• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*	$OpenBSD: misc.c,v 1.37 2009/04/19 20:34:05 sthen Exp $	*/
2 /*	$OpenBSD: path.c,v 1.12 2005/03/30 17:16:37 deraadt Exp $	*/
3 
4 /*-
5  * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
6  *		 2011, 2012
7  *	Thorsten Glaser <tg@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 1.205 2012/12/17 23:18:08 tg Exp $");
34 
35 #define KSH_CHVT_FLAG
36 #ifdef MKSH_SMALL
37 #undef KSH_CHVT_FLAG
38 #endif
39 #ifdef TIOCSCTTY
40 #define KSH_CHVT_CODE
41 #define KSH_CHVT_FLAG
42 #endif
43 #ifdef MKSH_LEGACY_MODE
44 #undef KSH_CHVT_CODE
45 #undef KSH_CHVT_FLAG
46 #endif
47 
48 /* type bits for unsigned char */
49 unsigned char chtypes[UCHAR_MAX + 1];
50 
51 static const unsigned char *pat_scan(const unsigned char *,
52     const unsigned char *, bool);
53 static int do_gmatch(const unsigned char *, const unsigned char *,
54     const unsigned char *, const unsigned char *);
55 static const unsigned char *cclass(const unsigned char *, unsigned char);
56 #ifdef KSH_CHVT_CODE
57 static void chvt(const char *);
58 #endif
59 
60 /*XXX this should go away */
61 static int make_path(const char *, const char *, char **, XString *, int *);
62 
63 #ifdef SETUID_CAN_FAIL_WITH_EAGAIN
64 /* we don't need to check for other codes, EPERM won't happen */
65 #define DO_SETUID(func, argvec) do {					\
66 	if ((func argvec) && errno == EAGAIN)				\
67 		errorf("%s failed with EAGAIN, probably due to a"	\
68 		    " too low process limit; aborting", #func);		\
69 } while (/* CONSTCOND */ 0)
70 #else
71 #define DO_SETUID(func, argvec) func argvec
72 #endif
73 
74 /*
75  * Fast character classes
76  */
77 void
setctypes(const char * s,int t)78 setctypes(const char *s, int t)
79 {
80 	unsigned int i;
81 
82 	if (t & C_IFS) {
83 		for (i = 0; i < UCHAR_MAX + 1; i++)
84 			chtypes[i] &= ~C_IFS;
85 		/* include \0 in C_IFS */
86 		chtypes[0] |= C_IFS;
87 	}
88 	while (*s != 0)
89 		chtypes[(unsigned char)*s++] |= t;
90 }
91 
92 void
initctypes(void)93 initctypes(void)
94 {
95 	int c;
96 
97 	for (c = 'a'; c <= 'z'; c++)
98 		chtypes[c] |= C_ALPHA;
99 	for (c = 'A'; c <= 'Z'; c++)
100 		chtypes[c] |= C_ALPHA;
101 	chtypes['_'] |= C_ALPHA;
102 	setctypes("0123456789", C_DIGIT);
103 	/* \0 added automatically */
104 	setctypes(TC_LEX1, C_LEX1);
105 	setctypes("*@#!$-?", C_VAR1);
106 	setctypes(TC_IFSWS, C_IFSWS);
107 	setctypes("=-+?", C_SUBOP1);
108 	setctypes("\t\n \"#$&'()*;<=>?[\\]`|", C_QUOTE);
109 }
110 
111 /* called from XcheckN() to grow buffer */
112 char *
Xcheck_grow(XString * xsp,const char * xp,size_t more)113 Xcheck_grow(XString *xsp, const char *xp, size_t more)
114 {
115 	const char *old_beg = xsp->beg;
116 
117 	if (more < xsp->len)
118 		more = xsp->len;
119 	/* (xsp->len + X_EXTRA) never overflows */
120 	checkoktoadd(more, xsp->len + X_EXTRA);
121 	xsp->beg = aresize(xsp->beg, (xsp->len += more) + X_EXTRA, xsp->areap);
122 	xsp->end = xsp->beg + xsp->len;
123 	return (xsp->beg + (xp - old_beg));
124 }
125 
126 #define SHFLAGS_DEFNS
127 #include "sh_flags.h"
128 
129 const struct shoption options[] = {
130 #define SHFLAGS_ITEMS
131 #include "sh_flags.h"
132 };
133 
134 /*
135  * translate -o option into F* constant (also used for test -o option)
136  */
137 size_t
option(const char * n)138 option(const char *n)
139 {
140 	size_t i;
141 
142 	if ((n[0] == '-' || n[0] == '+') && n[1] && !n[2]) {
143 		for (i = 0; i < NELEM(options); i++)
144 			if (options[i].c == n[1])
145 				return (i);
146 	} else for (i = 0; i < NELEM(options); i++)
147 		if (options[i].name && strcmp(options[i].name, n) == 0)
148 			return (i);
149 
150 	return ((size_t)-1);
151 }
152 
153 struct options_info {
154 	int opt_width;
155 	int opts[NELEM(options)];
156 };
157 
158 static char *options_fmt_entry(char *, size_t, unsigned int, const void *);
159 static void printoptions(bool);
160 
161 /* format a single select menu item */
162 static char *
options_fmt_entry(char * buf,size_t buflen,unsigned int i,const void * arg)163 options_fmt_entry(char *buf, size_t buflen, unsigned int i, const void *arg)
164 {
165 	const struct options_info *oi = (const struct options_info *)arg;
166 
167 	shf_snprintf(buf, buflen, "%-*s %s",
168 	    oi->opt_width, options[oi->opts[i]].name,
169 	    Flag(oi->opts[i]) ? "on" : "off");
170 	return (buf);
171 }
172 
173 static void
printoptions(bool verbose)174 printoptions(bool verbose)
175 {
176 	size_t i = 0;
177 
178 	if (verbose) {
179 		size_t n = 0, len, octs = 0;
180 		struct options_info oi;
181 
182 		/* verbose version */
183 		shf_puts("Current option settings\n", shl_stdout);
184 
185 		oi.opt_width = 0;
186 		while (i < NELEM(options)) {
187 			if (options[i].name) {
188 				oi.opts[n++] = i;
189 				len = strlen(options[i].name);
190 				if (len > octs)
191 					octs = len;
192 				len = utf_mbswidth(options[i].name);
193 				if ((int)len > oi.opt_width)
194 					oi.opt_width = (int)len;
195 			}
196 			++i;
197 		}
198 		print_columns(shl_stdout, n, options_fmt_entry, &oi,
199 		    octs + 4, oi.opt_width + 4, true);
200 	} else {
201 		/* short version like AT&T ksh93 */
202 		shf_puts(Tset, shl_stdout);
203 		while (i < (int)NELEM(options)) {
204 			if (Flag(i) && options[i].name)
205 				shprintf("%s %s %s", null, "-o",
206 				    options[i].name);
207 			++i;
208 		}
209 		shf_putc('\n', shl_stdout);
210 	}
211 }
212 
213 char *
getoptions(void)214 getoptions(void)
215 {
216 	size_t i;
217 	char m[(int)FNFLAGS + 1];
218 	char *cp = m;
219 
220 	for (i = 0; i < NELEM(options); i++)
221 		if (options[i].c && Flag(i))
222 			*cp++ = options[i].c;
223 	strndupx(cp, m, cp - m, ATEMP);
224 	return (cp);
225 }
226 
227 /* change a Flag(*) value; takes care of special actions */
228 void
change_flag(enum sh_flag f,int what,bool newset)229 change_flag(enum sh_flag f, int what, bool newset)
230 {
231 	unsigned char oldval;
232 	unsigned char newval;
233 
234 	oldval = Flag(f);
235 	Flag(f) = newval = (newset ? 1 : 0);
236 #ifndef MKSH_UNEMPLOYED
237 	if (f == FMONITOR) {
238 		if (what != OF_CMDLINE && newval != oldval)
239 			j_change();
240 	} else
241 #endif
242 #ifndef MKSH_NO_CMDLINE_EDITING
243 	  if ((
244 #if !MKSH_S_NOVI
245 	    f == FVI ||
246 #endif
247 	    f == FEMACS || f == FGMACS) && newval) {
248 #if !MKSH_S_NOVI
249 		Flag(FVI) =
250 #endif
251 		    Flag(FEMACS) = Flag(FGMACS) = 0;
252 		Flag(f) = newval;
253 	} else
254 #endif
255 	  if (f == FPRIVILEGED && oldval && !newval) {
256 		/* Turning off -p? */
257 
258 		/*XXX this can probably be optimised */
259 		kshegid = kshgid = getgid();
260 #if HAVE_SETRESUGID
261 		DO_SETUID(setresgid, (kshegid, kshegid, kshegid));
262 #if HAVE_SETGROUPS
263 		/* setgroups doesn't EAGAIN on Linux */
264 		setgroups(1, &kshegid);
265 #endif
266 		DO_SETUID(setresuid, (ksheuid, ksheuid, ksheuid));
267 #else
268 		/* seteuid, setegid, setgid don't EAGAIN on Linux */
269 		ksheuid = kshuid = getuid();
270 #ifndef MKSH__NO_SETEUGID
271 		seteuid(ksheuid);
272 #endif
273 		DO_SETUID(setuid, (ksheuid));
274 #ifndef MKSH__NO_SETEUGID
275 		setegid(kshegid);
276 #endif
277 		setgid(kshegid);
278 #endif
279 	} else if ((f == FPOSIX || f == FSH) && newval) {
280 		Flag(FPOSIX) = Flag(FSH) = Flag(FBRACEEXPAND) = 0;
281 		Flag(f) = newval;
282 	}
283 	/* Changing interactive flag? */
284 	if (f == FTALKING) {
285 		if ((what == OF_CMDLINE || what == OF_SET) && procpid == kshpid)
286 			Flag(FTALKING_I) = newval;
287 	}
288 }
289 
290 /*
291  * Parse command line and set command arguments. Returns the index of
292  * non-option arguments, -1 if there is an error.
