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      1 /*	$OpenBSD: misc.c,v 1.41 2015/09/10 22:48:58 nicm Exp $	*/
      2 /*	$OpenBSD: path.c,v 1.13 2015/09/05 09:47:08 jsg Exp $	*/
      3 
      4 /*-
      5  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
      6  *		 2011, 2012, 2013, 2014, 2015
      7  *	mirabilos <m (at) mirbsd.org>
      8  *
      9  * Provided that these terms and disclaimer and all copyright notices
     10  * are retained or reproduced in an accompanying document, permission
     11  * is granted to deal in this work without restriction, including un-
     12  * limited rights to use, publicly perform, distribute, sell, modify,
     13  * merge, give away, or sublicence.
     14  *
     15  * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
     16  * the utmost extent permitted by applicable law, neither express nor
     17  * implied; without malicious intent or gross negligence. In no event
     18  * may a licensor, author or contributor be held liable for indirect,
     19  * direct, other damage, loss, or other issues arising in any way out
     20  * of dealing in the work, even if advised of the possibility of such
     21  * damage or existence of a defect, except proven that it results out
     22  * of said person's immediate fault when using the work as intended.
     23  */
     24 
     25 #include "sh.h"
     26 #if !HAVE_GETRUSAGE
     27 #include <sys/times.h>
     28 #endif
     29 #if HAVE_GRP_H
     30 #include <grp.h>
     31 #endif
     32 
     33 __RCSID("$MirOS: src/bin/mksh/misc.c,v 1.240 2015/10/09 16:11:17 tg Exp $");
     34 
     35 #define KSH_CHVT_FLAG
     36 #ifdef MKSH_SMALL
     37 #undef KSH_CHVT_FLAG
     38 #endif
     39 #ifdef TIOCSCTTY
     40 #define KSH_CHVT_CODE
     41 #define KSH_CHVT_FLAG
     42 #endif
     43 #ifdef MKSH_LEGACY_MODE
     44 #undef KSH_CHVT_CODE
     45 #undef KSH_CHVT_FLAG
     46 #endif
     47 
     48 /* type bits for unsigned char */
     49 unsigned char chtypes[UCHAR_MAX + 1];
     50 
     51 static const unsigned char *pat_scan(const unsigned char *,
     52     const unsigned char *, bool) MKSH_A_PURE;
     53 static int do_gmatch(const unsigned char *, const unsigned char *,
     54     const unsigned char *, const unsigned char *) MKSH_A_PURE;
     55 static const unsigned char *gmatch_cclass(const unsigned char *, unsigned char)
     56     MKSH_A_PURE;
     57 #ifdef KSH_CHVT_CODE
     58 static void chvt(const Getopt *);
     59 #endif
     60 
     61 /*XXX this should go away */
     62 static int make_path(const char *, const char *, char **, XString *, int *);
     63 
     64 #ifdef SETUID_CAN_FAIL_WITH_EAGAIN
     65 /* we don't need to check for other codes, EPERM won't happen */
     66 #define DO_SETUID(func, argvec) do {					\
     67 	if ((func argvec) && errno == EAGAIN)				\
     68 		errorf("%s failed with EAGAIN, probably due to a"	\
     69 		    " too low process limit; aborting", #func);		\
     70 } while (/* CONSTCOND */ 0)
     71 #else
     72 #define DO_SETUID(func, argvec) func argvec
     73 #endif
     74 
     75 /*
     76  * Fast character classes
     77  */
     78 void
     79 setctypes(const char *s, int t)
     80 {
     81 	unsigned int i;
     82 
     83 	if (t & C_IFS) {
     84 		for (i = 0; i < UCHAR_MAX + 1; i++)
     85 			chtypes[i] &= ~C_IFS;
     86 		/* include \0 in C_IFS */
     87 		chtypes[0] |= C_IFS;
     88 	}
     89 	while (*s != 0)
     90 		chtypes[(unsigned char)*s++] |= t;
     91 }
     92 
     93 void
     94 initctypes(void)
     95 {
     96 	setctypes(letters_uc, C_ALPHA);
     97 	setctypes(letters_lc, C_ALPHA);
     98 	chtypes['_'] |= C_ALPHA;
     99 	setctypes("0123456789", C_DIGIT);
    100 	/* \0 added automatically */
    101 	setctypes(TC_LEX1, C_LEX1);
    102 	setctypes("*@#!$-?", C_VAR1);
    103 	setctypes(TC_IFSWS, C_IFSWS);
    104 	setctypes("=-+?", C_SUBOP1);
    105 	setctypes("\t\n \"#$&'()*;<=>?[\\]`|", C_QUOTE);
    106 }
    107 
    108 /* called from XcheckN() to grow buffer */
    109 char *
    110 Xcheck_grow(XString *xsp, const char *xp, size_t more)
    111 {
    112 	const char *old_beg = xsp->beg;
    113 
    114 	if (more < xsp->len)
    115 		more = xsp->len;
    116 	/* (xsp->len + X_EXTRA) never overflows */
    117 	checkoktoadd(more, xsp->len + X_EXTRA);
    118 	xsp->beg = aresize(xsp->beg, (xsp->len += more) + X_EXTRA, xsp->areap);
    119 	xsp->end = xsp->beg + xsp->len;
    120 	return (xsp->beg + (xp - old_beg));
    121 }
    122 
    123 
    124 #define SHFLAGS_DEFNS
    125 #define FN(sname,cname,flags,ochar)		\
    126 	static const struct {			\
    127 		/* character flag (if any) */	\
    128 		char c;				\
    129 		/* OF_* */			\
    130 		unsigned char optflags;		\
    131 		/* long name of option */	\
    132 		char name[sizeof(sname)];	\
    133 	} shoptione_ ## cname = {		\
    134 		ochar, flags, sname		\
    135 	};
    136 #include "sh_flags.gen"
    137 
    138 #define OFC(i) (options[i][-2])
    139 #define OFF(i) (((const unsigned char *)options[i])[-1])
    140 #define OFN(i) (options[i])
    141 
    142 const char * const options[] = {
    143 #define SHFLAGS_ITEMS
    144 #include "sh_flags.gen"
    145 };
    146 
    147 /*
    148  * translate -o option into F* constant (also used for test -o option)
    149  */
    150 size_t
    151 option(const char *n)
    152 {
    153 	size_t i = 0;
    154 
    155 	if ((n[0] == '-' || n[0] == '+') && n[1] && !n[2])
    156 		while (i < NELEM(options)) {
    157 			if (OFC(i) == n[1])
    158 				return (i);
    159 			++i;
    160 		}
    161 	else
    162 		while (i < NELEM(options)) {
    163 			if (!strcmp(OFN(i), n))
    164 				return (i);
    165 			++i;
    166 		}
    167 
    168 	return ((size_t)-1);
    169 }
    170 
    171 struct options_info {
    172 	int opt_width;
    173 	int opts[NELEM(options)];
    174 };
    175 
    176 static void options_fmt_entry(char *, size_t, unsigned int, const void *);
    177 static void printoptions(bool);
    178 
    179 /* format a single select menu item */
    180 static void
    181 options_fmt_entry(char *buf, size_t buflen, unsigned int i, const void *arg)
    182 {
    183 	const struct options_info *oi = (const struct options_info *)arg;
    184 
    185 	shf_snprintf(buf, buflen, "%-*s %s",
    186 	    oi->opt_width, OFN(oi->opts[i]),
    187 	    Flag(oi->opts[i]) ? "on" : "off");
    188 }
    189 
    190 static void
    191 printoptions(bool verbose)
    192 {
    193 	size_t i = 0;
    194 
    195 	if (verbose) {
    196 		size_t n = 0, len, octs = 0;
    197 		struct options_info oi;
    198 
    199 		/* verbose version */
    200 		shf_puts("Current option settings\n", shl_stdout);
    201 
    202 		oi.opt_width = 0;
    203 		while (i < NELEM(options)) {
    204 			if ((len = strlen(OFN(i)))) {
    205 				oi.opts[n++] = i;
    206 				if (len > octs)
    207 					octs = len;
    208 				len = utf_mbswidth(OFN(i));
    209 				if ((int)len > oi.opt_width)
    210 					oi.opt_width = (int)len;
    211 			}
    212 			++i;
    213 		}
    214 		print_columns(shl_stdout, n, options_fmt_entry, &oi,
    215 		    octs + 4, oi.opt_width + 4, true);
    216 	} else {
    217 		/* short version like AT&T ksh93 */
    218 		shf_puts(Tset, shl_stdout);
    219 		while (i < NELEM(options)) {
    220 			if (Flag(i) && OFN(i)[0])
    221 				shprintf(" -o %s", OFN(i));
    222 			++i;
    223 		}
    224 		shf_putc('\n', shl_stdout);
    225 	}
    226 }
    227 
    228 char *
    229 getoptions(void)
    230 {
    231 	size_t i = 0;
    232 	char c, m[(int)FNFLAGS + 1];
    233 	char *cp = m;
    234 
    235 	while (i < NELEM(options)) {
    236 		if ((c = OFC(i)) && Flag(i))
    237 			*cp++ = c;
    238 		++i;
    239 	}
    240 	strndupx(cp, m, cp - m, ATEMP);
    241 	return (cp);
    242 }
    243 
    244 /* change a Flag(*) value; takes care of special actions */
    245 void
    246 change_flag(enum sh_flag f, int what, bool newset)
    247 {
    248 	unsigned char oldval;
    249 	unsigned char newval = (newset ? 1 : 0);
    250 
    251 	if (f == FXTRACE) {
    252 		change_xtrace(newval, true);
    253 		return;
    254 	}
    255 	oldval = Flag(f);
    256 	Flag(f) = newval = (newset ? 1 : 0);
    257 #ifndef MKSH_UNEMPLOYED
    258 	if (f == FMONITOR) {
    259 		if (what != OF_CMDLINE && newval != oldval)
    260 			j_change();
    261 	} else
    262 #endif
    263 #ifndef MKSH_NO_CMDLINE_EDITING
    264 	  if ((
    265 #if !MKSH_S_NOVI
    266 	    f == FVI ||
    267 #endif
    268 	    f == FEMACS || f == FGMACS) && newval) {
    269 #if !MKSH_S_NOVI
    270 		Flag(FVI) =
    271 #endif
    272 		    Flag(FEMACS) = Flag(FGMACS) = 0;
    273 		Flag(f) = newval;
    274 	} else
    275 #endif
    276 	  if (f == FPRIVILEGED && oldval && !newval) {
    277 		/* Turning off -p? */
    278 
    279 		/*XXX this can probably be optimised */
    280 		kshegid = kshgid = getgid();
    281 		ksheuid = kshuid = getuid();
    282 #if HAVE_SETRESUGID
    283 		DO_SETUID(setresgid, (kshegid, kshegid, kshegid));
    284 #if HAVE_SETGROUPS
    285 		/* setgroups doesn't EAGAIN on Linux */
    286 		setgroups(1, &kshegid);
    287 #endif
    288 		DO_SETUID(setresuid, (ksheuid, ksheuid, ksheuid));
    289 #else /* !HAVE_SETRESUGID */
    290 		/* setgid, setegid, seteuid don't EAGAIN on Linux */
    291 		setgid(kshegid);
    292 #ifndef MKSH__NO_SETEUGID
    293 		setegid(kshegid);
    294 #endif
    295 		DO_SETUID(setuid, (ksheuid));
    296 #ifndef MKSH__NO_SETEUGID
    297 		seteuid(ksheuid);
    298 #endif
    299 #endif /* !HAVE_SETRESUGID */
    300 	} else if ((f == FPOSIX || f == FSH) && newval) {
    301 		/* Turning on -o posix or -o sh? */
    302 		Flag(FBRACEEXPAND) = 0;
    303 	} else if (f == FTALKING) {
    304 		/* Changing interactive flag? */
