1/*	$OpenBSD: main.c,v 1.57 2015/09/10 22:48:58 nicm Exp $	*/
2/*	$OpenBSD: tty.c,v 1.10 2014/08/10 02:44:26 guenther Exp $	*/
3/*	$OpenBSD: io.c,v 1.26 2015/09/11 08:00:27 guenther Exp $	*/
4/*	$OpenBSD: table.c,v 1.16 2015/09/01 13:12:31 tedu Exp $	*/
5
6/*-
7 * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
8 *		 2011, 2012, 2013, 2014, 2015, 2016, 2017
9 *	mirabilos <m@mirbsd.org>
10 *
11 * Provided that these terms and disclaimer and all copyright notices
12 * are retained or reproduced in an accompanying document, permission
13 * is granted to deal in this work without restriction, including un-
14 * limited rights to use, publicly perform, distribute, sell, modify,
15 * merge, give away, or sublicence.
16 *
17 * This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
18 * the utmost extent permitted by applicable law, neither express nor
19 * implied; without malicious intent or gross negligence. In no event
20 * may a licensor, author or contributor be held liable for indirect,
21 * direct, other damage, loss, or other issues arising in any way out
22 * of dealing in the work, even if advised of the possibility of such
23 * damage or existence of a defect, except proven that it results out
24 * of said person's immediate fault when using the work as intended.
25 */
26
27#define EXTERN
28#include "sh.h"
29
30#if HAVE_LANGINFO_CODESET
31#include <langinfo.h>
32#endif
33#if HAVE_SETLOCALE_CTYPE
34#include <locale.h>
35#endif
36
37__RCSID("$MirOS: src/bin/mksh/main.c,v 1.332 2017/04/12 16:01:45 tg Exp $");
38
39extern char **environ;
40
41#ifndef MKSHRC_PATH
42#define MKSHRC_PATH	"~/.mkshrc"
43#endif
44
45#ifndef MKSH_DEFAULT_TMPDIR
46#define MKSH_DEFAULT_TMPDIR	MKSH_UNIXROOT "/tmp"
47#endif
48
49static uint8_t isuc(const char *);
50static int main_init(int, const char *[], Source **, struct block **);
51void chvt_reinit(void);
52static void reclaim(void);
53static void remove_temps(struct temp *);
54static mksh_uari_t rndsetup(void);
55#ifdef SIGWINCH
56static void x_sigwinch(int);
57#endif
58
59static const char initsubs[] =
60    "${PS2=> }"
61    "${PS3=#? }"
62    "${PS4=+ }"
63    "${SECONDS=0}"
64    "${TMOUT=0}"
65    "${EPOCHREALTIME=}";
66
67static const char *initcoms[] = {
68	Ttypeset, "-r", initvsn, NULL,
69	Ttypeset, "-x", "HOME", TPATH, TSHELL, NULL,
70	Ttypeset, "-i10", "COLUMNS", "LINES", "SECONDS", "TMOUT", NULL,
71	Talias,
72	"integer=\\\\builtin typeset -i",
73	"local=\\\\builtin typeset",
74	/* not "alias -t --": hash -r needs to work */
75	"hash=\\\\builtin alias -t",
76	"type=\\\\builtin whence -v",
77	"autoload=\\\\builtin typeset -fu",
78	"functions=\\\\builtin typeset -f",
79	"history=\\\\builtin fc -l",
80	"nameref=\\\\builtin typeset -n",
81	"nohup=nohup ",
82	"r=\\\\builtin fc -e -",
83	"login=\\\\builtin exec login",
84	NULL,
85	 /* this is what AT&T ksh seems to track, with the addition of emacs */
86	Talias, "-tU",
87	Tcat, "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
88	"make", "mv", "pr", "rm", "sed", Tsh, "vi", "who", NULL,
89	NULL
90};
91
92static const char *restr_com[] = {
93	Ttypeset, "-r", TPATH, "ENV", TSHELL, NULL
94};
95
96static bool initio_done;
97
98/* top-level parsing and execution environment */
99static struct env env;
100struct env *e = &env;
101
102/* compile-time assertions */
103#define cta(name, expr) struct cta_ ## name { char t[(expr) ? 1 : -1]; }
104
105/* this one should be defined by the standard */
106cta(char_is_1_char, (sizeof(char) == 1) && (sizeof(signed char) == 1) &&
107    (sizeof(unsigned char) == 1));
108cta(char_is_8_bits, ((CHAR_BIT) == 8) && ((int)(unsigned char)0xFF == 0xFF) &&
109    ((int)(unsigned char)0x100 == 0) && ((int)(unsigned char)(int)-1 == 0xFF));
110/* the next assertion is probably not really needed */
111cta(short_is_2_char, sizeof(short) == 2);
112cta(short_size_no_matter_of_signedness, sizeof(short) == sizeof(unsigned short));
113/* the next assertion is probably not really needed */
114cta(int_is_4_char, sizeof(int) == 4);
115cta(int_size_no_matter_of_signedness, sizeof(int) == sizeof(unsigned int));
116
117cta(long_ge_int, sizeof(long) >= sizeof(int));
118cta(long_size_no_matter_of_signedness, sizeof(long) == sizeof(unsigned long));
119
120#ifndef MKSH_LEGACY_MODE
121/* the next assertion is probably not really needed */
122cta(ari_is_4_char, sizeof(mksh_ari_t) == 4);
123/* but this is */
124cta(ari_has_31_bit, 0 < (mksh_ari_t)(((((mksh_ari_t)1 << 15) << 15) - 1) * 2 + 1));
125/* the next assertion is probably not really needed */
126cta(uari_is_4_char, sizeof(mksh_uari_t) == 4);
127/* but the next three are; we REQUIRE unsigned integer wraparound */
128cta(uari_has_31_bit, 0 < (mksh_uari_t)(((((mksh_uari_t)1 << 15) << 15) - 1) * 2 + 1));
129cta(uari_has_32_bit, 0 < (mksh_uari_t)(((((mksh_uari_t)1 << 15) << 15) - 1) * 4 + 3));
130cta(uari_wrap_32_bit,
131    (mksh_uari_t)(((((mksh_uari_t)1 << 15) << 15) - 1) * 4 + 3) >
132    (mksh_uari_t)(((((mksh_uari_t)1 << 15) << 15) - 1) * 4 + 4));
133#endif
134/* these are always required */
135cta(ari_is_signed, (mksh_ari_t)-1 < (mksh_ari_t)0);
136cta(uari_is_unsigned, (mksh_uari_t)-1 > (mksh_uari_t)0);
137/* we require these to have the precisely same size and assume 2s complement */
138cta(ari_size_no_matter_of_signedness, sizeof(mksh_ari_t) == sizeof(mksh_uari_t));
139
140cta(sizet_size_no_matter_of_signedness, sizeof(ssize_t) == sizeof(size_t));
141cta(sizet_voidptr_same_size, sizeof(size_t) == sizeof(void *));
142cta(sizet_funcptr_same_size, sizeof(size_t) == sizeof(void (*)(void)));
143/* our formatting routines assume this */
144cta(ptr_fits_in_long, sizeof(size_t) <= sizeof(long));
145cta(ari_fits_in_long, sizeof(mksh_ari_t) <= sizeof(long));
146
147static mksh_uari_t
148rndsetup(void)
149{
150	register uint32_t h;
151	struct {
152		ALLOC_ITEM alloc_INT;
153		void *dataptr, *stkptr, *mallocptr;
154#if defined(__GLIBC__) && (__GLIBC__ >= 2)
155		sigjmp_buf jbuf;
156#endif
157		struct timeval tv;
158	} *bufptr;
159	char *cp;
160
161	cp = alloc(sizeof(*bufptr) - sizeof(ALLOC_ITEM), APERM);
