1/*	$OpenBSD: main.c,v 1.55 2015/02/09 09:09:30 jsg Exp $	*/
2/*	$OpenBSD: tty.c,v 1.10 2014/08/10 02:44:26 guenther Exp $	*/
3/*	$OpenBSD: io.c,v 1.25 2014/08/11 20:28:47 guenther Exp $	*/
4/*	$OpenBSD: table.c,v 1.15 2012/02/19 07:52:30 otto Exp $	*/
5
6/*-
7 * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
8 *		 2011, 2012, 2013, 2014, 2015
9 *	Thorsten Glaser <tg@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 1.285.2.4 2015/04/19 19:18:20 tg Exp $");
38
39extern char **environ;
40
41#ifndef MKSHRC_PATH
42#define MKSHRC_PATH	"~/.mkshrc"
43#endif
44
45#ifndef MKSH_DEFAULT_TMPDIR
46#define MKSH_DEFAULT_TMPDIR	"/tmp"
47#endif
48
49static uint8_t isuc(const char *);
50static int main_init(int, const char *[], Source **, struct block **);
51void chvt_reinit(void);
52static void reclaim(void);
53static void remove_temps(struct temp *);
54static mksh_uari_t rndsetup(void);
55#ifdef SIGWINCH
56static void x_sigwinch(int);
57#endif
58
59static const char initifs[] = "IFS= \t\n";
60
61static const char initsubs[] =
62    "${PS2=> } ${PS3=#? } ${PS4=+ } ${SECONDS=0} ${TMOUT=0} ${EPOCHREALTIME=}";
63
64static const char *initcoms[] = {
65	Ttypeset, "-r", initvsn, NULL,
66	Ttypeset, "-x", "HOME", "PATH", "SHELL", NULL,
67	Ttypeset, "-i10", "COLUMNS", "LINES", "SECONDS", "TMOUT", NULL,
68	Talias,
69	"integer=typeset -i",
70	Tlocal_typeset,
71	/* not "alias -t --": hash -r needs to work */
72	"hash=alias -t",
73	"type=whence -v",
74#if !defined(ANDROID) && !defined(MKSH_UNEMPLOYED)
75	/* not in Android for political reasons */
76	/* not in ARGE mksh due to no job control */
77	"stop=kill -STOP",
78#endif
79	"autoload=typeset -fu",
80	"functions=typeset -f",
81	"history=fc -l",
82	"nameref=typeset -n",
83	"nohup=nohup ",
84	Tr_fc_e_dash,
85	"source=PATH=$PATH:. command .",
86	"login=exec login",
87	NULL,
88	 /* this is what AT&T ksh seems to track, with the addition of emacs */
89	Talias, "-tU",
90	"cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
91	"make", "mv", "pr", "rm", "sed", "sh", "vi", "who", NULL,
92	NULL
93};
94
95static const char *restr_com[] = {
96	Ttypeset, "-r", "PATH", "ENV", "SHELL", NULL
97};
98
99static bool initio_done;
100
101/* top-level parsing and execution environment */
102static struct env env;
103struct env *e = &env;
104
105static mksh_uari_t
106rndsetup(void)
107{
108	register uint32_t h;
109	struct {
110		ALLOC_ITEM alloc_INT;
111		void *dataptr, *stkptr, *mallocptr;
112#if defined(__GLIBC__) && (__GLIBC__ >= 2)
113		sigjmp_buf jbuf;
114#endif
115		struct timeval tv;
116	} *bufptr;
117	char *cp;
118
119	cp = alloc(sizeof(*bufptr) - ALLOC_SIZE, APERM);
120#ifdef DEBUG
121	/* clear the allocated space, for valgrind */
122	memset(cp, 0, sizeof(*bufptr) - ALLOC_SIZE);
123#endif
124	/* undo what alloc() did to the malloc result address */
125	bufptr = (void *)(cp - ALLOC_SIZE);
126	/* PIE or something similar provides us with deltas here */
127	bufptr->dataptr = &rndsetupstate;
128	/* ASLR in at least Windows, Linux, some BSDs */
129	bufptr->stkptr = &bufptr;
130	/* randomised malloc in BSD (and possibly others) */
131	bufptr->mallocptr = bufptr;
132#if defined(__GLIBC__) && (__GLIBC__ >= 2)
133	/* glibc pointer guard */
134	sigsetjmp(bufptr->jbuf, 1);
135#endif
136	/* introduce variation (and yes, second arg MBZ for portability) */
137	mksh_TIME(bufptr->tv);
138
139	h = chvt_rndsetup(bufptr, sizeof(*bufptr));
140
141	afree(cp, APERM);
142	return ((mksh_uari_t)h);
143}
144
145void
146chvt_reinit(void)
147{
148	kshpid = procpid = getpid();
149	ksheuid = geteuid();
150	kshpgrp = getpgrp();
151	kshppid = getppid();
152}
153
154static const char *empty_argv[] = {
155	"mksh", NULL
156};
157
158static uint8_t
159isuc(const char *cx) {
160	char *cp, *x;
161	uint8_t rv = 0;
162
163	if (!cx || !*cx)
164		return (0);
165
166	/* uppercase a string duplicate */
167	strdupx(x, cx, ATEMP);
168	cp = x;
169	while ((*cp = ksh_toupper(*cp)))
170		++cp;
171
172	/* check for UTF-8 */
173	if (strstr(x, "UTF-8") || strstr(x, "UTF8"))
174		rv = 1;
175
176	/* free copy and out */
177	afree(x, ATEMP);
178	return (rv);
179}
180
181static int
182main_init(int argc, const char *argv[], Source **sp, struct block **lp)
183{
184	int argi, i;
185	Source *s = NULL;
186	struct block *l;
187	unsigned char restricted_shell, errexit, utf_flag;
188	char *cp;
189	const char *ccp, **wp;
190	struct tbl *vp;
191	struct stat s_stdin;
192#if !defined(_PATH_DEFPATH) && defined(_CS_PATH)
193	ssize_t k;
194#endif
195
196	/* do things like getpgrp() et al. */
197	chvt_reinit();
198
199	/* make sure argv[] is sane */
200	if (!*argv) {
201		argv = empty_argv;
202		argc = 1;
203	}
204	kshname = argv[0];
205
206	/* initialise permanent Area */
207	ainit(&aperm);
208
209	/* set up base environment */
210	env.type = E_NONE;
211	ainit(&env.area);
212	/* set up global l->vars and l->funs */
213	newblock();
214
215	/* Do this first so output routines (eg, errorf, shellf) can work */
216	initio();
217
218	/* determine the basename (without '-' or path) of the executable */
219	ccp = kshname;
220	goto begin_parse_kshname;
221	while ((i = ccp[argi++])) {
222		if (i == '/') {
223			ccp += argi;
224 begin_parse_kshname:
225			argi = 0;
226			if (*ccp == '-')
227				++ccp;
228		}
229	}
230	if (!*ccp)
231		ccp = empty_argv[0];
232
233	/*
234	 * Turn on nohup by default. (AT&T ksh does not have a nohup
235	 * option - it always sends the hup).
236	 */
237	Flag(FNOHUP) = 1;
238
239	/*
240	 * Turn on brace expansion by default. AT&T kshs that have
241	 * alternation always have it on.
242	 */
243	Flag(FBRACEEXPAND) = 1;
244
245	/*
246	 * Turn on "set -x" inheritance by default.