293  */
294 int
parse_args(const char ** argv,int what,bool * setargsp)295 parse_args(const char **argv,
296     /* OF_CMDLINE or OF_SET */
297     int what,
298     bool *setargsp)
299 {
300 	static char cmd_opts[NELEM(options) + 5]; /* o:T:\0 */
301 	static char set_opts[NELEM(options) + 6]; /* A:o;s\0 */
302 	bool set;
303 	char *opts;
304 	const char *array = NULL;
305 	Getopt go;
306 	size_t i;
307 	int optc, arrayset = 0;
308 	bool sortargs = false;
309 
310 	/* First call? Build option strings... */
311 	if (cmd_opts[0] == '\0') {
312 		char *p = cmd_opts, *q = set_opts;
313 
314 		/* see cmd_opts[] declaration */
315 		*p++ = 'o';
316 		*p++ = ':';
317 #ifdef KSH_CHVT_FLAG
318 		*p++ = 'T';
319 		*p++ = ':';
320 #endif
321 		/* see set_opts[] declaration */
322 		*q++ = 'A';
323 		*q++ = ':';
324 		*q++ = 'o';
325 		*q++ = ';';
326 		*q++ = 's';
327 
328 		for (i = 0; i < NELEM(options); i++) {
329 			if (options[i].c) {
330 				if (options[i].flags & OF_CMDLINE)
331 					*p++ = options[i].c;
332 				if (options[i].flags & OF_SET)
333 					*q++ = options[i].c;
334 			}
335 		}
336 		*p = '\0';
337 		*q = '\0';
338 	}
339 
340 	if (what == OF_CMDLINE) {
341 		const char *p = argv[0], *q;
342 		/*
343 		 * Set FLOGIN before parsing options so user can clear
344 		 * flag using +l.
345 		 */
346 		if (*p != '-')
347 			for (q = p; *q; )
348 				if (*q++ == '/')
349 					p = q;
350 		Flag(FLOGIN) = (*p == '-');
351 		opts = cmd_opts;
352 	} else if (what == OF_FIRSTTIME) {
353 		opts = cmd_opts;
354 	} else
355 		opts = set_opts;
356 	ksh_getopt_reset(&go, GF_ERROR|GF_PLUSOPT);
357 	while ((optc = ksh_getopt(argv, &go, opts)) != -1) {
358 		set = tobool(!(go.info & GI_PLUS));
359 		switch (optc) {
360 		case 'A':
361 			if (what == OF_FIRSTTIME)
362 				break;
363 			arrayset = set ? 1 : -1;
364 			array = go.optarg;
365 			break;
366 
367 		case 'o':
368 			if (what == OF_FIRSTTIME)
369 				break;
370 			if (go.optarg == NULL) {
371 				/*
372 				 * lone -o: print options
373 				 *
374 				 * Note that on the command line, -o requires
375 				 * an option (ie, can't get here if what is
376 				 * OF_CMDLINE).
377 				 */
378 				printoptions(set);
379 				break;
380 			}
381 			i = option(go.optarg);
382 			if ((i != (size_t)-1) && (set ? 1U : 0U) == Flag(i))
383 				/*
384 				 * Don't check the context if the flag
385 				 * isn't changing - makes "set -o interactive"
386 				 * work if you're already interactive. Needed
387 				 * if the output of "set +o" is to be used.
388 				 */
389 				;
390 			else if ((i != (size_t)-1) && (options[i].flags & what))
391 				change_flag((enum sh_flag)i, what, set);
392 			else {
393 				bi_errorf("%s: %s", go.optarg, "bad option");
394 				return (-1);
395 			}
396 			break;
397 
398 #ifdef KSH_CHVT_FLAG
399 		case 'T':
400 			if (what != OF_FIRSTTIME)
401 				break;
402 #ifndef KSH_CHVT_CODE
403 			errorf("no TIOCSCTTY ioctl");
404 #else
405 			change_flag(FTALKING, OF_CMDLINE, true);
406 			chvt(go.optarg);
407 			break;
408 #endif
409 #endif
410 
411 		case '?':
412 			return (-1);
413 
414 		default:
415 			if (what == OF_FIRSTTIME)
416 				break;
417 			/* -s: sort positional params (AT&T ksh stupidity) */
418 			if (what == OF_SET && optc == 's') {
419 				sortargs = true;
420 				break;
421 			}
422 			for (i = 0; i < NELEM(options); i++)
423 				if (optc == options[i].c &&
424 				    (what & options[i].flags)) {
425 					change_flag((enum sh_flag)i, what, set);
426 					break;
427 				}
428 			if (i == NELEM(options))
429 				internal_errorf("parse_args: '%c'", optc);
430 		}
431 	}
432 	if (!(go.info & GI_MINUSMINUS) && argv[go.optind] &&
433 	    (argv[go.optind][0] == '-' || argv[go.optind][0] == '+') &&
434 	    argv[go.optind][1] == '\0') {
435 		/* lone - clears -v and -x flags */
436 		if (argv[go.optind][0] == '-')
437 			Flag(FVERBOSE) = Flag(FXTRACE) = 0;
438 		/* set skips lone - or + option */
439 		go.optind++;
440 	}
441 	if (setargsp)
442 		/* -- means set $#/$* even if there are no arguments */
443 		*setargsp = !arrayset && ((go.info & GI_MINUSMINUS) ||
444 		    argv[go.optind]);
445 
446 	if (arrayset) {
447 		const char *ccp = NULL;
448 
449 		mkssert(array != NULL);
450 		if (*array)
451 			ccp = skip_varname(array, false);
452 		if (!ccp || !(!ccp[0] || (ccp[0] == '+' && !ccp[1]))) {
453 			bi_errorf("%s: %s", array, "is not an identifier");
454 			return (-1);
455 		}
456 	}
457 	if (sortargs) {
458 		for (i = go.optind; argv[i]; i++)
459 			;
460 		qsort(&argv[go.optind], i - go.optind, sizeof(void *),
461 		    xstrcmp);
462 	}
463 	if (arrayset)
464 		go.optind += set_array(array, tobool(arrayset > 0),
465 		    argv + go.optind);
466 
467 	return (go.optind);
468 }
469 
470 /* parse a decimal number: returns 0 if string isn't a number, 1 otherwise */
471 int
getn(const char * s,int * ai)472 getn(const char *s, int *ai)
473 {
474 	char c;
475 	unsigned int i = 0;
476 	bool neg = false;
477 
478 	do {
479 		c = *s++;
480 	} while (ksh_isspace(c));
481 
482 	switch (c) {
483 	case '-':
484 		neg = true;
485 		/* FALLTHROUGH */
486 	case '+':
487 		c = *s++;
488 		break;
489 	}
490 
491 	do {
492 		if (!ksh_isdigit(c))
493 			/* not numeric */
494 			return (0);
495 		if (i > 214748364U)
496 			/* overflow on multiplication */
497 			return (0);
498 		i = i * 10U + (unsigned int)(c - '0');
499 		/* now: i <= 2147483649U */
500 	} while ((c = *s++));
501 
502 	if (i > (neg ? 2147483648U : 2147483647U))
503 		/* overflow for signed 32-bit int */
504 		return (0);
505 
506 	*ai = neg ? -(int)i : (int)i;
507 	return (1);
508 }
509 
510 /**
511  * pattern simplifications:
512  * - @(x) -> x (not @(x|y) though)
513  * - ** -> *
514  */
515 static void *
simplify_gmatch_pattern(const unsigned char * sp)516 simplify_gmatch_pattern(const unsigned char *sp)
517 {
518 	uint8_t c;
519 	unsigned char *cp, *dp;
520 	const unsigned char *ps, *se;
521 
522 	cp = alloc(strlen((const void *)sp) + 1, ATEMP);
523 	goto simplify_gmatch_pat1a;
524 
525 	/* foo@(b@(a)r)b@(a|a)z -> foobarb@(a|a)z */
526  simplify_gmatch_pat1:
527 	sp = cp;
528  simplify_gmatch_pat1a:
529 	dp = cp;
530 	se = sp + strlen((const void *)sp);
531 	while ((c = *sp++)) {
532 		if (!ISMAGIC(c)) {
533 			*dp++ = c;
534 			continue;
535 		}
536 		switch ((c = *sp++)) {
537 		case 0x80|'@':
538 		/* simile for @ */
539 		case 0x80|' ':
540 			/* check whether it has only one clause */
541 			ps = pat_scan(sp, se, true);
542 			if (!ps || ps[-1] != /*(*/ ')')
543 				/* nope */
544 				break;
545 			/* copy inner clause until matching close */
546 			ps -= 2;
547 			while ((const unsigned char *)sp < ps)
548 				*dp++ = *sp++;
549 			/* skip MAGIC and closing parenthesis */
550 			sp += 2;
551 			/* copy the rest of the pattern */
552 			memmove(dp, sp, strlen((const void *)sp) + 1);
553 			/* redo from start */
554 			goto simplify_gmatch_pat1;
555 		}
556 		*dp++ = MAGIC;
557 		*dp++ = c;
558 	}
559 	*dp = '\0';
560 
561 	/* collapse adjacent asterisk wildcards */
562 	sp = dp = cp;
563 	while ((c = *sp++)) {
564 		if (!ISMAGIC(c)) {
565 			*dp++ = c;
566 			continue;
567 		}
568 		switch ((c = *sp++)) {
569 		case '*':
570 			while (ISMAGIC(sp[0]) && sp[1] == c)
571 				sp += 2;
572 			break;
573 		}
574 		*dp++ = MAGIC;
575 		*dp++ = c;
576 	}
577 	*dp = '\0';
578 
579 	/* return the result, allocated from ATEMP */
580 	return (cp);
581 }
582 
583 /* -------- gmatch.c -------- */
584 
585 /*
586  * int gmatch(string, pattern)
587  * char *string, *pattern;
588  *
589  * Match a pattern as in sh(1).