162	/* clear the allocated space, for valgrind and to avoid UB */
163	memset(cp, 0, sizeof(*bufptr) - sizeof(ALLOC_ITEM));
164	/* undo what alloc() did to the malloc result address */
165	bufptr = (void *)(cp - sizeof(ALLOC_ITEM));
166	/* PIE or something similar provides us with deltas here */
167	bufptr->dataptr = &rndsetupstate;
168	/* ASLR in at least Windows, Linux, some BSDs */
169	bufptr->stkptr = &bufptr;
170	/* randomised malloc in BSD (and possibly others) */
171	bufptr->mallocptr = bufptr;
172#if defined(__GLIBC__) && (__GLIBC__ >= 2)
173	/* glibc pointer guard */
174	sigsetjmp(bufptr->jbuf, 1);
175#endif
176	/* introduce variation (and yes, second arg MBZ for portability) */
177	mksh_TIME(bufptr->tv);
178
179#ifdef MKSH_ALLOC_CATCH_UNDERRUNS
180	mprotect(((char *)bufptr) + 4096, 4096, PROT_READ | PROT_WRITE);
181#endif
182	h = chvt_rndsetup(bufptr, sizeof(*bufptr));
183
184	afree(cp, APERM);
185	return ((mksh_uari_t)h);
186}
187
188void
189chvt_reinit(void)
190{
191	kshpid = procpid = getpid();
192	ksheuid = geteuid();
193	kshpgrp = getpgrp();
194	kshppid = getppid();
195}
196
197static const char *empty_argv[] = {
198	Tmksh, NULL
199};
200
201static uint8_t
202isuc(const char *cx) {
203	char *cp, *x;
204	uint8_t rv = 0;
205
206	if (!cx || !*cx)
207		return (0);
208
209	/* uppercase a string duplicate */
210	strdupx(x, cx, ATEMP);
211	cp = x;
212	while ((*cp = ksh_toupper(*cp)))
213		++cp;
214
215	/* check for UTF-8 */
216	if (strstr(x, "UTF-8") || strstr(x, "UTF8"))
217		rv = 1;
218
219	/* free copy and out */
220	afree(x, ATEMP);
221	return (rv);
222}
223
224static int
225main_init(int argc, const char *argv[], Source **sp, struct block **lp)
226{
227	int argi, i;
228	Source *s = NULL;
229	struct block *l;
230	unsigned char restricted_shell, errexit, utf_flag;
231	char *cp;
232	const char *ccp, **wp;
233	struct tbl *vp;
234	struct stat s_stdin;
235#if !defined(_PATH_DEFPATH) && defined(_CS_PATH)
236	ssize_t k;
237#endif
238
239#ifdef __OS2__
240	for (i = 0; i < 3; ++i)
241		if (!isatty(i))
242			setmode(i, O_BINARY);
243
244	os2_init(&argc, &argv);
245#endif
246
247	/* do things like getpgrp() et al. */
248	chvt_reinit();
249
250	/* make sure argv[] is sane, for weird OSes */
251	if (!*argv) {
252		argv = empty_argv;
253		argc = 1;
254	}
255	kshname = argv[0];
256
257	/* initialise permanent Area */
258	ainit(&aperm);
259	/* max. name length: -2147483648 = 11 (+ NUL) */
260	vtemp = alloc(offsetof(struct tbl, name[0]) + 12, APERM);
261
262	/* set up base environment */
263	env.type = E_NONE;
264	ainit(&env.area);
265	/* set up global l->vars and l->funs */
266	newblock();
267
268	/* Do this first so output routines (eg, errorf, shellf) can work */
269	initio();
270
271	/* determine the basename (without '-' or path) of the executable */
272	ccp = kshname;
273	goto begin_parsing_kshname;
274	while ((i = ccp[argi++])) {
275		if (mksh_cdirsep(i)) {
276			ccp += argi;
277 begin_parsing_kshname:
278			argi = 0;
279			if (*ccp == '-')
280				++ccp;
281		}
282	}
283	if (!*ccp)
284		ccp = empty_argv[0];
285
286	/*
287	 * Turn on nohup by default. (AT&T ksh does not have a nohup
288	 * option - it always sends the hup).
289	 */
290	Flag(FNOHUP) = 1;
291
292	/*
293	 * Turn on brace expansion by default. AT&T kshs that have
294	 * alternation always have it on.
295	 */
296	Flag(FBRACEEXPAND) = 1;
297
298	/*
299	 * Turn on "set -x" inheritance by default.
300	 */
301	Flag(FXTRACEREC) = 1;
302
303	/* define built-in commands and see if we were called as one */
304	ktinit(APERM, &builtins,
305	    /* currently up to 54 builtins: 75% of 128 = 2^7 */
306	    7);
307	for (i = 0; mkshbuiltins[i].name != NULL; i++)
308		if (!strcmp(ccp, builtin(mkshbuiltins[i].name,
309		    mkshbuiltins[i].func)))
310			Flag(FAS_BUILTIN) = 1;
311
312	if (!Flag(FAS_BUILTIN)) {
313		/* check for -T option early */
314		argi = parse_args(argv, OF_FIRSTTIME, NULL);
315		if (argi < 0)
316			return (1);
317
318#if defined(MKSH_BINSHPOSIX) || defined(MKSH_BINSHREDUCED)
319		/* are we called as -sh or /bin/sh or so? */
320		if (!strcmp(ccp, "sh" MKSH_EXE_EXT)) {
321			/* either also turns off braceexpand */
322#ifdef MKSH_BINSHPOSIX
323			/* enable better POSIX conformance */
324			change_flag(FPOSIX, OF_FIRSTTIME, true);
325#endif
326#ifdef MKSH_BINSHREDUCED
327			/* enable kludge/compat mode */
328			change_flag(FSH, OF_FIRSTTIME, true);
329#endif
330		}
331#endif
332	}
333
334	initvar();
335
336	initctypes();
337
338	inittraps();
339
340	coproc_init();
341
342	/* set up variable and command dictionaries */
343	ktinit(APERM, &taliases, 0);
344	ktinit(APERM, &aliases, 0);
345#ifndef MKSH_NOPWNAM
346	ktinit(APERM, &homedirs, 0);
347#endif
348
349	/* define shell keywords */
350	initkeywords();
351
352	init_histvec();
353
354	/* initialise tty size before importing environment */
355	change_winsz();
356
357#ifdef _PATH_DEFPATH
358	def_path = _PATH_DEFPATH;
359#else
360#ifdef _CS_PATH
361	if ((k = confstr(_CS_PATH, NULL, 0)) > 0 &&
362	    confstr(_CS_PATH, cp = alloc(k + 1, APERM), k + 1) == k + 1)
363		def_path = cp;
364	else
365#endif
366		/*
367		 * this is uniform across all OSes unless it
368		 * breaks somewhere hard; don't try to optimise,
369		 * e.g. add stuff for Interix or remove /usr
370		 * for HURD, because e.g. Debian GNU/HURD is
371		 * "keeping a regular /usr"; this is supposed
372		 * to be a sane 'basic' default PATH
373		 */
374		def_path = MKSH_UNIXROOT "/bin" MKSH_PATHSEPS
375		    MKSH_UNIXROOT "/usr/bin" MKSH_PATHSEPS
376		    MKSH_UNIXROOT "/sbin" MKSH_PATHSEPS
377		    MKSH_UNIXROOT "/usr/sbin";
378#endif
379
380	/*
381	 * Set PATH to def_path (will set the path global variable).
382	 * (import of environment below will probably change this setting).
383	 */
384	vp = global(TPATH);
385	/* setstr can't fail here */
386	setstr(vp, def_path, KSH_RETURN_ERROR);
387
388#ifndef MKSH_NO_CMDLINE_EDITING
389	/*
390	 * Set edit mode to emacs by default, may be overridden
391	 * by the environment or the user. Also, we want tab completion
392	 * on in vi by default.
