 	kshuid = getuid();
    370 	kshgid = getgid();
    371 	kshegid = getegid();
    372 
    373 	safe_prompt = ksheuid ? "$ " : "# ";
    374 	vp = global("PS1");
    375 	/* Set PS1 if unset or we are root and prompt doesn't contain a # */
    376 	if (!(vp->flag & ISSET) ||
    377 	    (!ksheuid && !strchr(str_val(vp), '#')))
    378 		/* setstr can't fail here */
    379 		setstr(vp, safe_prompt, KSH_RETURN_ERROR);
    380 	setint_n((vp = global("BASHPID")), 0, 10);
    381 	vp->flag |= INT_U;
    382 	setint_n((vp = global("PGRP")), (mksh_uari_t)kshpgrp, 10);
    383 	vp->flag |= INT_U;
    384 	setint_n((vp = global("PPID")), (mksh_uari_t)kshppid, 10);
    385 	vp->flag |= INT_U;
    386 	setint_n((vp = global("USER_ID")), (mksh_uari_t)ksheuid, 10);
    387 	vp->flag |= INT_U;
    388 	setint_n((vp = global("KSHUID")), (mksh_uari_t)kshuid, 10);
    389 	vp->flag |= INT_U;
    390 	setint_n((vp = global("KSHEGID")), (mksh_uari_t)kshegid, 10);
    391 	vp->flag |= INT_U;
    392 	setint_n((vp = global("KSHGID")), (mksh_uari_t)kshgid, 10);
    393 	vp->flag |= INT_U;
    394 	setint_n((vp = global("RANDOM")), rndsetup(), 10);
    395 	vp->flag |= INT_U;
    396 	setint_n((vp_pipest = global("PIPESTATUS")), 0, 10);
    397 
    398 	/* Set this before parsing arguments */
    399 	Flag(FPRIVILEGED) = kshuid != ksheuid || kshgid != kshegid;
    400 
    401 	/* this to note if monitor is set on command line (see below) */
    402 #ifndef MKSH_UNEMPLOYED
    403 	Flag(FMONITOR) = 127;
    404 #endif
    405 	/* this to note if utf-8 mode is set on command line (see below) */
    406 	UTFMODE = 2;
    407 
    408 	if (!Flag(FAS_BUILTIN)) {
    409 		argi = parse_args(argv, OF_CMDLINE, NULL);
    410 		if (argi < 0)
    411 			return (1);
    412 	}
    413 
    414 #ifdef DEBUG
    415 	/* test wraparound of arithmetic types */
    416 	{
    417 		volatile long xl;
    418 		volatile unsigned long xul;
    419 		volatile int xi;
    420 		volatile unsigned int xui;
    421 		volatile mksh_ari_t xa;
    422 		volatile mksh_uari_t xua, xua2;
    423 		volatile uint8_t xc;
    424 
    425 		xa = 2147483647;
    426 		xua = 2147483647;
    427 		++xa;
    428 		++xua;
    429 		xua2 = xa;
    430 		xl = xa;
    431 		xul = xua;
    432 		xa = 0;
    433 		xua = 0;
    434 		--xa;
    435 		--xua;
    436 		xi = xa;
    437 		xui = xua;
    438 		xa = -1;
    439 		xua = xa;
    440 		++xa;
    441 		++xua;
    442 		xc = 0;
    443 		--xc;
    444 		if ((xua2 != 2147483648UL) ||
    445 		    (xl != -2147483648L) || (xul != 2147483648UL) ||
    446 		    (xi != -1) || (xui != 4294967295U) ||
    447 		    (xa != 0) || (xua != 0) || (xc != 255))
    448 			errorf("integer wraparound test failed");
    449 	}
    450 #endif
    451 
    452 	/* process this later only, default to off (hysterical raisins) */
    453 	utf_flag = UTFMODE;
    454 	UTFMODE = 0;
    455 
    456 	if (Flag(FAS_BUILTIN)) {
    457 		/* auto-detect from environment variables, always */
    458 		utf_flag = 3;
    459 	} else if (Flag(FCOMMAND)) {
    460 		s = pushs(SSTRINGCMDLINE, ATEMP);
    461 		if (!(s->start = s->str = argv[argi++]))
    462 			errorf("%s %s", "-c", "requires an argument");
    463 #if !defined(MKSH_SMALL)
    464 		while (*s->str) {
    465 			if (*s->str != ' ' && ctype(*s->str, C_QUOTE))
    466 				break;
    467 			s->str++;
    468 		}
    469 		if (!*s->str)
    470 			s->flags |= SF_MAYEXEC;
    471 		s->str = s->start;
    472 #endif
    473 #ifdef MKSH_MIDNIGHTBSD01ASH_COMPAT
    474 		/* compatibility to MidnightBSD 0.1 /bin/sh (kludge) */
    475 		if (Flag(FSH) && argv[argi] && !strcmp(argv[argi], "--"))
    476 			++argi;
    477 #endif
    478 		if (argv[argi])
    479 			kshname = argv[argi++];
    480 	} else if (argi < argc && !Flag(FSTDIN)) {
    481 		s = pushs(SFILE, ATEMP);
    482 		s->file = argv[argi++];
    483 		s->u.shf = shf_open(s->file, O_RDONLY, 0,
    484 		    SHF_MAPHI | SHF_CLEXEC);
    485 		if (s->u.shf == NULL) {
    486 			shl_stdout_ok = false;
    487 			warningf(true, "%s: %s", s->file, cstrerror(errno));
    488 			/* mandated by SUSv4 */
    489 			exstat = 127;
    490 			unwind(LERROR);
    491 		}
    492 		kshname = s->file;
    493 	} else {
    494 		Flag(FSTDIN) = 1;
    495 		s = pushs(SSTDIN, ATEMP);
    496 		s->file = "<stdin>";
    497 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
    498 		    NULL);
    499 		if (isatty(0) && isatty(2)) {
    500 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
    501 			/* The following only if isatty(0) */
    502 			s->flags |= SF_TTY;
    503 			s->u.shf->flags |= SHF_INTERRUPT;
    504 			s->file = NULL;
    505 		}
    506 	}
    507 
    508 	/* this bizarreness is mandated by POSIX */
    509 	if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
    510 	    Flag(FTALKING))
    511 		reset_nonblock(0);
    512 
    513 	/* initialise job control */
    514 	j_init();
    515 	/* do this after j_init() which calls tty_init_state() */
    516 	if (Flag(FTALKING)) {
    517 		if (utf_flag == 2) {
    518 #ifndef MKSH_ASSUME_UTF8
    519 			/* auto-detect from locale or environment */
    520 			utf_flag = 4;
    521 #elif MKSH_ASSUME_UTF8
    522 			utf_flag = 1;
    523 #else
    524 			/* always disable UTF-8 (for interactive) */
    525 			utf_flag = 0;
    526 #endif
    527 		}
    528 #ifndef MKSH_NO_CMDLINE_EDITING
    529 		x_init();
    530 #endif
    531 	}
    532 
    533 #ifdef SIGWINCH
    534 	sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
    535 	setsig(&sigtraps[SIGWINCH], x_sigwinch,
    536 	    SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
    537 #endif
    538 
    539 	l = e->loc;
    540 	if (Flag(FAS_BUILTIN)) {
    541 		l->argc = argc;
    542 		l->argv = argv;
    543 		l->argv[0] = ccp;
    544 	} else {
    545 		l->argc = argc - argi;
    546 		/*
    547 		 * allocate a new array because otherwise, when we modify