590  * pattern character are prefixed with MAGIC by expand.
591  */
592 int
gmatchx(const char * s,const char * p,bool isfile)593 gmatchx(const char *s, const char *p, bool isfile)
594 {
595 	const char *se, *pe;
596 	char *pnew;
597 	int rv;
598 
599 	if (s == NULL || p == NULL)
600 		return (0);
601 
602 	se = s + strlen(s);
603 	pe = p + strlen(p);
604 	/*
605 	 * isfile is false iff no syntax check has been done on
606 	 * the pattern. If check fails, just to a strcmp().
607 	 */
608 	if (!isfile && !has_globbing(p, pe)) {
609 		size_t len = pe - p + 1;
610 		char tbuf[64];
611 		char *t = len <= sizeof(tbuf) ? tbuf : alloc(len, ATEMP);
612 		debunk(t, p, len);
613 		return (!strcmp(t, s));
614 	}
615 
616 	/*
617 	 * since the do_gmatch() engine sucks so much, we must do some
618 	 * pattern simplifications
619 	 */
620 	pnew = simplify_gmatch_pattern((const unsigned char *)p);
621 	pe = pnew + strlen(pnew);
622 
623 	rv = do_gmatch((const unsigned char *)s, (const unsigned char *)se,
624 	    (const unsigned char *)pnew, (const unsigned char *)pe);
625 	afree(pnew, ATEMP);
626 	return (rv);
627 }
628 
629 /**
630  * Returns if p is a syntacticly correct globbing pattern, false
631  * if it contains no pattern characters or if there is a syntax error.
632  * Syntax errors are:
633  *	- [ with no closing ]
634  *	- imbalanced $(...) expression
635  *	- [...] and *(...) not nested (eg, [a$(b|]c), *(a[b|c]d))
636  */
637 /*XXX
638  * - if no magic,
639  *	if dest given, copy to dst
640  *	return ?
641  * - if magic && (no globbing || syntax error)
642  *	debunk to dst
643  *	return ?
644  * - return ?
645  */
646 int
has_globbing(const char * xp,const char * xpe)647 has_globbing(const char *xp, const char *xpe)
648 {
649 	const unsigned char *p = (const unsigned char *) xp;
650 	const unsigned char *pe = (const unsigned char *) xpe;
651 	int c;
652 	int nest = 0, bnest = 0;
653 	bool saw_glob = false;
654 	/* inside [...] */
655 	bool in_bracket = false;
656 
657 	for (; p < pe; p++) {
658 		if (!ISMAGIC(*p))
659 			continue;
660 		if ((c = *++p) == '*' || c == '?')
661 			saw_glob = true;
662 		else if (c == '[') {
663 			if (!in_bracket) {
664 				saw_glob = true;
665 				in_bracket = true;
666 				if (ISMAGIC(p[1]) && p[2] == '!')
667 					p += 2;
668 				if (ISMAGIC(p[1]) && p[2] == ']')
669 					p += 2;
670 			}
671 			/*XXX Do we need to check ranges here? POSIX Q */
672 		} else if (c == ']') {
673 			if (in_bracket) {
674 				if (bnest)
675 					/* [a*(b]) */
676 					return (0);
677 				in_bracket = false;
678 			}
679 		} else if ((c & 0x80) && vstrchr("*+?@! ", c & 0x7f)) {
680 			saw_glob = true;
681 			if (in_bracket)
682 				bnest++;
683 			else
684 				nest++;
685 		} else if (c == '|') {
686 			if (in_bracket && !bnest)
687 				/* *(a[foo|bar]) */
688 				return (0);
689 		} else if (c == /*(*/ ')') {
690 			if (in_bracket) {
691 				if (!bnest--)
692 					/* *(a[b)c] */
693 					return (0);
694 			} else if (nest)
695 				nest--;
696 		}
697 		/*
698 		 * else must be a MAGIC-MAGIC, or MAGIC-!,
699 		 * MAGIC--, MAGIC-], MAGIC-{, MAGIC-, MAGIC-}
700 		 */
701 	}
702 	return (saw_glob && !in_bracket && !nest);
703 }
704 
705 /* Function must return either 0 or 1 (assumed by code for 0x80|'!') */
706 static int
do_gmatch(const unsigned char * s,const unsigned char * se,const unsigned char * p,const unsigned char * pe)707 do_gmatch(const unsigned char *s, const unsigned char *se,
708     const unsigned char *p, const unsigned char *pe)
709 {
710 	unsigned char sc, pc;
711 	const unsigned char *prest, *psub, *pnext;
712 	const unsigned char *srest;
713 
714 	if (s == NULL || p == NULL)
715 		return (0);
716 	while (p < pe) {
717 		pc = *p++;
718 		sc = s < se ? *s : '\0';
719 		s++;
720 		if (!ISMAGIC(pc)) {
721 			if (sc != pc)
722 				return (0);
723 			continue;
724 		}
725 		switch (*p++) {
726 		case '[':
727 			if (sc == 0 || (p = cclass(p, sc)) == NULL)
728 				return (0);
729 			break;
730 
731 		case '?':
732 			if (sc == 0)
733 				return (0);
734 			if (UTFMODE) {
735 				--s;
736 				s += utf_ptradj((const void *)s);
737 			}
738 			break;
739 
740 		case '*':
741 			if (p == pe)
742 				return (1);
743 			s--;
744 			do {
745 				if (do_gmatch(s, se, p, pe))
746 					return (1);
747 			} while (s++ < se);
748 			return (0);
749 
750 		/**
751 		 * [*+?@!](pattern|pattern|..)
752 		 * This is also needed for ${..%..}, etc.
753 		 */
754 
755 		/* matches one or more times */
756 		case 0x80|'+':
757 		/* matches zero or more times */
758 		case 0x80|'*':
759 			if (!(prest = pat_scan(p, pe, false)))
760 				return (0);
761 			s--;
762 			/* take care of zero matches */
763 			if (p[-1] == (0x80 | '*') &&
764 			    do_gmatch(s, se, prest, pe))
765 				return (1);
766 			for (psub = p; ; psub = pnext) {
767 				pnext = pat_scan(psub, pe, true);
768 				for (srest = s; srest <= se; srest++) {
769 					if (do_gmatch(s, srest, psub, pnext - 2) &&
770 					    (do_gmatch(srest, se, prest, pe) ||
771 					    (s != srest && do_gmatch(srest,
772 					    se, p - 2, pe))))
773 						return (1);
774 				}
775 				if (pnext == prest)
776 					break;
777 			}
778 			return (0);
779 
780 		/* matches zero or once */
781 		case 0x80|'?':
782 		/* matches one of the patterns */
783 		case 0x80|'@':
784 		/* simile for @ */
785 		case 0x80|' ':
786 			if (!(prest = pat_scan(p, pe, false)))
787 				return (0);
788 			s--;
789 			/* Take care of zero matches */
790 			if (p[-1] == (0x80 | '?') &&
791 			    do_gmatch(s, se, prest, pe))
792 				return (1);
793 			for (psub = p; ; psub = pnext) {
794 				pnext = pat_scan(psub, pe, true);
795 				srest = prest == pe ? se : s;
796 				for (; srest <= se; srest++) {
797 					if (do_gmatch(s, srest, psub, pnext - 2) &&
798 					    do_gmatch(srest, se, prest, pe))
799 						return (1);
800 				}
801 				if (pnext == prest)
802 					break;
803 			}
804 			return (0);
805 
806 		/* matches none of the patterns */
807 		case 0x80|'!':
808 			if (!(prest = pat_scan(p, pe, false)))
809 				return (0);
810 			s--;
811 			for (srest = s; srest <= se; srest++) {
812 				int matched = 0;
813 
814 				for (psub = p; ; psub = pnext) {
815 					pnext = pat_scan(psub, pe, true);
816 					if (do_gmatch(s, srest, psub,
817 					    pnext - 2)) {
818 						matched = 1;
819 						break;
820 					}
821 					if (pnext == prest)
822 						break;
823 				}
824 				if (!matched &&
825 				    do_gmatch(srest, se, prest, pe))
826 					return (1);
827 			}
828 			return (0);
829 
830 		default:
831 			if (sc != p[-1])
832 				return (0);
833 			break;
834 		}
835 	}
836 	return (s == se);
837 }
838 
839 static const unsigned char *
cclass(const unsigned char * p,unsigned char sub)840 cclass(const unsigned char *p, unsigned char sub)
841 {
842 	unsigned char c, d;
843 	bool notp, found = false;
844 	const unsigned char *orig_p = p;
845 
846 	if ((notp = tobool(ISMAGIC(*p) && *++p == '!')))