    305 		if ((what == OF_CMDLINE || what == OF_SET) && procpid == kshpid)
    306 			Flag(FTALKING_I) = newval;
    307 	}
    308 }
    309 
    310 void
    311 change_xtrace(unsigned char newval, bool dosnapshot)
    312 {
    313 	static bool in_xtrace;
    314 
    315 	if (in_xtrace)
    316 		return;
    317 
    318 	if (!dosnapshot && newval == Flag(FXTRACE))
    319 		return;
    320 
    321 	if (Flag(FXTRACE) == 2) {
    322 		shf_putc('\n', shl_xtrace);
    323 		Flag(FXTRACE) = 1;
    324 		shf_flush(shl_xtrace);
    325 	}
    326 
    327 	if (!dosnapshot && Flag(FXTRACE) == 1)
    328 		switch (newval) {
    329 		case 1:
    330 			return;
    331 		case 2:
    332 			goto changed_xtrace;
    333 		}
    334 
    335 	shf_flush(shl_xtrace);
    336 	if (shl_xtrace->fd != 2)
    337 		close(shl_xtrace->fd);
    338 	if (!newval || (shl_xtrace->fd = savefd(2)) == -1)
    339 		shl_xtrace->fd = 2;
    340 
    341  changed_xtrace:
    342 	if ((Flag(FXTRACE) = newval) == 2) {
    343 		in_xtrace = true;
    344 		Flag(FXTRACE) = 0;
    345 		shf_puts(substitute(str_val(global("PS4")), 0), shl_xtrace);
    346 		Flag(FXTRACE) = 2;
    347 		in_xtrace = false;
    348 	}
    349 }
    350 
    351 /*
    352  * Parse command line and set command arguments. Returns the index of
    353  * non-option arguments, -1 if there is an error.
    354  */
    355 int
    356 parse_args(const char **argv,
    357     /* OF_CMDLINE or OF_SET */
    358     int what,
    359     bool *setargsp)
    360 {
    361 	static const char cmd_opts[] =
    362 #define SHFLAGS_NOT_SET
    363 #define SHFLAGS_OPTCS
    364 #include "sh_flags.gen"
    365 #undef SHFLAGS_NOT_SET
    366 	    ;
    367 	static const char set_opts[] =
    368 #define SHFLAGS_NOT_CMD
    369 #define SHFLAGS_OPTCS
    370 #include "sh_flags.gen"
    371 #undef SHFLAGS_NOT_CMD
    372 	    ;
    373 	bool set;
    374 	const char *opts;
    375 	const char *array = NULL;
    376 	Getopt go;
    377 	size_t i;
    378 	int optc, arrayset = 0;
    379 	bool sortargs = false;
    380 	bool fcompatseen = false;
    381 
    382 	if (what == OF_CMDLINE) {
    383 		const char *p = argv[0], *q;
    384 		/*
    385 		 * Set FLOGIN before parsing options so user can clear
    386 		 * flag using +l.
    387 		 */
    388 		if (*p != '-')
    389 			for (q = p; *q; )
    390 				if (*q++ == '/')
    391 					p = q;
    392 		Flag(FLOGIN) = (*p == '-');
    393 		opts = cmd_opts;
    394 	} else if (what == OF_FIRSTTIME) {
    395 		opts = cmd_opts;
    396 	} else
    397 		opts = set_opts;
    398 	ksh_getopt_reset(&go, GF_ERROR|GF_PLUSOPT);
    399 	while ((optc = ksh_getopt(argv, &go, opts)) != -1) {
    400 		set = tobool(!(go.info & GI_PLUS));
    401 		switch (optc) {
    402 		case 'A':
    403 			if (what == OF_FIRSTTIME)
    404 				break;
    405 			arrayset = set ? 1 : -1;
    406 			array = go.optarg;
    407 			break;
    408 
    409 		case 'o':
    410 			if (what == OF_FIRSTTIME)
    411 				break;
    412 			if (go.optarg == NULL) {
    413 				/*
    414 				 * lone -o: print options
    415 				 *
    416 				 * Note that on the command line, -o requires
    417 				 * an option (ie, can't get here if what is
    418 				 * OF_CMDLINE).
    419 				 */
    420 				printoptions(set);
    421 				break;
    422 			}
    423 			i = option(go.optarg);
    424 			if ((i == FPOSIX || i == FSH) && set && !fcompatseen) {
    425 				/*
    426 				 * If running 'set -o posix' or
    427 				 * 'set -o sh', turn off the other;
    428 				 * if running 'set -o posix -o sh'
    429 				 * allow both to be set though.
    430 				 */
    431 				Flag(FPOSIX) = 0;
    432 				Flag(FSH) = 0;
    433 				fcompatseen = true;
    434 			}
    435 			if ((i != (size_t)-1) && (set ? 1U : 0U) == Flag(i))
    436 				/*
    437 				 * Don't check the context if the flag
    438 				 * isn't changing - makes "set -o interactive"
    439 				 * work if you're already interactive. Needed
    440 				 * if the output of "set +o" is to be used.
    441 				 */
    442 				;
    443 			else if ((i != (size_t)-1) && (OFF(i) & what))
    444 				change_flag((enum sh_flag)i, what, set);
    445 			else {
    446 				bi_errorf("%s: %s", go.optarg, "bad option");
    447 				return (-1);
    448 			}
    449 			break;
    450 
    451 #ifdef KSH_CHVT_FLAG
    452 		case 'T':
    453 			if (what != OF_FIRSTTIME)
    454 				break;
    455 #ifndef KSH_CHVT_CODE
    456 			errorf("no TIOCSCTTY ioctl");
    457 #else
    458 			change_flag(FTALKING, OF_CMDLINE, true);
    459 			chvt(&go);
    460 			break;
    461 #endif
    462 #endif
    463 
    464 		case '?':
    465 			return (-1);
    466 
    467 		default:
    468 			if (what == OF_FIRSTTIME)
    469 				break;
    470 			/* -s: sort positional params (AT&T ksh stupidity) */
    471 			if (what == OF_SET && optc == 's') {
    472 				sortargs = true;
    473 				break;
    474 			}
    475 			for (i = 0; i < NELEM(options); i++)
    476 				if (optc == OFC(i) &&
    477 				    (what & OFF(i))) {
    478 					change_flag((enum sh_flag)i, what, set);
    479 					break;
    480 				}
    481 			if (i == NELEM(options))
    482 				internal_errorf("parse_args: '%c'", optc);
    483 		}
    484 	}
    485 	if (!(go.info & GI_MINUSMINUS) && argv[go.optind] &&
    486 	    (argv[go.optind][0] == '-' || argv[go.optind][0] == '+') &&
    487 	    argv[go.optind][1] == '\0') {
    488 		/* lone - clears -v and -x flags */
    489 		if (argv[go.optind][0] == '-') {
    490 			Flag(FVERBOSE) = 0;
    491 			change_xtrace(0, false);
    492 		}
    493 		/* set skips lone - or + option */
    494 		go.optind++;
    495 	}
    496 	if (setargsp)
    497 		/* -- means set $#/$* even if there are no arguments */
    498 		*setargsp = !arrayset && ((go.info & GI_MINUSMINUS) ||
    499 		    argv[go.optind]);
    500 
    501 	if (arrayset) {
    502 		const char *ccp = NULL;
    503 
    504 		if (*array)
    505 			ccp = skip_varname(array, false);
    506 		if (!ccp || !(!ccp[0] || (ccp[0] == '+' && !ccp[1]))) {
    507 			bi_errorf("%s: %s", array, "is not an identifier");
    508 			return (-1);
    509 		}
    510 	}
    511 	if (sortargs) {
    512 		for (i = go.optind; argv[i]; i++)
    513 			;
    514 		qsort(&argv[go.optind], i - go.optind, sizeof(void *),
    515 		    xstrcmp);
    516 	}
    517 	if (arrayset)
    518 		go.optind += set_array(array, tobool(arrayset > 0),
    519 		    argv + go.optind);
    520 
    521 	return (go.optind);
    522 }
    523 
    524 /* parse a decimal number: returns 0 if string isn't a number, 1 otherwise */
    525 int
    526 getn(const char *s, int *ai)
    527 {
    528 	char c;
    529 	mksh_ari_u num;
    530 	bool neg = false;
    531 
    532 	num.u = 0;
    533 
    534 	do {
    535 		c = *s++;
    536 	} while (ksh_isspace(c));
    537 
    538 	switch (c) {
    539 	case '-':
    540 		neg = true;
    541 		/* FALLTHROUGH */
    542 	case '+':
    543 		c = *s++;
    544 		break;
    545 	}
    546 
    547 	do {
    548 		if (!ksh_isdigit(c))
    549 			/* not numeric */
    550 			return (0);
    551 		if (num.u > 214748364U)
    552 			/* overflow on multiplication */
    553 			return (0);
    554 		num.u = num.u * 10U + (unsigned int)ksh_numdig(c);
    555 		/* now: num.u <= 2147483649U */
    556 	} while ((c = *s++));
    557 
    558 	if (num.u > (neg ? 2147483648U : 2147483647U))
    559 		/* overflow for signed 32-bit int */
    560 		return (0);
    561 
    562 	if (neg)
    563 		num.u = -num.u;
    564 	*ai = num.i;
    565 	return (1);
    566 }
    567 
    568 /**
    569  * pattern simplifications:
    570  * - @(x) -> x (not @(x|y) though)
    571  * - ** -> *
    572  */
    573 static void *
    574 simplify_gmatch_pattern(const unsigned char *sp)
    575 {
    576 	uint8_t c;
    577 	unsigned char *cp, *dp;
    578 	const unsigned char *ps, *se;
    579 
    580 	cp = alloc(strlen((const void *)sp) + 1, ATEMP);
    581 	goto simplify_gmatch_pat1a;
    582 
    583 	/* foo@(b@(a)r)b@(a|a)z -> foobarb@(a|a)z */
    584  simplify_gmatch_pat1:
    585 	sp = cp;
    586  simplify_gmatch_pat1a:
    587 	dp = cp;
    588 	se = sp + strlen((const void *)sp);
    589 	while ((c = *sp++)) {
    590 		if (!ISMAGIC(c)) {
    591 			*dp++ = c;
    592 			continue;
    593 		}
    594 		switch ((c = *sp++)) {
    595 		case 0x80|'@':
    596 		/* simile for @ */
    597 		case 0x80|' ':
    598 			/* check whether it has only one clause */
    599 			ps = pat_scan(sp, se, true);
    600 			if (!ps || ps[-1] != /*(*/ ')')
    601 				/* nope */
    602 				break;
    603 			/* copy inner clause until matching close */
    604 			ps -= 2;
    605 			while ((const unsigned char *)sp < ps)
    606 				*dp++ = *sp++;
    607 			/* skip MAGIC and closing parenthesis */
    608 			sp += 2;
    609 			/* copy the rest of the pattern */
    610 			memmove(dp, sp, strlen((const void *)sp) + 1);
    611 			/* redo from start */
    612 			goto simplify_gmatch_pat1;
    613 		}
    614 		*dp++ = MAGIC;
    615 		*dp++ = c;
    616 	}
    617 	*dp = '\0';
    618 
    619 	/* collapse adjacent asterisk wildcards */
    620 	sp = dp = cp;
    621 	while ((c = *sp++)) {
    622 		if (!ISMAGIC(c)) {
    623 			*dp++ = c;
    624 			continue;
    625 		}
    626 		switch ((c = *sp++)) {
    627 		case '*':
    628 			while (ISMAGIC(sp[0]) && sp[1] == c)
    629 				sp += 2;
    630 			break;
    631 		}
    632 		*dp++ = MAGIC;
    633 		*dp++ = c;
    634 	}
    635 	*dp = '\0';
    636 
    637 	/* return the result, allocated from ATEMP */
    638 	return (cp);
    639 }
    640 
    641 /* -------- gmatch.c -------- */
    642 
    643 /*
    644  * int gmatch(string, pattern)
    645  * char *string, *pattern;
    646  *
    647  * Match a pattern as in sh(1).