    548 		 * it in-place, ps(1) output changes; the meaning of argc
    549 		 * here is slightly different as it excludes kshname, and
    550 		 * we add a trailing NULL sentinel as well
    551 		 */
    552 		l->argv = alloc2(l->argc + 2, sizeof(void *), APERM);
    553 		l->argv[0] = kshname;
    554 		memcpy(&l->argv[1], &argv[argi], l->argc * sizeof(void *));
    555 		l->argv[l->argc + 1] = NULL;
    556 		getopts_reset(1);
    557 	}
    558 
    559 	/* divine the initial state of the utf8-mode Flag */
    560 	ccp = null;
    561 	switch (utf_flag) {
    562 
    563 	/* auto-detect from locale or environment */
    564 	case 4:
    565 #if HAVE_SETLOCALE_CTYPE
    566 		ccp = setlocale(LC_CTYPE, "");
    567 #if HAVE_LANGINFO_CODESET
    568 		if (!isuc(ccp))
    569 			ccp = nl_langinfo(CODESET);
    570 #endif
    571 		if (!isuc(ccp))
    572 			ccp = null;
    573 		/* FALLTHROUGH */
    574 #endif
    575 
    576 	/* auto-detect from environment */
    577 	case 3:
    578 		/* these were imported from environ earlier */
    579 		if (ccp == null)
    580 			ccp = str_val(global("LC_ALL"));
    581 		if (ccp == null)
    582 			ccp = str_val(global("LC_CTYPE"));
    583 		if (ccp == null)
    584 			ccp = str_val(global("LANG"));
    585 		UTFMODE = isuc(ccp);
    586 		break;
    587 
    588 	/* not set on command line, not FTALKING */
    589 	case 2:
    590 	/* unknown values */
    591 	default:
    592 		utf_flag = 0;
    593 		/* FALLTHROUGH */
    594 
    595 	/* known values */
    596 	case 1:
    597 	case 0:
    598 		UTFMODE = utf_flag;
    599 		break;
    600 	}
    601 
    602 	/* Disable during .profile/ENV reading */
    603 	restricted = Flag(FRESTRICTED);
    604 	Flag(FRESTRICTED) = 0;
    605 	errexit = Flag(FERREXIT);
    606 	Flag(FERREXIT) = 0;
    607 
    608 	/*
    609 	 * Do this before profile/$ENV so that if it causes problems in them,
    610 	 * user will know why things broke.
    611 	 */
    612 	if (!current_wd[0] && Flag(FTALKING))
    613 		warningf(false, "can't determine current directory");
    614 
    615 	if (Flag(FLOGIN)) {
    616 		include(MKSH_SYSTEM_PROFILE, 0, NULL, true);
    617 		if (!Flag(FPRIVILEGED))
    618 			include(substitute("$HOME/.profile", 0), 0,
    619 			    NULL, true);
    620 	}
    621 	if (Flag(FPRIVILEGED))
    622 		include(MKSH_SUID_PROFILE, 0, NULL, true);
    623 	else if (Flag(FTALKING)) {
    624 		char *env_file;
    625 
    626 		/* include $ENV */
    627 		env_file = substitute(substitute("${ENV:-" MKSHRC_PATH "}", 0),
    628 		    DOTILDE);
    629 		if (*env_file != '\0')
    630 			include(env_file, 0, NULL, true);
    631 	}
    632 
    633 	if (restricted) {
    634 		shcomexec(restr_com);
    635 		/* After typeset command... */
    636 		Flag(FRESTRICTED) = 1;
    637 	}
    638 	Flag(FERREXIT) = errexit;
    639 
    640 	if (Flag(FTALKING) && s)
    641 		hist_init(s);
    642 	else
    643 		/* set after ENV */
    644 		Flag(FTRACKALL) = 1;
    645 
    646 	alarm_init();
    647 
    648 	*sp = s;
    649 	*lp = l;
    650 	return (0);
    651 }
    652 
    653 /* this indirection barrier reduces stack usage during normal operation */
    654 
    655 int
    656 main(int argc, const char *argv[])
    657 {
    658 	int rv;
    659 	Source *s;
    660 	struct block *l;
    661 
    662 	if ((rv = main_init(argc, argv, &s, &l)) == 0) {
    663 		if (Flag(FAS_BUILTIN)) {
    664 			rv = shcomexec(l->argv);
    665 		} else {
    666 			shell(s, true);
    667 			/* NOTREACHED */
    668 		}
    669 	}
    670 	return (rv);
    671 }
    672 
    673 int
    674 include(const char *name, int argc, const char **argv, bool intr_ok)
    675 {
    676 	Source *volatile s = NULL;
    677 	struct shf *shf;
    678 	const char **volatile old_argv;
    679 	volatile int old_argc;
    680 	int i;
    681 
    682 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
    683 	if (shf == NULL)
    684 		return (-1);
    685 
    686 	if (argv) {
    687 		old_argv = e->loc->argv;
    688 		old_argc = e->loc->argc;
    689 	} else {
    690 		old_argv = NULL;
    691 		old_argc = 0;
    692 	}
    693 	newenv(E_INCL);
    694 	if ((i = kshsetjmp(e->jbuf))) {
    695 		quitenv(s ? s->u.shf : NULL);
    696 		if (old_argv) {
    697 			e->loc->argv = old_argv;
    698 			e->loc->argc = old_argc;
    699 		}
    700 		switch (i) {
    701 		case LRETURN:
    702 		case LERROR:
    703 			/* see below */
    704 			return (exstat & 0xFF);
    705 		case LINTR:
    706 			/*
    707 			 * intr_ok is set if we are including .profile or $ENV.
    708 			 * If user ^Cs out, we don't want to kill the shell...
    709 			 */
    710 			if (intr_ok && ((exstat & 0xFF) - 128) != SIGTERM)
    711 				return (1);
    712 			/* FALLTHROUGH */
    713 		case LEXIT:
    714 		case LLEAVE:
    715 		case LSHELL:
    716 			unwind(i);
    717 			/* NOTREACHED */
    718 		default:
    719 			internal_errorf("%s %d", "include", i);
    720 			/* NOTREACHED */
    721 		}
    722 	}
    723 	if (argv) {
    724 		e->loc->argv = argv;
    725 		e->loc->argc = argc;
    726 	}
    727 	s = pushs(SFILE, ATEMP);
    728 	s->u.shf = shf;
    729 	strdupx(s->file, name, ATEMP);
    730 	i = shell(s, false);
    731 	quitenv(s->u.shf);
    732 	if (old_argv) {
    733 		e->loc->argv = old_argv;
    734 		e->loc->argc = old_argc;
    735 	}
    736 	/* & 0xff to ensure value not -1 */
    737 	return (i & 0xFF);
    738 }
    739 
    740 /* spawn a command into a shell optionally keeping track of the line number */
    741 int
    742 command(const char *comm, int line)
    743 {
    744 	Source *s;
    745 
    746 	s = pushs(SSTRING, ATEMP);
    747 	s->start = s->str = comm;
    748 	s->line = line;
    749 	return (shell(s, false));
    750 }
    751 
    752 /*
    753  * run the commands from the input source, returning status.