847 		p++;
848 	do {
849 		c = *p++;
850 		if (ISMAGIC(c)) {
851 			c = *p++;
852 			if ((c & 0x80) && !ISMAGIC(c)) {
853 				/* extended pattern matching: *+?@! */
854 				c &= 0x7F;
855 				/* XXX the ( char isn't handled as part of [] */
856 				if (c == ' ')
857 					/* simile for @: plain (..) */
858 					c = '(' /*)*/;
859 			}
860 		}
861 		if (c == '\0')
862 			/* No closing ] - act as if the opening [ was quoted */
863 			return (sub == '[' ? orig_p : NULL);
864 		if (ISMAGIC(p[0]) && p[1] == '-' &&
865 		    (!ISMAGIC(p[2]) || p[3] != ']')) {
866 			/* MAGIC- */
867 			p += 2;
868 			d = *p++;
869 			if (ISMAGIC(d)) {
870 				d = *p++;
871 				if ((d & 0x80) && !ISMAGIC(d))
872 					d &= 0x7f;
873 			}
874 			/* POSIX says this is an invalid expression */
875 			if (c > d)
876 				return (NULL);
877 		} else
878 			d = c;
879 		if (c == sub || (c <= sub && sub <= d))
880 			found = true;
881 	} while (!(ISMAGIC(p[0]) && p[1] == ']'));
882 
883 	return ((found != notp) ? p+2 : NULL);
884 }
885 
886 /* Look for next ) or | (if match_sep) in *(foo|bar) pattern */
887 static const unsigned char *
pat_scan(const unsigned char * p,const unsigned char * pe,bool match_sep)888 pat_scan(const unsigned char *p, const unsigned char *pe, bool match_sep)
889 {
890 	int nest = 0;
891 
892 	for (; p < pe; p++) {
893 		if (!ISMAGIC(*p))
894 			continue;
895 		if ((*++p == /*(*/ ')' && nest-- == 0) ||
896 		    (*p == '|' && match_sep && nest == 0))
897 			return (p + 1);
898 		if ((*p & 0x80) && vstrchr("*+?@! ", *p & 0x7f))
899 			nest++;
900 	}
901 	return (NULL);
902 }
903 
904 int
xstrcmp(const void * p1,const void * p2)905 xstrcmp(const void *p1, const void *p2)
906 {
907 	return (strcmp(*(const char * const *)p1, *(const char * const *)p2));
908 }
909 
910 /* Initialise a Getopt structure */
911 void
ksh_getopt_reset(Getopt * go,int flags)912 ksh_getopt_reset(Getopt *go, int flags)
913 {
914 	go->optind = 1;
915 	go->optarg = NULL;
916 	go->p = 0;
917 	go->flags = flags;
918 	go->info = 0;
919 	go->buf[1] = '\0';
920 }
921 
922 
923 /**
924  * getopt() used for shell built-in commands, the getopts command, and
925  * command line options.
926  * A leading ':' in options means don't print errors, instead return '?'
927  * or ':' and set go->optarg to the offending option character.
928  * If GF_ERROR is set (and option doesn't start with :), errors result in
929  * a call to bi_errorf().
930  *
931  * Non-standard features:
932  *	- ';' is like ':' in options, except the argument is optional
933  *	  (if it isn't present, optarg is set to 0).
934  *	  Used for 'set -o'.
935  *	- ',' is like ':' in options, except the argument always immediately
936  *	  follows the option character (optarg is set to the null string if
937  *	  the option is missing).
938  *	  Used for 'read -u2', 'print -u2' and fc -40.
939  *	- '#' is like ':' in options, expect that the argument is optional
940  *	  and must start with a digit. If the argument doesn't start with a
941  *	  digit, it is assumed to be missing and normal option processing
942  *	  continues (optarg is set to 0 if the option is missing).
943  *	  Used for 'typeset -LZ4'.
944  *	- accepts +c as well as -c IF the GF_PLUSOPT flag is present. If an
945  *	  option starting with + is accepted, the GI_PLUS flag will be set
946  *	  in go->info.
947  */
948 int
ksh_getopt(const char ** argv,Getopt * go,const char * optionsp)949 ksh_getopt(const char **argv, Getopt *go, const char *optionsp)
950 {
951 	char c;
952 	const char *o;
953 
954 	if (go->p == 0 || (c = argv[go->optind - 1][go->p]) == '\0') {
955 		const char *arg = argv[go->optind], flag = arg ? *arg : '\0';
956 
957 		go->p = 1;
958 		if (flag == '-' && arg[1] == '-' && arg[2] == '\0') {
959 			go->optind++;
960 			go->p = 0;
961 			go->info |= GI_MINUSMINUS;
962 			return (-1);
963 		}
964 		if (arg == NULL ||
965 		    ((flag != '-' ) &&
966 		    /* neither a - nor a + (if + allowed) */
967 		    (!(go->flags & GF_PLUSOPT) || flag != '+')) ||
968 		    (c = arg[1]) == '\0') {
969 			go->p = 0;
970 			return (-1);
971 		}
972 		go->optind++;
973 		go->info &= ~(GI_MINUS|GI_PLUS);
974 		go->info |= flag == '-' ? GI_MINUS : GI_PLUS;
975 	}
976 	go->p++;
977 	if (c == '?' || c == ':' || c == ';' || c == ',' || c == '#' ||
978 	    !(o = cstrchr(optionsp, c))) {
979 		if (optionsp[0] == ':') {
980 			go->buf[0] = c;
981 			go->optarg = go->buf;
982 		} else {
983 			warningf(true, "%s%s-%c: %s",
984 			    (go->flags & GF_NONAME) ? "" : argv[0],
985 			    (go->flags & GF_NONAME) ? "" : ": ", c,
986 			    "unknown option");
987 			if (go->flags & GF_ERROR)
988 				bi_errorfz();
989 		}
990 		return ('?');
991 	}
992 	/**
993 	 * : means argument must be present, may be part of option argument
994 	 *   or the next argument
995 	 * ; same as : but argument may be missing
996 	 * , means argument is part of option argument, and may be null.
997 	 */
998 	if (*++o == ':' || *o == ';') {
999 		if (argv[go->optind - 1][go->p])
1000 			go->optarg = argv[go->optind - 1] + go->p;
1001 		else if (argv[go->optind])
1002 			go->optarg = argv[go->optind++];
1003 		else if (*o == ';')
1004 			go->optarg = NULL;
1005 		else {
1006 			if (optionsp[0] == ':') {
1007 				go->buf[0] = c;
1008 				go->optarg = go->buf;
1009 				return (':');
1010 			}
1011 			warningf(true, "%s%s-%c: %s",
1012 			    (go->flags & GF_NONAME) ? "" : argv[0],
1013 			    (go->flags & GF_NONAME) ? "" : ": ", c,
1014 			    "requires an argument");
1015 			if (go->flags & GF_ERROR)
1016 				bi_errorfz();
1017 			return ('?');
1018 		}
1019 		go->p = 0;
1020 	} else if (*o == ',') {
1021 		/* argument is attached to option character, even if null */
1022 		go->optarg = argv[go->optind - 1] + go->p;
1023 		go->p = 0;
1024 	} else if (*o == '#') {
1025 		/*
1026 		 * argument is optional and may be attached or unattached
1027 		 * but must start with a digit. optarg is set to 0 if the
1028 		 * argument is missing.
1029 		 */
1030 		if (argv[go->optind - 1][go->p]) {
1031 			if (ksh_isdigit(argv[go->optind - 1][go->p])) {
1032 				go->optarg = argv[go->optind - 1] + go->p;
1033 				go->p = 0;
1034 			} else
1035 				go->optarg = NULL;
1036 		} else {
1037 			if (argv[go->optind] && ksh_isdigit(argv[go->optind][0])) {
1038 				go->optarg = argv[go->optind++];
1039 				go->p = 0;
1040 			} else
1041 				go->optarg = NULL;
1042 		}
1043 	}
1044 	return (c);
1045 }
1046 
1047 /*
1048  * print variable/alias value using necessary quotes
1049  * (POSIX says they should be suitable for re-entry...)
1050  * No trailing newline is printed.
