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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 $");
38 
39 extern char **environ;
40 
41 #ifndef MKSHRC_PATH
42 #define MKSHRC_PATH	"~/.mkshrc"
43 #endif
44 
45 #ifndef MKSH_DEFAULT_TMPDIR
46 #define MKSH_DEFAULT_TMPDIR	MKSH_UNIXROOT "/tmp"
47 #endif
48 
49 static uint8_t isuc(const char *);
50 static int main_init(int, const char *[], Source **, struct block **);
51 void chvt_reinit(void);
52 static void reclaim(void);
53 static void remove_temps(struct temp *);
54 static mksh_uari_t rndsetup(void);
55 #ifdef SIGWINCH
56 static void x_sigwinch(int);
57 #endif
58 
59 static const char initsubs[] =
60     "${PS2=> }"
61     "${PS3=#? }"
62     "${PS4=+ }"
63     "${SECONDS=0}"
64     "${TMOUT=0}"
65     "${EPOCHREALTIME=}";
66 
67 static 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 
92 static const char *restr_com[] = {
93 	Ttypeset, "-r", TPATH, "ENV", TSHELL, NULL
94 };
95 
96 static bool initio_done;
97 
98 /* top-level parsing and execution environment */
99 static struct env env;
100 struct 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 */
106 cta(char_is_1_char, (sizeof(char) == 1) && (sizeof(signed char) == 1) &&
107     (sizeof(unsigned char) == 1));
108 cta(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 */
111 cta(short_is_2_char, sizeof(short) == 2);
112 cta(short_size_no_matter_of_signedness, sizeof(short) == sizeof(unsigned short));
113 /* the next assertion is probably not really needed */
114 cta(int_is_4_char, sizeof(int) == 4);
115 cta(int_size_no_matter_of_signedness, sizeof(int) == sizeof(unsigned int));
116 
117 cta(long_ge_int, sizeof(long) >= sizeof(int));
118 cta(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 */
122 cta(ari_is_4_char, sizeof(mksh_ari_t) == 4);
123 /* but this is */
124 cta(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 */
126 cta(uari_is_4_char, sizeof(mksh_uari_t) == 4);
127 /* but the next three are; we REQUIRE unsigned integer wraparound */
128 cta(uari_has_31_bit, 0 < (mksh_uari_t)(((((mksh_uari_t)1 << 15) << 15) - 1) * 2 + 1));
129 cta(uari_has_32_bit, 0 < (mksh_uari_t)(((((mksh_uari_t)1 << 15) << 15) - 1) * 4 + 3));
130 cta(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 */
135 cta(ari_is_signed, (mksh_ari_t)-1 < (mksh_ari_t)0);
136 cta(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 */
138 cta(ari_size_no_matter_of_signedness, sizeof(mksh_ari_t) == sizeof(mksh_uari_t));
139 
140 cta(sizet_size_no_matter_of_signedness, sizeof(ssize_t) == sizeof(size_t));
141 cta(sizet_voidptr_same_size, sizeof(size_t) == sizeof(void *));
142 cta(sizet_funcptr_same_size, sizeof(size_t) == sizeof(void (*)(void)));
143 /* our formatting routines assume this */
144 cta(ptr_fits_in_long, sizeof(size_t) <= sizeof(long));
145 cta(ari_fits_in_long, sizeof(mksh_ari_t) <= sizeof(long));
146 
147 static mksh_uari_t
rndsetup(void)148 rndsetup(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 
188 void
chvt_reinit(void)189 chvt_reinit(void)
190 {
191 	kshpid = procpid = getpid();
192 	ksheuid = geteuid();
193 	kshpgrp = getpgrp();
194 	kshppid = getppid();
195 }
196 
197 static const char *empty_argv[] = {
198 	Tmksh, NULL
199 };
200 
201 static uint8_t
isuc(const char * cx)202 isuc(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 
224 static int
main_init(int argc,const char * argv[],Source ** sp,struct block ** lp)225 main_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 
705 int
main(int argc,const char * argv[])706 main(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 
723 int
include(const char * name,int argc,const char ** argv,bool intr_ok)724 include(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 */
791 int
command(const char * comm,int line)792 command(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  */
808 int
shell(Source * volatile s,volatile int level)809 shell(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 */
935 void
unwind(int i)936 unwind(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 
989 void
newenv(int type)990 newenv(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 
1015 void
quitenv(struct shf * shf)1016 quitenv(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 */
1101 void
cleanup_parents_env(void)1102 cleanup_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 */
1133 void
cleanup_proc_env(void)1134 cleanup_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 */
1143 static void
reclaim(void)1144 reclaim(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 
1166 static void
remove_temps(struct temp * tp)1167 remove_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  */