    754  */
    755 int
    756 shell(Source * volatile s, volatile bool toplevel)
    757 {
    758 	struct op *t;
    759 	volatile bool wastty = tobool(s->flags & SF_TTY);
    760 	volatile uint8_t attempts = 13;
    761 	volatile bool interactive = Flag(FTALKING) && toplevel;
    762 	volatile bool sfirst = true;
    763 	Source *volatile old_source = source;
    764 	int i;
    765 
    766 	newenv(E_PARSE);
    767 	if (interactive)
    768 		really_exit = false;
    769 	switch ((i = kshsetjmp(e->jbuf))) {
    770 	case 0:
    771 		break;
    772 	case LINTR:
    773 		/* we get here if SIGINT not caught or ignored */
    774 	case LERROR:
    775 	case LSHELL:
    776 		if (interactive) {
    777 			if (i == LINTR)
    778 				shellf("\n");
    779 			/*
    780 			 * Reset any eof that was read as part of a
    781 			 * multiline command.
    782 			 */
    783 			if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
    784 				s->type = SSTDIN;
    785 			/*
    786 			 * Used by exit command to get back to
    787 			 * top level shell. Kind of strange since
    788 			 * interactive is set if we are reading from
    789 			 * a tty, but to have stopped jobs, one only
    790 			 * needs FMONITOR set (not FTALKING/SF_TTY)...
    791 			 */
    792 			/* toss any input we have so far */
    793 			yyrecursive_pop(true);
    794 			s->start = s->str = null;
    795 			retrace_info = NULL;
    796 			herep = heres;
    797 			break;
    798 		}
    799 		/* FALLTHROUGH */
    800 	case LEXIT:
    801 	case LLEAVE:
    802 	case LRETURN:
    803 		source = old_source;
    804 		quitenv(NULL);
    805 		/* keep on going */
    806 		unwind(i);
    807 		/* NOTREACHED */
    808 	default:
    809 		source = old_source;
    810 		quitenv(NULL);
    811 		internal_errorf("%s %d", "shell", i);
    812 		/* NOTREACHED */
    813 	}
    814 	while (/* CONSTCOND */ 1) {
    815 		if (trap)
    816 			runtraps(0);
    817 
    818 		if (s->next == NULL) {
    819 			if (Flag(FVERBOSE))
    820 				s->flags |= SF_ECHO;
    821 			else
    822 				s->flags &= ~SF_ECHO;
    823 		}
    824 		if (interactive) {
    825 			j_notify();
    826 			set_prompt(PS1, s);
    827 		}
    828 		t = compile(s, sfirst);
    829 		sfirst = false;
    830 		if (!t)
    831 			goto source_no_tree;
    832 		if (t->type == TEOF) {
    833 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
    834 				shellf("Use 'exit' to leave mksh\n");
    835 				s->type = SSTDIN;
    836 			} else if (wastty && !really_exit &&
    837 			    j_stopped_running()) {
    838 				really_exit = true;
    839 				s->type = SSTDIN;
    840 			} else {
    841 				/*
    842 				 * this for POSIX which says EXIT traps
    843 				 * shall be taken in the environment
    844 				 * immediately after the last command
    845 				 * executed.
    846 				 */
    847 				if (toplevel)
    848 					unwind(LEXIT);
    849 				break;
    850 			}
    851 		}
    852 #if !defined(MKSH_SMALL)
    853 		  else if ((s->flags & SF_MAYEXEC) && t->type == TCOM)
    854 			t->u.evalflags |= DOTCOMEXEC;
    855 #endif
    856 		if (!Flag(FNOEXEC) || (s->flags & SF_TTY))
    857 			exstat = execute(t, 0, NULL) & 0xFF;
    858 
    859 		if (t->type != TEOF && interactive && really_exit)
    860 			really_exit = false;
    861 
    862  source_no_tree:
    863 		reclaim();
    864 	}
    865 	quitenv(NULL);
    866 	source = old_source;
    867 	return (exstat & 0xFF);
    868 }
    869 
    870 /* return to closest error handler or shell(), exit if none found */
    871 /* note: i MUST NOT be 0 */
    872 void
    873 unwind(int i)
    874 {
    875 	/*
    876 	 * This is a kludge. We need to restore everything that was
    877 	 * changed in the new environment, see cid 1005090337C7A669439
    878 	 * and 10050903386452ACBF1, but fail to even save things most of
    879 	 * the time. funcs.c:c_eval() changes FERREXIT temporarily to 0,
    880 	 * which needs to be restored thus (related to Debian #696823).
    881 	 * We did not save the shell flags, so we use a special or'd
    882 	 * value here... this is mostly to clean up behind *other*
    883 	 * callers of unwind(LERROR) here; exec.c has the regular case.
    884 	 */
    885 	if (Flag(FERREXIT) & 0x80) {
    886 		/* GNU bash does not run this trapsig */
    887 		trapsig(ksh_SIGERR);
    888 		Flag(FERREXIT) &= ~0x80;
    889 	}
    890 
    891 	/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
    892 	if (i == LEXIT ||
    893 	    ((i == LERROR || i == LINTR) && sigtraps[ksh_SIGEXIT].trap)) {
    894 		++trap_nested;
    895 		runtrap(&sigtraps[ksh_SIGEXIT], trap_nested == 1);
    896 		--trap_nested;
    897 		i = LLEAVE;
    898 	} else if (Flag(FERREXIT) == 1 && (i == LERROR || i == LINTR)) {
    899 		++trap_nested;
    900 		runtrap(&sigtraps[ksh_SIGERR], trap_nested == 1);
    901 		--trap_nested;
    902 		i = LLEAVE;
    903 	}
    904 
    905 	while (/* CONSTCOND */ 1) {
    906 		switch (e->type) {
    907 		case E_PARSE:
    908 		case E_FUNC:
    909 		case E_INCL:
    910 		case E_LOOP:
    911 		case E_ERRH:
    912 			kshlongjmp(e->jbuf, i);
    913 			/* NOTREACHED */
    914 		case E_NONE:
    915 			if (i == LINTR)
    916 				e->flags |= EF_FAKE_SIGDIE;
    917 			/* FALLTHROUGH */
    918 		default:
    919 			quitenv(NULL);
    920 		}
    921 	}
    922 }
    923 
    924 void
    925 newenv(int type)
    926 {
    927 	struct env *ep;
    928 	char *cp;
    929 
    930 	/*
    931 	 * struct env includes ALLOC_ITEM for alignment constraints
    932 	 * so first get the actually used memory, then assign it
    933 	 */
    934 	cp = alloc(sizeof(struct env) - ALLOC_SIZE, ATEMP);
    935 	/* undo what alloc() did to the malloc result address */
    936 	ep = (void *)(cp - ALLOC_SIZE);
    937 	/* initialise public members of struct env (not the ALLOC_ITEM) */
    938 	ainit(&ep->area);
    939 	ep->oenv = e;
    940 	ep->loc = e->loc;
    941 	ep->savefd = NULL;
    942 	ep->temps = NULL;
    943 	ep->yyrecursive_statep = NULL;
    944 	ep->type = type;
    945 	ep->flags = 0;
    946 	/* jump buffer is invalid because flags == 0 */
    947 	e = ep;
    948 }
    949 
    950 void
    951 quitenv(struct shf *shf)
    952 {
    953 	struct env *ep = e;
    954 	char *cp;
    955 	int fd;
    956 
    957 	yyrecursive_pop(true);
    958 	while (ep->oenv && ep->oenv->loc != ep->loc)
    959 		popblock();
    960 	if (ep->savefd != NULL) {
    961 		for (fd = 0; fd < NUFILE; fd++)
    962 			/* if ep->savefd[fd] < 0, means fd was closed */
    963 			if (ep->savefd[fd])
    964 				restfd(fd, ep->savefd[fd]);
    965 		if (ep->savefd[2])
    966 			/* Clear any write errors */
    967 			shf_reopen(2, SHF_WR, shl_out);
    968 	}
    969 	/*
    970 	 * Bottom of the stack.