393	 */
394	change_flag(FEMACS, OF_SPECIAL, true);
395#if !MKSH_S_NOVI
396	Flag(FVITABCOMPLETE) = 1;
397#endif
398#endif
399
400	/* import environment */
401	if (environ != NULL) {
402		wp = (const char **)environ;
403		while (*wp != NULL) {
404			rndpush(*wp);
405			typeset(*wp, IMPORT | EXPORT, 0, 0, 0);
406			++wp;
407		}
408	}
409
410	/* override default PATH regardless of environment */
411#ifdef MKSH_DEFPATH_OVERRIDE
412	 vp = global(TPATH);
413	 setstr(vp, MKSH_DEFPATH_OVERRIDE, KSH_RETURN_ERROR);
414#endif
415
416	/* for security */
417	typeset("IFS= \t\n", 0, 0, 0, 0);
418
419	/* assign default shell variable values */
420	typeset("PATHSEP=" MKSH_PATHSEPS, 0, 0, 0, 0);
421	substitute(initsubs, 0);
422
423	/* Figure out the current working directory and set $PWD */
424	vp = global(TPWD);
425	cp = str_val(vp);
426	/* Try to use existing $PWD if it is valid */
427	set_current_wd((mksh_abspath(cp) && test_eval(NULL, TO_FILEQ, cp,
428	    Tdot, true)) ? cp : NULL);
429	if (current_wd[0])
430		simplify_path(current_wd);
431	/* Only set pwd if we know where we are or if it had a bogus value */
432	if (current_wd[0] || *cp)
433		/* setstr can't fail here */
434		setstr(vp, current_wd, KSH_RETURN_ERROR);
435
436	for (wp = initcoms; *wp != NULL; wp++) {
437		c_builtin(wp);
438		while (*wp != NULL)
439			wp++;
440	}
441	setint_n(global("OPTIND"), 1, 10);
442
443	kshuid = getuid();
444	kshgid = getgid();
445	kshegid = getegid();
446
447	safe_prompt = ksheuid ? "$ " : "# ";
448	vp = global("PS1");
449	/* Set PS1 if unset or we are root and prompt doesn't contain a # */
450	if (!(vp->flag & ISSET) ||
451	    (!ksheuid && !strchr(str_val(vp), '#')))
452		/* setstr can't fail here */
453		setstr(vp, safe_prompt, KSH_RETURN_ERROR);
454	setint_n((vp = global("BASHPID")), 0, 10);
455	vp->flag |= INT_U;
456	setint_n((vp = global("PGRP")), (mksh_uari_t)kshpgrp, 10);
457	vp->flag |= INT_U;
458	setint_n((vp = global("PPID")), (mksh_uari_t)kshppid, 10);
459	vp->flag |= INT_U;
460	setint_n((vp = global("USER_ID")), (mksh_uari_t)ksheuid, 10);
461	vp->flag |= INT_U;
462	setint_n((vp = global("KSHUID")), (mksh_uari_t)kshuid, 10);
463	vp->flag |= INT_U;
464	setint_n((vp = global("KSHEGID")), (mksh_uari_t)kshegid, 10);
465	vp->flag |= INT_U;
466	setint_n((vp = global("KSHGID")), (mksh_uari_t)kshgid, 10);
467	vp->flag |= INT_U;
468	setint_n((vp = global("RANDOM")), rndsetup(), 10);
469	vp->flag |= INT_U;
470	setint_n((vp_pipest = global("PIPESTATUS")), 0, 10);
471
472	/* Set this before parsing arguments */
473	Flag(FPRIVILEGED) = (kshuid != ksheuid || kshgid != kshegid) ? 2 : 0;
474
475	/* this to note if monitor is set on command line (see below) */
476#ifndef MKSH_UNEMPLOYED
477	Flag(FMONITOR) = 127;
478#endif
479	/* this to note if utf-8 mode is set on command line (see below) */
480	UTFMODE = 2;
481
482	if (!Flag(FAS_BUILTIN)) {
483		argi = parse_args(argv, OF_CMDLINE, NULL);
484		if (argi < 0)
485			return (1);
486	}
487
488	/* process this later only, default to off (hysterical raisins) */
489	utf_flag = UTFMODE;
490	UTFMODE = 0;
491
492	if (Flag(FAS_BUILTIN)) {
493		/* auto-detect from environment variables, always */
494		utf_flag = 3;
495	} else if (Flag(FCOMMAND)) {
496		s = pushs(SSTRINGCMDLINE, ATEMP);
497		if (!(s->start = s->str = argv[argi++]))
498			errorf(Tf_optfoo, "", "", 'c', Treq_arg);
499		while (*s->str) {
500			if (*s->str != ' ' && ctype(*s->str, C_QUOTE))
501				break;
502			s->str++;
503		}
504		if (!*s->str)
505			s->flags |= SF_MAYEXEC;
506		s->str = s->start;
507#ifdef MKSH_MIDNIGHTBSD01ASH_COMPAT
508		/* compatibility to MidnightBSD 0.1 /bin/sh (kludge) */
509		if (Flag(FSH) && argv[argi] && !strcmp(argv[argi], "--"))
510			++argi;
511#endif
512		if (argv[argi])
513			kshname = argv[argi++];
514	} else if (argi < argc && !Flag(FSTDIN)) {
515		s = pushs(SFILE, ATEMP);
516#ifdef __OS2__
517		/*
518		 * A bug in OS/2 extproc (like shebang) handling makes
519		 * it not pass the full pathname of a script, so we need
520		 * to search for it. This changes the behaviour of a
521		 * simple "mksh foo", but can't be helped.
522		 */
523		s->file = argv[argi++];
524		if (search_access(s->file, X_OK) != 0)
525			s->file = search_path(s->file, path, X_OK, NULL);
526		if (!s->file || !*s->file)
527			s->file = argv[argi - 1];
528#else
529		s->file = argv[argi++];
530#endif
531		s->u.shf = shf_open(s->file, O_RDONLY, 0,
532		    SHF_MAPHI | SHF_CLEXEC);
533		if (s->u.shf == NULL) {
534			shl_stdout_ok = false;
535			warningf(true, Tf_sD_s, s->file, cstrerror(errno));
536			/* mandated by SUSv4 */
537			exstat = 127;
538			unwind(LERROR);
539		}
540		kshname = s->file;
541	} else {
542		Flag(FSTDIN) = 1;
543		s = pushs(SSTDIN, ATEMP);
544		s->file = "<stdin>";
545		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
546		    NULL);
547		if (isatty(0) && isatty(2)) {
548			Flag(FTALKING) = Flag(FTALKING_I) = 1;
549			/* The following only if isatty(0) */
550			s->flags |= SF_TTY;
551			s->u.shf->flags |= SHF_INTERRUPT;
552			s->file = NULL;
553		}
554	}
555
556	/* this bizarreness is mandated by POSIX */
557	if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
558	    Flag(FTALKING))
559		reset_nonblock(0);
560
561	/* initialise job control */
562	j_init();
563	/* do this after j_init() which calls tty_init_state() */
564	if (Flag(FTALKING)) {
565		if (utf_flag == 2) {
566#ifndef MKSH_ASSUME_UTF8
567			/* auto-detect from locale or environment */
568			utf_flag = 4;
569#else /* this may not be an #elif */
570#if MKSH_ASSUME_UTF8
571			utf_flag = 1;
572#else
573			/* always disable UTF-8 (for interactive) */
574			utf_flag = 0;
575#endif
576#endif
577		}
578#ifndef MKSH_NO_CMDLINE_EDITING
579		x_init();
580#endif
581	}
582
583#ifdef SIGWINCH
584	sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
585	setsig(&sigtraps[SIGWINCH], x_sigwinch,
586	    SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
587#endif
588
589	l = e->loc;
590	if (Flag(FAS_BUILTIN)) {
591		l->argc = argc;
592		l->argv = argv;
593		l->argv[0] = ccp;
594	} else {
595		l->argc = argc - argi;
596		/*
597		 * allocate a new array because otherwise, when we modify
598		 * it in-place, ps(1) output changes; the meaning of argc
599		 * here is slightly different as it excludes kshname, and
600		 * we add a trailing NULL sentinel as well
601		 */
602		l->argv = alloc2(l->argc + 2, sizeof(void *), APERM);
603		l->argv[0] = kshname;
604		memcpy(&l->argv[1], &argv[argi], l->argc * sizeof(void *));
605		l->argv[l->argc + 1] = NULL;
606		getopts_reset(1);
607	}
608
609	/* divine the initial state of the utf8-mode Flag */
610	ccp = null;
611	switch (utf_flag) {
612
613	/* auto-detect from locale or environment */
614	case 4:
615#if HAVE_SETLOCALE_CTYPE
616		ccp = setlocale(LC_CTYPE, "");
617#if HAVE_LANGINFO_CODESET
618		if (!isuc(ccp))
619			ccp = nl_langinfo(CODESET);
620#endif
621		if (!isuc(ccp))
622			ccp = null;
623#endif
624		/* FALLTHROUGH */
625
626	/* auto-detect from environment */
627	case 3:
628		/* these were imported from environ earlier */
629		if (ccp == null)
630			ccp = str_val(global("LC_ALL"));
631		if (ccp == null)
632			ccp = str_val(global("LC_CTYPE"));
633		if (ccp == null)
634			ccp = str_val(global("LANG"));
635		UTFMODE = isuc(ccp);
636		break;
637
638	/* not set on command line, not FTALKING */
639	case 2:
640	/* unknown values */
641	default:
642		utf_flag = 0;
643		/* FALLTHROUGH */
644
645	/* known values */
646	case 1:
647	case 0:
648		UTFMODE = utf_flag;
649		break;
650	}
651
652	/* Disable during .profile/ENV reading */
653	restricted_shell = Flag(FRESTRICTED);
654	Flag(FRESTRICTED) = 0;
655	errexit = Flag(FERREXIT);
656	Flag(FERREXIT) = 0;
657
658	/*
659	 * Do this before profile/$ENV so that if it causes problems in them,
660	 * user will know why things broke.