    648  * pattern character are prefixed with MAGIC by expand.
    649  */
    650 int
    651 gmatchx(const char *s, const char *p, bool isfile)
    652 {
    653 	const char *se, *pe;
    654 	char *pnew;
    655 	int rv;
    656 
    657 	if (s == NULL || p == NULL)
    658 		return (0);
    659 
    660 	se = s + strlen(s);
    661 	pe = p + strlen(p);
    662 	/*
    663 	 * isfile is false iff no syntax check has been done on
    664 	 * the pattern. If check fails, just to a strcmp().
    665 	 */
    666 	if (!isfile && !has_globbing(p, pe)) {
    667 		size_t len = pe - p + 1;
    668 		char tbuf[64];
    669 		char *t = len <= sizeof(tbuf) ? tbuf : alloc(len, ATEMP);
    670 		debunk(t, p, len);
    671 		return (!strcmp(t, s));
    672 	}
    673 
    674 	/*
    675 	 * since the do_gmatch() engine sucks so much, we must do some
    676 	 * pattern simplifications
    677 	 */
    678 	pnew = simplify_gmatch_pattern((const unsigned char *)p);
    679 	pe = pnew + strlen(pnew);
    680 
    681 	rv = do_gmatch((const unsigned char *)s, (const unsigned char *)se,
    682 	    (const unsigned char *)pnew, (const unsigned char *)pe);
    683 	afree(pnew, ATEMP);
    684 	return (rv);
    685 }
    686 
    687 /**
    688  * Returns if p is a syntacticly correct globbing pattern, false
    689  * if it contains no pattern characters or if there is a syntax error.
    690  * Syntax errors are:
    691  *	- [ with no closing ]
    692  *	- imbalanced $(...) expression
    693  *	- [...] and *(...) not nested (eg, [a$(b|]c), *(a[b|c]d))
    694  */
    695 /*XXX
    696  * - if no magic,
    697  *	if dest given, copy to dst
    698  *	return ?
    699  * - if magic && (no globbing || syntax error)
    700  *	debunk to dst
    701  *	return ?
    702  * - return ?
    703  */
    704 int
    705 has_globbing(const char *xp, const char *xpe)
    706 {
    707 	const unsigned char *p = (const unsigned char *) xp;
    708 	const unsigned char *pe = (const unsigned char *) xpe;
    709 	int c;
    710 	int nest = 0, bnest = 0;
    711 	bool saw_glob = false;
    712 	/* inside [...] */
    713 	bool in_bracket = false;
    714 
    715 	for (; p < pe; p++) {
    716 		if (!ISMAGIC(*p))
    717 			continue;
    718 		if ((c = *++p) == '*' || c == '?')
    719 			saw_glob = true;
    720 		else if (c == '[') {
    721 			if (!in_bracket) {
    722 				saw_glob = true;
    723 				in_bracket = true;
    724 				if (ISMAGIC(p[1]) && p[2] == '!')
    725 					p += 2;
    726 				if (ISMAGIC(p[1]) && p[2] == ']')
    727 					p += 2;
    728 			}
    729 			/*XXX Do we need to check ranges here? POSIX Q */
    730 		} else if (c == ']') {
    731 			if (in_bracket) {
    732 				if (bnest)
    733 					/* [a*(b]) */
    734 					return (0);
    735 				in_bracket = false;
    736 			}
    737 		} else if ((c & 0x80) && vstrchr("*+?@! ", c & 0x7f)) {
    738 			saw_glob = true;
    739 			if (in_bracket)
    740 				bnest++;
    741 			else
    742 				nest++;
    743 		} else if (c == '|') {
    744 			if (in_bracket && !bnest)
    745 				/* *(a[foo|bar]) */
    746 				return (0);
    747 		} else if (c == /*(*/ ')') {
    748 			if (in_bracket) {
    749 				if (!bnest--)
    750 					/* *(a[b)c] */
    751 					return (0);
    752 			} else if (nest)
    753 				nest--;
    754 		}
    755 		/*
    756 		 * else must be a MAGIC-MAGIC, or MAGIC-!,
    757 		 * MAGIC--, MAGIC-], MAGIC-{, MAGIC-, MAGIC-}
    758 		 */
    759 	}
    760 	return (saw_glob && !in_bracket && !nest);
    761 }
    762 
    763 /* Function must return either 0 or 1 (assumed by code for 0x80|'!') */
    764 static int
    765 do_gmatch(const unsigned char *s, const unsigned char *se,
    766     const unsigned char *p, const unsigned char *pe)
    767 {
    768 	unsigned char sc, pc;
    769 	const unsigned char *prest, *psub, *pnext;
    770 	const unsigned char *srest;
    771 
    772 	if (s == NULL || p == NULL)
    773 		return (0);
    774 	while (p < pe) {
    775 		pc = *p++;
    776 		sc = s < se ? *s : '\0';
    777 		s++;
    778 		if (!ISMAGIC(pc)) {
    779 			if (sc != pc)
    780 				return (0);
    781 			continue;
    782 		}
    783 		switch (*p++) {
    784 		case '[':
    785 			if (sc == 0 || (p = gmatch_cclass(p, sc)) == NULL)
    786 				return (0);
    787 			break;
    788 
    789 		case '?':
    790 			if (sc == 0)
    791 				return (0);
    792 			if (UTFMODE) {
    793 				--s;
    794 				s += utf_ptradj((const void *)s);
    795 			}
    796 			break;
    797 
    798 		case '*':
    799 			if (p == pe)
    800 				return (1);
    801 			s--;
    802 			do {
    803 				if (do_gmatch(s, se, p, pe))
    804 					return (1);
    805 			} while (s++ < se);
    806 			return (0);
    807 
    808 		/**
    809 		 * [*+?@!](pattern|pattern|..)
    810 		 * This is also needed for ${..%..}, etc.
    811 		 */
    812 
    813 		/* matches one or more times */
    814 		case 0x80|'+':
    815 		/* matches zero or more times */
    816 		case 0x80|'*':
    817 			if (!(prest = pat_scan(p, pe, false)))
    818 				return (0);
    819 			s--;
    820 			/* take care of zero matches */
    821 			if (p[-1] == (0x80 | '*') &&
    822 			    do_gmatch(s, se, prest, pe))
    823 				return (1);
    824 			for (psub = p; ; psub = pnext) {
    825 				pnext = pat_scan(psub, pe, true);
    826 				for (srest = s; srest <= se; srest++) {
    827 					if (do_gmatch(s, srest, psub, pnext - 2) &&
    828 					    (do_gmatch(srest, se, prest, pe) ||
    829 					    (s != srest && do_gmatch(srest,
    830 					    se, p - 2, pe))))
    831 						return (1);
    832 				}
    833 				if (pnext == prest)
    834 					break;
    835 			}
    836 			return (0);
    837 
    838 		/* matches zero or once */
    839 		case 0x80|'?':
    840 		/* matches one of the patterns */
    841 		case 0x80|'@':
    842 		/* simile for @ */
    843 		case 0x80|' ':
    844 			if (!(prest = pat_scan(p, pe, false)))
    845 				return (0);
    846 			s--;
    847 			/* Take care of zero matches */
    848 			if (p[-1] == (0x80 | '?') &&
    849 			    do_gmatch(s, se, prest, pe))
    850 				return (1);
    851 			for (psub = p; ; psub = pnext) {
    852 				pnext = pat_scan(psub, pe, true);
    853 				srest = prest == pe ? se : s;
    854 				for (; srest <= se; srest++) {
    855 					if (do_gmatch(s, srest, psub, pnext - 2) &&
    856 					    do_gmatch(srest, se, prest, pe))
    857 						return (1);
    858 				}
    859 				if (pnext == prest)
    860 					break;
    861 			}
    862 			return (0);
    863 
    864 		/* matches none of the patterns */
    865 		case 0x80|'!':
    866 			if (!(prest = pat_scan(p, pe, false)))
    867 				return (0);
    868 			s--;
    869 			for (srest = s; srest <= se; srest++) {
    870 				int matched = 0;
    871 
    872 				for (psub = p; ; psub = pnext) {
    873 					pnext = pat_scan(psub, pe, true);
    874 					if (do_gmatch(s, srest, psub,
    875 					    pnext - 2)) {
    876 						matched = 1;
    877 						break;
    878 					}
    879 					if (pnext == prest)
    880 						break;
    881 				}
    882 				if (!matched &&
    883 				    do_gmatch(srest, se, prest, pe))
    884 					return (1);
    885 			}
    886 			return (0);
    887 
    888 		default:
    889 			if (sc != p[-1])
    890 				return (0);
    891 			break;
    892 		}
    893 	}
    894 	return (s == se);
    895 }
    896 
    897 static const unsigned char *
    898 gmatch_cclass(const unsigned char *p, unsigned char sub)
    899 {
    900 	unsigned char c, d;
    901 	bool notp, found = false;
    902 	const unsigned char *orig_p = p;
    903 
    904 	if ((notp = tobool(ISMAGIC(*p) && *++p == '!')))