    971 	 * Either main shell is exiting or cleanup_parents_env() was called.
    972 	 */
    973 	if (ep->oenv == NULL) {
    974 #ifdef DEBUG_LEAKS
    975 		int i;
    976 #endif
    977 
    978 		if (ep->type == E_NONE) {
    979 			/* Main shell exiting? */
    980 #if HAVE_PERSISTENT_HISTORY
    981 			if (Flag(FTALKING))
    982 				hist_finish();
    983 #endif
    984 			j_exit();
    985 			if (ep->flags & EF_FAKE_SIGDIE) {
    986 				int sig = (exstat & 0xFF) - 128;
    987 
    988 				/*
    989 				 * ham up our death a bit (AT&T ksh
    990 				 * only seems to do this for SIGTERM)
    991 				 * Don't do it for SIGQUIT, since we'd
    992 				 * dump a core..
    993 				 */
    994 				if ((sig == SIGINT || sig == SIGTERM) &&
    995 				    (kshpgrp == kshpid)) {
    996 					setsig(&sigtraps[sig], SIG_DFL,
    997 					    SS_RESTORE_CURR | SS_FORCE);
    998 					kill(0, sig);
    999 				}
   1000 			}
   1001 		}
   1002 		if (shf)
   1003 			shf_close(shf);
   1004 		reclaim();
   1005 #ifdef DEBUG_LEAKS
   1006 #ifndef MKSH_NO_CMDLINE_EDITING
   1007 		x_done();
   1008 #endif
   1009 		afreeall(APERM);
   1010 		for (fd = 3; fd < NUFILE; fd++)
   1011 			if ((i = fcntl(fd, F_GETFD, 0)) != -1 &&
   1012 			    (i & FD_CLOEXEC))
   1013 				close(fd);
   1014 		close(2);
   1015 		close(1);
   1016 		close(0);
   1017 #endif
   1018 		exit(exstat & 0xFF);
   1019 	}
   1020 	if (shf)
   1021 		shf_close(shf);
   1022 	reclaim();
   1023 
   1024 	e = e->oenv;
   1025 
   1026 	/* free the struct env - tricky due to the ALLOC_ITEM inside */
   1027 	cp = (void *)ep;
   1028 	afree(cp + ALLOC_SIZE, ATEMP);
   1029 }
   1030 
   1031 /* Called after a fork to cleanup stuff left over from parents environment */
   1032 void
   1033 cleanup_parents_env(void)
   1034 {
   1035 	struct env *ep;
   1036 	int fd;
   1037 
   1038 	mkssert(e != NULL);
   1039 
   1040 	/*
   1041 	 * Don't clean up temporary files - parent will probably need them.
   1042 	 * Also, can't easily reclaim memory since variables, etc. could be
   1043 	 * anywhere.
   1044 	 */
   1045 
   1046 	/* close all file descriptors hiding in savefd */
   1047 	for (ep = e; ep; ep = ep->oenv) {
   1048 		if (ep->savefd) {
   1049 			for (fd = 0; fd < NUFILE; fd++)
   1050 				if (ep->savefd[fd] > 0)
   1051 					close(ep->savefd[fd]);
   1052 			afree(ep->savefd, &ep->area);
   1053 			ep->savefd = NULL;
   1054 		}
   1055 #ifdef DEBUG_LEAKS
   1056 		if (ep->type != E_NONE)
   1057 			ep->type = E_GONE;
   1058 #endif
   1059 	}
   1060 #ifndef DEBUG_LEAKS
   1061 	e->oenv = NULL;
   1062 #endif
   1063 }
   1064 
   1065 /* Called just before an execve cleanup stuff temporary files */
   1066 void
   1067 cleanup_proc_env(void)
   1068 {
   1069 	struct env *ep;
   1070 
   1071 	for (ep = e; ep; ep = ep->oenv)
   1072 		remove_temps(ep->temps);
   1073 }
   1074 
   1075 /* remove temp files and free ATEMP Area */
   1076 static void
   1077 reclaim(void)
   1078 {
   1079 	struct block *l;
   1080 
   1081 	while ((l = e->loc) && (!e->oenv || e->oenv->loc != l)) {
   1082 		e->loc = l->next;
   1083 		afreeall(&l->area);
   1084 	}
   1085 
   1086 	remove_temps(e->temps);
   1087 	e->temps = NULL;
   1088 	afreeall(&e->area);
   1089 }
   1090 
   1091 static void
   1092 remove_temps(struct temp *tp)
   1093 {
   1094 	for (; tp != NULL; tp = tp->next)
   1095 		if (tp->pid == procpid)
   1096 			unlink(tp->tffn);
   1097 }
   1098 
   1099 /*
   1100  * Initialise tty_fd. Used for tracking the size of the terminal,
   1101  * saving/resetting tty modes upon forground job completion, and
   1102  * for setting up the tty process group. Return values:
   1103  *	0 = got controlling tty
   1104  *	1 = got terminal but no controlling tty
   1105  *	2 = cannot find a terminal
   1106  *	3 = cannot dup fd
   1107  *	4 = cannot make fd close-on-exec
   1108  * An existing tty_fd is cached if no "better" one could be found,
   1109  * i.e. if tty_devtty was already set or the new would not set it.