661	 */
662	if (!current_wd[0] && Flag(FTALKING))
663		warningf(false, "can't determine current directory");
664
665	if (Flag(FLOGIN))
666		include(MKSH_SYSTEM_PROFILE, 0, NULL, true);
667	if (!Flag(FPRIVILEGED)) {
668		if (Flag(FLOGIN))
669			include(substitute("$HOME/.profile", 0), 0, NULL, true);
670		if (Flag(FTALKING)) {
671			cp = substitute(substitute("${ENV:-" MKSHRC_PATH "}",
672			    0), DOTILDE);
673			if (cp[0] != '\0')
674				include(cp, 0, NULL, true);
675		}
676	} else {
677		include(MKSH_SUID_PROFILE, 0, NULL, true);
678		/* turn off -p if not set explicitly */
679		if (Flag(FPRIVILEGED) != 1)
680			change_flag(FPRIVILEGED, OF_INTERNAL, false);
681	}
682
683	if (restricted_shell) {
684		c_builtin(restr_com);
685		/* After typeset command... */
686		Flag(FRESTRICTED) = 1;
687	}
688	Flag(FERREXIT) = errexit;
689
690	if (Flag(FTALKING) && s)
691		hist_init(s);
692	else
693		/* set after ENV */
694		Flag(FTRACKALL) = 1;
695
696	alarm_init();
697
698	*sp = s;
699	*lp = l;
700	return (0);
701}
702
703/* this indirection barrier reduces stack usage during normal operation */
704
705int
706main(int argc, const char *argv[])
707{
708	int rv;
709	Source *s;
710	struct block *l;
711
712	if ((rv = main_init(argc, argv, &s, &l)) == 0) {
713		if (Flag(FAS_BUILTIN)) {
714			rv = c_builtin(l->argv);
715		} else {
716			shell(s, 0);
717			/* NOTREACHED */
718		}
719	}
720	return (rv);
721}
722
723int
724include(const char *name, int argc, const char **argv, bool intr_ok)
725{
726	Source *volatile s = NULL;
727	struct shf *shf;
728	const char **volatile old_argv;
729	volatile int old_argc;
730	int i;
731
732	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
733	if (shf == NULL)
734		return (-1);
735
736	if (argv) {
737		old_argv = e->loc->argv;
738		old_argc = e->loc->argc;
739	} else {
740		old_argv = NULL;
741		old_argc = 0;
742	}
743	newenv(E_INCL);
744	if ((i = kshsetjmp(e->jbuf))) {
745		quitenv(s ? s->u.shf : NULL);
746		if (old_argv) {
747			e->loc->argv = old_argv;
748			e->loc->argc = old_argc;
749		}
750		switch (i) {
751		case LRETURN:
752		case LERROR:
753			/* see below */
754			return (exstat & 0xFF);
755		case LINTR:
756			/*
757			 * intr_ok is set if we are including .profile or $ENV.
758			 * If user ^Cs out, we don't want to kill the shell...
759			 */
760			if (intr_ok && ((exstat & 0xFF) - 128) != SIGTERM)
761				return (1);
762			/* FALLTHROUGH */
763		case LEXIT:
764		case LLEAVE:
765		case LSHELL:
766			unwind(i);
767			/* NOTREACHED */
768		default:
769			internal_errorf(Tunexpected_type, Tunwind, Tsource, i);
770			/* NOTREACHED */
771		}
772	}
773	if (argv) {
774		e->loc->argv = argv;
775		e->loc->argc = argc;
776	}
777	s = pushs(SFILE, ATEMP);
778	s->u.shf = shf;
779	strdupx(s->file, name, ATEMP);
780	i = shell(s, 1);
781	quitenv(s->u.shf);
782	if (old_argv) {
783		e->loc->argv = old_argv;
784		e->loc->argc = old_argc;
785	}
786	/* & 0xff to ensure value not -1 */
787	return (i & 0xFF);
788}
789
790/* spawn a command into a shell optionally keeping track of the line number */
791int
792command(const char *comm, int line)
793{
794	Source *s, *sold = source;
795	int rv;
796
797	s = pushs(SSTRING, ATEMP);
798	s->start = s->str = comm;
799	s->line = line;
800	rv = shell(s, 1);
801	source = sold;
802	return (rv);
803}
804
805/*
806 * run the commands from the input source, returning status.
807 */
808int
809shell(Source * volatile s, volatile int level)
810{
811	struct op *t;
812	volatile bool wastty = tobool(s->flags & SF_TTY);
813	volatile uint8_t attempts = 13;
814	volatile bool interactive = (level == 0) && Flag(FTALKING);
815	volatile bool sfirst = true;
816	Source *volatile old_source = source;
817	int i;
818
819	newenv(level == 2 ? E_EVAL : E_PARSE);
820	if (interactive)
821		really_exit = false;
822	switch ((i = kshsetjmp(e->jbuf))) {
823	case 0:
824		break;
825	case LBREAK:
826	case LCONTIN:
827		if (level != 2) {
828			source = old_source;
829			quitenv(NULL);
830			internal_errorf(Tf_cant_s, Tshell,
831			    i == LBREAK ? Tbreak : Tcontinue);
832			/* NOTREACHED */
833		}
834		/* assert: interactive == false */
835		/* FALLTHROUGH */
836	case LINTR:
837		/* we get here if SIGINT not caught or ignored */
838	case LERROR:
839	case LSHELL:
840		if (interactive) {
841			if (i == LINTR)
842				shellf("\n");
843			/*
844			 * Reset any eof that was read as part of a
845			 * multiline command.
846			 */
847			if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
848				s->type = SSTDIN;
849			/*
850			 * Used by exit command to get back to
851			 * top level shell. Kind of strange since
852			 * interactive is set if we are reading from
853			 * a tty, but to have stopped jobs, one only
854			 * needs FMONITOR set (not FTALKING/SF_TTY)...
855			 */
856			/* toss any input we have so far */
857			yyrecursive_pop(true);
858			s->start = s->str = null;
859			retrace_info = NULL;
860			herep = heres;
861			break;
862		}
863		/* FALLTHROUGH */
864	case LEXIT:
865	case LLEAVE:
866	case LRETURN:
867		source = old_source;
868		quitenv(NULL);
869		/* keep on going */
870		unwind(i);
871		/* NOTREACHED */
872	default:
873		source = old_source;
874		quitenv(NULL);
875		internal_errorf(Tunexpected_type, Tunwind, Tshell, i);
876		/* NOTREACHED */
877	}
878	while (/* CONSTCOND */ 1) {
879		if (trap)
880			runtraps(0);
881
882		if (s->next == NULL) {
883			if (Flag(FVERBOSE))
884				s->flags |= SF_ECHO;
885			else
886				s->flags &= ~SF_ECHO;
887		}
888		if (interactive) {
889			j_notify();
890			set_prompt(PS1, s);
891		}
892		t = compile(s, sfirst, true);
893		if (interactive)
894			histsave(&s->line, NULL, HIST_FLUSH, true);
895		sfirst = false;
896		if (!t)
897			goto source_no_tree;
898		if (t->type == TEOF) {
899			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
900				shellf("Use 'exit' to leave mksh\n");
901				s->type = SSTDIN;
902			} else if (wastty && !really_exit &&
903			    j_stopped_running()) {
904				really_exit = true;
905				s->type = SSTDIN;
906			} else {
907				/*
908				 * this for POSIX which says EXIT traps
909				 * shall be taken in the environment
910				 * immediately after the last command
911				 * executed.
912				 */
913				if (level == 0)
914					unwind(LEXIT);
915				break;
916			}
917		} else if ((s->flags & SF_MAYEXEC) && t->type == TCOM)
918			t->u.evalflags |= DOTCOMEXEC;
919		if (!Flag(FNOEXEC) || (s->flags & SF_TTY))
920			exstat = execute(t, 0, NULL) & 0xFF;
921
922		if (t->type != TEOF && interactive && really_exit)
923			really_exit = false;
924
925 source_no_tree:
926		reclaim();
927	}
928	quitenv(NULL);
929	source = old_source;
930	return (exstat & 0xFF);
931}
932
933/* return to closest error handler or shell(), exit if none found */
934/* note: i MUST NOT be 0 */
935void
936unwind(int i)
937{
938	/*
939	 * This is a kludge. We need to restore everything that was
940	 * changed in the new environment, see cid 1005090337C7A669439
941	 * and 10050903386452ACBF1, but fail to even save things most of
942	 * the time. funcs.c:c_eval() changes FERREXIT temporarily to 0,
943	 * which needs to be restored thus (related to Debian #696823).
944	 * We did not save the shell flags, so we use a special or'd
945	 * value here... this is mostly to clean up behind *other*
946	 * callers of unwind(LERROR) here; exec.c has the regular case.