    905 		p++;
    906 	do {
    907 		c = *p++;
    908 		if (ISMAGIC(c)) {
    909 			c = *p++;
    910 			if ((c & 0x80) && !ISMAGIC(c)) {
    911 				/* extended pattern matching: *+?@! */
    912 				c &= 0x7F;
    913 				/* XXX the ( char isn't handled as part of [] */
    914 				if (c == ' ')
    915 					/* simile for @: plain (..) */
    916 					c = '(' /*)*/;
    917 			}
    918 		}
    919 		if (c == '\0')
    920 			/* No closing ] - act as if the opening [ was quoted */
    921 			return (sub == '[' ? orig_p : NULL);
    922 		if (ISMAGIC(p[0]) && p[1] == '-' &&
    923 		    (!ISMAGIC(p[2]) || p[3] != ']')) {
    924 			/* MAGIC- */
    925 			p += 2;
    926 			d = *p++;
    927 			if (ISMAGIC(d)) {
    928 				d = *p++;
    929 				if ((d & 0x80) && !ISMAGIC(d))
    930 					d &= 0x7f;
    931 			}
    932 			/* POSIX says this is an invalid expression */
    933 			if (c > d)
    934 				return (NULL);
    935 		} else
    936 			d = c;
    937 		if (c == sub || (c <= sub && sub <= d))
    938 			found = true;
    939 	} while (!(ISMAGIC(p[0]) && p[1] == ']'));
    940 
    941 	return ((found != notp) ? p+2 : NULL);
    942 }
    943 
    944 /* Look for next ) or | (if match_sep) in *(foo|bar) pattern */
    945 static const unsigned char *
    946 pat_scan(const unsigned char *p, const unsigned char *pe, bool match_sep)
    947 {
    948 	int nest = 0;
    949 
    950 	for (; p < pe; p++) {
    951 		if (!ISMAGIC(*p))
    952 			continue;
    953 		if ((*++p == /*(*/ ')' && nest-- == 0) ||
    954 		    (*p == '|' && match_sep && nest == 0))
    955 			return (p + 1);
    956 		if ((*p & 0x80) && vstrchr("*+?@! ", *p & 0x7f))
    957 			nest++;
    958 	}
    959 	return (NULL);
    960 }
    961 
    962 int
    963 xstrcmp(const void *p1, const void *p2)
    964 {
    965 	return (strcmp(*(const char * const *)p1, *(const char * const *)p2));
    966 }
    967 
    968 /* Initialise a Getopt structure */
    969 void
    970 ksh_getopt_reset(Getopt *go, int flags)
    971 {
    972 	go->optind = 1;
    973 	go->optarg = NULL;
    974 	go->p = 0;
    975 	go->flags = flags;
    976 	go->info = 0;
    977 	go->buf[1] = '\0';
    978 }
    979 
    980 
    981 /**
    982  * getopt() used for shell built-in commands, the getopts command, and
    983  * command line options.
    984  * A leading ':' in options means don't print errors, instead return '?'
    985  * or ':' and set go->optarg to the offending option character.
    986  * If GF_ERROR is set (and option doesn't start with :), errors result in
    987  * a call to bi_errorf().
    988  *
    989  * Non-standard features:
    990  *	- ';' is like ':' in options, except the argument is optional
    991  *	  (if it isn't present, optarg is set to 0).
    992  *	  Used for 'set -o'.
    993  *	- ',' is like ':' in options, except the argument always immediately
    994  *	  follows the option character (optarg is set to the null string if
    995  *	  the option is missing).
    996  *	  Used for 'read -u2', 'print -u2' and fc -40.
    997  *	- '#' is like ':' in options, expect that the argument is optional
    998  *	  and must start with a digit. If the argument doesn't start with a
    999  *	  digit, it is assumed to be missing and normal option processing
   1000  *	  continues (optarg is set to 0 if the option is missing).
   1001  *	  Used for 'typeset -LZ4'.
   1002  *	- accepts +c as well as -c IF the GF_PLUSOPT flag is present. If an
   1003  *	  option starting with + is accepted, the GI_PLUS flag will be set
   1004  *	  in go->info.
   1005  */
   1006 int
   1007 ksh_getopt(const char **argv, Getopt *go, const char *optionsp)
   1008 {
   1009 	char c;
   1010 	const char *o;
   1011 
   1012 	if (go->p == 0 || (c = argv[go->optind - 1][go->p]) == '\0') {
   1013 		const char *arg = argv[go->optind], flag = arg ? *arg : '\0';
   1014 
   1015 		go->p = 1;
   1016 		if (flag == '-' && ksh_isdash(arg + 1)) {
   1017 			go->optind++;
   1018 			go->p = 0;
   1019 			go->info |= GI_MINUSMINUS;
   1020 			return (-1);
   1021 		}
   1022 		if (arg == NULL ||
   1023 		    ((flag != '-' ) &&
   1024 		    /* neither a - nor a + (if + allowed) */
   1025 		    (!(go->flags & GF_PLUSOPT) || flag != '+')) ||
   1026 		    (c = arg[1]) == '\0') {
   1027 			go->p = 0;
   1028 			return (-1);
   1029 		}
   1030 		go->optind++;
   1031 		go->info &= ~(GI_MINUS|GI_PLUS);
   1032 		go->info |= flag == '-' ? GI_MINUS : GI_PLUS;
   1033 	}
   1034 	go->p++;
   1035 	if (c == '?' || c == ':' || c == ';' || c == ',' || c == '#' ||
   1036 	    !(o = cstrchr(optionsp, c))) {
   1037 		if (optionsp[0] == ':') {
   1038 			go->buf[0] = c;
   1039 			go->optarg = go->buf;
   1040 		} else {
   1041 			warningf(true, "%s%s-%c: %s",
   1042 			    (go->flags & GF_NONAME) ? "" : argv[0],
   1043 			    (go->flags & GF_NONAME) ? "" : ": ", c,
   1044 			    "unknown option");
   1045 			if (go->flags & GF_ERROR)
   1046 				bi_errorfz();
   1047 		}
   1048 		return ('?');
   1049 	}
   1050 	/**
   1051 	 * : means argument must be present, may be part of option argument
   1052 	 *   or the next argument
   1053 	 * ; same as : but argument may be missing
   1054 	 * , means argument is part of option argument, and may be null.
   1055 	 */
   1056 	if (*++o == ':' || *o == ';') {
   1057 		if (argv[go->optind - 1][go->p])
   1058 			go->optarg = argv[go->optind - 1] + go->p;
   1059 		else if (argv[go->optind])
   1060 			go->optarg = argv[go->optind++];
   1061 		else if (*o == ';')
   1062 			go->optarg = NULL;
   1063 		else {
   1064 			if (optionsp[0] == ':') {
   1065 				go->buf[0] = c;
   1066 				go->optarg = go->buf;
   1067 				return (':');
   1068 			}
   1069 			warningf(true, "%s%s-%c: %s",
   1070 			    (go->flags & GF_NONAME) ? "" : argv[0],
   1071 			    (go->flags & GF_NONAME) ? "" : ": ", c,
   1072 			    "requires an argument");
   1073 			if (go->flags & GF_ERROR)
   1074 				bi_errorfz();
   1075 			return ('?');
   1076 		}
   1077 		go->p = 0;
   1078 	} else if (*o == ',') {
   1079 		/* argument is attached to option character, even if null */
   1080 		go->optarg = argv[go->optind - 1] + go->p;
   1081 		go->p = 0;
   1082 	} else if (*o == '#') {
   1083 		/*
   1084 		 * argument is optional and may be attached or unattached
   1085 		 * but must start with a digit. optarg is set to 0 if the
   1086 		 * argument is missing.
   1087 		 */
   1088 		if (argv[go->optind - 1][go->p]) {
   1089 			if (ksh_isdigit(argv[go->optind - 1][go->p])) {
   1090 				go->optarg = argv[go->optind - 1] + go->p;
   1091 				go->p = 0;
   1092 			} else
   1093 				go->optarg = NULL;
   1094 		} else {
   1095 			if (argv[go->optind] && ksh_isdigit(argv[go->optind][0])) {
   1096 				go->optarg = argv[go->optind++];
   1097 				go->p = 0;
   1098 			} else
   1099 				go->optarg = NULL;
   1100 		}
   1101 	}
   1102 	return (c);
   1103 }
   1104 
   1105 /*
   1106  * print variable/alias value using necessary quotes
   1107  * (POSIX says they should be suitable for re-entry...)
   1108  * No trailing newline is printed.