247	 */
248	Flag(FXTRACEREC) = 1;
249
250	/* define built-in commands and see if we were called as one */
251	ktinit(APERM, &builtins,
252	    /* currently up to 51 builtins: 75% of 128 = 2^7 */
253	    7);
254	for (i = 0; mkshbuiltins[i].name != NULL; i++)
255		if (!strcmp(ccp, builtin(mkshbuiltins[i].name,
256		    mkshbuiltins[i].func)))
257			Flag(FAS_BUILTIN) = 1;
258
259	if (!Flag(FAS_BUILTIN)) {
260		/* check for -T option early */
261		argi = parse_args(argv, OF_FIRSTTIME, NULL);
262		if (argi < 0)
263			return (1);
264
265#if defined(MKSH_BINSHPOSIX) || defined(MKSH_BINSHREDUCED)
266		/* are we called as -sh or /bin/sh or so? */
267		if (!strcmp(ccp, "sh")) {
268			/* either also turns off braceexpand */
269#ifdef MKSH_BINSHPOSIX
270			/* enable better POSIX conformance */
271			change_flag(FPOSIX, OF_FIRSTTIME, true);
272#endif
273#ifdef MKSH_BINSHREDUCED
274			/* enable kludge/compat mode */
275			change_flag(FSH, OF_FIRSTTIME, true);
276#endif
277		}
278#endif
279	}
280
281	initvar();
282
283	initctypes();
284
285	inittraps();
286
287	coproc_init();
288
289	/* set up variable and command dictionaries */
290	ktinit(APERM, &taliases, 0);
291	ktinit(APERM, &aliases, 0);
292#ifndef MKSH_NOPWNAM
293	ktinit(APERM, &homedirs, 0);
294#endif
295
296	/* define shell keywords */
297	initkeywords();
298
299	init_histvec();
300
301	/* initialise tty size before importing environment */
302	change_winsz();
303
304#ifdef _PATH_DEFPATH
305	def_path = _PATH_DEFPATH;
306#else
307#ifdef _CS_PATH
308	if ((k = confstr(_CS_PATH, NULL, 0)) > 0 &&
309	    confstr(_CS_PATH, cp = alloc(k + 1, APERM), k + 1) == k + 1)
310		def_path = cp;
311	else
312#endif
313		/*
314		 * this is uniform across all OSes unless it
315		 * breaks somewhere; don't try to optimise,
316		 * e.g. add stuff for Interix or remove /usr
317		 * for HURD, because e.g. Debian GNU/HURD is
318		 * "keeping a regular /usr"; this is supposed
319		 * to be a sane 'basic' default PATH
320		 */
321		def_path = "/bin:/usr/bin:/sbin:/usr/sbin";
322#endif
323
324	/*
325	 * Set PATH to def_path (will set the path global variable).
326	 * (import of environment below will probably change this setting).
327	 */
328	vp = global("PATH");
329	/* setstr can't fail here */
330	setstr(vp, def_path, KSH_RETURN_ERROR);
331
332#ifndef MKSH_NO_CMDLINE_EDITING
333	/*
334	 * Set edit mode to emacs by default, may be overridden
335	 * by the environment or the user. Also, we want tab completion
336	 * on in vi by default.
337	 */
338	change_flag(FEMACS, OF_SPECIAL, true);
339#if !MKSH_S_NOVI
340	Flag(FVITABCOMPLETE) = 1;
341#endif
342#endif
343
344	/* import environment */
345	if (environ != NULL) {
346		wp = (const char **)environ;
347		while (*wp != NULL) {
348			rndpush(*wp);
349			typeset(*wp, IMPORT | EXPORT, 0, 0, 0);
350			++wp;
351		}
352	}
353
354	/* for security */
355	typeset(initifs, 0, 0, 0, 0);
356
357	/* assign default shell variable values */
358	substitute(initsubs, 0);
359
360	/* Figure out the current working directory and set $PWD */
361	vp = global("PWD");
362	cp = str_val(vp);
363	/* Try to use existing $PWD if it is valid */
364	set_current_wd((cp[0] == '/' && test_eval(NULL, TO_FILEQ, cp, ".",
365	    true)) ? cp : NULL);
366	if (current_wd[0])
367		simplify_path(current_wd);
368	/* Only set pwd if we know where we are or if it had a bogus value */
369	if (current_wd[0] || *cp)
370		/* setstr can't fail here */
371		setstr(vp, current_wd, KSH_RETURN_ERROR);
372
373	for (wp = initcoms; *wp != NULL; wp++) {
374		shcomexec(wp);
375		while (*wp != NULL)
376			wp++;
377	}
378	setint_n(global("OPTIND"), 1, 10);
379
380	kshuid = getuid();
381	kshgid = getgid();
382	kshegid = getegid();
383
384	safe_prompt = ksheuid ? "$ " : "# ";
385	vp = global("PS1");
386	/* Set PS1 if unset or we are root and prompt doesn't contain a # */
387	if (!(vp->flag & ISSET) ||
388	    (!ksheuid && !strchr(str_val(vp), '#')))
389		/* setstr can't fail here */
390		setstr(vp, safe_prompt, KSH_RETURN_ERROR);
391	setint_n((vp = global("BASHPID")), 0, 10);
392	vp->flag |= INT_U;
393	setint_n((vp = global("PGRP")), (mksh_uari_t)kshpgrp, 10);
394	vp->flag |= INT_U;
395	setint_n((vp = global("PPID")), (mksh_uari_t)kshppid, 10);
396	vp->flag |= INT_U;
397	setint_n((vp = global("USER_ID")), (mksh_uari_t)ksheuid, 10);
398	vp->flag |= INT_U;
399	setint_n((vp = global("KSHUID")), (mksh_uari_t)kshuid, 10);
400	vp->flag |= INT_U;
401	setint_n((vp = global("KSHEGID")), (mksh_uari_t)kshegid, 10);
402	vp->flag |= INT_U;
403	setint_n((vp = global("KSHGID")), (mksh_uari_t)kshgid, 10);
404	vp->flag |= INT_U;
405	setint_n((vp = global("RANDOM")), rndsetup(), 10);
406	vp->flag |= INT_U;
407	setint_n((vp_pipest = global("PIPESTATUS")), 0, 10);
408
409	/* Set this before parsing arguments */
410	Flag(FPRIVILEGED) = (
411#if HAVE_ISSETUGID
412	    issetugid() ||
413#endif
414	    kshuid != ksheuid || kshgid != kshegid) ? 2 : 0;
415
416	/* this to note if monitor is set on command line (see below) */
417#ifndef MKSH_UNEMPLOYED
418	Flag(FMONITOR) = 127;
419#endif
420	/* this to note if utf-8 mode is set on command line (see below) */
421	UTFMODE = 2;
422
423	if (!Flag(FAS_BUILTIN)) {
424		argi = parse_args(argv, OF_CMDLINE, NULL);
425		if (argi < 0)
426			return (1);
427	}
428
429	/* process this later only, default to off (hysterical raisins) */
430	utf_flag = UTFMODE;
431	UTFMODE = 0;
432
433	if (Flag(FAS_BUILTIN)) {
434		/* auto-detect from environment variables, always */
435		utf_flag = 3;
436	} else if (Flag(FCOMMAND)) {
437		s = pushs(SSTRINGCMDLINE, ATEMP);
438		if (!(s->start = s->str = argv[argi++]))
439			errorf("%s %s", "-c", "requires an argument");
440		while (*s->str) {
441			if (*s->str != ' ' && ctype(*s->str, C_QUOTE))
442				break;
443			s->str++;
444		}
445		if (!*s->str)
446			s->flags |= SF_MAYEXEC;
447		s->str = s->start;
448#ifdef MKSH_MIDNIGHTBSD01ASH_COMPAT
449		/* compatibility to MidnightBSD 0.1 /bin/sh (kludge) */
450		if (Flag(FSH) && argv[argi] && !strcmp(argv[argi], "--"))
451			++argi;
452#endif
453		if (argv[argi])
454			kshname = argv[argi++];
455	} else if (argi < argc && !Flag(FSTDIN)) {
456		s = pushs(SFILE, ATEMP);
457		s->file = argv[argi++];
458		s->u.shf = shf_open(s->file, O_RDONLY, 0,
459		    SHF_MAPHI | SHF_CLEXEC);
460		if (s->u.shf == NULL) {
461			shl_stdout_ok = false;
462			warningf(true, "%s: %s", s->file, cstrerror(errno));
463			/* mandated by SUSv4 */
464			exstat = 127;
465			unwind(LERROR);
466		}