947	 */
948	if (Flag(FERREXIT) & 0x80) {
949		/* GNU bash does not run this trapsig */
950		trapsig(ksh_SIGERR);
951		Flag(FERREXIT) &= ~0x80;
952	}
953
954	/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
955	if (i == LEXIT || ((i == LERROR || i == LINTR) &&
956	    sigtraps[ksh_SIGEXIT].trap &&
957	    (!Flag(FTALKING) || Flag(FERREXIT)))) {
958		++trap_nested;
959		runtrap(&sigtraps[ksh_SIGEXIT], trap_nested == 1);
960		--trap_nested;
961		i = LLEAVE;
962	} else if (Flag(FERREXIT) == 1 && (i == LERROR || i == LINTR)) {
963		++trap_nested;
964		runtrap(&sigtraps[ksh_SIGERR], trap_nested == 1);
965		--trap_nested;
966		i = LLEAVE;
967	}
968
969	while (/* CONSTCOND */ 1) {
970		switch (e->type) {
971		case E_PARSE:
972		case E_FUNC:
973		case E_INCL:
974		case E_LOOP:
975		case E_ERRH:
976		case E_EVAL:
977			kshlongjmp(e->jbuf, i);
978			/* NOTREACHED */
979		case E_NONE:
980			if (i == LINTR)
981				e->flags |= EF_FAKE_SIGDIE;
982			/* FALLTHROUGH */
983		default:
984			quitenv(NULL);
985		}
986	}
987}
988
989void
990newenv(int type)
991{
992	struct env *ep;
993	char *cp;
994
995	/*
996	 * struct env includes ALLOC_ITEM for alignment constraints
997	 * so first get the actually used memory, then assign it
998	 */
999	cp = alloc(sizeof(struct env) - sizeof(ALLOC_ITEM), ATEMP);
1000	/* undo what alloc() did to the malloc result address */
1001	ep = (void *)(cp - sizeof(ALLOC_ITEM));
1002	/* initialise public members of struct env (not the ALLOC_ITEM) */
1003	ainit(&ep->area);
1004	ep->oenv = e;
1005	ep->loc = e->loc;
1006	ep->savefd = NULL;
1007	ep->temps = NULL;
1008	ep->yyrecursive_statep = NULL;
1009	ep->type = type;
1010	ep->flags = 0;
1011	/* jump buffer is invalid because flags == 0 */
1012	e = ep;
1013}
1014
1015void
1016quitenv(struct shf *shf)
1017{
1018	struct env *ep = e;
1019	char *cp;
1020	int fd;
1021
1022	yyrecursive_pop(true);
1023	while (ep->oenv && ep->oenv->loc != ep->loc)
1024		popblock();
1025	if (ep->savefd != NULL) {
1026		for (fd = 0; fd < NUFILE; fd++)
1027			/* if ep->savefd[fd] < 0, means fd was closed */
1028			if (ep->savefd[fd])
1029				restfd(fd, ep->savefd[fd]);
1030		if (ep->savefd[2])
1031			/* Clear any write errors */
1032			shf_reopen(2, SHF_WR, shl_out);
1033	}
1034	/*
1035	 * Bottom of the stack.
1036	 * Either main shell is exiting or cleanup_parents_env() was called.
1037	 */
1038	if (ep->oenv == NULL) {
1039#ifdef DEBUG_LEAKS
1040		int i;
1041#endif
1042
1043		if (ep->type == E_NONE) {
1044			/* Main shell exiting? */
1045#if HAVE_PERSISTENT_HISTORY
1046			if (Flag(FTALKING))
1047				hist_finish();
1048#endif
1049			j_exit();
1050			if (ep->flags & EF_FAKE_SIGDIE) {
1051				int sig = (exstat & 0xFF) - 128;
1052
1053				/*
1054				 * ham up our death a bit (AT&T ksh
1055				 * only seems to do this for SIGTERM)
1056				 * Don't do it for SIGQUIT, since we'd
1057				 * dump a core..
1058				 */
1059				if ((sig == SIGINT || sig == SIGTERM) &&
1060				    (kshpgrp == kshpid)) {
1061					setsig(&sigtraps[sig], SIG_DFL,
1062					    SS_RESTORE_CURR | SS_FORCE);
1063					kill(0, sig);
1064				}
1065			}
1066		}
1067		if (shf)
1068			shf_close(shf);
1069		reclaim();
1070#ifdef DEBUG_LEAKS
1071#ifndef MKSH_NO_CMDLINE_EDITING
1072		x_done();
1073#endif
1074#ifndef MKSH_NOPROSPECTOFWORK
1075		/* block at least SIGCHLD during/after afreeall */
1076		sigprocmask(SIG_BLOCK, &sm_sigchld, NULL);
1077#endif
1078		afreeall(APERM);
1079		for (fd = 3; fd < NUFILE; fd++)
1080			if ((i = fcntl(fd, F_GETFD, 0)) != -1 &&
1081			    (i & FD_CLOEXEC))
1082				close(fd);
1083		close(2);
1084		close(1);
1085		close(0);
1086#endif
1087		exit(exstat & 0xFF);
1088	}
1089	if (shf)
1090		shf_close(shf);
1091	reclaim();
1092
1093	e = e->oenv;
1094
1095	/* free the struct env - tricky due to the ALLOC_ITEM inside */
1096	cp = (void *)ep;
1097	afree(cp + sizeof(ALLOC_ITEM), ATEMP);
1098}
1099
1100/* Called after a fork to cleanup stuff left over from parents environment */
1101void
1102cleanup_parents_env(void)
1103{
1104	struct env *ep;
1105	int fd;
1106
1107	/*
1108	 * Don't clean up temporary files - parent will probably need them.
1109	 * Also, can't easily reclaim memory since variables, etc. could be
1110	 * anywhere.
1111	 */
1112
1113	/* close all file descriptors hiding in savefd */
1114	for (ep = e; ep; ep = ep->oenv) {
1115		if (ep->savefd) {
1116			for (fd = 0; fd < NUFILE; fd++)
1117				if (ep->savefd[fd] > 0)
1118					close(ep->savefd[fd]);
1119			afree(ep->savefd, &ep->area);
1120			ep->savefd = NULL;
1121		}
1122#ifdef DEBUG_LEAKS
1123		if (ep->type != E_NONE)
1124			ep->type = E_GONE;
1125#endif
1126	}
1127#ifndef DEBUG_LEAKS
1128	e->oenv = NULL;
1129#endif
1130}
1131
1132/* Called just before an execve cleanup stuff temporary files */
1133void
1134cleanup_proc_env(void)
1135{
1136	struct env *ep;
1137
1138	for (ep = e; ep; ep = ep->oenv)
1139		remove_temps(ep->temps);
1140}
1141
1142/* remove temp files and free ATEMP Area */
1143static void
1144reclaim(void)
1145{
1146	struct block *l;
1147
1148	while ((l = e->loc) && (!e->oenv || e->oenv->loc != l)) {
1149		e->loc = l->next;
1150		afreeall(&l->area);
1151	}
1152
1153	remove_temps(e->temps);
1154	e->temps = NULL;
1155
1156	/*
1157	 * if the memory backing source is reclaimed, things
1158	 * will end up badly when a function expecting it to
1159	 * be valid is run; a NULL pointer is easily debugged
1160	 */
1161	if (source && source->areap == &e->area)
1162		source = NULL;
1163	afreeall(&e->area);
1164}
1165
1166static void
1167remove_temps(struct temp *tp)
1168{
1169	while (tp) {
1170		if (tp->pid == procpid)
1171			unlink(tp->tffn);
1172		tp = tp->next;
1173	}
1174}
1175
1176/*
1177 * Initialise tty_fd. Used for tracking the size of the terminal,
1178 * saving/resetting tty modes upon forground job completion, and
1179 * for setting up the tty process group. Return values:
1180 *	0 = got controlling tty
1181 *	1 = got terminal but no controlling tty
1182 *	2 = cannot find a terminal
1183 *	3 = cannot dup fd
1184 *	4 = cannot make fd close-on-exec
1185 * An existing tty_fd is cached if no "better" one could be found,
1186 * i.e. if tty_devtty was already set or the new would not set it.