   1109  */
   1110 void
   1111 print_value_quoted(struct shf *shf, const char *s)
   1112 {
   1113 	unsigned char c;
   1114 	const unsigned char *p = (const unsigned char *)s;
   1115 	bool inquote = true;
   1116 
   1117 	/* first, check whether any quotes are needed */
   1118 	while ((c = *p++) >= 32)
   1119 		if (ctype(c, C_QUOTE))
   1120 			inquote = false;
   1121 
   1122 	p = (const unsigned char *)s;
   1123 	if (c == 0) {
   1124 		if (inquote) {
   1125 			/* nope, use the shortcut */
   1126 			shf_puts(s, shf);
   1127 			return;
   1128 		}
   1129 
   1130 		/* otherwise, quote nicely via state machine */
   1131 		while ((c = *p++) != 0) {
   1132 			if (c == '\'') {
   1133 				/*
   1134 				 * multiple single quotes or any of them
   1135 				 * at the beginning of a string look nicer
   1136 				 * this way than when simply substituting
   1137 				 */
   1138 				if (inquote) {
   1139 					shf_putc('\'', shf);
   1140 					inquote = false;
   1141 				}
   1142 				shf_putc('\\', shf);
   1143 			} else if (!inquote) {
   1144 				shf_putc('\'', shf);
   1145 				inquote = true;
   1146 			}
   1147 			shf_putc(c, shf);
   1148 		}
   1149 	} else {
   1150 		unsigned int wc;
   1151 		size_t n;
   1152 
   1153 		/* use $'...' quote format */
   1154 		shf_putc('$', shf);
   1155 		shf_putc('\'', shf);
   1156 		while ((c = *p) != 0) {
   1157 			if (c >= 0xC2) {
   1158 				n = utf_mbtowc(&wc, (const char *)p);
   1159 				if (n != (size_t)-1) {
   1160 					p += n;
   1161 					shf_fprintf(shf, "\\u%04X", wc);
   1162 					continue;
   1163 				}
   1164 			}
   1165 			++p;
   1166 			switch (c) {
   1167 			/* see unbksl() in this file for comments */
   1168 			case 7:
   1169 				c = 'a';
   1170 				if (0)
   1171 					/* FALLTHROUGH */
   1172 			case '\b':
   1173 				  c = 'b';
   1174 				if (0)
   1175 					/* FALLTHROUGH */
   1176 			case '\f':
   1177 				  c = 'f';
   1178 				if (0)
   1179 					/* FALLTHROUGH */
   1180 			case '\n':
   1181 				  c = 'n';
   1182 				if (0)
   1183 					/* FALLTHROUGH */
   1184 			case '\r':
   1185 				  c = 'r';
   1186 				if (0)
   1187 					/* FALLTHROUGH */
   1188 			case '\t':
   1189 				  c = 't';
   1190 				if (0)
   1191 					/* FALLTHROUGH */
   1192 			case 11:
   1193 				  c = 'v';
   1194 				if (0)
   1195 					/* FALLTHROUGH */
   1196 			case '\033':
   1197 				/* take E not e because \e is \ in *roff */
   1198 				  c = 'E';
   1199 				/* FALLTHROUGH */
   1200 			case '\\':
   1201 				shf_putc('\\', shf);
   1202 
   1203 				if (0)
   1204 					/* FALLTHROUGH */
   1205 			default:
   1206 				  if (c < 32 || c > 0x7E) {
   1207 					/* FALLTHROUGH */
   1208 			case '\'':
   1209 					shf_fprintf(shf, "\\%03o", c);
   1210 					break;
   1211 				}
   1212 
   1213 				shf_putc(c, shf);
   1214 				break;
   1215 			}
   1216 		}
   1217 		inquote = true;
   1218 	}
   1219 	if (inquote)
   1220 		shf_putc('\'', shf);
   1221 }
   1222 
   1223 /*
   1224  * Print things in columns and rows - func() is called to format
   1225  * the i-th element
   1226  */
   1227 void
   1228 print_columns(struct shf *shf, unsigned int n,
   1229     void (*func)(char *, size_t, unsigned int, const void *),
   1230     const void *arg, size_t max_oct, size_t max_colz, bool prefcol)
   1231 {
   1232 	unsigned int i, r, c, rows, cols, nspace, max_col;
   1233 	char *str;
   1234 
   1235 	if (!n)
   1236 		return;
   1237 
   1238 	if (max_colz > 2147483646) {
   1239 #ifndef MKSH_SMALL
   1240 		internal_warningf("print_columns called with %s=%zu >= INT_MAX",
   1241 		    "max_col", max_colz);
   1242 #endif
   1243 		return;
   1244 	}
   1245 	max_col = (unsigned int)max_colz;
   1246 
   1247 	if (max_oct > 2147483646) {
   1248 #ifndef MKSH_SMALL
   1249 		internal_warningf("print_columns called with %s=%zu >= INT_MAX",
   1250 		    "max_oct", max_oct);
   1251 #endif
   1252 		return;
   1253 	}
   1254 	++max_oct;
   1255 	str = alloc(max_oct, ATEMP);
   1256 
   1257 	/*
   1258 	 * We use (max_col + 2) to consider the separator space.
   1259 	 * Note that no spaces are printed after the last column
   1260 	 * to avoid problems with terminals that have auto-wrap,
   1261 	 * but we need to also take this into account in x_cols.
   1262 	 */
   1263 	cols = (x_cols + 1) / (max_col + 2);
   1264 
   1265 	/* if we can only print one column anyway, skip the goo */
   1266 	if (cols < 2) {
   1267 		for (i = 0; i < n; ++i) {
   1268 			(*func)(str, max_oct, i, arg);
   1269 			shf_puts(str, shf);
   1270 			shf_putc('\n', shf);
   1271 		}
   1272 		goto out;
   1273 	}
   1274 
   1275 	rows = (n + cols - 1) / cols;
   1276 	if (prefcol && cols > rows) {
   1277 		cols = rows;
   1278 		rows = (n + cols - 1) / cols;
   1279 	}
   1280 
   1281 	nspace = (x_cols - max_col * cols) / cols;
   1282 	if (nspace < 2)
   1283 		nspace = 2;
   1284 	max_col = -max_col;
   1285 	for (r = 0; r < rows; r++) {
   1286 		for (c = 0; c < cols; c++) {
   1287 			if ((i = c * rows + r) >= n)
   1288 				break;
   1289 			(*func)(str, max_oct, i, arg);
   1290 			if (i + rows >= n)
   1291 				shf_puts(str, shf);
   1292 			else
   1293 				shf_fprintf(shf, "%*s%*s",
   1294 				    max_col, str, nspace, null);
   1295 		}
   1296 		shf_putchar('\n', shf);
   1297 	}
   1298  out:
   1299 	afree(str, ATEMP);
   1300 }
   1301 
   1302 /* strip all NUL bytes from buf; output is NUL-terminated if stripped */
   1303 void
   1304 strip_nuls(char *buf, size_t len)
   1305 {
   1306 	char *cp, *dp, *ep;
   1307 
   1308 	if (!len || !(dp = memchr(buf, '\0', len)))
   1309 		return;
   1310 
   1311 	ep = buf + len;
   1312 	cp = dp;
   1313 
   1314  cp_has_nul_byte:
   1315 	while (cp++ < ep && *cp == '\0')
   1316 		;	/* nothing */
   1317 	while (cp < ep && *cp != '\0')
   1318 		*dp++ = *cp++;
   1319 	if (cp < ep)
   1320 		goto cp_has_nul_byte;
   1321 
   1322 	*dp = '\0';
   1323 }
   1324 
   1325 /*
   1326  * Like read(2), but if read fails due to non-blocking flag,
   1327  * resets flag and restarts read.
   1328  */
   1329 ssize_t
   1330 blocking_read(int fd, char *buf, size_t nbytes)
   1331 {
   1332 	ssize_t ret;
   1333 	bool tried_reset = false;
   1334 
   1335 	while ((ret = read(fd, buf, nbytes)) < 0) {
   1336 		if (!tried_reset && errno == EAGAIN) {
   1337 			if (reset_nonblock(fd) > 0) {
   1338 				tried_reset = true;
   1339 				continue;
   1340 			}
   1341 			errno = EAGAIN;
   1342 		}
   1343 		break;
   1344 	}
   1345 	return (ret);
   1346 }
   1347 
   1348 /*
   1349  * Reset the non-blocking flag on the specified file descriptor.
   1350  * Returns -1 if there was an error, 0 if non-blocking wasn't set,
   1351  * 1 if it was.