467		kshname = s->file;
468	} else {
469		Flag(FSTDIN) = 1;
470		s = pushs(SSTDIN, ATEMP);
471		s->file = "<stdin>";
472		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
473		    NULL);
474		if (isatty(0) && isatty(2)) {
475			Flag(FTALKING) = Flag(FTALKING_I) = 1;
476			/* The following only if isatty(0) */
477			s->flags |= SF_TTY;
478			s->u.shf->flags |= SHF_INTERRUPT;
479			s->file = NULL;
480		}
481	}
482
483	/* this bizarreness is mandated by POSIX */
484	if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
485	    Flag(FTALKING))
486		reset_nonblock(0);
487
488	/* initialise job control */
489	j_init();
490	/* do this after j_init() which calls tty_init_state() */
491	if (Flag(FTALKING)) {
492		if (utf_flag == 2) {
493#ifndef MKSH_ASSUME_UTF8
494			/* auto-detect from locale or environment */
495			utf_flag = 4;
496#else /* this may not be an #elif */
497#if MKSH_ASSUME_UTF8
498			utf_flag = 1;
499#else
500			/* always disable UTF-8 (for interactive) */
501			utf_flag = 0;
502#endif
503#endif
504		}
505#ifndef MKSH_NO_CMDLINE_EDITING
506		x_init();
507#endif
508	}
509
510#ifdef SIGWINCH
511	sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
512	setsig(&sigtraps[SIGWINCH], x_sigwinch,
513	    SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
514#endif
515
516	l = e->loc;
517	if (Flag(FAS_BUILTIN)) {
518		l->argc = argc;
519		l->argv = argv;
520		l->argv[0] = ccp;
521	} else {
522		l->argc = argc - argi;
523		/*
524		 * allocate a new array because otherwise, when we modify
525		 * it in-place, ps(1) output changes; the meaning of argc
526		 * here is slightly different as it excludes kshname, and
527		 * we add a trailing NULL sentinel as well
528		 */
529		l->argv = alloc2(l->argc + 2, sizeof(void *), APERM);
530		l->argv[0] = kshname;
531		memcpy(&l->argv[1], &argv[argi], l->argc * sizeof(void *));
532		l->argv[l->argc + 1] = NULL;
533		getopts_reset(1);
534	}
535
536	/* divine the initial state of the utf8-mode Flag */
537	ccp = null;
538	switch (utf_flag) {
539
540	/* auto-detect from locale or environment */
541	case 4:
542#if HAVE_SETLOCALE_CTYPE
543		ccp = setlocale(LC_CTYPE, "");
544#if HAVE_LANGINFO_CODESET
545		if (!isuc(ccp))
546			ccp = nl_langinfo(CODESET);
547#endif
548		if (!isuc(ccp))
549			ccp = null;
550		/* FALLTHROUGH */
551#endif
552
553	/* auto-detect from environment */
554	case 3:
555		/* these were imported from environ earlier */
556		if (ccp == null)
557			ccp = str_val(global("LC_ALL"));
558		if (ccp == null)
559			ccp = str_val(global("LC_CTYPE"));
560		if (ccp == null)
561			ccp = str_val(global("LANG"));
562		UTFMODE = isuc(ccp);
563		break;
564
565	/* not set on command line, not FTALKING */
566	case 2:
567	/* unknown values */
568	default:
569		utf_flag = 0;
570		/* FALLTHROUGH */
571
572	/* known values */
573	case 1:
574	case 0:
575		UTFMODE = utf_flag;
576		break;
577	}
578
579	/* Disable during .profile/ENV reading */
580	restricted_shell = Flag(FRESTRICTED);
581	Flag(FRESTRICTED) = 0;
582	errexit = Flag(FERREXIT);
583	Flag(FERREXIT) = 0;
584
585	/*
586	 * Do this before profile/$ENV so that if it causes problems in them,
587	 * user will know why things broke.
588	 */
589	if (!current_wd[0] && Flag(FTALKING))
590		warningf(false, "can't determine current directory");
591
592	if (Flag(FLOGIN))
593		include(MKSH_SYSTEM_PROFILE, 0, NULL, true);
594	if (!Flag(FPRIVILEGED)) {
595		if (Flag(FLOGIN))
596			include(substitute("$HOME/.profile", 0), 0, NULL, true);
597		if (Flag(FTALKING)) {
598			cp = substitute(substitute("${ENV:-" MKSHRC_PATH "}",
599			    0), DOTILDE);
600			if (cp[0] != '\0')
601				include(cp, 0, NULL, true);
602		}
603	} else {
604		include(MKSH_SUID_PROFILE, 0, NULL, true);
605		/* turn off -p if not set explicitly */
606		if (Flag(FPRIVILEGED) != 1)
607			change_flag(FPRIVILEGED, OF_INTERNAL, false);
608	}
609
610	if (restricted_shell) {
611		shcomexec(restr_com);
612		/* After typeset command... */
613		Flag(FRESTRICTED) = 1;
614	}
615	Flag(FERREXIT) = errexit;
616
617	if (Flag(FTALKING) && s)
618		hist_init(s);
619	else
620		/* set after ENV */
621		Flag(FTRACKALL) = 1;
622
623	alarm_init();
624
625	*sp = s;
626	*lp = l;
627	return (0);
628}
629
630/* this indirection barrier reduces stack usage during normal operation */
631
632int
633main(int argc, const char *argv[])
634{
635	int rv;
636	Source *s;
637	struct block *l;
638
639	if ((rv = main_init(argc, argv, &s, &l)) == 0) {
640		if (Flag(FAS_BUILTIN)) {
641			rv = shcomexec(l->argv);
642		} else {
643			shell(s, true);
644			/* NOTREACHED */
645		}
646	}
647	return (rv);
648}
649
650int
651include(const char *name, int argc, const char **argv, bool intr_ok)
652{
653	Source *volatile s = NULL;
654	struct shf *shf;
655	const char **volatile old_argv;
656	volatile int old_argc;
657	int i;
658
659	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
660	if (shf == NULL)
661		return (-1);
662
663	if (argv) {
664		old_argv = e->loc->argv;
665		old_argc = e->loc->argc;
666	} else {
667		old_argv = NULL;
668		old_argc = 0;
669	}
670	newenv(E_INCL);
671	if ((i = kshsetjmp(e->jbuf))) {
672		quitenv(s ? s->u.shf : NULL);
673		if (old_argv) {
674			e->loc->argv = old_argv;
675			e->loc->argc = old_argc;
676		}
677		switch (i) {
678		case LRETURN:
679		case LERROR:
680			/* see below */
681			return (exstat & 0xFF);
682		case LINTR:
683			/*
684			 * intr_ok is set if we are including .profile or $ENV.
685			 * If user ^Cs out, we don't want to kill the shell...
686			 */
687			if (intr_ok && ((exstat & 0xFF) - 128) != SIGTERM)
688				return (1);
689			/* FALLTHROUGH */
690		case LEXIT:
691		case LLEAVE:
692		case LSHELL:
693			unwind(i);
694			/* NOTREACHED */
695		default:
696			internal_errorf("%s %d", "include", i);
697			/* NOTREACHED */
698		}
699	}
700	if (argv) {
701		e->loc->argv = argv;
702		e->loc->argc = argc;
703	}
704	s = pushs(SFILE, ATEMP);
705	s->u.shf = shf;
706	strdupx(s->file, name, ATEMP);
707	i = shell(s, false);
708	quitenv(s->u.shf);
709	if (old_argv) {
710		e->loc->argv = old_argv;
711		e->loc->argc = old_argc;
712	}
713	/* & 0xff to ensure value not -1 */
714	return (i & 0xFF);
715}
716
717/* spawn a command into a shell optionally keeping track of the line number */
718int
719command(const char *comm, int line)
720{
721	Source *s;
722
723	s = pushs(SSTRING, ATEMP);
724	s->start = s->str = comm;
725	s->line = line;
726	return (shell(s, false));
727}
728
729/*
730 * run the commands from the input source, returning status.