   1110  */
   1111 int
   1112 tty_init_fd(void)
   1113 {
   1114 	int fd, rv, eno = 0;
   1115 	bool do_close = false, is_devtty = true;
   1116 
   1117 	if (tty_devtty) {
   1118 		/* already got a tty which is /dev/tty */
   1119 		return (0);
   1120 	}
   1121 
   1122 #ifdef _UWIN
   1123 	/*XXX imake style */
   1124 	if (isatty(3)) {
   1125 		/* fd 3 on UWIN _is_ /dev/tty (or our controlling tty) */
   1126 		fd = 3;
   1127 		goto got_fd;
   1128 	}
   1129 #endif
   1130 	if ((fd = open("/dev/tty", O_RDWR, 0)) >= 0) {
   1131 		do_close = true;
   1132 		goto got_fd;
   1133 	}
   1134 	eno = errno;
   1135 
   1136 	if (tty_fd >= 0) {
   1137 		/* already got a non-devtty one */
   1138 		rv = 1;
   1139 		goto out;
   1140 	}
   1141 	is_devtty = false;
   1142 
   1143 	if (isatty((fd = 0)) || isatty((fd = 2)))
   1144 		goto got_fd;
   1145 	/* cannot find one */
   1146 	rv = 2;
   1147 	/* assert: do_close == false */
   1148 	goto out;
   1149 
   1150  got_fd:
   1151 	if ((rv = fcntl(fd, F_DUPFD, FDBASE)) < 0) {
   1152 		eno = errno;
   1153 		rv = 3;
   1154 		goto out;
   1155 	}
   1156 	if (fcntl(rv, F_SETFD, FD_CLOEXEC) < 0) {
   1157 		eno = errno;
   1158 		close(rv);
   1159 		rv = 4;
   1160 		goto out;
   1161 	}
   1162 	tty_fd = rv;
   1163 	tty_devtty = is_devtty;
   1164 	rv = eno = 0;
   1165  out:
   1166 	if (do_close)
   1167 		close(fd);
   1168 	errno = eno;
   1169 	return (rv);
   1170 }
   1171 
   1172 /* A shell error occurred (eg, syntax error, etc.) */
   1173 
   1174 #define VWARNINGF_ERRORPREFIX	1
   1175 #define VWARNINGF_FILELINE	2
   1176 #define VWARNINGF_BUILTIN	4
   1177 #define VWARNINGF_INTERNAL	8
   1178 
   1179 static void vwarningf(unsigned int, const char *, va_list)
   1180     MKSH_A_FORMAT(__printf__, 2, 0);
   1181 
   1182 static void
   1183 vwarningf(unsigned int flags, const char *fmt, va_list ap)
   1184 {
   1185 	if (fmt) {
   1186 		if (flags & VWARNINGF_INTERNAL)
   1187 			shf_fprintf(shl_out, "internal error: ");
   1188 		if (flags & VWARNINGF_ERRORPREFIX)
   1189 			error_prefix(tobool(flags & VWARNINGF_FILELINE));
   1190 		if ((flags & VWARNINGF_BUILTIN) &&
   1191 		    /* not set when main() calls parse_args() */
   1192 		    builtin_argv0 && builtin_argv0 != kshname)
   1193 			shf_fprintf(shl_out, "%s: ", builtin_argv0);
   1194 		shf_vfprintf(shl_out, fmt, ap);
   1195 		shf_putchar('\n', shl_out);
   1196 	}
   1197 	shf_flush(shl_out);
   1198 }
   1199 
   1200 void
   1201 errorfx(int rc, const char *fmt, ...)
   1202 {
   1203 	va_list va;
   1204 
   1205 	exstat = rc;
   1206 
   1207 	/* debugging: note that stdout not valid */
   1208 	shl_stdout_ok = false;
   1209 
   1210 	va_start(va, fmt);
   1211 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
   1212 	va_end(va);
   1213 	unwind(LERROR);
   1214 }
   1215 
   1216 void
   1217 errorf(const char *fmt, ...)
   1218 {
   1219 	va_list va;
   1220 
   1221 	exstat = 1;
   1222 
   1223 	/* debugging: note that stdout not valid */
   1224 	shl_stdout_ok = false;
   1225 
   1226 	va_start(va, fmt);
   1227 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
   1228 	va_end(va);
   1229 	unwind(LERROR);
   1230 }
   1231 
   1232 /* like errorf(), but no unwind is done */
   1233 void
   1234 warningf(bool fileline, const char *fmt, ...)
   1235 {
   1236 	va_list va;
   1237 
   1238 	va_start(va, fmt);
   1239 	vwarningf(VWARNINGF_ERRORPREFIX | (fileline ? VWARNINGF_FILELINE : 0),
   1240 	    fmt, va);
   1241 	va_end(va);
   1242 }
   1243 
   1244 /*
   1245  * Used by built-in utilities to prefix shell and utility name to message
   1246  * (also unwinds environments for special builtins).
   1247  */
   1248 void
   1249 bi_errorf(const char *fmt, ...)
   1250 {
   1251 	va_list va;
   1252 
   1253 	/* debugging: note that stdout not valid */
   1254 	shl_stdout_ok = false;
   1255 
   1256 	exstat = 1;
   1257 
   1258 	va_start(va, fmt);
   1259 	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE |
   1260 	    VWARNINGF_BUILTIN, fmt, va);
   1261 	va_end(va);
   1262 
   1263 	/*
   1264 	 * POSIX special builtins and ksh special builtins cause
   1265 	 * non-interactive shells to exit.
   1266 	 * XXX odd use of KEEPASN; also may not want LERROR here
   1267 	 */
   1268 	if (builtin_flag & SPEC_BI) {
   1269 		builtin_argv0 = NULL;
   1270 		unwind(LERROR);
   1271 	}
   1272 }
   1273 
   1274 /* Called when something that shouldn't happen does */
   1275 void
   1276 internal_errorf(const char *fmt, ...)
   1277 {
   1278 	va_list va;
   1279 
   1280 	va_start(va, fmt);
   1281 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
   1282 	va_end(va);
   1283 	unwind(LERROR);
   1284 }
   1285 
   1286 void
   1287 internal_warningf(const char *fmt, ...)
   1288 {
   1289 	va_list va;
   1290 
   1291 	va_start(va, fmt);
   1292 	vwarningf(VWARNINGF_INTERNAL, fmt, va);
   1293 	va_end(va);
   1294 }
   1295 
   1296 /* used by error reporting functions to print "ksh: .kshrc[25]: " */
   1297 void
   1298 error_prefix(bool fileline)
   1299 {
   1300 	/* Avoid foo: foo[2]: ... */
   1301 	if (!fileline || !source || !source->file ||
   1302 	    strcmp(source->file, kshname) != 0)
   1303 		shf_fprintf(shl_out, "%s: ", kshname + (*kshname == '-'));
   1304 	if (fileline && source && source->file != NULL) {
   1305 		shf_fprintf(shl_out, "%s[%d]: ", source->file,
   1306 		    source->errline > 0 ? source->errline : source->line);
   1307 		source->errline = 0;
   1308 	}
   1309 }
   1310 
   1311 /* printf to shl_out (stderr) with flush */
   1312 void
   1313 shellf(const char *fmt, ...)
   1314 {
   1315 	va_list va;
   1316 
   1317 	if (!initio_done)
   1318 		/* shl_out may not be set up yet... */
   1319 		return;
   1320 	va_start(va, fmt);
   1321 	shf_vfprintf(shl_out, fmt, va);
   1322 	va_end(va);
   1323 	shf_flush(shl_out);
   1324 }
   1325 
   1326 /* printf to shl_stdout (stdout) */
   1327 void
   1328 shprintf(const char *fmt, ...)