   1352  */
   1353 int
   1354 reset_nonblock(int fd)
   1355 {
   1356 	int flags;
   1357 
   1358 	if ((flags = fcntl(fd, F_GETFL, 0)) < 0)
   1359 		return (-1);
   1360 	if (!(flags & O_NONBLOCK))
   1361 		return (0);
   1362 	flags &= ~O_NONBLOCK;
   1363 	if (fcntl(fd, F_SETFL, flags) < 0)
   1364 		return (-1);
   1365 	return (1);
   1366 }
   1367 
   1368 /* getcwd(3) equivalent, allocates from ATEMP but doesn't resize */
   1369 char *
   1370 ksh_get_wd(void)
   1371 {
   1372 #ifdef MKSH__NO_PATH_MAX
   1373 	char *rv, *cp;
   1374 
   1375 	if ((cp = get_current_dir_name())) {
   1376 		strdupx(rv, cp, ATEMP);
   1377 		free_gnu_gcdn(cp);
   1378 	} else
   1379 		rv = NULL;
   1380 #else
   1381 	char *rv;
   1382 
   1383 	if (!getcwd((rv = alloc(PATH_MAX + 1, ATEMP)), PATH_MAX)) {
   1384 		afree(rv, ATEMP);
   1385 		rv = NULL;
   1386 	}
   1387 #endif
   1388 
   1389 	return (rv);
   1390 }
   1391 
   1392 #ifndef ELOOP
   1393 #define ELOOP		E2BIG
   1394 #endif
   1395 
   1396 char *
   1397 do_realpath(const char *upath)
   1398 {
   1399 	char *xp, *ip, *tp, *ipath, *ldest = NULL;
   1400 	XString xs;
   1401 	size_t pos, len;
   1402 	int llen;
   1403 	struct stat sb;
   1404 #ifdef MKSH__NO_PATH_MAX
   1405 	size_t ldestlen = 0;
   1406 #define pathlen sb.st_size
   1407 #define pathcnd (ldestlen < (pathlen + 1))
   1408 #else
   1409 #define pathlen PATH_MAX
   1410 #define pathcnd (!ldest)
   1411 #endif
   1412 	/* max. recursion depth */
   1413 	int symlinks = 32;
   1414 
   1415 	if (mksh_abspath(upath)) {
   1416 		/* upath is an absolute pathname */
   1417 		strdupx(ipath, upath, ATEMP);
   1418 	} else {
   1419 		/* upath is a relative pathname, prepend cwd */
   1420 		if ((tp = ksh_get_wd()) == NULL || !mksh_abspath(tp))
   1421 			return (NULL);
   1422 		ipath = shf_smprintf("%s%s%s", tp, "/", upath);
   1423 		afree(tp, ATEMP);
   1424 	}
   1425 
   1426 	/* ipath and upath are in memory at the same time -> unchecked */
   1427 	Xinit(xs, xp, strlen(ip = ipath) + 1, ATEMP);
   1428 
   1429 	/* now jump into the deep of the loop */
   1430 	goto beginning_of_a_pathname;
   1431 
   1432 	while (*ip) {
   1433 		/* skip slashes in input */
   1434 		while (*ip == '/')
   1435 			++ip;
   1436 		if (!*ip)
   1437 			break;
   1438 
   1439 		/* get next pathname component from input */
   1440 		tp = ip;
   1441 		while (*ip && *ip != '/')
   1442 			++ip;
   1443 		len = ip - tp;
   1444 
   1445 		/* check input for "." and ".." */
   1446 		if (tp[0] == '.') {
   1447 			if (len == 1)
   1448 				/* just continue with the next one */
   1449 				continue;
   1450 			else if (len == 2 && tp[1] == '.') {
   1451 				/* strip off last pathname component */
   1452 				while (xp > Xstring(xs, xp))
   1453 					if (*--xp == '/')
   1454 						break;
   1455 				/* then continue with the next one */
   1456 				continue;
   1457 			}
   1458 		}
   1459 
   1460 		/* store output position away, then append slash to output */
   1461 		pos = Xsavepos(xs, xp);
   1462 		/* 1 for the '/' and len + 1 for tp and the NUL from below */
   1463 		XcheckN(xs, xp, 1 + len + 1);
   1464 		Xput(xs, xp, '/');
   1465 
   1466 		/* append next pathname component to output */
   1467 		memcpy(xp, tp, len);
   1468 		xp += len;
   1469 		*xp = '\0';
   1470 
   1471 		/* lstat the current output, see if it's a symlink */
   1472 		if (mksh_lstat(Xstring(xs, xp), &sb)) {
   1473 			/* lstat failed */
   1474 			if (errno == ENOENT) {
   1475 				/* because the pathname does not exist */
   1476 				while (*ip == '/')
   1477 					/* skip any trailing slashes */
   1478 					++ip;
   1479 				/* no more components left? */
   1480 				if (!*ip)
   1481 					/* we can still return successfully */
   1482 					break;
   1483 				/* more components left? fall through */
   1484 			}
   1485 			/* not ENOENT or not at the end of ipath */
   1486 			goto notfound;
   1487 		}
   1488 
   1489 		/* check if we encountered a symlink? */
   1490 		if (S_ISLNK(sb.st_mode)) {
   1491 #ifndef MKSH__NO_SYMLINK
   1492 			/* reached maximum recursion depth? */
   1493 			if (!symlinks--) {
   1494 				/* yep, prevent infinite loops */
   1495 				errno = ELOOP;
   1496 				goto notfound;
   1497 			}
   1498 
   1499 			/* get symlink(7) target */
   1500 			if (pathcnd) {
   1501 #ifdef MKSH__NO_PATH_MAX
   1502 				if (notoktoadd(pathlen, 1)) {
   1503 					errno = ENAMETOOLONG;
   1504 					goto notfound;
   1505 				}
   1506 #endif
   1507 				ldest = aresize(ldest, pathlen + 1, ATEMP);
   1508 			}
   1509 			llen = readlink(Xstring(xs, xp), ldest, pathlen);
   1510 			if (llen < 0)
   1511 				/* oops... */
   1512 				goto notfound;
   1513 			ldest[llen] = '\0';
   1514 
   1515 			/*
   1516 			 * restart if symlink target is an absolute path,
   1517 			 * otherwise continue with currently resolved prefix
   1518 			 */
   1519 			/* append rest of current input path to link target */
   1520 			tp = shf_smprintf("%s%s%s", ldest, *ip ? "/" : "", ip);
   1521 			afree(ipath, ATEMP);
   1522 			ip = ipath = tp;
   1523 			if (!mksh_abspath(ldest)) {
   1524 				/* symlink target is a relative path */
   1525 				xp = Xrestpos(xs, xp, pos);
   1526 			} else
   1527 #endif
   1528 			  {
   1529 				/* symlink target is an absolute path */
   1530 				xp = Xstring(xs, xp);
   1531  beginning_of_a_pathname:
   1532 				/* assert: (ip == ipath)[0] == '/' */
   1533 				/* assert: xp == xs.beg => start of path */
   1534 
   1535 				/* exactly two leading slashes? (SUSv4 3.266) */
   1536 				if (ip[1] == '/' && ip[2] != '/') {
   1537 					/* keep them, e.g. for UNC pathnames */
   1538 					Xput(xs, xp, '/');
   1539 				}
   1540 			}
   1541 		}
   1542 		/* otherwise (no symlink) merely go on */
   1543 	}
   1544 
   1545 	/*
   1546 	 * either found the target and successfully resolved it,
   1547 	 * or found its parent directory and may create it
   1548 	 */
   1549 	if (Xlength(xs, xp) == 0)
   1550 		/*
   1551 		 * if the resolved pathname is "", make it "/",
   1552 		 * otherwise do not add a trailing slash
   1553 		 */
   1554 		Xput(xs, xp, '/');
   1555 	Xput(xs, xp, '\0');
   1556 
   1557 	/*
   1558 	 * if source path had a trailing slash, check if target path
   1559 	 * is not a non-directory existing file
   1560 	 */
   1561 	if (ip > ipath && ip[-1] == '/') {
   1562 		if (stat(Xstring(xs, xp), &sb)) {
   1563 			if (errno != ENOENT)
   1564 				goto notfound;
   1565 		} else if (!S_ISDIR(sb.st_mode)) {
   1566 			errno = ENOTDIR;
   1567 			goto notfound;
   1568 		}
   1569 		/* target now either does not exist or is a directory */
   1570 	}
   1571 
   1572 	/* return target path */
   1573 	afree(ldest, ATEMP);
   1574 	afree(ipath, ATEMP);
   1575 	return (Xclose(xs, xp));
   1576 
   1577  notfound:
   1578 	/* save; freeing memory might trash it */
   1579 	llen = errno;
   1580 	afree(ldest, ATEMP);
   1581 	afree(ipath, ATEMP);
   1582 	Xfree(xs, xp);
   1583 	errno = llen;
   1584 	return (NULL);
   1585 
   1586 #undef pathlen
   1587 #undef pathcnd
   1588 }
   1589 
   1590 /**
   1591  *	Makes a filename into result using the following algorithm.
   1592  *	- make result NULL
   1593  *	- if file starts with '/', append file to result & set cdpathp to NULL
   1594  *	- if file starts with ./ or ../ append cwd and file to result
   1595  *	  and set cdpathp to NULL
   1596  *	- if the first element of cdpathp doesnt start with a '/' xx or '.' xx
   1597  *	  then cwd is appended to result.
   1598  *	- the first element of cdpathp is appended to result
   1599  *	- file is appended to result
   1600  *	- cdpathp is set to the start of the next element in cdpathp (or NULL
   1601  *	  if there are no more elements.
   1602  *	The return value indicates whether a non-null element from cdpathp
   1603  *	was appended to result.
   1604  */
   1605 static int
   1606 make_path(const char *cwd, const char *file,
   1607     /* pointer to colon-separated list */
   1608     char **cdpathp,
   1609     XString *xsp,
   1610     int *phys_pathp)
   1611 {
   1612 	int rval = 0;
   1613 	bool use_cdpath = true;
   1614 	char *plist;
   1615 	size_t len, plen = 0;
   1616 	char *xp = Xstring(*xsp, xp);
   1617 
   1618 	if (!file)
   1619 		file = null;
   1620 
   1621 	if (mksh_abspath(file)) {
   1622 		*phys_pathp = 0;
   1623 		use_cdpath = false;
   1624 	} else {
   1625 		if (file[0] == '.') {
   1626 			char c = file[1];
   1627 
   1628 			if (c == '.')
   1629 				c = file[2];
   1630 			if (c == '/' || c == '\0')
   1631 				use_cdpath = false;
   1632 		}
   1633 
   1634 		plist = *cdpathp;
   1635 		if (!plist)
   1636 			use_cdpath = false;
   1637 		else if (use_cdpath) {
   1638 			char *pend = plist;
   1639 
   1640 			while (*pend && *pend != MKSH_PATHSEPC)
   1641 				++pend;
   1642 			plen = pend - plist;
   1643 			*cdpathp = *pend ? pend + 1 : NULL;
   1644 		}
   1645 
   1646 		if ((!use_cdpath || !plen || !mksh_abspath(plist)) &&
   1647 		    (cwd && *cwd)) {
   1648 			len = strlen(cwd);
   1649 			XcheckN(*xsp, xp, len);
   1650 			memcpy(xp, cwd, len);
   1651 			xp += len;
   1652 			if (cwd[len - 1] != '/')
   1653 				Xput(*xsp, xp, '/');
   1654 		}
   1655 		*phys_pathp = Xlength(*xsp, xp);
   1656 		if (use_cdpath && plen) {
   1657 			XcheckN(*xsp, xp, plen);
   1658 			memcpy(xp, plist, plen);
   1659 			xp += plen;
   1660 			if (plist[plen - 1] != '/')
   1661 				Xput(*xsp, xp, '/');
   1662 			rval = 1;
   1663 		}
   1664 	}
   1665 
   1666 	len = strlen(file) + 1;
   1667 	XcheckN(*xsp, xp, len);
   1668 	memcpy(xp, file, len);
   1669 
   1670 	if (!use_cdpath)
   1671 		*cdpathp = NULL;
   1672 
   1673 	return (rval);
   1674 }
   1675 
   1676 /*-
   1677  * Simplify pathnames containing "." and ".." entries.
   1678  *
   1679  * simplify_path(this)			= that
   1680  * /a/b/c/./../d/..			/a/b
   1681  * //./C/foo/bar/../baz			//C/foo/baz
   1682  * /foo/				/foo
   1683  * /foo/../../bar			/bar
   1684  * /foo/./blah/..			/foo
   1685  * .					.
   1686  * ..					..