731 */
732int
733shell(Source * volatile s, volatile bool toplevel)
734{
735	struct op *t;
736	volatile bool wastty = tobool(s->flags & SF_TTY);
737	volatile uint8_t attempts = 13;
738	volatile bool interactive = Flag(FTALKING) && toplevel;
739	volatile bool sfirst = true;
740	Source *volatile old_source = source;
741	int i;
742
743	newenv(E_PARSE);
744	if (interactive)
745		really_exit = false;
746	switch ((i = kshsetjmp(e->jbuf))) {
747	case 0:
748		break;
749	case LINTR:
750		/* we get here if SIGINT not caught or ignored */
751	case LERROR:
752	case LSHELL:
753		if (interactive) {
754			if (i == LINTR)
755				shellf("\n");
756			/*
757			 * Reset any eof that was read as part of a
758			 * multiline command.
759			 */
760			if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
761				s->type = SSTDIN;
762			/*
763			 * Used by exit command to get back to
764			 * top level shell. Kind of strange since
765			 * interactive is set if we are reading from
766			 * a tty, but to have stopped jobs, one only
767			 * needs FMONITOR set (not FTALKING/SF_TTY)...
768			 */
769			/* toss any input we have so far */
770			yyrecursive_pop(true);
771			s->start = s->str = null;
772			retrace_info = NULL;
773			herep = heres;
774			break;
775		}
776		/* FALLTHROUGH */
777	case LEXIT:
778	case LLEAVE:
779	case LRETURN:
780		source = old_source;
781		quitenv(NULL);
782		/* keep on going */
783		unwind(i);
784		/* NOTREACHED */
785	default:
786		source = old_source;
787		quitenv(NULL);
788		internal_errorf("%s %d", "shell", i);
789		/* NOTREACHED */
790	}
791	while (/* CONSTCOND */ 1) {
792		if (trap)
793			runtraps(0);
794
795		if (s->next == NULL) {
796			if (Flag(FVERBOSE))
797				s->flags |= SF_ECHO;
798			else
799				s->flags &= ~SF_ECHO;
800		}
801		if (interactive) {
802			j_notify();
803			set_prompt(PS1, s);
804		}
805		t = compile(s, sfirst);
806		sfirst = false;
807		if (!t)
808			goto source_no_tree;
809		if (t->type == TEOF) {
810			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
811				shellf("Use 'exit' to leave mksh\n");
812				s->type = SSTDIN;
813			} else if (wastty && !really_exit &&
814			    j_stopped_running()) {
815				really_exit = true;
816				s->type = SSTDIN;
817			} else {
818				/*
819				 * this for POSIX which says EXIT traps
820				 * shall be taken in the environment
821				 * immediately after the last command
822				 * executed.
823				 */
824				if (toplevel)
825					unwind(LEXIT);
826				break;
827			}
828		} else if ((s->flags & SF_MAYEXEC) && t->type == TCOM)
829			t->u.evalflags |= DOTCOMEXEC;
830		if (!Flag(FNOEXEC) || (s->flags & SF_TTY))
831			exstat = execute(t, 0, NULL) & 0xFF;
832
833		if (t->type != TEOF && interactive && really_exit)
834			really_exit = false;
835
836 source_no_tree:
837		reclaim();
838	}
839	quitenv(NULL);
840	source = old_source;
841	return (exstat & 0xFF);
842}
843
844/* return to closest error handler or shell(), exit if none found */
845/* note: i MUST NOT be 0 */
846void
847unwind(int i)
848{
849	/*
850	 * This is a kludge. We need to restore everything that was
851	 * changed in the new environment, see cid 1005090337C7A669439
852	 * and 10050903386452ACBF1, but fail to even save things most of
853	 * the time. funcs.c:c_eval() changes FERREXIT temporarily to 0,
854	 * which needs to be restored thus (related to Debian #696823).
855	 * We did not save the shell flags, so we use a special or'd
856	 * value here... this is mostly to clean up behind *other*
857	 * callers of unwind(LERROR) here; exec.c has the regular case.
858	 */
859	if (Flag(FERREXIT) & 0x80) {
860		/* GNU bash does not run this trapsig */
861		trapsig(ksh_SIGERR);
862		Flag(FERREXIT) &= ~0x80;
863	}
864
865	/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
866	if (i == LEXIT || ((i == LERROR || i == LINTR) &&
867	    sigtraps[ksh_SIGEXIT].trap &&
868	    (!Flag(FTALKING) || Flag(FERREXIT)))) {
869		++trap_nested;
870		runtrap(&sigtraps[ksh_SIGEXIT], trap_nested == 1);
871		--trap_nested;
872		i = LLEAVE;
873	} else if (Flag(FERREXIT) == 1 && (i == LERROR || i == LINTR)) {
874		++trap_nested;
875		runtrap(&sigtraps[ksh_SIGERR], trap_nested == 1);
876		--trap_nested;
877		i = LLEAVE;
878	}
879
880	while (/* CONSTCOND */ 1) {
881		switch (e->type) {
882		case E_PARSE:
883		case E_FUNC:
884		case E_INCL:
885		case E_LOOP:
886		case E_ERRH:
887			kshlongjmp(e->jbuf, i);
888			/* NOTREACHED */
889		case E_NONE:
890			if (i == LINTR)
891				e->flags |= EF_FAKE_SIGDIE;
892			/* FALLTHROUGH */
893		default:
894			quitenv(NULL);
895			/*
896			 * quitenv() may have reclaimed the memory
897			 * used by source which will end badly when
898			 * we jump to a function that expects it to
899			 * be valid
900			 */
901			source = NULL;
902		}
903	}
904}
905
906void
907newenv(int type)
908{
909	struct env *ep;
910	char *cp;
911
912	/*
913	 * struct env includes ALLOC_ITEM for alignment constraints
914	 * so first get the actually used memory, then assign it
915	 */
916	cp = alloc(sizeof(struct env) - ALLOC_SIZE, ATEMP);
917	/* undo what alloc() did to the malloc result address */
918	ep = (void *)(cp - ALLOC_SIZE);
919	/* initialise public members of struct env (not the ALLOC_ITEM) */
920	ainit(&ep->area);
921	ep->oenv = e;
922	ep->loc = e->loc;
923	ep->savefd = NULL;
924	ep->temps = NULL;
925	ep->yyrecursive_statep = NULL;
926	ep->type = type;
927	ep->flags = 0;
928	/* jump buffer is invalid because flags == 0 */
929	e = ep;
930}
931
932void
933quitenv(struct shf *shf)
934{
935	struct env *ep = e;
936	char *cp;
937	int fd;
938
939	yyrecursive_pop(true);
940	while (ep->oenv && ep->oenv->loc != ep->loc)
941		popblock();
942	if (ep->savefd != NULL) {
943		for (fd = 0; fd < NUFILE; fd++)
944			/* if ep->savefd[fd] < 0, means fd was closed */
945			if (ep->savefd[fd])
946				restfd(fd, ep->savefd[fd]);
947		if (ep->savefd[2])
948			/* Clear any write errors */
949			shf_reopen(2, SHF_WR, shl_out);
950	}
951	/*
952	 * Bottom of the stack.
953	 * Either main shell is exiting or cleanup_parents_env() was called.