1187 */
1188int
1189tty_init_fd(void)
1190{
1191	int fd, rv, eno = 0;
1192	bool do_close = false, is_devtty = true;
1193
1194	if (tty_devtty) {
1195		/* already got a tty which is /dev/tty */
1196		return (0);
1197	}
1198
1199#ifdef _UWIN
1200	/*XXX imake style */
1201	if (isatty(3)) {
1202		/* fd 3 on UWIN _is_ /dev/tty (or our controlling tty) */
1203		fd = 3;
1204		goto got_fd;
1205	}
1206#endif
1207	if ((fd = open(T_devtty, O_RDWR, 0)) >= 0) {
1208		do_close = true;
1209		goto got_fd;
1210	}
1211	eno = errno;
1212
1213	if (tty_fd >= 0) {
1214		/* already got a non-devtty one */
1215		rv = 1;
1216		goto out;
1217	}
1218	is_devtty = false;
1219
1220	if (isatty((fd = 0)) || isatty((fd = 2)))
1221		goto got_fd;
1222	/* cannot find one */
1223	rv = 2;
1224	/* assert: do_close == false */
1225	goto out;
1226
1227 got_fd:
1228	if ((rv = fcntl(fd, F_DUPFD, FDBASE)) < 0) {
1229		eno = errno;
1230		rv = 3;
1231		goto out;
1232	}
1233	if (fcntl(rv, F_SETFD, FD_CLOEXEC) < 0) {
1234		eno = errno;
1235		close(rv);
1236		rv = 4;
1237		goto out;
1238	}
1239	tty_fd = rv;
1240	tty_devtty = is_devtty;
1241	rv = eno = 0;
1242 out:
1243	if (do_close)
1244		close(fd);
1245	errno = eno;
1246	return (rv);
1247}
1248
1249/* A shell error occurred (eg, syntax error, etc.) */
1250
1251#define VWARNINGF_ERRORPREFIX	1
1252#define VWARNINGF_FILELINE	2
1253#define VWARNINGF_BUILTIN	4
1254#define VWARNINGF_INTERNAL	8
1255
1256static void vwarningf(unsigned int, const char *, va_list)
1257    MKSH_A_FORMAT(__printf__, 2, 0);
1258
1259static void
1260vwarningf(unsigned int flags, const char *fmt, va_list ap)
1261{
1262	if (fmt) {
1263		if (flags & VWARNINGF_INTERNAL)
1264			shf_fprintf(shl_out, Tf_sD_, "internal error");
1265		if (flags & VWARNINGF_ERRORPREFIX)
1266			error_prefix(tobool(flags & VWARNINGF_FILELINE));
1267		if ((flags & VWARNINGF_BUILTIN) &&
1268		    /* not set when main() calls parse_args() */
1269		    builtin_argv0 && builtin_argv0 != kshname)
1270			shf_fprintf(shl_out, Tf_sD_, builtin_argv0);
1271		shf_vfprintf(shl_out, fmt, ap);
1272		shf_putchar('\n', shl_out);
1273	}
1274	shf_flush(shl_out);
1275}
1276
1277void
1278errorfx(int rc, const char *fmt, ...)
1279{
1280	va_list va;
1281
1282	exstat = rc;
1283
1284	/* debugging: note that stdout not valid */
1285	shl_stdout_ok = false;
1286
1287	va_start(va, fmt);
1288	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1289	va_end(va);
1290	unwind(LERROR);
1291}
1292
1293void
1294errorf(const char *fmt, ...)
1295{
1296	va_list va;
1297
1298	exstat = 1;
1299
1300	/* debugging: note that stdout not valid */
1301	shl_stdout_ok = false;
1302
1303	va_start(va, fmt);
1304	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1305	va_end(va);
1306	unwind(LERROR);
1307}
1308
1309/* like errorf(), but no unwind is done */
1310void
1311warningf(bool fileline, const char *fmt, ...)
1312{
1313	va_list va;
1314
1315	va_start(va, fmt);
1316	vwarningf(VWARNINGF_ERRORPREFIX | (fileline ? VWARNINGF_FILELINE : 0),
1317	    fmt, va);
1318	va_end(va);
1319}
1320
1321/*
1322 * Used by built-in utilities to prefix shell and utility name to message
1323 * (also unwinds environments for special builtins).
1324 */
1325void
1326bi_errorf(const char *fmt, ...)
1327{
1328	va_list va;
1329
1330	/* debugging: note that stdout not valid */
1331	shl_stdout_ok = false;
1332
1333	exstat = 1;
1334
1335	va_start(va, fmt);
1336	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE |
1337	    VWARNINGF_BUILTIN, fmt, va);
1338	va_end(va);
1339
1340	/* POSIX special builtins cause non-interactive shells to exit */
1341	if (builtin_spec) {
1342		builtin_argv0 = NULL;
1343		/* may not want to use LERROR here */
1344		unwind(LERROR);
1345	}
1346}
1347
1348/* Called when something that shouldn't happen does */
1349void
1350internal_errorf(const char *fmt, ...)
1351{
1352	va_list va;
1353
1354	va_start(va, fmt);
1355	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1356	va_end(va);
1357	unwind(LERROR);
1358}
1359
1360void
1361internal_warningf(const char *fmt, ...)
1362{
1363	va_list va;
1364
1365	va_start(va, fmt);
1366	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1367	va_end(va);
1368}
1369
1370/* used by error reporting functions to print "ksh: .kshrc[25]: " */
1371void
1372error_prefix(bool fileline)
1373{
1374	/* Avoid foo: foo[2]: ... */
1375	if (!fileline || !source || !source->file ||
1376	    strcmp(source->file, kshname) != 0)
1377		shf_fprintf(shl_out, Tf_sD_, kshname + (*kshname == '-'));
1378	if (fileline && source && source->file != NULL) {
1379		shf_fprintf(shl_out, "%s[%lu]: ", source->file,
1380		    (unsigned long)(source->errline ?
1381		    source->errline : source->line));
1382		source->errline = 0;
1383	}
1384}
1385
1386/* printf to shl_out (stderr) with flush */
1387void
1388shellf(const char *fmt, ...)
1389{
1390	va_list va;
1391
1392	if (!initio_done)
1393		/* shl_out may not be set up yet... */
1394		return;
1395	va_start(va, fmt);
1396	shf_vfprintf(shl_out, fmt, va);
1397	va_end(va);
1398	shf_flush(shl_out);
1399}
1400
1401/* printf to shl_stdout (stdout) */
1402void
1403shprintf(const char *fmt, ...)
1404{
1405	va_list va;
1406
1407	if (!shl_stdout_ok)
1408		internal_errorf("shl_stdout not valid");
1409	va_start(va, fmt);
1410	shf_vfprintf(shl_stdout, fmt, va);
1411	va_end(va);
1412}
1413
1414/* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
1415int
1416can_seek(int fd)
1417{
1418	struct stat statb;
1419
1420	return (fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
1421	    SHF_UNBUF : 0);
1422}
1423
1424#ifdef DF
1425int shl_dbg_fd;
1426#define NSHF_IOB 4
1427#else
1428#define NSHF_IOB 3
1429#endif
1430struct shf shf_iob[NSHF_IOB];
1431
1432void
1433initio(void)
1434{
1435#ifdef DF
1436	const char *lfp;
1437#endif
1438
1439	/* force buffer allocation */
1440	shf_fdopen(1, SHF_WR, shl_stdout);
1441	shf_fdopen(2, SHF_WR, shl_out);
1442	shf_fdopen(2, SHF_WR, shl_xtrace);
1443#ifdef DF
1444	if ((lfp = getenv("SDMKSH_PATH")) == NULL) {
1445		if ((lfp = getenv("HOME")) == NULL || !mksh_abspath(lfp))
1446			errorf("can't get home directory");
1447		lfp = shf_smprintf(Tf_sSs, lfp, "mksh-dbg.txt");
1448	}
1449
1450	if ((shl_dbg_fd = open(lfp, O_WRONLY | O_APPEND | O_CREAT, 0600)) < 0)
1451		errorf("can't open debug output file %s", lfp);
1452	if (shl_dbg_fd < FDBASE) {
1453		int nfd;
1454
1455		nfd = fcntl(shl_dbg_fd, F_DUPFD, FDBASE);
1456		close(shl_dbg_fd);
1457		if ((shl_dbg_fd = nfd) == -1)
1458			errorf("can't dup debug output file");
1459	}
1460	fcntl(shl_dbg_fd, F_SETFD, FD_CLOEXEC);
1461	shf_fdopen(shl_dbg_fd, SHF_WR, shl_dbg);
1462	DF("=== open ===");
1463#endif
1464	initio_done = true;
1465}
1466
1467/* A dup2() with error checking */
1468int
1469ksh_dup2(int ofd, int nfd, bool errok)
1470{
1471	int rv;
1472
1473	if (((rv = dup2(ofd, nfd)) < 0) && !errok && (errno != EBADF))
1474		errorf(Ttoo_many_files);
1475
1476#ifdef __ultrix
1477	/*XXX imake style */
1478	if (rv >= 0)
1479		fcntl(nfd, F_SETFD, 0);
1480#endif
1481
1482	return (rv);
1483}
1484
1485/*
1486 * Move fd from user space (0 <= fd < 10) to shell space (fd >= 10),
1487 * set close-on-exec flag. See FDBASE in sh.h, maybe 24 not 10 here.