1051  */
1052 void
print_value_quoted(struct shf * shf,const char * s)1053 print_value_quoted(struct shf *shf, const char *s)
1054 {
1055 	unsigned char c;
1056 	const unsigned char *p = (const unsigned char *)s;
1057 	bool inquote = true;
1058 
1059 	/* first, check whether any quotes are needed */
1060 	while ((c = *p++) >= 32)
1061 		if (ctype(c, C_QUOTE))
1062 			inquote = false;
1063 
1064 	p = (const unsigned char *)s;
1065 	if (c == 0) {
1066 		if (inquote) {
1067 			/* nope, use the shortcut */
1068 			shf_puts(s, shf);
1069 			return;
1070 		}
1071 
1072 		/* otherwise, quote nicely via state machine */
1073 		while ((c = *p++) != 0) {
1074 			if (c == '\'') {
1075 				/*
1076 				 * multiple single quotes or any of them
1077 				 * at the beginning of a string look nicer
1078 				 * this way than when simply substituting
1079 				 */
1080 				if (inquote) {
1081 					shf_putc('\'', shf);
1082 					inquote = false;
1083 				}
1084 				shf_putc('\\', shf);
1085 			} else if (!inquote) {
1086 				shf_putc('\'', shf);
1087 				inquote = true;
1088 			}
1089 			shf_putc(c, shf);
1090 		}
1091 	} else {
1092 		unsigned int wc;
1093 		size_t n;
1094 
1095 		/* use $'...' quote format */
1096 		shf_putc('$', shf);
1097 		shf_putc('\'', shf);
1098 		while ((c = *p) != 0) {
1099 			if (c >= 0xC2) {
1100 				n = utf_mbtowc(&wc, (const char *)p);
1101 				if (n != (size_t)-1) {
1102 					p += n;
1103 					shf_fprintf(shf, "\\u%04X", wc);
1104 					continue;
1105 				}
1106 			}
1107 			++p;
1108 			switch (c) {
1109 			/* see unbksl() in this file for comments */
1110 			case 7:
1111 				c = 'a';
1112 				if (0)
1113 					/* FALLTHROUGH */
1114 			case '\b':
1115 				  c = 'b';
1116 				if (0)
1117 					/* FALLTHROUGH */
1118 			case '\f':
1119 				  c = 'f';
1120 				if (0)
1121 					/* FALLTHROUGH */
1122 			case '\n':
1123 				  c = 'n';
1124 				if (0)
1125 					/* FALLTHROUGH */
1126 			case '\r':
1127 				  c = 'r';
1128 				if (0)
1129 					/* FALLTHROUGH */
1130 			case '\t':
1131 				  c = 't';
1132 				if (0)
1133 					/* FALLTHROUGH */
1134 			case 11:
1135 				  c = 'v';
1136 				if (0)
1137 					/* FALLTHROUGH */
1138 			case '\033':
1139 				/* take E not e because \e is \ in *roff */
1140 				  c = 'E';
1141 				/* FALLTHROUGH */
1142 			case '\\':
1143 				shf_putc('\\', shf);
1144 
1145 				if (0)
1146 					/* FALLTHROUGH */
1147 			default:
1148 				  if (c < 32 || c > 0x7E) {
1149 					/* FALLTHROUGH */
1150 			case '\'':
1151 					shf_fprintf(shf, "\\%03o", c);
1152 					break;
1153 				}
1154 
1155 				shf_putc(c, shf);
1156 				break;
1157 			}
1158 		}
1159 		inquote = true;
1160 	}
1161 	if (inquote)
1162 		shf_putc('\'', shf);
1163 }
1164 
1165 /*
1166  * Print things in columns and rows - func() is called to format
1167  * the i-th element
1168  */
1169 void
print_columns(struct shf * shf,unsigned int n,char * (* func)(char *,size_t,unsigned int,const void *),const void * arg,size_t max_oct,size_t max_colz,bool prefcol)1170 print_columns(struct shf *shf, unsigned int n,
1171     char *(*func)(char *, size_t, unsigned int, const void *),
1172     const void *arg, size_t max_oct, size_t max_colz, bool prefcol)
1173 {
1174 	unsigned int i, r, c, rows, cols, nspace, max_col;
1175 	char *str;
1176 
1177 	if (!n)
1178 		return;
1179 
1180 	if (max_colz > 2147483646) {
1181 #ifndef MKSH_SMALL
1182 		internal_warningf("print_columns called with %s=%zu >= INT_MAX",
1183 		    "max_col", max_colz);
1184 #endif
1185 		return;
1186 	}
1187 	max_col = (unsigned int)max_colz;
1188 
1189 	if (max_oct > 2147483646) {
1190 #ifndef MKSH_SMALL
1191 		internal_warningf("print_columns called with %s=%zu >= INT_MAX",
1192 		    "max_oct", max_oct);
1193 #endif
1194 		return;
1195 	}
1196 	++max_oct;
1197 	str = alloc(max_oct, ATEMP);
1198 
1199 	/*
1200 	 * We use (max_col + 1) to consider the space separator.
1201 	 * Note that no space is printed after the last column
1202 	 * to avoid problems with terminals that have auto-wrap.
1203 	 */
1204 	cols = x_cols / (max_col + 1);
1205 
1206 	/* if we can only print one column anyway, skip the goo */
1207 	if (cols < 2) {
1208 		for (i = 0; i < n; ++i)
1209 			shf_fprintf(shf, "%s \n",
1210 			    (*func)(str, max_oct, i, arg));
1211 		goto out;
1212 	}
1213 
1214 	rows = (n + cols - 1) / cols;
1215 	if (prefcol && cols > rows) {
1216 		i = rows;
1217 		rows = cols > n ? n : cols;
1218 		cols = i;
1219 	}
1220 
1221 	max_col = -max_col;
1222 	nspace = (x_cols + max_col * cols) / cols;
1223 	if (nspace <= 0)
1224 		nspace = 1;
1225 	for (r = 0; r < rows; r++) {
1226 		for (c = 0; c < cols; c++) {
1227 			i = c * rows + r;
1228 			if (i < n) {
1229 				shf_fprintf(shf, "%*s", max_col,
1230 				    (*func)(str, max_oct, i, arg));
1231 				if (c + 1 < cols)
1232 					shf_fprintf(shf, "%*s", nspace, null);
1233 			}
1234 		}
1235 		shf_putchar('\n', shf);
1236 	}
1237  out:
1238 	afree(str, ATEMP);
1239 }
1240 
1241 /* Strip any nul bytes from buf - returns new length (nbytes - # of nuls) */
1242 void
strip_nuls(char * buf,int nbytes)1243 strip_nuls(char *buf, int nbytes)
1244 {
1245 	char *dst;
1246 
1247 	/*
1248 	 * nbytes check because some systems (older FreeBSDs) have a
1249 	 * buggy memchr()
1250 	 */
1251 	if (nbytes && (dst = memchr(buf, '\0', nbytes))) {
1252 		char *end = buf + nbytes;
1253 		char *p, *q;
1254 
1255 		for (p = dst; p < end; p = q) {
1256 			/* skip a block of nulls */
1257 			while (++p < end && *p == '\0')
1258 				;
1259 			/* find end of non-null block */
1260 			if (!(q = memchr(p, '\0', end - p)))
1261 				q = end;
1262 			memmove(dst, p, q - p);
1263 			dst += q - p;
1264 		}
1265 		*dst = '\0';
1266 	}
1267 }
1268 
1269 /*
1270  * Like read(2), but if read fails due to non-blocking flag,
1271  * resets flag and restarts read.
1272  */
1273 ssize_t
blocking_read(int fd,char * buf,size_t nbytes)1274 blocking_read(int fd, char *buf, size_t nbytes)
1275 {
1276 	ssize_t ret;
1277 	bool tried_reset = false;
1278 
1279 	while ((ret = read(fd, buf, nbytes)) < 0) {
1280 		if (!tried_reset && errno == EAGAIN) {
1281 			if (reset_nonblock(fd) > 0) {
1282 				tried_reset = true;
1283 				continue;
1284 			}
1285 			errno = EAGAIN;
1286 		}
1287 		break;
1288 	}
1289 	return (ret);
1290 }
1291 
1292 /*
1293  * Reset the non-blocking flag on the specified file descriptor.
1294  * Returns -1 if there was an error, 0 if non-blocking wasn't set,
1295  * 1 if it was.
1296  */
1297 int
reset_nonblock(int fd)1298 reset_nonblock(int fd)
1299 {
1300 	int flags;
1301 
1302 	if ((flags = fcntl(fd, F_GETFL, 0)) < 0)
1303 		return (-1);
1304 	if (!(flags & O_NONBLOCK))
1305 		return (0);
1306 	flags &= ~O_NONBLOCK;
1307 	if (fcntl(fd, F_SETFL, flags) < 0)
1308 		return (-1);
1309 	return (1);
1310 }
1311 
1312 /* getcwd(3) equivalent, allocates from ATEMP but doesn't resize */
1313 char *
ksh_get_wd(void)1314 ksh_get_wd(void)
1315 {
1316 #ifdef MKSH__NO_PATH_MAX
1317 	char *rv, *cp;
1318 
1319 	if ((cp = get_current_dir_name())) {
1320 		strdupx(rv, cp, ATEMP);
1321 		free_gnu_gcdn(cp);
1322 	} else
1323 		rv = NULL;
1324 #else
1325 	char *rv;
1326 
1327 	if (!getcwd((rv = alloc(PATH_MAX + 1, ATEMP)), PATH_MAX)) {
1328 		afree(rv, ATEMP);
1329 		rv = NULL;
1330 	}
1331 #endif
1332 
1333 	return (rv);
1334 }
1335 
1336 #ifndef ELOOP
1337 #define ELOOP		E2BIG
1338 #endif
1339 
1340 char *
do_realpath(const char * upath)1341 do_realpath(const char *upath)
1342 {
1343 	char *xp, *ip, *tp, *ipath, *ldest = NULL;
1344 	XString xs;
1345 	ptrdiff_t pos;
1346 	size_t len;
1347 	int llen;
1348 	struct stat sb;
1349 #ifdef MKSH__NO_PATH_MAX
1350 	size_t ldestlen = 0;
1351 #define pathlen sb.st_size
1352 #define pathcnd (ldestlen < (pathlen + 1))
1353 #else
1354 #define pathlen PATH_MAX
1355 #define pathcnd (!ldest)
1356 #endif
1357 	/* max. recursion depth */
1358 	int symlinks = 32;
1359 
1360 	if (upath[0] == '/') {