   1687  * ./foo				foo
   1688  * foo/../../../bar			../../bar
   1689  */
   1690 void
   1691 simplify_path(char *p)
   1692 {
   1693 	char *dp, *ip, *sp, *tp;
   1694 	size_t len;
   1695 	bool needslash;
   1696 
   1697 	switch (*p) {
   1698 	case 0:
   1699 		return;
   1700 	case '/':
   1701 		/* exactly two leading slashes? (SUSv4 3.266) */
   1702 		if (p[1] == '/' && p[2] != '/')
   1703 			/* keep them, e.g. for UNC pathnames */
   1704 			++p;
   1705 		needslash = true;
   1706 		break;
   1707 	default:
   1708 		needslash = false;
   1709 	}
   1710 	dp = ip = sp = p;
   1711 
   1712 	while (*ip) {
   1713 		/* skip slashes in input */
   1714 		while (*ip == '/')
   1715 			++ip;
   1716 		if (!*ip)
   1717 			break;
   1718 
   1719 		/* get next pathname component from input */
   1720 		tp = ip;
   1721 		while (*ip && *ip != '/')
   1722 			++ip;
   1723 		len = ip - tp;
   1724 
   1725 		/* check input for "." and ".." */
   1726 		if (tp[0] == '.') {
   1727 			if (len == 1)
   1728 				/* just continue with the next one */
   1729 				continue;
   1730 			else if (len == 2 && tp[1] == '.') {
   1731 				/* parent level, but how? */
   1732 				if (mksh_abspath(p))
   1733 					/* absolute path, only one way */
   1734 					goto strip_last_component;
   1735 				else if (dp > sp) {
   1736 					/* relative path, with subpaths */
   1737 					needslash = false;
   1738  strip_last_component:
   1739 					/* strip off last pathname component */
   1740 					while (dp > sp)
   1741 						if (*--dp == '/')
   1742 							break;
   1743 				} else {
   1744 					/* relative path, at its beginning */
   1745 					if (needslash)
   1746 						/* or already dotdot-slash'd */
   1747 						*dp++ = '/';
   1748 					/* keep dotdot-slash if not absolute */
   1749 					*dp++ = '.';
   1750 					*dp++ = '.';
   1751 					needslash = true;
   1752 					sp = dp;
   1753 				}
   1754 				/* then continue with the next one */
   1755 				continue;
   1756 			}
   1757 		}
   1758 
   1759 		if (needslash)
   1760 			*dp++ = '/';
   1761 
   1762 		/* append next pathname component to output */
   1763 		memmove(dp, tp, len);
   1764 		dp += len;
   1765 
   1766 		/* append slash if we continue */
   1767 		needslash = true;
   1768 		/* try next component */
   1769 	}
   1770 	if (dp == p)
   1771 		/* empty path -> dot */
   1772 		*dp++ = needslash ? '/' : '.';
   1773 	*dp = '\0';
   1774 }
   1775 
   1776 void
   1777 set_current_wd(const char *nwd)
   1778 {
   1779 	char *allocd = NULL;
   1780 
   1781 	if (nwd == NULL) {
   1782 		allocd = ksh_get_wd();
   1783 		nwd = allocd ? allocd : null;
   1784 	}
   1785 
   1786 	afree(current_wd, APERM);
   1787 	strdupx(current_wd, nwd, APERM);
   1788 
   1789 	afree(allocd, ATEMP);
   1790 }
   1791 
   1792 int
   1793 c_cd(const char **wp)
   1794 {
   1795 	int optc, rv, phys_path;
   1796 	bool physical = tobool(Flag(FPHYSICAL));
   1797 	/* was a node from cdpath added in? */
   1798 	int cdnode;
   1799 	/* show where we went?, error for $PWD */
   1800 	bool printpath = false, eflag = false;
   1801 	struct tbl *pwd_s, *oldpwd_s;
   1802 	XString xs;
   1803 	char *dir, *allocd = NULL, *tryp, *pwd, *cdpath;
   1804 
   1805 	while ((optc = ksh_getopt(wp, &builtin_opt, "eLP")) != -1)
   1806 		switch (optc) {
   1807 		case 'e':
   1808 			eflag = true;
   1809 			break;
   1810 		case 'L':
   1811 			physical = false;
   1812 			break;
   1813 		case 'P':
   1814 			physical = true;
   1815 			break;
   1816 		case '?':
   1817 			return (2);
   1818 		}
   1819 	wp += builtin_opt.optind;
   1820 
   1821 	if (Flag(FRESTRICTED)) {
   1822 		bi_errorf("restricted shell - can't cd");
   1823 		return (2);
   1824 	}
   1825 
   1826 	pwd_s = global("PWD");
   1827 	oldpwd_s = global("OLDPWD");
   1828 
   1829 	if (!wp[0]) {
   1830 		/* No arguments - go home */
   1831 		if ((dir = str_val(global("HOME"))) == null) {
   1832 			bi_errorf("no home directory (HOME not set)");
   1833 			return (2);
   1834 		}
   1835 	} else if (!wp[1]) {
   1836 		/* One argument: - or dir */
   1837 		strdupx(allocd, wp[0], ATEMP);
   1838 		if (ksh_isdash((dir = allocd))) {
   1839 			afree(allocd, ATEMP);
   1840 			allocd = NULL;
   1841 			dir = str_val(oldpwd_s);
   1842 			if (dir == null) {
   1843 				bi_errorf("no OLDPWD");
   1844 				return (2);
   1845 			}
   1846 			printpath = true;
   1847 		}
   1848 	} else if (!wp[2]) {
   1849 		/* Two arguments - substitute arg1 in PWD for arg2 */
   1850 		size_t ilen, olen, nlen, elen;
   1851 		char *cp;
   1852 
   1853 		if (!current_wd[0]) {
   1854 			bi_errorf("can't determine current directory");
   1855 			return (2);
   1856 		}
   1857 		/*
   1858 		 * substitute arg1 for arg2 in current path.
   1859 		 * if the first substitution fails because the cd fails
   1860 		 * we could try to find another substitution. For now
   1861 		 * we don't
   1862 		 */
   1863 		if ((cp = strstr(current_wd, wp[0])) == NULL) {
   1864 			bi_errorf("bad substitution");
   1865 			return (2);
   1866 		}
   1867 		/*-
   1868 		 * ilen = part of current_wd before wp[0]
   1869 		 * elen = part of current_wd after wp[0]
   1870 		 * because current_wd and wp[1] need to be in memory at the
   1871 		 * same time beforehand the addition can stay unchecked
   1872 		 */
   1873 		ilen = cp - current_wd;
   1874 		olen = strlen(wp[0]);
   1875 		nlen = strlen(wp[1]);
   1876 		elen = strlen(current_wd + ilen + olen) + 1;
   1877 		dir = allocd = alloc(ilen + nlen + elen, ATEMP);
   1878 		memcpy(dir, current_wd, ilen);
   1879 		memcpy(dir + ilen, wp[1], nlen);
   1880 		memcpy(dir + ilen + nlen, current_wd + ilen + olen, elen);
   1881 		printpath = true;
   1882 	} else {
   1883 		bi_errorf("too many arguments");
   1884 		return (2);
   1885 	}
   1886 
   1887 #ifdef MKSH__NO_PATH_MAX
   1888 	/* only a first guess; make_path will enlarge xs if necessary */
   1889 	XinitN(xs, 1024, ATEMP);
   1890 #else
   1891 	XinitN(xs, PATH_MAX, ATEMP);
   1892 #endif
   1893 
   1894 	cdpath = str_val(global("CDPATH"));
   1895 	do {
   1896 		cdnode = make_path(current_wd, dir, &cdpath, &xs, &phys_path);
   1897 		if (physical)
   1898 			rv = chdir(tryp = Xstring(xs, xp) + phys_path);
   1899 		else {
   1900 			simplify_path(Xstring(xs, xp));
   1901 			rv = chdir(tryp = Xstring(xs, xp));
   1902 		}
   1903 	} while (rv < 0 && cdpath != NULL);
   1904 
   1905 	if (rv < 0) {
   1906 		if (cdnode)
   1907 			bi_errorf("%s: %s", dir, "bad directory");
   1908 		else
   1909 			bi_errorf("%s: %s", tryp, cstrerror(errno));
   1910 		afree(allocd, ATEMP);
   1911 		Xfree(xs, xp);
   1912 		return (2);
   1913 	}
   1914 
   1915 	rv = 0;
   1916 
   1917 	/* allocd (above) => dir, which is no longer used */
   1918 	afree(allocd, ATEMP);
   1919 	allocd = NULL;
   1920 
   1921 	/* Clear out tracked aliases with relative paths */
   1922 	flushcom(false);
   1923 
   1924 	/*
   1925 	 * Set OLDPWD (note: unsetting OLDPWD does not disable this
   1926 	 * setting in AT&T ksh)
   1927 	 */
   1928 	if (current_wd[0])
   1929 		/* Ignore failure (happens if readonly or integer) */
   1930 		setstr(oldpwd_s, current_wd, KSH_RETURN_ERROR);
   1931 
   1932 	if (!mksh_abspath(Xstring(xs, xp))) {
   1933 		pwd = NULL;
   1934 	} else if (!physical) {
   1935 		goto norealpath_PWD;
   1936 	} else if ((pwd = allocd = do_realpath(Xstring(xs, xp))) == NULL) {
   1937 		if (eflag)
   1938 			rv = 1;
   1939  norealpath_PWD:
   1940 		pwd = Xstring(xs, xp);
   1941 	}
   1942 
   1943 	/* Set PWD */
   1944 	if (pwd) {
   1945 		char *ptmp = pwd;
   1946 
   1947 		set_current_wd(ptmp);
   1948 		/* Ignore failure (happens if readonly or integer) */
   1949 		setstr(pwd_s, ptmp, KSH_RETURN_ERROR);
   1950 	} else {
   1951 		set_current_wd(null);
   1952 		pwd = Xstring(xs, xp);
   1953 		/* XXX unset $PWD? */
   1954 		if (eflag)
   1955 			rv = 1;
   1956 	}
   1957 	if (printpath || cdnode)