   1329 {
   1330 	va_list va;
   1331 
   1332 	if (!shl_stdout_ok)
   1333 		internal_errorf("shl_stdout not valid");
   1334 	va_start(va, fmt);
   1335 	shf_vfprintf(shl_stdout, fmt, va);
   1336 	va_end(va);
   1337 }
   1338 
   1339 /* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
   1340 int
   1341 can_seek(int fd)
   1342 {
   1343 	struct stat statb;
   1344 
   1345 	return (fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
   1346 	    SHF_UNBUF : 0);
   1347 }
   1348 
   1349 #ifdef DF
   1350 int shl_dbg_fd;
   1351 #define NSHF_IOB 4
   1352 #else
   1353 #define NSHF_IOB 3
   1354 #endif
   1355 struct shf shf_iob[NSHF_IOB];
   1356 
   1357 void
   1358 initio(void)
   1359 {
   1360 #ifdef DF
   1361 	const char *lfp;
   1362 #endif
   1363 
   1364 	/* force buffer allocation */
   1365 	shf_fdopen(1, SHF_WR, shl_stdout);
   1366 	shf_fdopen(2, SHF_WR, shl_out);
   1367 	shf_fdopen(2, SHF_WR, shl_spare);
   1368 #ifdef DF
   1369 	if ((lfp = getenv("SDMKSH_PATH")) == NULL) {
   1370 		if ((lfp = getenv("HOME")) == NULL || *lfp != '/')
   1371 			errorf("cannot get home directory");
   1372 		lfp = shf_smprintf("%s/mksh-dbg.txt", lfp);
   1373 	}
   1374 
   1375 	if ((shl_dbg_fd = open(lfp, O_WRONLY | O_APPEND | O_CREAT, 0600)) < 0)
   1376 		errorf("cannot open debug output file %s", lfp);
   1377 	if (shl_dbg_fd < FDBASE) {
   1378 		int nfd;
   1379 
   1380 		nfd = fcntl(shl_dbg_fd, F_DUPFD, FDBASE);
   1381 		close(shl_dbg_fd);
   1382 		if ((shl_dbg_fd = nfd) == -1)
   1383 			errorf("cannot dup debug output file");
   1384 	}
   1385 	fcntl(shl_dbg_fd, F_SETFD, FD_CLOEXEC);
   1386 	shf_fdopen(shl_dbg_fd, SHF_WR, shl_dbg);
   1387 	DF("=== open ===");
   1388 #endif
   1389 	initio_done = true;
   1390 }
   1391 
   1392 /* A dup2() with error checking */
   1393 int
   1394 ksh_dup2(int ofd, int nfd, bool errok)
   1395 {
   1396 	int rv;
   1397 
   1398 	if (((rv = dup2(ofd, nfd)) < 0) && !errok && (errno != EBADF))
   1399 		errorf("too many files open in shell");
   1400 
   1401 #ifdef __ultrix
   1402 	/*XXX imake style */
   1403 	if (rv >= 0)
   1404 		fcntl(nfd, F_SETFD, 0);
   1405 #endif
   1406 
   1407 	return (rv);
   1408 }
   1409 
   1410 /*
   1411  * Move fd from user space (0 <= fd < 10) to shell space (fd >= 10),
   1412  * set close-on-exec flag. See FDBASE in sh.h, maybe 24 not 10 here.
   1413  */
   1414 short
   1415 savefd(int fd)
   1416 {
   1417 	int nfd = fd;
   1418 
   1419 	if (fd < FDBASE && (nfd = fcntl(fd, F_DUPFD, FDBASE)) < 0 &&
   1420 	    errno == EBADF)
   1421 		return (-1);
   1422 	if (nfd < 0 || nfd > SHRT_MAX)
   1423 		errorf("too many files open in shell");
   1424 	fcntl(nfd, F_SETFD, FD_CLOEXEC);
   1425 	return ((short)nfd);
   1426 }
   1427 
   1428 void
   1429 restfd(int fd, int ofd)
   1430 {
   1431 	if (fd == 2)
   1432 		shf_flush(&shf_iob[/* fd */ 2]);
   1433 	if (ofd < 0)
   1434 		/* original fd closed */
   1435 		close(fd);
   1436 	else if (fd != ofd) {
   1437 		/*XXX: what to do if this dup fails? */
   1438 		ksh_dup2(ofd, fd, true);
   1439 		close(ofd);
   1440 	}
   1441 }
   1442 
   1443 void
   1444 openpipe(int *pv)
   1445 {
   1446 	int lpv[2];
   1447 
   1448 	if (pipe(lpv) < 0)
   1449 		errorf("can't create pipe - try again");
   1450 	pv[0] = savefd(lpv[0]);
   1451 	if (pv[0] != lpv[0])
   1452 		close(lpv[0]);
   1453 	pv[1] = savefd(lpv[1]);
   1454 	if (pv[1] != lpv[1])
   1455 		close(lpv[1]);
   1456 }
   1457 
   1458 void
   1459 closepipe(int *pv)
   1460 {
   1461 	close(pv[0]);
   1462 	close(pv[1]);
   1463 }
   1464 
   1465 /*
   1466  * Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
   1467  * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
   1468  */
   1469 int
   1470 check_fd(const char *name, int mode, const char **emsgp)
   1471 {
   1472 	int fd, fl;
   1473 
   1474 	if (name[0] == 'p' && !name[1])
   1475 		return (coproc_getfd(mode, emsgp));
   1476 	for (fd = 0; ksh_isdigit(*name); ++name)
   1477 		fd = (fd * 10) + *name - '0';
   1478 	if (*name || fd >= FDBASE) {
   1479 		if (emsgp)
   1480 			*emsgp = "illegal file descriptor name";
   1481 		return (-1);
   1482 	}
   1483 	if ((fl = fcntl(fd, F_GETFL, 0)) < 0) {
   1484 		if (emsgp)
   1485 			*emsgp = "bad file descriptor";
   1486 		return (-1);
   1487 	}
   1488 	fl &= O_ACCMODE;
   1489 	/*
   1490 	 * X_OK is a kludge to disable this check for dups (x<&1):
   1491 	 * historical shells never did this check (XXX don't know what
   1492 	 * POSIX has to say).
   1493 	 */
   1494 	if (!(mode & X_OK) && fl != O_RDWR && (
   1495 	    ((mode & R_OK) && fl != O_RDONLY) ||
   1496 	    ((mode & W_OK) && fl != O_WRONLY))) {
   1497 		if (emsgp)
   1498 			*emsgp = (fl == O_WRONLY) ?
   1499 			    "fd not open for reading" :
   1500 			    "fd not open for writing";
   1501 		return (-1);
   1502 	}
   1503 	return (fd);
   1504 }
   1505 
   1506 /* Called once from main */
   1507 void
   1508 coproc_init(void)
   1509 {
   1510 	coproc.read = coproc.readw = coproc.write = -1;
   1511 	coproc.njobs = 0;
   1512 	coproc.id = 0;
   1513 }
   1514 
   1515 /* Called by c_read() when eof is read - close fd if it is the co-process fd */
   1516 void
   1517 coproc_read_close(int fd)
   1518 {
   1519 	if (coproc.read >= 0 && fd == coproc.read) {
   1520 		coproc_readw_close(fd);
   1521 		close(coproc.read);
   1522 		coproc.read = -1;
   1523 	}
   1524 }
   1525 
   1526 /*
   1527  * Called by c_read() and by iosetup() to close the other side of the
   1528  * read pipe, so reads will actually terminate.
   1529  */
   1530 void
   1531 coproc_readw_close(int fd)
   1532 {
   1533 	if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
   1534 		close(coproc.readw);
   1535 		coproc.readw = -1;
   1536 	}
   1537 }
   1538 
   1539 /*
   1540  * Called by c_print when a write to a fd fails with EPIPE and by iosetup
   1541  * when co-process input is dup'd
   1542  */
   1543 void
   1544 coproc_write_close(int fd)
   1545 {
   1546 	if (coproc.write >= 0 && fd == coproc.write) {
   1547 		close(coproc.write);
   1548 		coproc.write = -1;
   1549 	}
   1550 }
   1551 
   1552 /*
   1553  * Called to check for existence of/value of the co-process file descriptor.