1361 		/* upath is an absolute pathname */
1362 		strdupx(ipath, upath, ATEMP);
1363 	} else {
1364 		/* upath is a relative pathname, prepend cwd */
1365 		if ((tp = ksh_get_wd()) == NULL || tp[0] != '/')
1366 			return (NULL);
1367 		ipath = shf_smprintf("%s%s%s", tp, "/", upath);
1368 		afree(tp, ATEMP);
1369 	}
1370 
1371 	/* ipath and upath are in memory at the same time -> unchecked */
1372 	Xinit(xs, xp, strlen(ip = ipath) + 1, ATEMP);
1373 
1374 	/* now jump into the deep of the loop */
1375 	goto beginning_of_a_pathname;
1376 
1377 	while (*ip) {
1378 		/* skip slashes in input */
1379 		while (*ip == '/')
1380 			++ip;
1381 		if (!*ip)
1382 			break;
1383 
1384 		/* get next pathname component from input */
1385 		tp = ip;
1386 		while (*ip && *ip != '/')
1387 			++ip;
1388 		len = ip - tp;
1389 
1390 		/* check input for "." and ".." */
1391 		if (tp[0] == '.') {
1392 			if (len == 1)
1393 				/* just continue with the next one */
1394 				continue;
1395 			else if (len == 2 && tp[1] == '.') {
1396 				/* strip off last pathname component */
1397 				while (xp > Xstring(xs, xp))
1398 					if (*--xp == '/')
1399 						break;
1400 				/* then continue with the next one */
1401 				continue;
1402 			}
1403 		}
1404 
1405 		/* store output position away, then append slash to output */
1406 		pos = Xsavepos(xs, xp);
1407 		/* 1 for the '/' and len + 1 for tp and the NUL from below */
1408 		XcheckN(xs, xp, 1 + len + 1);
1409 		Xput(xs, xp, '/');
1410 
1411 		/* append next pathname component to output */
1412 		memcpy(xp, tp, len);
1413 		xp += len;
1414 		*xp = '\0';
1415 
1416 		/* lstat the current output, see if it's a symlink */
1417 		if (mksh_lstat(Xstring(xs, xp), &sb)) {
1418 			/* lstat failed */
1419 			if (errno == ENOENT) {
1420 				/* because the pathname does not exist */
1421 				while (*ip == '/')
1422 					/* skip any trailing slashes */
1423 					++ip;
1424 				/* no more components left? */
1425 				if (!*ip)
1426 					/* we can still return successfully */
1427 					break;
1428 				/* more components left? fall through */
1429 			}
1430 			/* not ENOENT or not at the end of ipath */
1431 			goto notfound;
1432 		}
1433 
1434 		/* check if we encountered a symlink? */
1435 		if (S_ISLNK(sb.st_mode)) {
1436 #ifndef MKSH__NO_SYMLINK
1437 			/* reached maximum recursion depth? */
1438 			if (!symlinks--) {
1439 				/* yep, prevent infinite loops */
1440 				errno = ELOOP;
1441 				goto notfound;
1442 			}
1443 
1444 			/* get symlink(7) target */
1445 			if (pathcnd) {
1446 #ifdef MKSH__NO_PATH_MAX
1447 				if (notoktoadd(pathlen, 1)) {
1448 					errno = ENAMETOOLONG;
1449 					goto notfound;
1450 				}
1451 #endif
1452 				ldest = aresize(ldest, pathlen + 1, ATEMP);
1453 			}
1454 			llen = readlink(Xstring(xs, xp), ldest, pathlen);
1455 			if (llen < 0)
1456 				/* oops... */
1457 				goto notfound;
1458 			ldest[llen] = '\0';
1459 
1460 			/*
1461 			 * restart if symlink target is an absolute path,
1462 			 * otherwise continue with currently resolved prefix
1463 			 */
1464 			/* append rest of current input path to link target */
1465 			tp = shf_smprintf("%s%s%s", ldest, *ip ? "/" : "", ip);
1466 			afree(ipath, ATEMP);
1467 			ip = ipath = tp;
1468 			if (ldest[0] != '/') {
1469 				/* symlink target is a relative path */
1470 				xp = Xrestpos(xs, xp, pos);
1471 			} else
1472 #endif
1473 			  {
1474 				/* symlink target is an absolute path */
1475 				xp = Xstring(xs, xp);
1476  beginning_of_a_pathname:
1477 				/* assert: (ip == ipath)[0] == '/' */
1478 				/* assert: xp == xs.beg => start of path */
1479 
1480 				/* exactly two leading slashes? (SUSv4 3.266) */
1481 				if (ip[1] == '/' && ip[2] != '/') {
1482 					/* keep them, e.g. for UNC pathnames */
1483 					Xput(xs, xp, '/');
1484 				}
1485 			}
1486 		}
1487 		/* otherwise (no symlink) merely go on */
1488 	}
1489 
1490 	/*
1491 	 * either found the target and successfully resolved it,
1492 	 * or found its parent directory and may create it
1493 	 */
1494 	if (Xlength(xs, xp) == 0)
1495 		/*
1496 		 * if the resolved pathname is "", make it "/",
1497 		 * otherwise do not add a trailing slash
1498 		 */
1499 		Xput(xs, xp, '/');
1500 	Xput(xs, xp, '\0');
1501 
1502 	/*
1503 	 * if source path had a trailing slash, check if target path
1504 	 * is not a non-directory existing file
1505 	 */
1506 	if (ip > ipath && ip[-1] == '/') {
1507 		if (stat(Xstring(xs, xp), &sb)) {
1508 			if (errno != ENOENT)
1509 				goto notfound;
1510 		} else if (!S_ISDIR(sb.st_mode)) {
1511 			errno = ENOTDIR;
1512 			goto notfound;
1513 		}
1514 		/* target now either does not exist or is a directory */
1515 	}
1516 
1517 	/* return target path */
1518 	if (ldest != NULL)
1519 		afree(ldest, ATEMP);
1520 	afree(ipath, ATEMP);
1521 	return (Xclose(xs, xp));
1522 
1523  notfound:
1524 	/* save; freeing memory might trash it */
1525 	llen = errno;
1526 	if (ldest != NULL)
1527 		afree(ldest, ATEMP);
1528 	afree(ipath, ATEMP);
1529 	Xfree(xs, xp);
1530 	errno = llen;
1531 	return (NULL);
1532 
1533 #undef pathlen
1534 #undef pathcnd
1535 }
1536 
1537 /**
1538  *	Makes a filename into result using the following algorithm.
1539  *	- make result NULL
1540  *	- if file starts with '/', append file to result & set cdpathp to NULL
1541  *	- if file starts with ./ or ../ append cwd and file to result
1542  *	  and set cdpathp to NULL
1543  *	- if the first element of cdpathp doesnt start with a '/' xx or '.' xx
1544  *	  then cwd is appended to result.
1545  *	- the first element of cdpathp is appended to result
1546  *	- file is appended to result
1547  *	- cdpathp is set to the start of the next element in cdpathp (or NULL
1548  *	  if there are no more elements.
1549  *	The return value indicates whether a non-null element from cdpathp
1550  *	was appended to result.
1551  */
1552 static int
make_path(const char * cwd,const char * file,char ** cdpathp,XString * xsp,int * phys_pathp)1553 make_path(const char *cwd, const char *file,
1554     /* pointer to colon-separated list */
1555     char **cdpathp,
1556     XString *xsp,
1557     int *phys_pathp)
1558 {
1559 	int rval = 0;
1560 	bool use_cdpath = true;
1561 	char *plist;
1562 	size_t len, plen = 0;
1563 	char *xp = Xstring(*xsp, xp);
1564 
1565 	if (!file)
1566 		file = null;
1567 
1568 	if (file[0] == '/') {
1569 		*phys_pathp = 0;
1570 		use_cdpath = false;
1571 	} else {
1572 		if (file[0] == '.') {
1573 			char c = file[1];
1574 
1575 			if (c == '.')
1576 				c = file[2];
1577 			if (c == '/' || c == '\0')
1578 				use_cdpath = false;
1579 		}
1580 
1581 		plist = *cdpathp;
1582 		if (!plist)
1583 			use_cdpath = false;
1584 		else if (use_cdpath) {
1585 			char *pend;
1586 
1587 			for (pend = plist; *pend && *pend != ':'; pend++)
1588 				;
1589 			plen = pend - plist;
1590 			*cdpathp = *pend ? pend + 1 : NULL;
1591 		}
1592 
1593 		if ((!use_cdpath || !plen || plist[0] != '/') &&
1594 		    (cwd && *cwd)) {
1595 			len = strlen(cwd);
1596 			XcheckN(*xsp, xp, len);
1597 			memcpy(xp, cwd, len);
1598 			xp += len;
1599 			if (cwd[len - 1] != '/')
1600 				Xput(*xsp, xp, '/');
1601 		}
1602 		*phys_pathp = Xlength(*xsp, xp);
1603 		if (use_cdpath && plen) {
1604 			XcheckN(*xsp, xp, plen);
1605 			memcpy(xp, plist, plen);
1606 			xp += plen;
1607 			if (plist[plen - 1] != '/')
1608 				Xput(*xsp, xp, '/');
1609 			rval = 1;
1610 		}
1611 	}
1612 
1613 	len = strlen(file) + 1;
1614 	XcheckN(*xsp, xp, len);
1615 	memcpy(xp, file, len);
1616 
1617 	if (!use_cdpath)
1618 		*cdpathp = NULL;
1619 
1620 	return (rval);
1621 }
1622 
1623 /*-
1624  * Simplify pathnames containing "." and ".." entries.
1625  *
1626  * simplify_path(this)			= that
1627  * /a/b/c/./../d/..			/a/b
1628  * //./C/foo/bar/../baz			//C/foo/baz
1629  * /foo/				/foo
1630  * /foo/../../bar			/bar
1631  * /foo/./blah/..			/foo
1632  * .					.
1633  * ..					..