954	 */
955	if (ep->oenv == NULL) {
956#ifdef DEBUG_LEAKS
957		int i;
958#endif
959
960		if (ep->type == E_NONE) {
961			/* Main shell exiting? */
962#if HAVE_PERSISTENT_HISTORY
963			if (Flag(FTALKING))
964				hist_finish();
965#endif
966			j_exit();
967			if (ep->flags & EF_FAKE_SIGDIE) {
968				int sig = (exstat & 0xFF) - 128;
969
970				/*
971				 * ham up our death a bit (AT&T ksh
972				 * only seems to do this for SIGTERM)
973				 * Don't do it for SIGQUIT, since we'd
974				 * dump a core..
975				 */
976				if ((sig == SIGINT || sig == SIGTERM) &&
977				    (kshpgrp == kshpid)) {
978					setsig(&sigtraps[sig], SIG_DFL,
979					    SS_RESTORE_CURR | SS_FORCE);
980					kill(0, sig);
981				}
982			}
983		}
984		if (shf)
985			shf_close(shf);
986		reclaim();
987#ifdef DEBUG_LEAKS
988#ifndef MKSH_NO_CMDLINE_EDITING
989		x_done();
990#endif
991#ifndef MKSH_NOPROSPECTOFWORK
992		/* block at least SIGCHLD during/after afreeall */
993		sigprocmask(SIG_BLOCK, &sm_sigchld, NULL);
994#endif
995		afreeall(APERM);
996		for (fd = 3; fd < NUFILE; fd++)
997			if ((i = fcntl(fd, F_GETFD, 0)) != -1 &&
998			    (i & FD_CLOEXEC))
999				close(fd);
1000		close(2);
1001		close(1);
1002		close(0);
1003#endif
1004		exit(exstat & 0xFF);
1005	}
1006	if (shf)
1007		shf_close(shf);
1008	reclaim();
1009
1010	e = e->oenv;
1011
1012	/* free the struct env - tricky due to the ALLOC_ITEM inside */
1013	cp = (void *)ep;
1014	afree(cp + ALLOC_SIZE, ATEMP);
1015}
1016
1017/* Called after a fork to cleanup stuff left over from parents environment */
1018void
1019cleanup_parents_env(void)
1020{
1021	struct env *ep;
1022	int fd;
1023
1024	/*
1025	 * Don't clean up temporary files - parent will probably need them.
1026	 * Also, can't easily reclaim memory since variables, etc. could be
1027	 * anywhere.
1028	 */
1029
1030	/* close all file descriptors hiding in savefd */
1031	for (ep = e; ep; ep = ep->oenv) {
1032		if (ep->savefd) {
1033			for (fd = 0; fd < NUFILE; fd++)
1034				if (ep->savefd[fd] > 0)
1035					close(ep->savefd[fd]);
1036			afree(ep->savefd, &ep->area);
1037			ep->savefd = NULL;
1038		}
1039#ifdef DEBUG_LEAKS
1040		if (ep->type != E_NONE)
1041			ep->type = E_GONE;
1042#endif
1043	}
1044#ifndef DEBUG_LEAKS
1045	e->oenv = NULL;
1046#endif
1047}
1048
1049/* Called just before an execve cleanup stuff temporary files */
1050void
1051cleanup_proc_env(void)
1052{
1053	struct env *ep;
1054
1055	for (ep = e; ep; ep = ep->oenv)
1056		remove_temps(ep->temps);
1057}
1058
1059/* remove temp files and free ATEMP Area */
1060static void
1061reclaim(void)
1062{
1063	struct block *l;
1064
1065	while ((l = e->loc) && (!e->oenv || e->oenv->loc != l)) {
1066		e->loc = l->next;
1067		afreeall(&l->area);
1068	}
1069
1070	remove_temps(e->temps);
1071	e->temps = NULL;
1072	afreeall(&e->area);
1073}
1074
1075static void
1076remove_temps(struct temp *tp)
1077{
1078	for (; tp != NULL; tp = tp->next)
1079		if (tp->pid == procpid)
1080			unlink(tp->tffn);
1081}
1082
1083/*
1084 * Initialise tty_fd. Used for tracking the size of the terminal,
1085 * saving/resetting tty modes upon forground job completion, and
1086 * for setting up the tty process group. Return values:
1087 *	0 = got controlling tty
1088 *	1 = got terminal but no controlling tty
1089 *	2 = cannot find a terminal
1090 *	3 = cannot dup fd
1091 *	4 = cannot make fd close-on-exec
1092 * An existing tty_fd is cached if no "better" one could be found,
1093 * i.e. if tty_devtty was already set or the new would not set it.
1094 */
1095int
1096tty_init_fd(void)
1097{
1098	int fd, rv, eno = 0;
1099	bool do_close = false, is_devtty = true;
1100
1101	if (tty_devtty) {
1102		/* already got a tty which is /dev/tty */
1103		return (0);
1104	}
1105
1106#ifdef _UWIN
1107	/*XXX imake style */
1108	if (isatty(3)) {
1109		/* fd 3 on UWIN _is_ /dev/tty (or our controlling tty) */
1110		fd = 3;
1111		goto got_fd;
1112	}
1113#endif
1114	if ((fd = open("/dev/tty", O_RDWR, 0)) >= 0) {
1115		do_close = true;
1116		goto got_fd;
1117	}
1118	eno = errno;
1119
1120	if (tty_fd >= 0) {
1121		/* already got a non-devtty one */
1122		rv = 1;
1123		goto out;
1124	}
1125	is_devtty = false;
1126
1127	if (isatty((fd = 0)) || isatty((fd = 2)))
1128		goto got_fd;
1129	/* cannot find one */
1130	rv = 2;
1131	/* assert: do_close == false */
1132	goto out;
1133
1134 got_fd:
1135	if ((rv = fcntl(fd, F_DUPFD, FDBASE)) < 0) {
1136		eno = errno;
1137		rv = 3;
1138		goto out;
1139	}
1140	if (fcntl(rv, F_SETFD, FD_CLOEXEC) < 0) {
1141		eno = errno;
1142		close(rv);
1143		rv = 4;
1144		goto out;
1145	}
1146	tty_fd = rv;
1147	tty_devtty = is_devtty;
1148	rv = eno = 0;
1149 out:
1150	if (do_close)
1151		close(fd);
1152	errno = eno;
1153	return (rv);
1154}
1155
1156/* A shell error occurred (eg, syntax error, etc.) */
1157
1158#define VWARNINGF_ERRORPREFIX	1
1159#define VWARNINGF_FILELINE	2
1160#define VWARNINGF_BUILTIN	4
1161#define VWARNINGF_INTERNAL	8
1162
1163static void vwarningf(unsigned int, const char *, va_list)
1164    MKSH_A_FORMAT(__printf__, 2, 0);
1165
1166static void
1167vwarningf(unsigned int flags, const char *fmt, va_list ap)
1168{
1169	if (fmt) {
1170		if (flags & VWARNINGF_INTERNAL)
1171			shf_fprintf(shl_out, "internal error: ");
1172		if (flags & VWARNINGF_ERRORPREFIX)
1173			error_prefix(tobool(flags & VWARNINGF_FILELINE));
1174		if ((flags & VWARNINGF_BUILTIN) &&
1175		    /* not set when main() calls parse_args() */
1176		    builtin_argv0 && builtin_argv0 != kshname)
1177			shf_fprintf(shl_out, "%s: ", builtin_argv0);
1178		shf_vfprintf(shl_out, fmt, ap);
1179		shf_putchar('\n', shl_out);
1180	}
1181	shf_flush(shl_out);
1182}
1183
1184void
1185errorfx(int rc, const char *fmt, ...)
1186{
1187	va_list va;
1188
1189	exstat = rc;
1190
1191	/* debugging: note that stdout not valid */
1192	shl_stdout_ok = false;
1193
1194	va_start(va, fmt);
1195	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1196	va_end(va);
1197	unwind(LERROR);
1198}
1199
1200void
1201errorf(const char *fmt, ...)