1488 */
1489short
1490savefd(int fd)
1491{
1492	int nfd = fd;
1493
1494	if (fd < FDBASE && (nfd = fcntl(fd, F_DUPFD, FDBASE)) < 0 &&
1495	    (errno == EBADF || errno == EPERM))
1496		return (-1);
1497	if (nfd < 0 || nfd > SHRT_MAX)
1498		errorf(Ttoo_many_files);
1499	fcntl(nfd, F_SETFD, FD_CLOEXEC);
1500	return ((short)nfd);
1501}
1502
1503void
1504restfd(int fd, int ofd)
1505{
1506	if (fd == 2)
1507		shf_flush(&shf_iob[/* fd */ 2]);
1508	if (ofd < 0)
1509		/* original fd closed */
1510		close(fd);
1511	else if (fd != ofd) {
1512		/*XXX: what to do if this dup fails? */
1513		ksh_dup2(ofd, fd, true);
1514		close(ofd);
1515	}
1516}
1517
1518void
1519openpipe(int *pv)
1520{
1521	int lpv[2];
1522
1523	if (pipe(lpv) < 0)
1524		errorf("can't create pipe - try again");
1525	pv[0] = savefd(lpv[0]);
1526	if (pv[0] != lpv[0])
1527		close(lpv[0]);
1528	pv[1] = savefd(lpv[1]);
1529	if (pv[1] != lpv[1])
1530		close(lpv[1]);
1531#ifdef __OS2__
1532	setmode(pv[0], O_BINARY);
1533	setmode(pv[1], O_BINARY);
1534#endif
1535}
1536
1537void
1538closepipe(int *pv)
1539{
1540	close(pv[0]);
1541	close(pv[1]);
1542}
1543
1544/*
1545 * Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
1546 * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
1547 */
1548int
1549check_fd(const char *name, int mode, const char **emsgp)
1550{
1551	int fd, fl;
1552
1553	if (!name[0] || name[1])
1554		goto illegal_fd_name;
1555	if (name[0] == 'p')
1556		return (coproc_getfd(mode, emsgp));
1557	if (!ksh_isdigit(name[0])) {
1558 illegal_fd_name:
1559		if (emsgp)
1560			*emsgp = "illegal file descriptor name";
1561		return (-1);
1562	}
1563
1564	if ((fl = fcntl((fd = ksh_numdig(name[0])), F_GETFL, 0)) < 0) {
1565		if (emsgp)
1566			*emsgp = "bad file descriptor";
1567		return (-1);
1568	}
1569	fl &= O_ACCMODE;
1570	/*
1571	 * X_OK is a kludge to disable this check for dups (x<&1):
1572	 * historical shells never did this check (XXX don't know what
1573	 * POSIX has to say).
1574	 */
1575	if (!(mode & X_OK) && fl != O_RDWR && (
1576	    ((mode & R_OK) && fl != O_RDONLY) ||
1577	    ((mode & W_OK) && fl != O_WRONLY))) {
1578		if (emsgp)
1579			*emsgp = (fl == O_WRONLY) ?
1580			    "fd not open for reading" :
1581			    "fd not open for writing";
1582		return (-1);
1583	}
1584	return (fd);
1585}
1586
1587/* Called once from main */
1588void
1589coproc_init(void)
1590{
1591	coproc.read = coproc.readw = coproc.write = -1;
1592	coproc.njobs = 0;
1593	coproc.id = 0;
1594}
1595
1596/* Called by c_read() when eof is read - close fd if it is the co-process fd */
1597void
1598coproc_read_close(int fd)
1599{
1600	if (coproc.read >= 0 && fd == coproc.read) {
1601		coproc_readw_close(fd);
1602		close(coproc.read);
1603		coproc.read = -1;
1604	}
1605}
1606
1607/*
1608 * Called by c_read() and by iosetup() to close the other side of the
1609 * read pipe, so reads will actually terminate.
1610 */
1611void
1612coproc_readw_close(int fd)
1613{
1614	if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
1615		close(coproc.readw);
1616		coproc.readw = -1;
1617	}
1618}
1619
1620/*
1621 * Called by c_print when a write to a fd fails with EPIPE and by iosetup
1622 * when co-process input is dup'd
1623 */
1624void
1625coproc_write_close(int fd)
1626{
1627	if (coproc.write >= 0 && fd == coproc.write) {
1628		close(coproc.write);
1629		coproc.write = -1;
1630	}
1631}
1632
1633/*
1634 * Called to check for existence of/value of the co-process file descriptor.
1635 * (Used by check_fd() and by c_read/c_print to deal with -p option).
1636 */
1637int
1638coproc_getfd(int mode, const char **emsgp)
1639{
1640	int fd = (mode & R_OK) ? coproc.read : coproc.write;
1641
1642	if (fd >= 0)
1643		return (fd);
1644	if (emsgp)
1645		*emsgp = "no coprocess";
1646	return (-1);
1647}
1648
1649/*
1650 * called to close file descriptors related to the coprocess (if any)
1651 * Should be called with SIGCHLD blocked.
1652 */
1653void
1654coproc_cleanup(int reuse)
1655{
1656	/* This to allow co-processes to share output pipe */
1657	if (!reuse || coproc.readw < 0 || coproc.read < 0) {
1658		if (coproc.read >= 0) {
1659			close(coproc.read);
1660			coproc.read = -1;
1661		}
1662		if (coproc.readw >= 0) {
1663			close(coproc.readw);
1664			coproc.readw = -1;
1665		}
1666	}
1667	if (coproc.write >= 0) {
1668		close(coproc.write);
1669		coproc.write = -1;
1670	}
1671}
1672
1673struct temp *
1674maketemp(Area *ap, Temp_type type, struct temp **tlist)
1675{
1676	char *cp;
1677	size_t len;
1678	int i, j;
1679	struct temp *tp;
1680	const char *dir;
1681	struct stat sb;
1682
1683	dir = tmpdir ? tmpdir : MKSH_DEFAULT_TMPDIR;
1684	/* add "/shXXXXXX.tmp" plus NUL */
1685	len = strlen(dir);
1686	checkoktoadd(len, offsetof(struct temp, tffn[0]) + 14);
1687	tp = alloc(offsetof(struct temp, tffn[0]) + 14 + len, ap);
1688
1689	tp->shf = NULL;
1690	tp->pid = procpid;
1691	tp->type = type;
1692
1693	if (stat(dir, &sb) || !S_ISDIR(sb.st_mode)) {
1694		tp->tffn[0] = '\0';
1695		goto maketemp_out;
1696	}
1697
1698	cp = (void *)tp;
1699	cp += offsetof(struct temp, tffn[0]);
1700	memcpy(cp, dir, len);
1701	cp += len;
1702	memcpy(cp, "/shXXXXXX.tmp", 14);
1703	/* point to the first of six Xes */
1704	cp += 3;
1705
1706	/* cyclically attempt to open a temporary file */
1707	do {
1708		/* generate random part of filename */
1709		len = 0;
1710		do {
1711			cp[len++] = digits_lc[rndget() % 36];
1712		} while (len < 6);
1713
1714		/* check if this one works */
1715		if ((i = binopen3(tp->tffn, O_CREAT | O_EXCL | O_RDWR,
1716		    0600)) < 0 && errno != EEXIST)
1717			goto maketemp_out;
1718	} while (i < 0);
1719
1720	if (type == TT_FUNSUB) {
1721		/* map us high and mark as close-on-exec */
1722		if ((j = savefd(i)) != i) {
1723			close(i);
1724			i = j;
1725		}
1726
1727		/* operation mode for the shf */
1728		j = SHF_RD;
1729	} else
1730		j = SHF_WR;
1731
1732	/* shf_fdopen cannot fail, so no fd leak */
1733	tp->shf = shf_fdopen(i, j, NULL);
1734
1735 maketemp_out:
1736	tp->next = *tlist;
1737	*tlist = tp;
1738	return (tp);
1739}
1740
1741/*
1742 * We use a similar collision resolution algorithm as Python 2.5.4
1743 * but with a slightly tweaked implementation written from scratch.