1634  * ./foo				foo
1635  * foo/../../../bar			../../bar
1636  */
1637 void
simplify_path(char * p)1638 simplify_path(char *p)
1639 {
1640 	char *dp, *ip, *sp, *tp;
1641 	size_t len;
1642 	bool needslash;
1643 
1644 	switch (*p) {
1645 	case 0:
1646 		return;
1647 	case '/':
1648 		/* exactly two leading slashes? (SUSv4 3.266) */
1649 		if (p[1] == '/' && p[2] != '/')
1650 			/* keep them, e.g. for UNC pathnames */
1651 			++p;
1652 		needslash = true;
1653 		break;
1654 	default:
1655 		needslash = false;
1656 	}
1657 	dp = ip = sp = p;
1658 
1659 	while (*ip) {
1660 		/* skip slashes in input */
1661 		while (*ip == '/')
1662 			++ip;
1663 		if (!*ip)
1664 			break;
1665 
1666 		/* get next pathname component from input */
1667 		tp = ip;
1668 		while (*ip && *ip != '/')
1669 			++ip;
1670 		len = ip - tp;
1671 
1672 		/* check input for "." and ".." */
1673 		if (tp[0] == '.') {
1674 			if (len == 1)
1675 				/* just continue with the next one */
1676 				continue;
1677 			else if (len == 2 && tp[1] == '.') {
1678 				/* parent level, but how? */
1679 				if (*p == '/')
1680 					/* absolute path, only one way */
1681 					goto strip_last_component;
1682 				else if (dp > sp) {
1683 					/* relative path, with subpaths */
1684 					needslash = false;
1685  strip_last_component:
1686 					/* strip off last pathname component */
1687 					while (dp > sp)
1688 						if (*--dp == '/')
1689 							break;
1690 				} else {
1691 					/* relative path, at its beginning */
1692 					if (needslash)
1693 						/* or already dotdot-slash'd */
1694 						*dp++ = '/';
1695 					/* keep dotdot-slash if not absolute */
1696 					*dp++ = '.';
1697 					*dp++ = '.';
1698 					needslash = true;
1699 					sp = dp;
1700 				}
1701 				/* then continue with the next one */
1702 				continue;
1703 			}
1704 		}
1705 
1706 		if (needslash)
1707 			*dp++ = '/';
1708 
1709 		/* append next pathname component to output */
1710 		memmove(dp, tp, len);
1711 		dp += len;
1712 
1713 		/* append slash if we continue */
1714 		needslash = true;
1715 		/* try next component */
1716 	}
1717 	if (dp == p)
1718 		/* empty path -> dot */
1719 		*dp++ = needslash ? '/' : '.';
1720 	*dp = '\0';
1721 }
1722 
1723 void
set_current_wd(const char * nwd)1724 set_current_wd(const char *nwd)
1725 {
1726 	char *allocd = NULL;
1727 
1728 	if (nwd == NULL) {
1729 		allocd = ksh_get_wd();
1730 		nwd = allocd ? allocd : null;
1731 	}
1732 
1733 	afree(current_wd, APERM);
1734 	strdupx(current_wd, nwd, APERM);
1735 
1736 	afree(allocd, ATEMP);
1737 }
1738 
1739 int
c_cd(const char ** wp)1740 c_cd(const char **wp)
1741 {
1742 	int optc, rv, phys_path;
1743 	bool physical = tobool(Flag(FPHYSICAL));
1744 	/* was a node from cdpath added in? */
1745 	int cdnode;
1746 	/* show where we went?, error for $PWD */
1747 	bool printpath = false, eflag = false;
1748 	struct tbl *pwd_s, *oldpwd_s;
1749 	XString xs;
1750 	char *dir, *allocd = NULL, *tryp, *pwd, *cdpath;
1751 
1752 	while ((optc = ksh_getopt(wp, &builtin_opt, "eLP")) != -1)
1753 		switch (optc) {
1754 		case 'e':
1755 			eflag = true;
1756 			break;
1757 		case 'L':
1758 			physical = false;
1759 			break;
1760 		case 'P':
1761 			physical = true;
1762 			break;
1763 		case '?':
1764 			return (2);
1765 		}
1766 	wp += builtin_opt.optind;
1767 
1768 	if (Flag(FRESTRICTED)) {
1769 		bi_errorf("restricted shell - can't cd");
1770 		return (2);
1771 	}
1772 
1773 	pwd_s = global("PWD");
1774 	oldpwd_s = global("OLDPWD");
1775 
1776 	if (!wp[0]) {
1777 		/* No arguments - go home */
1778 		if ((dir = str_val(global("HOME"))) == null) {
1779 			bi_errorf("no home directory (HOME not set)");
1780 			return (2);
1781 		}
1782 	} else if (!wp[1]) {
1783 		/* One argument: - or dir */
1784 		strdupx(allocd, wp[0], ATEMP);
1785 		if (ksh_isdash((dir = allocd))) {
1786 			afree(allocd, ATEMP);
1787 			allocd = NULL;
1788 			dir = str_val(oldpwd_s);
1789 			if (dir == null) {
1790 				bi_errorf("no OLDPWD");
1791 				return (2);
1792 			}
1793 			printpath = true;
1794 		}
1795 	} else if (!wp[2]) {
1796 		/* Two arguments - substitute arg1 in PWD for arg2 */
1797 		size_t ilen, olen, nlen, elen;
1798 		char *cp;
1799 
1800 		if (!current_wd[0]) {
1801 			bi_errorf("can't determine current directory");
1802 			return (2);
1803 		}
1804 		/*
1805 		 * substitute arg1 for arg2 in current path.
1806 		 * if the first substitution fails because the cd fails
1807 		 * we could try to find another substitution. For now
1808 		 * we don't
1809 		 */
1810 		if ((cp = strstr(current_wd, wp[0])) == NULL) {
1811 			bi_errorf("bad substitution");
1812 			return (2);
1813 		}
1814 		/*-
1815 		 * ilen = part of current_wd before wp[0]
1816 		 * elen = part of current_wd after wp[0]
1817 		 * because current_wd and wp[1] need to be in memory at the
1818 		 * same time beforehand the addition can stay unchecked
1819 		 */
1820 		ilen = cp - current_wd;
1821 		olen = strlen(wp[0]);
1822 		nlen = strlen(wp[1]);
1823 		elen = strlen(current_wd + ilen + olen) + 1;
1824 		dir = allocd = alloc(ilen + nlen + elen, ATEMP);
1825 		memcpy(dir, current_wd, ilen);
1826 		memcpy(dir + ilen, wp[1], nlen);
1827 		memcpy(dir + ilen + nlen, current_wd + ilen + olen, elen);
1828 		printpath = true;
1829 	} else {
1830 		bi_errorf("too many arguments");
1831 		return (2);
1832 	}
1833 
1834 #ifdef MKSH__NO_PATH_MAX
1835 	/* only a first guess; make_path will enlarge xs if necessary */
1836 	XinitN(xs, 1024, ATEMP);
1837 #else
1838 	XinitN(xs, PATH_MAX, ATEMP);
1839 #endif
1840 
1841 	cdpath = str_val(global("CDPATH"));
1842 	do {
1843 		cdnode = make_path(current_wd, dir, &cdpath, &xs, &phys_path);
1844 		if (physical)
1845 			rv = chdir(tryp = Xstring(xs, xp) + phys_path);
1846 		else {
1847 			simplify_path(Xstring(xs, xp));
1848 			rv = chdir(tryp = Xstring(xs, xp));
1849 		}
1850 	} while (rv < 0 && cdpath != NULL);
1851 
1852 	if (rv < 0) {
1853 		if (cdnode)
1854 			bi_errorf("%s: %s", dir, "bad directory");
1855 		else
1856 			bi_errorf("%s: %s", tryp, cstrerror(errno));
1857 		afree(allocd, ATEMP);
1858 		Xfree(xs, xp);
1859 		return (2);
1860 	}
1861 
1862 	rv = 0;
1863 
1864 	/* allocd (above) => dir, which is no longer used */
1865 	afree(allocd, ATEMP);
1866 	allocd = NULL;
1867 
1868 	/* Clear out tracked aliases with relative paths */
1869 	flushcom(false);
1870 
1871 	/*
1872 	 * Set OLDPWD (note: unsetting OLDPWD does not disable this
1873 	 * setting in AT&T ksh)
1874 	 */
1875 	if (current_wd[0])
1876 		/* Ignore failure (happens if readonly or integer) */
1877 		setstr(oldpwd_s, current_wd, KSH_RETURN_ERROR);
1878 
1879 	if (Xstring(xs, xp)[0] != '/') {
1880 		pwd = NULL;
1881 	} else if (!physical) {
1882 		goto norealpath_PWD;
1883 	} else if ((pwd = allocd = do_realpath(Xstring(xs, xp))) == NULL) {
1884 		if (eflag)
1885 			rv = 1;
1886  norealpath_PWD:
1887 		pwd = Xstring(xs, xp);
1888 	}
1889 
1890 	/* Set PWD */
1891 	if (pwd) {
1892 		char *ptmp = pwd;
1893 
1894 		set_current_wd(ptmp);
1895 		/* Ignore failure (happens if readonly or integer) */
1896 		setstr(pwd_s, ptmp, KSH_RETURN_ERROR);
1897 	} else {
1898 		set_current_wd(null);
1899 		pwd = Xstring(xs, xp);
1900 		/* XXX unset $PWD? */
1901 		if (eflag)
1902 			rv = 1;
1903 	}
1904 	if (printpath || cdnode)
1905 		shprintf("%s\n", pwd);
1906 
1907 	afree(allocd, ATEMP);
1908 	Xfree(xs, xp);