1202{
1203	va_list va;
1204
1205	exstat = 1;
1206
1207	/* debugging: note that stdout not valid */
1208	shl_stdout_ok = false;
1209
1210	va_start(va, fmt);
1211	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
1212	va_end(va);
1213	unwind(LERROR);
1214}
1215
1216/* like errorf(), but no unwind is done */
1217void
1218warningf(bool fileline, const char *fmt, ...)
1219{
1220	va_list va;
1221
1222	va_start(va, fmt);
1223	vwarningf(VWARNINGF_ERRORPREFIX | (fileline ? VWARNINGF_FILELINE : 0),
1224	    fmt, va);
1225	va_end(va);
1226}
1227
1228/*
1229 * Used by built-in utilities to prefix shell and utility name to message
1230 * (also unwinds environments for special builtins).
1231 */
1232void
1233bi_errorf(const char *fmt, ...)
1234{
1235	va_list va;
1236
1237	/* debugging: note that stdout not valid */
1238	shl_stdout_ok = false;
1239
1240	exstat = 1;
1241
1242	va_start(va, fmt);
1243	vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE |
1244	    VWARNINGF_BUILTIN, fmt, va);
1245	va_end(va);
1246
1247	/*
1248	 * POSIX special builtins and ksh special builtins cause
1249	 * non-interactive shells to exit.
1250	 * XXX odd use of KEEPASN; also may not want LERROR here
1251	 */
1252	if (builtin_spec) {
1253		builtin_argv0 = NULL;
1254		unwind(LERROR);
1255	}
1256}
1257
1258/* Called when something that shouldn't happen does */
1259void
1260internal_errorf(const char *fmt, ...)
1261{
1262	va_list va;
1263
1264	va_start(va, fmt);
1265	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1266	va_end(va);
1267	unwind(LERROR);
1268}
1269
1270void
1271internal_warningf(const char *fmt, ...)
1272{
1273	va_list va;
1274
1275	va_start(va, fmt);
1276	vwarningf(VWARNINGF_INTERNAL, fmt, va);
1277	va_end(va);
1278}
1279
1280/* used by error reporting functions to print "ksh: .kshrc[25]: " */
1281void
1282error_prefix(bool fileline)
1283{
1284	/* Avoid foo: foo[2]: ... */
1285	if (!fileline || !source || !source->file ||
1286	    strcmp(source->file, kshname) != 0)
1287		shf_fprintf(shl_out, "%s: ", kshname + (*kshname == '-'));
1288	if (fileline && source && source->file != NULL) {
1289		shf_fprintf(shl_out, "%s[%lu]: ", source->file,
1290		    (unsigned long)(source->errline ?
1291		    source->errline : source->line));
1292		source->errline = 0;
1293	}
1294}
1295
1296/* printf to shl_out (stderr) with flush */
1297void
1298shellf(const char *fmt, ...)
1299{
1300	va_list va;
1301
1302	if (!initio_done)
1303		/* shl_out may not be set up yet... */
1304		return;
1305	va_start(va, fmt);
1306	shf_vfprintf(shl_out, fmt, va);
1307	va_end(va);
1308	shf_flush(shl_out);
1309}
1310
1311/* printf to shl_stdout (stdout) */
1312void
1313shprintf(const char *fmt, ...)
1314{
1315	va_list va;
1316
1317	if (!shl_stdout_ok)
1318		internal_errorf("shl_stdout not valid");
1319	va_start(va, fmt);
1320	shf_vfprintf(shl_stdout, fmt, va);
1321	va_end(va);
1322}
1323
1324/* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
1325int
1326can_seek(int fd)
1327{
1328	struct stat statb;
1329
1330	return (fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
1331	    SHF_UNBUF : 0);
1332}
1333
1334#ifdef DF
1335int shl_dbg_fd;
1336#define NSHF_IOB 4
1337#else
1338#define NSHF_IOB 3
1339#endif
1340struct shf shf_iob[NSHF_IOB];
1341
1342void
1343initio(void)
1344{
1345#ifdef DF
1346	const char *lfp;
1347#endif
1348
1349	/* force buffer allocation */
1350	shf_fdopen(1, SHF_WR, shl_stdout);
1351	shf_fdopen(2, SHF_WR, shl_out);
1352	shf_fdopen(2, SHF_WR, shl_xtrace);
1353#ifdef DF
1354	if ((lfp = getenv("SDMKSH_PATH")) == NULL) {
1355		if ((lfp = getenv("HOME")) == NULL || *lfp != '/')
1356			errorf("cannot get home directory");
1357		lfp = shf_smprintf("%s/mksh-dbg.txt", lfp);
1358	}
1359
1360	if ((shl_dbg_fd = open(lfp, O_WRONLY | O_APPEND | O_CREAT, 0600)) < 0)
1361		errorf("cannot open debug output file %s", lfp);
1362	if (shl_dbg_fd < FDBASE) {
1363		int nfd;
1364
1365		nfd = fcntl(shl_dbg_fd, F_DUPFD, FDBASE);
1366		close(shl_dbg_fd);
1367		if ((shl_dbg_fd = nfd) == -1)
1368			errorf("cannot dup debug output file");
1369	}
1370	fcntl(shl_dbg_fd, F_SETFD, FD_CLOEXEC);
1371	shf_fdopen(shl_dbg_fd, SHF_WR, shl_dbg);
1372	DF("=== open ===");
1373#endif
1374	initio_done = true;
1375}
1376
1377/* A dup2() with error checking */
1378int
1379ksh_dup2(int ofd, int nfd, bool errok)
1380{
1381	int rv;
1382
1383	if (((rv = dup2(ofd, nfd)) < 0) && !errok && (errno != EBADF))
1384		errorf("too many files open in shell");
1385
1386#ifdef __ultrix
1387	/*XXX imake style */
1388	if (rv >= 0)
1389		fcntl(nfd, F_SETFD, 0);
1390#endif
1391
1392	return (rv);
1393}
1394
1395/*
1396 * Move fd from user space (0 <= fd < 10) to shell space (fd >= 10),
1397 * set close-on-exec flag. See FDBASE in sh.h, maybe 24 not 10 here.
1398 */
1399short
1400savefd(int fd)
1401{
1402	int nfd = fd;
1403
1404	if (fd < FDBASE && (nfd = fcntl(fd, F_DUPFD, FDBASE)) < 0 &&
1405	    errno == EBADF)
1406		return (-1);
1407	if (nfd < 0 || nfd > SHRT_MAX)
1408		errorf("too many files open in shell");
1409	fcntl(nfd, F_SETFD, FD_CLOEXEC);
1410	return ((short)nfd);
1411}
1412
1413void
1414restfd(int fd, int ofd)
1415{
1416	if (fd == 2)
1417		shf_flush(&shf_iob[/* fd */ 2]);
1418	if (ofd < 0)
1419		/* original fd closed */
1420		close(fd);
1421	else if (fd != ofd) {
1422		/*XXX: what to do if this dup fails? */
1423		ksh_dup2(ofd, fd, true);
1424		close(ofd);
1425	}
1426}
1427
1428void
1429openpipe(int *pv)
1430{
1431	int lpv[2];
1432
1433	if (pipe(lpv) < 0)
1434		errorf("can't create pipe - try again");
1435	pv[0] = savefd(lpv[0]);
1436	if (pv[0] != lpv[0])
1437		close(lpv[0]);
1438	pv[1] = savefd(lpv[1]);
1439	if (pv[1] != lpv[1])
1440		close(lpv[1]);
1441}
1442
1443void
1444closepipe(int *pv)
1445{
1446	close(pv[0]);
1447	close(pv[1]);
1448}
1449
1450/*
1451 * Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
1452 * a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
1453 */
1454int
1455check_fd(const char *name, int mode, const char **emsgp)
1456{
1457	int fd = 0, fl;
1458
1459	if (name[0] == 'p' && !name[1])
1460		return (coproc_getfd(mode, emsgp));
1461	while (ksh_isdigit(*name)) {
1462		fd = (fd * 10) + *name - '0';
1463		if (fd >= FDBASE) {
1464			if (emsgp)
1465				*emsgp = "file descriptor too large";
1466			return (-1);
1467		}
1468		++name;
1469	}
1470	if (*name) {
1471		if (emsgp)
1472			*emsgp = "illegal file descriptor name";
1473		return (-1);
1474	}
1475	if ((fl = fcntl(fd, F_GETFL, 0)) < 0) {
1476		if (emsgp)
1477			*emsgp = "bad file descriptor";
1478		return (-1);
1479	}
1480	fl &= O_ACCMODE;
1481	/*
1482	 * X_OK is a kludge to disable this check for dups (x<&1):
1483	 * historical shells never did this check (XXX don't know what
1484	 * POSIX has to say).