1188 int
tty_init_fd(void)1189 tty_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 
1256 static void vwarningf(unsigned int, const char *, va_list)
1257     MKSH_A_FORMAT(__printf__, 2, 0);
1258 
1259 static void
vwarningf(unsigned int flags,const char * fmt,va_list ap)1260 vwarningf(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 
1277 void
errorfx(int rc,const char * fmt,...)1278 errorfx(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 
1293 void
errorf(const char * fmt,...)1294 errorf(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 */
1310 void
warningf(bool fileline,const char * fmt,...)1311 warningf(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  */
1325 void
bi_errorf(const char * fmt,...)1326 bi_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 */
1349 void
internal_errorf(const char * fmt,...)1350 internal_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 
1360 void
internal_warningf(const char * fmt,...)1361 internal_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]: " */
1371 void
error_prefix(bool fileline)1372 error_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 */
1387 void
shellf(const char * fmt,...)1388 shellf(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) */
1402 void
shprintf(const char * fmt,...)1403 shprintf(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) */
1415 int
can_seek(int fd)1416 can_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
1425 int shl_dbg_fd;
1426 #define NSHF_IOB 4
1427 #else
1428 #define NSHF_IOB 3
1429 #endif
1430 struct shf shf_iob[NSHF_IOB];
1431 
1432 void
initio(void)1433 initio(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 */
1468 int
ksh_dup2(int ofd,int nfd,bool errok)1469 ksh_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  */
1489 short
savefd(int fd)1490 savefd(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 
1503 void
restfd(int fd,int ofd)1504 restfd(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 
1518 void
openpipe(int * pv)1519 openpipe(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 
1537 void
closepipe(int * pv)1538 closepipe(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  */
1548 int
check_fd(const char * name,int mode,const char ** emsgp)1549 check_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 */
1588 void
coproc_init(void)1589 coproc_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 */
1597 void
coproc_read_close(int fd)1598 coproc_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  */
1611 void
coproc_readw_close(int fd)1612 coproc_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  */
1624 void
coproc_write_close(int fd)1625 coproc_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  */
1637 int
coproc_getfd(int mode,const char ** emsgp)1638 coproc_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  */
1653 void
coproc_cleanup(int reuse)1654 coproc_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 
1673 struct temp *
maketemp(Area * ap,Temp_type type,struct temp ** tlist)1674 maketemp(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 
1749 static void tgrow(struct table *);
1750 static int tnamecmp(const void *, const void *);
1751 
1752 static void
tgrow(struct table * tp)1753 tgrow(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 
1802 void
ktinit(Area * ap,struct table * tp,uint8_t initshift)1803 ktinit(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 */
1813 struct tbl *
ktscan(struct table * tp,const char * name,uint32_t h,struct tbl *** ppp)1814 ktscan(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) */
1838 struct tbl *
ktenter(struct table * tp,const char * n,uint32_t h)1839 ktenter(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 
1872 void
ktwalk(struct tstate * ts,struct table * tp)1873 ktwalk(struct tstate *ts, struct table *tp)
1874 {
1875 	ts->left = (size_t)1 << (tp->tshift);
1876 	ts->next = tp->tbls;
1877 }
1878 
1879 struct tbl *
ktnext(struct tstate * ts)1880 ktnext(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 
1890 static int
tnamecmp(const void * p1,const void * p2)1891 tnamecmp(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 
1899 struct tbl **
ktsort(struct table * tp)1900 ktsort(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
1923 static void
x_sigwinch(int sig MKSH_A_UNUSED)1924 x_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
1933 void
DF(const char * fmt,...)1934 DF(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 
1956 void
x_mkraw(int fd,mksh_ttyst * ocb,bool forread)1957 x_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