   1554  * (Used by check_fd() and by c_read/c_print to deal with -p option).
   1555  */
   1556 int
   1557 coproc_getfd(int mode, const char **emsgp)
   1558 {
   1559 	int fd = (mode & R_OK) ? coproc.read : coproc.write;
   1560 
   1561 	if (fd >= 0)
   1562 		return (fd);
   1563 	if (emsgp)
   1564 		*emsgp = "no coprocess";
   1565 	return (-1);
   1566 }
   1567 
   1568 /*
   1569  * called to close file descriptors related to the coprocess (if any)
   1570  * Should be called with SIGCHLD blocked.
   1571  */
   1572 void
   1573 coproc_cleanup(int reuse)
   1574 {
   1575 	/* This to allow co-processes to share output pipe */
   1576 	if (!reuse || coproc.readw < 0 || coproc.read < 0) {
   1577 		if (coproc.read >= 0) {
   1578 			close(coproc.read);
   1579 			coproc.read = -1;
   1580 		}
   1581 		if (coproc.readw >= 0) {
   1582 			close(coproc.readw);
   1583 			coproc.readw = -1;
   1584 		}
   1585 	}
   1586 	if (coproc.write >= 0) {
   1587 		close(coproc.write);
   1588 		coproc.write = -1;
   1589 	}
   1590 }
   1591 
   1592 struct temp *
   1593 maketemp(Area *ap, Temp_type type, struct temp **tlist)
   1594 {
   1595 	char *cp;
   1596 	size_t len;
   1597 	int i;
   1598 	struct temp *tp;
   1599 	const char *dir;
   1600 	struct stat sb;
   1601 
   1602 	dir = tmpdir ? tmpdir : MKSH_DEFAULT_TMPDIR;
   1603 	/* add "/shXXXXXX.tmp" plus NUL */
   1604 	len = strlen(dir);
   1605 	checkoktoadd(len, offsetof(struct temp, tffn[0]) + 14);
   1606 	tp = alloc(offsetof(struct temp, tffn[0]) + 14 + len, ap);
   1607 
   1608 	tp->shf = NULL;
   1609 	tp->pid = procpid;
   1610 	tp->type = type;
   1611 
   1612 	if (stat(dir, &sb) || !S_ISDIR(sb.st_mode)) {
   1613 		tp->tffn[0] = '\0';
   1614 		goto maketemp_out;
   1615 	}
   1616 
   1617 	cp = (void *)tp;
   1618 	cp += offsetof(struct temp, tffn[0]);
   1619 	memcpy(cp, dir, len);
   1620 	cp += len;
   1621 	memcpy(cp, "/shXXXXXX.tmp", 14);
   1622 	/* point to the first of six Xes */
   1623 	cp += 3;
   1624 	/* generate random part of filename */
   1625 	len = -1;
   1626 	do {
   1627 		i = rndget() % 36;
   1628 		cp[++len] = i < 26 ? 'a' + i : '0' + i - 26;
   1629 	} while (len < 5);
   1630 
   1631 	/* cyclically attempt to open a temporary file */
   1632 	while ((i = open(tp->tffn, O_CREAT | O_EXCL | O_RDWR, 0600)) < 0) {
   1633 		if (errno != EEXIST)
   1634 			goto maketemp_out;
   1635 		/* count down from z to a then from 9 to 0 */
   1636 		while (cp[len] == '0')
   1637 			if (!len--)
   1638 				goto maketemp_out;
   1639 		if (cp[len] == 'a')
   1640 			cp[len] = '9';
   1641 		else
   1642 			--cp[len];
   1643 		/* do another cycle */
   1644 	}
   1645 
   1646 	if (type == TT_FUNSUB) {
   1647 		int nfd;
   1648 
   1649 		/* map us high and mark as close-on-exec */
   1650 		if ((nfd = savefd(i)) != i) {
   1651 			close(i);
   1652 			i = nfd;
   1653 		}
   1654 	}
   1655 
   1656 	/* shf_fdopen cannot fail, so no fd leak */
   1657 	tp->shf = shf_fdopen(i, SHF_WR, NULL);
   1658 
   1659  maketemp_out:
   1660 	tp->next = *tlist;
   1661 	*tlist = tp;
   1662 	return (tp);
   1663 }
   1664 
   1665 /*
   1666  * We use a similar collision resolution algorithm as Python 2.5.4
   1667  * but with a slightly tweaked implementation written from scratch.
   1668  */
   1669 
   1670 #define	INIT_TBLSHIFT	3	/* initial table shift (2^3 = 8) */
   1671 #define PERTURB_SHIFT	5	/* see Python 2.5.4 Objects/dictobject.c */
   1672 
   1673 static void tgrow(struct table *);
   1674 static int tnamecmp(const void *, const void *);
   1675 
   1676 static void
   1677 tgrow(struct table *tp)
   1678 {
   1679 	size_t i, j, osize, mask, perturb;
   1680 	struct tbl *tblp, **pp;
   1681 	struct tbl **ntblp, **otblp = tp->tbls;
   1682 
   1683 	if (tp->tshift > 29)
   1684 		internal_errorf("hash table size limit reached");
   1685 
   1686 	/* calculate old size, new shift and new size */
   1687 	osize = (size_t)1 << (tp->tshift++);
   1688 	i = osize << 1;
   1689 
   1690 	ntblp = alloc2(i, sizeof(struct tbl *), tp->areap);
   1691 	/* multiplication cannot overflow: alloc2 checked that */
   1692 	memset(ntblp, 0, i * sizeof(struct tbl *));
   1693 
   1694 	/* table can get very full when reaching its size limit */
   1695 	tp->nfree = (tp->tshift == 30) ? 0x3FFF0000UL :
   1696 	    /* but otherwise, only 75% */
   1697 	    ((i * 3) / 4);
   1698 	tp->tbls = ntblp;
   1699 	if (otblp == NULL)
   1700 		return;
   1701 
   1702 	mask = i - 1;
   1703 	for (i = 0; i < osize; i++)
   1704 		if ((tblp = otblp[i]) != NULL) {
   1705 			if ((tblp->flag & DEFINED)) {
   1706 				/* search for free hash table slot */
   1707 				j = perturb = tblp->ua.hval;
   1708 				goto find_first_empty_slot;
   1709  find_next_empty_slot:
   1710 				j = (j << 2) + j + perturb + 1;
   1711 				perturb >>= PERTURB_SHIFT;
   1712  find_first_empty_slot:
   1713 				pp = &ntblp[j & mask];
   1714 				if (*pp != NULL)
   1715 					goto find_next_empty_slot;
   1716 				/* found an empty hash table slot */
   1717 				*pp = tblp;
   1718 				tp->nfree--;
   1719 			} else if (!(tblp->flag & FINUSE)) {
   1720 				afree(tblp, tp->areap);
   1721 			}
   1722 		}
   1723 	afree(otblp, tp->areap);
   1724 }
   1725 
   1726 void
   1727 ktinit(Area *ap, struct table *tp, uint8_t initshift)
   1728 {
   1729 	tp->areap = ap;
   1730 	tp->tbls = NULL;
   1731 	tp->tshift = ((initshift > INIT_TBLSHIFT) ?