1485	 */
1486	if (!(mode & X_OK) && fl != O_RDWR && (
1487	    ((mode & R_OK) && fl != O_RDONLY) ||
1488	    ((mode & W_OK) && fl != O_WRONLY))) {
1489		if (emsgp)
1490			*emsgp = (fl == O_WRONLY) ?
1491			    "fd not open for reading" :
1492			    "fd not open for writing";
1493		return (-1);
1494	}
1495	return (fd);
1496}
1497
1498/* Called once from main */
1499void
1500coproc_init(void)
1501{
1502	coproc.read = coproc.readw = coproc.write = -1;
1503	coproc.njobs = 0;
1504	coproc.id = 0;
1505}
1506
1507/* Called by c_read() when eof is read - close fd if it is the co-process fd */
1508void
1509coproc_read_close(int fd)
1510{
1511	if (coproc.read >= 0 && fd == coproc.read) {
1512		coproc_readw_close(fd);
1513		close(coproc.read);
1514		coproc.read = -1;
1515	}
1516}
1517
1518/*
1519 * Called by c_read() and by iosetup() to close the other side of the
1520 * read pipe, so reads will actually terminate.
1521 */
1522void
1523coproc_readw_close(int fd)
1524{
1525	if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
1526		close(coproc.readw);
1527		coproc.readw = -1;
1528	}
1529}
1530
1531/*
1532 * Called by c_print when a write to a fd fails with EPIPE and by iosetup
1533 * when co-process input is dup'd
1534 */
1535void
1536coproc_write_close(int fd)
1537{
1538	if (coproc.write >= 0 && fd == coproc.write) {
1539		close(coproc.write);
1540		coproc.write = -1;
1541	}
1542}
1543
1544/*
1545 * Called to check for existence of/value of the co-process file descriptor.
1546 * (Used by check_fd() and by c_read/c_print to deal with -p option).
1547 */
1548int
1549coproc_getfd(int mode, const char **emsgp)
1550{
1551	int fd = (mode & R_OK) ? coproc.read : coproc.write;
1552
1553	if (fd >= 0)
1554		return (fd);
1555	if (emsgp)
1556		*emsgp = "no coprocess";
1557	return (-1);
1558}
1559
1560/*
1561 * called to close file descriptors related to the coprocess (if any)
1562 * Should be called with SIGCHLD blocked.
1563 */
1564void
1565coproc_cleanup(int reuse)
1566{
1567	/* This to allow co-processes to share output pipe */
1568	if (!reuse || coproc.readw < 0 || coproc.read < 0) {
1569		if (coproc.read >= 0) {
1570			close(coproc.read);
1571			coproc.read = -1;
1572		}
1573		if (coproc.readw >= 0) {
1574			close(coproc.readw);
1575			coproc.readw = -1;
1576		}
1577	}
1578	if (coproc.write >= 0) {
1579		close(coproc.write);
1580		coproc.write = -1;
1581	}
1582}
1583
1584struct temp *
1585maketemp(Area *ap, Temp_type type, struct temp **tlist)
1586{
1587	char *cp;
1588	size_t len;
1589	int i, j;
1590	struct temp *tp;
1591	const char *dir;
1592	struct stat sb;
1593
1594	dir = tmpdir ? tmpdir : MKSH_DEFAULT_TMPDIR;
1595	/* add "/shXXXXXX.tmp" plus NUL */
1596	len = strlen(dir);
1597	checkoktoadd(len, offsetof(struct temp, tffn[0]) + 14);
1598	tp = alloc(offsetof(struct temp, tffn[0]) + 14 + len, ap);
1599
1600	tp->shf = NULL;
1601	tp->pid = procpid;
1602	tp->type = type;
1603
1604	if (stat(dir, &sb) || !S_ISDIR(sb.st_mode)) {
1605		tp->tffn[0] = '\0';
1606		goto maketemp_out;
1607	}
1608
1609	cp = (void *)tp;
1610	cp += offsetof(struct temp, tffn[0]);
1611	memcpy(cp, dir, len);
1612	cp += len;
1613	memcpy(cp, "/shXXXXXX.tmp", 14);
1614	/* point to the first of six Xes */
1615	cp += 3;
1616	/* generate random part of filename */
1617	len = -1;
1618	do {
1619		i = rndget() % 36;
1620		cp[++len] = i < 26 ? 'a' + i : '0' + i - 26;
1621	} while (len < 5);
1622
1623	/* cyclically attempt to open a temporary file */
1624	while ((i = open(tp->tffn, O_CREAT | O_EXCL | O_RDWR | O_BINARY,
1625	    0600)) < 0) {
1626		if (errno != EEXIST)
1627			goto maketemp_out;
1628		/* count down from z to a then from 9 to 0 */
1629		while (cp[len] == '0')
1630			if (!len--)
1631				goto maketemp_out;
1632		if (cp[len] == 'a')
1633			cp[len] = '9';
1634		else
1635			--cp[len];
1636		/* do another cycle */
1637	}
1638
1639	if (type == TT_FUNSUB) {
1640		/* map us high and mark as close-on-exec */
1641		if ((j = savefd(i)) != i) {
1642			close(i);
1643			i = j;
1644		}
1645
1646		/* operation mode for the shf */
1647		j = SHF_RD;
1648	} else
1649		j = SHF_WR;
1650
1651	/* shf_fdopen cannot fail, so no fd leak */
1652	tp->shf = shf_fdopen(i, j, NULL);
1653
1654 maketemp_out:
1655	tp->next = *tlist;
1656	*tlist = tp;
1657	return (tp);
1658}
1659
1660/*
1661 * We use a similar collision resolution algorithm as Python 2.5.4
1662 * but with a slightly tweaked implementation written from scratch.