1744 */
1745
1746#define	INIT_TBLSHIFT	3	/* initial table shift (2^3 = 8) */
1747#define PERTURB_SHIFT	5	/* see Python 2.5.4 Objects/dictobject.c */
1748
1749static void tgrow(struct table *);
1750static int tnamecmp(const void *, const void *);
1751
1752static void
1753tgrow(struct table *tp)
1754{
1755	size_t i, j, osize, mask, perturb;
1756	struct tbl *tblp, **pp;
1757	struct tbl **ntblp, **otblp = tp->tbls;
1758
1759	if (tp->tshift > 29)
1760		internal_errorf("hash table size limit reached");
1761
1762	/* calculate old size, new shift and new size */
1763	osize = (size_t)1 << (tp->tshift++);
1764	i = osize << 1;
1765
1766	ntblp = alloc2(i, sizeof(struct tbl *), tp->areap);
1767	/* multiplication cannot overflow: alloc2 checked that */
1768	memset(ntblp, 0, i * sizeof(struct tbl *));
1769
1770	/* table can get very full when reaching its size limit */
1771	tp->nfree = (tp->tshift == 30) ? 0x3FFF0000UL :
1772	    /* but otherwise, only 75% */
1773	    ((i * 3) / 4);
1774	tp->tbls = ntblp;
1775	if (otblp == NULL)
1776		return;
1777
1778	mask = i - 1;
1779	for (i = 0; i < osize; i++)
1780		if ((tblp = otblp[i]) != NULL) {
1781			if ((tblp->flag & DEFINED)) {
1782				/* search for free hash table slot */
1783				j = perturb = tblp->ua.hval;
1784				goto find_first_empty_slot;
1785 find_next_empty_slot:
1786				j = (j << 2) + j + perturb + 1;
1787				perturb >>= PERTURB_SHIFT;
1788 find_first_empty_slot:
1789				pp = &ntblp[j & mask];
1790				if (*pp != NULL)
1791					goto find_next_empty_slot;
1792				/* found an empty hash table slot */
1793				*pp = tblp;
1794				tp->nfree--;
1795			} else if (!(tblp->flag & FINUSE)) {
1796				afree(tblp, tp->areap);
1797			}
1798		}
1799	afree(otblp, tp->areap);
1800}
1801
1802void
1803ktinit(Area *ap, struct table *tp, uint8_t initshift)
1804{
1805	tp->areap = ap;
1806	tp->tbls = NULL;
1807	tp->tshift = ((initshift > INIT_TBLSHIFT) ?
1808	    initshift : INIT_TBLSHIFT) - 1;
1809	tgrow(tp);
1810}
1811
1812/* table, name (key) to search for, hash(name), rv pointer to tbl ptr */
1813struct tbl *
1814ktscan(struct table *tp, const char *name, uint32_t h, struct tbl ***ppp)
1815{
1816	size_t j, perturb, mask;
1817	struct tbl **pp, *p;
1818
1819	mask = ((size_t)1 << (tp->tshift)) - 1;
1820	/* search for hash table slot matching name */
1821	j = perturb = h;
1822	goto find_first_slot;
1823 find_next_slot:
1824	j = (j << 2) + j + perturb + 1;
1825	perturb >>= PERTURB_SHIFT;
1826 find_first_slot:
1827	pp = &tp->tbls[j & mask];
1828	if ((p = *pp) != NULL && (p->ua.hval != h || !(p->flag & DEFINED) ||
1829	    strcmp(p->name, name)))
1830		goto find_next_slot;
1831	/* p == NULL if not found, correct found entry otherwise */
1832	if (ppp)
1833		*ppp = pp;
1834	return (p);
1835}
1836
1837/* table, name (key) to enter, hash(n) */
1838struct tbl *
1839ktenter(struct table *tp, const char *n, uint32_t h)
1840{
1841	struct tbl **pp, *p;
1842	size_t len;
1843
1844 Search:
1845	if ((p = ktscan(tp, n, h, &pp)))
1846		return (p);
1847
1848	if (tp->nfree == 0) {
1849		/* too full */
1850		tgrow(tp);
1851		goto Search;
1852	}
1853
1854	/* create new tbl entry */
1855	len = strlen(n);
1856	checkoktoadd(len, offsetof(struct tbl, name[0]) + 1);
1857	p = alloc(offsetof(struct tbl, name[0]) + ++len, tp->areap);
1858	p->flag = 0;
1859	p->type = 0;
1860	p->areap = tp->areap;
1861	p->ua.hval = h;
1862	p->u2.field = 0;
1863	p->u.array = NULL;
1864	memcpy(p->name, n, len);
1865
1866	/* enter in tp->tbls */
1867	tp->nfree--;
1868	*pp = p;
1869	return (p);
1870}
1871
1872void
1873ktwalk(struct tstate *ts, struct table *tp)
1874{
1875	ts->left = (size_t)1 << (tp->tshift);
1876	ts->next = tp->tbls;
1877}
1878
1879struct tbl *
1880ktnext(struct tstate *ts)
1881{
1882	while (--ts->left >= 0) {
1883		struct tbl *p = *ts->next++;
1884		if (p != NULL && (p->flag & DEFINED))
1885			return (p);
1886	}
1887	return (NULL);
1888}
1889
1890static int
1891tnamecmp(const void *p1, const void *p2)
1892{
1893	const struct tbl *a = *((const struct tbl * const *)p1);
1894	const struct tbl *b = *((const struct tbl * const *)p2);
1895
1896	return (strcmp(a->name, b->name));
1897}
1898
1899struct tbl **
1900ktsort(struct table *tp)
1901{
1902	size_t i;
1903	struct tbl **p, **sp, **dp;
1904
1905	/*
1906	 * since the table is never entirely full, no need to reserve
1907	 * additional space for the trailing NULL appended below
1908	 */
1909	i = (size_t)1 << (tp->tshift);
1910	p = alloc2(i, sizeof(struct tbl *), ATEMP);
1911	sp = tp->tbls;		/* source */
1912	dp = p;			/* dest */
1913	while (i--)
1914		if ((*dp = *sp++) != NULL && (((*dp)->flag & DEFINED) ||
1915		    ((*dp)->flag & ARRAY)))
1916			dp++;
1917	qsort(p, (i = dp - p), sizeof(struct tbl *), tnamecmp);
1918	p[i] = NULL;
1919	return (p);
1920}
1921
1922#ifdef SIGWINCH
1923static void
1924x_sigwinch(int sig MKSH_A_UNUSED)
1925{
1926	/* this runs inside interrupt context, with errno saved */
1927
1928	got_winch = 1;
1929}
1930#endif
1931
1932#ifdef DF
1933void
1934DF(const char *fmt, ...)
1935{
1936	va_list args;
1937	struct timeval tv;
1938	mirtime_mjd mjd;
1939
1940	mksh_lockfd(shl_dbg_fd);
1941	mksh_TIME(tv);
1942	timet2mjd(&mjd, tv.tv_sec);
1943	shf_fprintf(shl_dbg, "[%02u:%02u:%02u (%u) %u.%06u] ",
1944	    (unsigned)mjd.sec / 3600, ((unsigned)mjd.sec / 60) % 60,
1945	    (unsigned)mjd.sec % 60, (unsigned)getpid(),
1946	    (unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
1947	va_start(args, fmt);
1948	shf_vfprintf(shl_dbg, fmt, args);
1949	va_end(args);
1950	shf_putc('\n', shl_dbg);
1951	shf_flush(shl_dbg);
1952	mksh_unlkfd(shl_dbg_fd);
1953}
1954#endif
1955
1956void
1957x_mkraw(int fd, mksh_ttyst *ocb, bool forread)
1958{
1959	mksh_ttyst cb;
1960
1961	if (ocb)
1962		mksh_tcget(fd, ocb);
1963	else
1964		ocb = &tty_state;
1965
1966	cb = *ocb;
1967	if (forread) {
1968		cb.c_iflag &= ~(ISTRIP);
1969		cb.c_lflag &= ~(ICANON) | ECHO;
1970	} else {
1971		cb.c_iflag &= ~(INLCR | ICRNL | ISTRIP);
1972		cb.c_lflag &= ~(ISIG | ICANON | ECHO);
1973	}
1974#if defined(VLNEXT) && defined(_POSIX_VDISABLE)
1975	/* OSF/1 processes lnext when ~icanon */
1976	cb.c_cc[VLNEXT] = _POSIX_VDISABLE;
1977#endif
1978	/* SunOS 4.1.x & OSF/1 processes discard(flush) when ~icanon */
1979#if defined(VDISCARD) && defined(_POSIX_VDISABLE)
1980	cb.c_cc[VDISCARD] = _POSIX_VDISABLE;
1981#endif
1982	cb.c_cc[VTIME] = 0;
1983	cb.c_cc[VMIN] = 1;
1984
1985	mksh_tcset(fd, &cb);
1986}
1987