   1732 	    initshift : INIT_TBLSHIFT) - 1;
   1733 	tgrow(tp);
   1734 }
   1735 
   1736 /* table, name (key) to search for, hash(name), rv pointer to tbl ptr */
   1737 struct tbl *
   1738 ktscan(struct table *tp, const char *name, uint32_t h, struct tbl ***ppp)
   1739 {
   1740 	size_t j, perturb, mask;
   1741 	struct tbl **pp, *p;
   1742 
   1743 	mask = ((size_t)1 << (tp->tshift)) - 1;
   1744 	/* search for hash table slot matching name */
   1745 	j = perturb = h;
   1746 	goto find_first_slot;
   1747  find_next_slot:
   1748 	j = (j << 2) + j + perturb + 1;
   1749 	perturb >>= PERTURB_SHIFT;
   1750  find_first_slot:
   1751 	pp = &tp->tbls[j & mask];
   1752 	if ((p = *pp) != NULL && (p->ua.hval != h || !(p->flag & DEFINED) ||
   1753 	    strcmp(p->name, name)))
   1754 		goto find_next_slot;
   1755 	/* p == NULL if not found, correct found entry otherwise */
   1756 	if (ppp)
   1757 		*ppp = pp;
   1758 	return (p);
   1759 }
   1760 
   1761 /* table, name (key) to enter, hash(n) */
   1762 struct tbl *
   1763 ktenter(struct table *tp, const char *n, uint32_t h)
   1764 {
   1765 	struct tbl **pp, *p;
   1766 	size_t len;
   1767 
   1768  Search:
   1769 	if ((p = ktscan(tp, n, h, &pp)))
   1770 		return (p);
   1771 
   1772 	if (tp->nfree == 0) {
   1773 		/* too full */
   1774 		tgrow(tp);
   1775 		goto Search;
   1776 	}
   1777 
   1778 	/* create new tbl entry */
   1779 	len = strlen(n);
   1780 	checkoktoadd(len, offsetof(struct tbl, name[0]) + 1);
   1781 	p = alloc(offsetof(struct tbl, name[0]) + ++len, tp->areap);
   1782 	p->flag = 0;
   1783 	p->type = 0;
   1784 	p->areap = tp->areap;
   1785 	p->ua.hval = h;
   1786 	p->u2.field = 0;
   1787 	p->u.array = NULL;
   1788 	memcpy(p->name, n, len);
   1789 
   1790 	/* enter in tp->tbls */
   1791 	tp->nfree--;
   1792 	*pp = p;
   1793 	return (p);
   1794 }
   1795 
   1796 void
   1797 ktwalk(struct tstate *ts, struct table *tp)
   1798 {
   1799 	ts->left = (size_t)1 << (tp->tshift);
   1800 	ts->next = tp->tbls;
   1801 }
   1802 
   1803 struct tbl *
   1804 ktnext(struct tstate *ts)
   1805 {
   1806 	while (--ts->left >= 0) {
   1807 		struct tbl *p = *ts->next++;
   1808 		if (p != NULL && (p->flag & DEFINED))
   1809 			return (p);
   1810 	}
   1811 	return (NULL);
   1812 }
   1813 
   1814 static int
   1815 tnamecmp(const void *p1, const void *p2)
   1816 {
   1817 	const struct tbl *a = *((const struct tbl * const *)p1);
   1818 	const struct tbl *b = *((const struct tbl * const *)p2);
   1819 
   1820 	return (strcmp(a->name, b->name));
   1821 }
   1822 
   1823 struct tbl **
   1824 ktsort(struct table *tp)
   1825 {
   1826 	size_t i;
   1827 	struct tbl **p, **sp, **dp;
   1828 
   1829 	/*
   1830 	 * since the table is never entirely full, no need to reserve
   1831 	 * additional space for the trailing NULL appended below
   1832 	 */
   1833 	i = (size_t)1 << (tp->tshift);
   1834 	p = alloc2(i, sizeof(struct tbl *), ATEMP);
   1835 	sp = tp->tbls;		/* source */
   1836 	dp = p;			/* dest */
   1837 	while (i--)
   1838 		if ((*dp = *sp++) != NULL && (((*dp)->flag & DEFINED) ||
   1839 		    ((*dp)->flag & ARRAY)))
   1840 			dp++;
   1841 	qsort(p, (i = dp - p), sizeof(struct tbl *), tnamecmp);
   1842 	p[i] = NULL;
   1843 	return (p);
   1844 }
   1845 
   1846 #ifdef SIGWINCH
   1847 static void
   1848 x_sigwinch(int sig MKSH_A_UNUSED)
   1849 {
   1850 	/* this runs inside interrupt context, with errno saved */
   1851 
   1852 	got_winch = 1;
   1853 }
   1854 #endif
   1855 
   1856 #ifdef DF
   1857 void
   1858 DF(const char *fmt, ...)
   1859 {
   1860 	va_list args;
   1861 	struct timeval tv;
   1862 	mirtime_mjd mjd;
   1863 
   1864 	mksh_lockfd(shl_dbg_fd);
   1865 	mksh_TIME(tv);
   1866 	timet2mjd(&mjd, tv.tv_sec);
   1867 	shf_fprintf(shl_dbg, "[%02u:%02u:%02u (%u) %u.%06u] ",
   1868 	    (unsigned)mjd.sec / 3600, ((unsigned)mjd.sec / 60) % 60,
   1869 	    (unsigned)mjd.sec % 60, (unsigned)getpid(),
   1870 	    (unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
   1871 	va_start(args, fmt);
   1872 	shf_vfprintf(shl_dbg, fmt, args);
   1873 	va_end(args);
   1874 	shf_putc('\n', shl_dbg);
   1875 	shf_flush(shl_dbg);
   1876 	mksh_unlkfd(shl_dbg_fd);
   1877 }
   1878 #endif
   1879 
   1880 void
   1881 x_mkraw(int fd, mksh_ttyst *ocb, bool forread)
   1882 {
   1883 	mksh_ttyst cb;
   1884 
   1885 	if (ocb)
   1886 		mksh_tcget(fd, ocb);
   1887 	else
   1888 		ocb = &tty_state;
   1889 
   1890 	cb = *ocb;
   1891 	if (forread) {
   1892 		cb.c_lflag &= ~(ICANON) | ECHO;
   1893 	} else {
   1894 		cb.c_iflag &= ~(INLCR | ICRNL);
   1895 		cb.c_lflag &= ~(ISIG | ICANON | ECHO);
   1896 	}
   1897 #if defined(VLNEXT) && defined(_POSIX_VDISABLE)
   1898 	/* OSF/1 processes lnext when ~icanon */
   1899 	cb.c_cc[VLNEXT] = _POSIX_VDISABLE;
   1900 #endif
   1901 	/* SunOS 4.1.x & OSF/1 processes discard(flush) when ~icanon */
   1902 #if defined(VDISCARD) && defined(_POSIX_VDISABLE)
   1903 	cb.c_cc[VDISCARD] = _POSIX_VDISABLE;
   1904 #endif
   1905 	cb.c_cc[VTIME] = 0;
   1906 	cb.c_cc[VMIN] = 1;
   1907 
   1908 	mksh_tcset(fd, &cb);
   1909 }
   1910