1663 */
1664
1665#define	INIT_TBLSHIFT	3	/* initial table shift (2^3 = 8) */
1666#define PERTURB_SHIFT	5	/* see Python 2.5.4 Objects/dictobject.c */
1667
1668static void tgrow(struct table *);
1669static int tnamecmp(const void *, const void *);
1670
1671static void
1672tgrow(struct table *tp)
1673{
1674	size_t i, j, osize, mask, perturb;
1675	struct tbl *tblp, **pp;
1676	struct tbl **ntblp, **otblp = tp->tbls;
1677
1678	if (tp->tshift > 29)
1679		internal_errorf("hash table size limit reached");
1680
1681	/* calculate old size, new shift and new size */
1682	osize = (size_t)1 << (tp->tshift++);
1683	i = osize << 1;
1684
1685	ntblp = alloc2(i, sizeof(struct tbl *), tp->areap);
1686	/* multiplication cannot overflow: alloc2 checked that */
1687	memset(ntblp, 0, i * sizeof(struct tbl *));
1688
1689	/* table can get very full when reaching its size limit */
1690	tp->nfree = (tp->tshift == 30) ? 0x3FFF0000UL :
1691	    /* but otherwise, only 75% */
1692	    ((i * 3) / 4);
1693	tp->tbls = ntblp;
1694	if (otblp == NULL)
1695		return;
1696
1697	mask = i - 1;
1698	for (i = 0; i < osize; i++)
1699		if ((tblp = otblp[i]) != NULL) {
1700			if ((tblp->flag & DEFINED)) {
1701				/* search for free hash table slot */
1702				j = perturb = tblp->ua.hval;
1703				goto find_first_empty_slot;
1704 find_next_empty_slot:
1705				j = (j << 2) + j + perturb + 1;
1706				perturb >>= PERTURB_SHIFT;
1707 find_first_empty_slot:
1708				pp = &ntblp[j & mask];
1709				if (*pp != NULL)
1710					goto find_next_empty_slot;
1711				/* found an empty hash table slot */
1712				*pp = tblp;
1713				tp->nfree--;
1714			} else if (!(tblp->flag & FINUSE)) {
1715				afree(tblp, tp->areap);
1716			}
1717		}
1718	afree(otblp, tp->areap);
1719}
1720
1721void
1722ktinit(Area *ap, struct table *tp, uint8_t initshift)
1723{
1724	tp->areap = ap;
1725	tp->tbls = NULL;
1726	tp->tshift = ((initshift > INIT_TBLSHIFT) ?
1727	    initshift : INIT_TBLSHIFT) - 1;
1728	tgrow(tp);
1729}
1730
1731/* table, name (key) to search for, hash(name), rv pointer to tbl ptr */
1732struct tbl *
1733ktscan(struct table *tp, const char *name, uint32_t h, struct tbl ***ppp)
1734{
1735	size_t j, perturb, mask;
1736	struct tbl **pp, *p;
1737
1738	mask = ((size_t)1 << (tp->tshift)) - 1;
1739	/* search for hash table slot matching name */
1740	j = perturb = h;
1741	goto find_first_slot;
1742 find_next_slot:
1743	j = (j << 2) + j + perturb + 1;
1744	perturb >>= PERTURB_SHIFT;
1745 find_first_slot:
1746	pp = &tp->tbls[j & mask];
1747	if ((p = *pp) != NULL && (p->ua.hval != h || !(p->flag & DEFINED) ||
1748	    strcmp(p->name, name)))
1749		goto find_next_slot;
1750	/* p == NULL if not found, correct found entry otherwise */
1751	if (ppp)
1752		*ppp = pp;
1753	return (p);
1754}
1755
1756/* table, name (key) to enter, hash(n) */
1757struct tbl *
1758ktenter(struct table *tp, const char *n, uint32_t h)
1759{
1760	struct tbl **pp, *p;
1761	size_t len;
1762
1763 Search:
1764	if ((p = ktscan(tp, n, h, &pp)))
1765		return (p);
1766
1767	if (tp->nfree == 0) {
1768		/* too full */
1769		tgrow(tp);
1770		goto Search;
1771	}
1772
1773	/* create new tbl entry */
1774	len = strlen(n);
1775	checkoktoadd(len, offsetof(struct tbl, name[0]) + 1);
1776	p = alloc(offsetof(struct tbl, name[0]) + ++len, tp->areap);
1777	p->flag = 0;
1778	p->type = 0;
1779	p->areap = tp->areap;
1780	p->ua.hval = h;
1781	p->u2.field = 0;
1782	p->u.array = NULL;
1783	memcpy(p->name, n, len);
1784
1785	/* enter in tp->tbls */
1786	tp->nfree--;
1787	*pp = p;
1788	return (p);
1789}
1790
1791void
1792ktwalk(struct tstate *ts, struct table *tp)
1793{
1794	ts->left = (size_t)1 << (tp->tshift);
1795	ts->next = tp->tbls;
1796}
1797
1798struct tbl *
1799ktnext(struct tstate *ts)
1800{
1801	while (--ts->left >= 0) {
1802		struct tbl *p = *ts->next++;
1803		if (p != NULL && (p->flag & DEFINED))
1804			return (p);
1805	}
1806	return (NULL);
1807}
1808
1809static int
1810tnamecmp(const void *p1, const void *p2)
1811{
1812	const struct tbl *a = *((const struct tbl * const *)p1);
1813	const struct tbl *b = *((const struct tbl * const *)p2);
1814
1815	return (strcmp(a->name, b->name));
1816}
1817
1818struct tbl **
1819ktsort(struct table *tp)
1820{
1821	size_t i;
1822	struct tbl **p, **sp, **dp;
1823
1824	/*
1825	 * since the table is never entirely full, no need to reserve
1826	 * additional space for the trailing NULL appended below
1827	 */
1828	i = (size_t)1 << (tp->tshift);
1829	p = alloc2(i, sizeof(struct tbl *), ATEMP);
1830	sp = tp->tbls;		/* source */
1831	dp = p;			/* dest */
1832	while (i--)
1833		if ((*dp = *sp++) != NULL && (((*dp)->flag & DEFINED) ||
1834		    ((*dp)->flag & ARRAY)))
1835			dp++;
1836	qsort(p, (i = dp - p), sizeof(struct tbl *), tnamecmp);
1837	p[i] = NULL;
1838	return (p);
1839}
1840
1841#ifdef SIGWINCH
1842static void
1843x_sigwinch(int sig MKSH_A_UNUSED)
1844{
1845	/* this runs inside interrupt context, with errno saved */
1846
1847	got_winch = 1;
1848}
1849#endif
1850
1851#ifdef DF
1852void
1853DF(const char *fmt, ...)
1854{
1855	va_list args;
1856	struct timeval tv;
1857	mirtime_mjd mjd;
1858
1859	mksh_lockfd(shl_dbg_fd);
1860	mksh_TIME(tv);
1861	timet2mjd(&mjd, tv.tv_sec);
1862	shf_fprintf(shl_dbg, "[%02u:%02u:%02u (%u) %u.%06u] ",
1863	    (unsigned)mjd.sec / 3600, ((unsigned)mjd.sec / 60) % 60,
1864	    (unsigned)mjd.sec % 60, (unsigned)getpid(),
1865	    (unsigned)tv.tv_sec, (unsigned)tv.tv_usec);
1866	va_start(args, fmt);
1867	shf_vfprintf(shl_dbg, fmt, args);
1868	va_end(args);
1869	shf_putc('\n', shl_dbg);
1870	shf_flush(shl_dbg);
1871	mksh_unlkfd(shl_dbg_fd);
1872}
1873#endif
1874
1875void
1876x_mkraw(int fd, mksh_ttyst *ocb, bool forread)
1877{
1878	mksh_ttyst cb;
1879
1880	if (ocb)
1881		mksh_tcget(fd, ocb);
1882	else
1883		ocb = &tty_state;
1884
1885	cb = *ocb;
1886	if (forread) {
1887		cb.c_iflag &= ~(ISTRIP);
1888		cb.c_lflag &= ~(ICANON) | ECHO;
1889	} else {
1890		cb.c_iflag &= ~(INLCR | ICRNL | ISTRIP);
1891		cb.c_lflag &= ~(ISIG | ICANON | ECHO);
1892	}
1893#if defined(VLNEXT) && defined(_POSIX_VDISABLE)
1894	/* OSF/1 processes lnext when ~icanon */
1895	cb.c_cc[VLNEXT] = _POSIX_VDISABLE;
1896#endif
1897	/* SunOS 4.1.x & OSF/1 processes discard(flush) when ~icanon */
1898#if defined(VDISCARD) && defined(_POSIX_VDISABLE)
1899	cb.c_cc[VDISCARD] = _POSIX_VDISABLE;
1900#endif
1901	cb.c_cc[VTIME] = 0;
1902	cb.c_cc[VMIN] = 1;
1903
1904	mksh_tcset(fd, &cb);
1905}
1906