1909 	return (rv);
1910 }
1911 
1912 
1913 #ifdef KSH_CHVT_CODE
1914 extern void chvt_reinit(void);
1915 
1916 static void
chvt(const char * fn)1917 chvt(const char *fn)
1918 {
1919 	char dv[20];
1920 	struct stat sb;
1921 	int fd;
1922 
1923 	if (*fn == '-') {
1924 		memcpy(dv, "-/dev/null", sizeof("-/dev/null"));
1925 		fn = dv + 1;
1926 	} else {
1927 		if (stat(fn, &sb)) {
1928 			memcpy(dv, "/dev/ttyC", 9);
1929 			strlcpy(dv + 9, fn, sizeof(dv) - 9);
1930 			if (stat(dv, &sb)) {
1931 				strlcpy(dv + 8, fn, sizeof(dv) - 8);
1932 				if (stat(dv, &sb))
1933 					errorf("%s: %s %s", "chvt",
1934 					    "can't find tty", fn);
1935 			}
1936 			fn = dv;
1937 		}
1938 		if (!(sb.st_mode & S_IFCHR))
1939 			errorf("%s %s %s", "chvt: not a char", "device", fn);
1940 		if ((sb.st_uid != 0) && chown(fn, 0, 0))
1941 			warningf(false, "%s: %s %s", "chvt", "can't chown root", fn);
1942 		if (((sb.st_mode & 07777) != 0600) && chmod(fn, (mode_t)0600))
1943 			warningf(false, "%s: %s %s", "chvt", "can't chmod 0600", fn);
1944 #if HAVE_REVOKE
1945 		if (revoke(fn))
1946 #endif
1947 			warningf(false, "%s: %s %s", "chvt",
1948 			    "new shell is potentially insecure, can't revoke",
1949 			    fn);
1950 	}
1951 	if ((fd = open(fn, O_RDWR)) < 0) {
1952 		sleep(1);
1953 		if ((fd = open(fn, O_RDWR)) < 0)
1954 			errorf("%s: %s %s", "chvt", "can't open", fn);
1955 	}
1956 	switch (fork()) {
1957 	case -1:
1958 		errorf("%s: %s %s", "chvt", "fork", "failed");
1959 	case 0:
1960 		break;
1961 	default:
1962 		exit(0);
1963 	}
1964 	if (setsid() == -1)
1965 		errorf("%s: %s %s", "chvt", "setsid", "failed");
1966 	if (fn != dv + 1) {
1967 		if (ioctl(fd, TIOCSCTTY, NULL) == -1)
1968 			errorf("%s: %s %s", "chvt", "TIOCSCTTY", "failed");
1969 		if (tcflush(fd, TCIOFLUSH))
1970 			errorf("%s: %s %s", "chvt", "TCIOFLUSH", "failed");
1971 	}
1972 	ksh_dup2(fd, 0, false);
1973 	ksh_dup2(fd, 1, false);
1974 	ksh_dup2(fd, 2, false);
1975 	if (fd > 2)
1976 		close(fd);
1977 	{
1978 		register uint32_t h;
1979 
1980 		NZATInit(h);
1981 		NZATUpdateMem(h, &rndsetupstate, sizeof(rndsetupstate));
1982 		NZAATFinish(h);
1983 		rndset((long)h);
1984 	}
1985 	chvt_reinit();
1986 }
1987 #endif
1988 
1989 #ifdef DEBUG
1990 char *
strchr(char * p,int ch)1991 strchr(char *p, int ch)
1992 {
1993 	for (;; ++p) {
1994 		if (*p == ch)
1995 			return (p);
1996 		if (!*p)
1997 			return (NULL);
1998 	}
1999 	/* NOTREACHED */
2000 }
2001 
2002 char *
strstr(char * b,const char * l)2003 strstr(char *b, const char *l)
2004 {
2005 	char first, c;
2006 	size_t n;
2007 
2008 	if ((first = *l++) == '\0')
2009 		return (b);
2010 	n = strlen(l);
2011  strstr_look:
2012 	while ((c = *b++) != first)
2013 		if (c == '\0')
2014 			return (NULL);
2015 	if (strncmp(b, l, n))
2016 		goto strstr_look;
2017 	return (b - 1);
2018 }
2019 #endif
2020 
2021 #if defined(MKSH_SMALL) && !defined(MKSH_SMALL_BUT_FAST)
2022 char *
strndup_i(const char * src,size_t len,Area * ap)2023 strndup_i(const char *src, size_t len, Area *ap)
2024 {
2025 	char *dst = NULL;
2026 
2027 	if (src != NULL) {
2028 		dst = alloc(len + 1, ap);
2029 		memcpy(dst, src, len);
2030 		dst[len] = '\0';
2031 	}
2032 	return (dst);
2033 }
2034 
2035 char *
strdup_i(const char * src,Area * ap)2036 strdup_i(const char *src, Area *ap)
2037 {
2038 	return (src == NULL ? NULL : strndup_i(src, strlen(src), ap));
2039 }
2040 #endif
2041 
2042 #if !HAVE_GETRUSAGE
2043 #define INVTCK(r,t)	do {						\
2044 	r.tv_usec = ((t) % (1000000 / CLK_TCK)) * (1000000 / CLK_TCK);	\
2045 	r.tv_sec = (t) / CLK_TCK;					\
2046 } while (/* CONSTCOND */ 0)
2047 
2048 int
getrusage(int what,struct rusage * ru)2049 getrusage(int what, struct rusage *ru)
2050 {
2051 	struct tms tms;
2052 	clock_t u, s;
2053 
2054 	if (/* ru == NULL || */ times(&tms) == (clock_t)-1)
2055 		return (-1);
2056 
2057 	switch (what) {
2058 	case RUSAGE_SELF:
2059 		u = tms.tms_utime;
2060 		s = tms.tms_stime;
2061 		break;
2062 	case RUSAGE_CHILDREN:
2063 		u = tms.tms_cutime;
2064 		s = tms.tms_cstime;
2065 		break;
2066 	default:
2067 		errno = EINVAL;
2068 		return (-1);
2069 	}
2070 	INVTCK(ru->ru_utime, u);
2071 	INVTCK(ru->ru_stime, s);
2072 	return (0);
2073 }
2074 #endif
2075 
2076 /*
2077  * process the string available via fg (get a char)
2078  * and fp (put back a char) for backslash escapes,
2079  * assuming the first call to *fg gets the char di-
2080  * rectly after the backslash; return the character
2081  * (0..0xFF), Unicode (wc + 0x100), or -1 if no known
2082  * escape sequence was found
2083  */
2084 int
unbksl(bool cstyle,int (* fg)(void),void (* fp)(int))2085 unbksl(bool cstyle, int (*fg)(void), void (*fp)(int))
2086 {
2087 	int wc, i, c, fc;
2088 
2089 	fc = (*fg)();
2090 	switch (fc) {
2091 	case 'a':
2092 		/*
2093 		 * according to the comments in pdksh, \007 seems
2094 		 * to be more portable than \a (due to HP-UX cc,
2095 		 * Ultrix cc, old pcc, etc.) so we avoid the escape
2096 		 * sequence altogether in mksh and assume ASCII
2097 		 */
2098 		wc = 7;
2099 		break;
2100 	case 'b':
2101 		wc = '\b';
2102 		break;
2103 	case 'c':
2104 		if (!cstyle)
2105 			goto unknown_escape;
2106 		c = (*fg)();
2107 		wc = CTRL(c);
2108 		break;
2109 	case 'E':
2110 	case 'e':
2111 		wc = 033;
2112 		break;
2113 	case 'f':
2114 		wc = '\f';
2115 		break;
2116 	case 'n':
2117 		wc = '\n';
2118 		break;
2119 	case 'r':
2120 		wc = '\r';
2121 		break;
2122 	case 't':
2123 		wc = '\t';
2124 		break;
2125 	case 'v':
2126 		/* assume ASCII here as well */
2127 		wc = 11;
2128 		break;
2129 	case '1':
2130 	case '2':
2131 	case '3':
2132 	case '4':
2133 	case '5':
2134 	case '6':
2135 	case '7':
2136 		if (!cstyle)
2137 			goto unknown_escape;
2138 		/* FALLTHROUGH */
2139 	case '0':
2140 		if (cstyle)
2141 			(*fp)(fc);
2142 		/*
2143 		 * look for an octal number with up to three
2144 		 * digits, not counting the leading zero;
2145 		 * convert it to a raw octet
2146 		 */
2147 		wc = 0;
2148 		i = 3;
2149 		while (i--)
2150 			if ((c = (*fg)()) >= '0' && c <= '7')
2151 				wc = (wc << 3) + (c - '0');
2152 			else {
2153 				(*fp)(c);
2154 				break;
2155 			}
2156 		break;
2157 	case 'U':
2158 		i = 8;
2159 		if (/* CONSTCOND */ 0)
2160 		/* FALLTHROUGH */
2161 	case 'u':
2162 		i = 4;
2163 		if (/* CONSTCOND */ 0)
2164 		/* FALLTHROUGH */
2165 	case 'x':
2166 		i = cstyle ? -1 : 2;
2167 		/**
2168 		 * x:	look for a hexadecimal number with up to
2169 		 *	two (C style: arbitrary) digits; convert
2170 		 *	to raw octet (C style: Unicode if >0xFF)
2171 		 * u/U:	look for a hexadecimal number with up to
2172 		 *	four (U: eight) digits; convert to Unicode
2173 		 */
2174 		wc = 0;
2175 		while (i--) {
2176 			wc <<= 4;
2177 			if ((c = (*fg)()) >= '0' && c <= '9')
2178 				wc += c - '0';
2179 			else if (c >= 'A' && c <= 'F')
2180 				wc += c - 'A' + 10;
2181 			else if (c >= 'a' && c <= 'f')
2182 				wc += c - 'a' + 10;
2183 			else {
2184 				wc >>= 4;
2185 				(*fp)(c);
2186 				break;
2187 			}
2188 		}
2189 		if ((cstyle && wc > 0xFF) || fc != 'x')
2190 			/* Unicode marker */
2191 			wc += 0x100;
2192 		break;
2193 	case '\'':
2194 		if (!cstyle)
2195 			goto unknown_escape;
2196 		wc = '\'';
2197 		break;
2198 	case '\\':
2199 		wc = '\\';
2200 		break;
2201 	default:
2202  unknown_escape:
2203 		(*fp)(fc);
2204 		return (-1);
2205 	}
2206 
2207 	return (wc);
2208 }
2209