   1958 		shprintf("%s\n", pwd);
   1959 
   1960 	afree(allocd, ATEMP);
   1961 	Xfree(xs, xp);
   1962 	return (rv);
   1963 }
   1964 
   1965 
   1966 #ifdef KSH_CHVT_CODE
   1967 extern void chvt_reinit(void);
   1968 
   1969 static void
   1970 chvt(const Getopt *go)
   1971 {
   1972 	const char *dv = go->optarg;
   1973 	char *cp = NULL;
   1974 	int fd;
   1975 
   1976 	switch (*dv) {
   1977 	case '-':
   1978 		dv = "/dev/null";
   1979 		break;
   1980 	case '!':
   1981 		++dv;
   1982 		/* FALLTHROUGH */
   1983 	default: {
   1984 		struct stat sb;
   1985 
   1986 		if (stat(dv, &sb)) {
   1987 			cp = shf_smprintf("/dev/ttyC%s", dv);
   1988 			dv = cp;
   1989 			if (stat(dv, &sb)) {
   1990 				memmove(cp + 1, cp, /* /dev/tty */ 8);
   1991 				dv = cp + 1;
   1992 				if (stat(dv, &sb)) {
   1993 					errorf("%s: %s: %s", "chvt",
   1994 					    "can't find tty", go->optarg);
   1995 				}
   1996 			}
   1997 		}
   1998 		if (!(sb.st_mode & S_IFCHR))
   1999 			errorf("%s: %s: %s", "chvt", "not a char device", dv);
   2000 #ifndef MKSH_DISABLE_REVOKE_WARNING
   2001 #if HAVE_REVOKE
   2002 		if (revoke(dv))
   2003 #endif
   2004 			warningf(false, "%s: %s %s", "chvt",
   2005 			    "new shell is potentially insecure, can't revoke",
   2006 			    dv);
   2007 #endif
   2008 	    }
   2009 	}
   2010 	if ((fd = binopen2(dv, O_RDWR)) < 0) {
   2011 		sleep(1);
   2012 		if ((fd = binopen2(dv, O_RDWR)) < 0) {
   2013 			errorf("%s: %s %s", "chvt", "can't open", dv);
   2014 		}
   2015 	}
   2016 	if (go->optarg[0] != '!') {
   2017 		switch (fork()) {
   2018 		case -1:
   2019 			errorf("%s: %s %s", "chvt", "fork", "failed");
   2020 		case 0:
   2021 			break;
   2022 		default:
   2023 			exit(0);
   2024 		}
   2025 	}
   2026 	if (setsid() == -1)
   2027 		errorf("%s: %s %s", "chvt", "setsid", "failed");
   2028 	if (go->optarg[0] != '-') {
   2029 		if (ioctl(fd, TIOCSCTTY, NULL) == -1)
   2030 			errorf("%s: %s %s", "chvt", "TIOCSCTTY", "failed");
   2031 		if (tcflush(fd, TCIOFLUSH))
   2032 			errorf("%s: %s %s", "chvt", "TCIOFLUSH", "failed");
   2033 	}
   2034 	ksh_dup2(fd, 0, false);
   2035 	ksh_dup2(fd, 1, false);
   2036 	ksh_dup2(fd, 2, false);
   2037 	if (fd > 2)
   2038 		close(fd);
   2039 	rndset((unsigned long)chvt_rndsetup(go, sizeof(Getopt)));
   2040 	chvt_reinit();
   2041 }
   2042 #endif
   2043 
   2044 #ifdef DEBUG
   2045 char *
   2046 strchr(char *p, int ch)
   2047 {
   2048 	for (;; ++p) {
   2049 		if (*p == ch)
   2050 			return (p);
   2051 		if (!*p)
   2052 			return (NULL);
   2053 	}
   2054 	/* NOTREACHED */
   2055 }
   2056 
   2057 char *
   2058 strstr(char *b, const char *l)
   2059 {
   2060 	char first, c;
   2061 	size_t n;
   2062 
   2063 	if ((first = *l++) == '\0')
   2064 		return (b);
   2065 	n = strlen(l);
   2066  strstr_look:
   2067 	while ((c = *b++) != first)
   2068 		if (c == '\0')
   2069 			return (NULL);
   2070 	if (strncmp(b, l, n))
   2071 		goto strstr_look;
   2072 	return (b - 1);
   2073 }
   2074 #endif
   2075 
   2076 #if defined(MKSH_SMALL) && !defined(MKSH_SMALL_BUT_FAST)
   2077 char *
   2078 strndup_i(const char *src, size_t len, Area *ap)
   2079 {
   2080 	char *dst = NULL;
   2081 
   2082 	if (src != NULL) {
   2083 		dst = alloc(len + 1, ap);
   2084 		memcpy(dst, src, len);
   2085 		dst[len] = '\0';
   2086 	}
   2087 	return (dst);
   2088 }
   2089 
   2090 char *
   2091 strdup_i(const char *src, Area *ap)
   2092 {
   2093 	return (src == NULL ? NULL : strndup_i(src, strlen(src), ap));
   2094 }
   2095 #endif
   2096 
   2097 #if !HAVE_GETRUSAGE
   2098 #define INVTCK(r,t)	do {						\
   2099 	r.tv_usec = ((t) % (1000000 / CLK_TCK)) * (1000000 / CLK_TCK);	\
   2100 	r.tv_sec = (t) / CLK_TCK;					\
   2101 } while (/* CONSTCOND */ 0)
   2102 
   2103 int
   2104 getrusage(int what, struct rusage *ru)
   2105 {
   2106 	struct tms tms;
   2107 	clock_t u, s;
   2108 
   2109 	if (/* ru == NULL || */ times(&tms) == (clock_t)-1)
   2110 		return (-1);
   2111 
   2112 	switch (what) {
   2113 	case RUSAGE_SELF:
   2114 		u = tms.tms_utime;
   2115 		s = tms.tms_stime;
   2116 		break;
   2117 	case RUSAGE_CHILDREN:
   2118 		u = tms.tms_cutime;
   2119 		s = tms.tms_cstime;
   2120 		break;
   2121 	default:
   2122 		errno = EINVAL;
   2123 		return (-1);
   2124 	}
   2125 	INVTCK(ru->ru_utime, u);
   2126 	INVTCK(ru->ru_stime, s);
   2127 	return (0);
   2128 }
   2129 #endif
   2130 
   2131 /*
   2132  * process the string available via fg (get a char)
   2133  * and fp (put back a char) for backslash escapes,
   2134  * assuming the first call to *fg gets the char di-
   2135  * rectly after the backslash; return the character
   2136  * (0..0xFF), Unicode (wc + 0x100), or -1 if no known
   2137  * escape sequence was found
   2138  */
   2139 int
   2140 unbksl(bool cstyle, int (*fg)(void), void (*fp)(int))
   2141 {
   2142 	int wc, i, c, fc;
   2143 
   2144 	fc = (*fg)();
   2145 	switch (fc) {
   2146 	case 'a':
   2147 		/*
   2148 		 * according to the comments in pdksh, \007 seems
   2149 		 * to be more portable than \a (due to HP-UX cc,
   2150 		 * Ultrix cc, old pcc, etc.) so we avoid the escape
   2151 		 * sequence altogether in mksh and assume ASCII
   2152 		 */
   2153 		wc = 7;
   2154 		break;
   2155 	case 'b':
   2156 		wc = '\b';
   2157 		break;
   2158 	case 'c':
   2159 		if (!cstyle)
   2160 			goto unknown_escape;
   2161 		c = (*fg)();
   2162 		wc = CTRL(c);
   2163 		break;
   2164 	case 'E':
   2165 	case 'e':
   2166 		wc = 033;
   2167 		break;
   2168 	case 'f':
   2169 		wc = '\f';
   2170 		break;
   2171 	case 'n':
   2172 		wc = '\n';
   2173 		break;
   2174 	case 'r':
   2175 		wc = '\r';
   2176 		break;
   2177 	case 't':
   2178 		wc = '\t';
   2179 		break;
   2180 	case 'v':
   2181 		/* assume ASCII here as well */
   2182 		wc = 11;
   2183 		break;
   2184 	case '1':
   2185 	case '2':
   2186 	case '3':
   2187 	case '4':
   2188 	case '5':
   2189 	case '6':
   2190 	case '7':
   2191 		if (!cstyle)
   2192 			goto unknown_escape;
   2193 		/* FALLTHROUGH */
   2194 	case '0':
   2195 		if (cstyle)
   2196 			(*fp)(fc);
   2197 		/*
   2198 		 * look for an octal number with up to three
   2199 		 * digits, not counting the leading zero;
   2200 		 * convert it to a raw octet
   2201 		 */
   2202 		wc = 0;
   2203 		i = 3;
   2204 		while (i--)
   2205 			if ((c = (*fg)()) >= ord('0') && c <= ord('7'))
   2206 				wc = (wc << 3) + ksh_numdig(c);
   2207 			else {
   2208 				(*fp)(c);
   2209 				break;
   2210 			}
   2211 		break;
   2212 	case 'U':
   2213 		i = 8;
   2214 		if (/* CONSTCOND */ 0)
   2215 			/* FALLTHROUGH */
   2216 	case 'u':
   2217 		  i = 4;
   2218 		if (/* CONSTCOND */ 0)
   2219 			/* FALLTHROUGH */
   2220 	case 'x':
   2221 		  i = cstyle ? -1 : 2;
   2222 		/**
   2223 		 * x:	look for a hexadecimal number with up to
   2224 		 *	two (C style: arbitrary) digits; convert
   2225 		 *	to raw octet (C style: Unicode if >0xFF)
   2226 		 * u/U:	look for a hexadecimal number with up to
   2227 		 *	four (U: eight) digits; convert to Unicode
   2228 		 */
   2229 		wc = 0;
   2230 		while (i--) {
   2231 			wc <<= 4;
   2232 			if ((c = (*fg)()) >= ord('0') && c <= ord('9'))
   2233 				wc += ksh_numdig(c);
   2234 			else if (c >= ord('A') && c <= ord('F'))
   2235 				wc += ksh_numuc(c) + 10;
   2236 			else if (c >= ord('a') && c <= ord('f'))
   2237 				wc += ksh_numlc(c) + 10;
   2238 			else {
   2239 				wc >>= 4;
   2240 				(*fp)(c);
   2241 				break;
   2242 			}
   2243 		}
   2244 		if ((cstyle && wc > 0xFF) || fc != 'x')
   2245 			/* Unicode marker */
   2246 			wc += 0x100;
   2247 		break;
   2248 	case '\'':
   2249 		if (!cstyle)
   2250 			goto unknown_escape;
   2251 		wc = '\'';
   2252 		break;
   2253 	case '\\':
   2254 		wc = '\\';
   2255 		break;
   2256 	default:
   2257  unknown_escape:
   2258 		(*fp)(fc);
   2259 		return (-1);
   2260 	}
   2261 
   2262 	return (wc);
   2263 }
   2264