xref: /netbsd-src/bin/ksh/main.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: main.c,v 1.11 2004/07/07 19:20:09 mycroft Exp $	*/
2 
3 /*
4  * startup, main loop, environments and error handling
5  */
6 #include <sys/cdefs.h>
7 
8 #ifndef lint
9 __RCSID("$NetBSD: main.c,v 1.11 2004/07/07 19:20:09 mycroft Exp $");
10 #endif
11 
12 
13 #define	EXTERN				/* define EXTERNs in sh.h */
14 
15 #include "sh.h"
16 #include "ksh_stat.h"
17 #include "ksh_time.h"
18 
19 extern char **environ;
20 
21 /*
22  * global data
23  */
24 
25 static void	reclaim ARGS((void));
26 static void	remove_temps ARGS((struct temp *tp));
27 static int	is_restricted ARGS((char *name));
28 
29 /*
30  * shell initialization
31  */
32 
33 static const char initifs[] = "IFS= \t\n";
34 
35 static const char initsubs[] = "${PS2=> } ${PS3=#? } ${PS4=+ }";
36 
37 static const char version_param[] =
38 #ifdef KSH
39 	"KSH_VERSION"
40 #else /* KSH */
41 	"SH_VERSION"
42 #endif /* KSH */
43 	;
44 
45 static const char *const initcoms [] = {
46 	"typeset", "-x", "SHELL", "PATH", "HOME", NULL,
47 	"typeset", "-r", version_param, NULL,
48 	"typeset", "-i", "PPID", NULL,
49 	"typeset", "-i", "OPTIND=1", NULL,
50 #ifdef KSH
51 	"eval", "typeset -i RANDOM MAILCHECK=\"${MAILCHECK-600}\" SECONDS=\"${SECONDS-0}\" TMOUT=\"${TMOUT-0}\"", NULL,
52 #endif /* KSH */
53 	"alias",
54 	 /* Standard ksh aliases */
55 	  "hash=alias -t",	/* not "alias -t --": hash -r needs to work */
56 	  "type=whence -v",
57 #ifdef JOBS
58 	  "stop=kill -STOP",
59 	  "suspend=kill -STOP $$",
60 #endif
61 #ifdef KSH
62 	  "autoload=typeset -fu",
63 	  "functions=typeset -f",
64 # ifdef HISTORY
65 	  "history=fc -l",
66 # endif /* HISTORY */
67 	  "integer=typeset -i",
68 	  "nohup=nohup ",
69 	  "local=typeset",
70 	  "r=fc -e -",
71 #endif /* KSH */
72 #ifdef KSH
73 	 /* Aliases that are builtin commands in at&t */
74 	  "login=exec login",
75 #ifndef __NetBSD__
76 	  "newgrp=exec newgrp",
77 #endif /* __NetBSD__ */
78 #endif /* KSH */
79 	  NULL,
80 	/* this is what at&t ksh seems to track, with the addition of emacs */
81 	"alias", "-tU",
82 	  "cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
83 	  "mail", "make", "mv", "pr", "rm", "sed", "sh", "vi", "who",
84 	  NULL,
85 #ifdef EXTRA_INITCOMS
86 	EXTRA_INITCOMS, NULL,
87 #endif /* EXTRA_INITCOMS */
88 	NULL
89 };
90 
91 int
92 main(int argc, char *argv[])
93 {
94 	register int i;
95 	int argi;
96 	Source *s;
97 	struct block *l;
98 	int restricted, errexit;
99 	char **wp;
100 	struct env env;
101 	pid_t ppid;
102 
103 #ifdef MEM_DEBUG
104 	chmem_set_defaults("ct", 1);
105 	/* chmem_push("+c", 1); */
106 #endif /* MEM_DEBUG */
107 
108 #ifdef OS2
109 	setmode (0, O_BINARY);
110 	setmode (1, O_TEXT);
111 #endif
112 
113 	/* make sure argv[] is sane */
114 	if (!*argv) {
115 		static const char	*empty_argv[] = {
116 					    "pdksh", (char *) 0
117 					};
118 
119 		argv = (char **) empty_argv;
120 		argc = 1;
121 	}
122 	kshname = *argv;
123 
124 	ainit(&aperm);		/* initialize permanent Area */
125 
126 	/* set up base environment */
127 	memset(&env, 0, sizeof(env));
128 	env.type = E_NONE;
129 	ainit(&env.area);
130 	e = &env;
131 	newblock();		/* set up global l->vars and l->funs */
132 
133 	/* Do this first so output routines (eg, errorf, shellf) can work */
134 	initio();
135 
136 	initvar();
137 
138 	initctypes();
139 
140 	inittraps();
141 
142 #ifdef KSH
143 	coproc_init();
144 #endif /* KSH */
145 
146 	/* set up variable and command dictionaries */
147 	tinit(&taliases, APERM, 0);
148 	tinit(&aliases, APERM, 0);
149 	tinit(&homedirs, APERM, 0);
150 
151 	/* define shell keywords */
152 	initkeywords();
153 
154 	/* define built-in commands */
155 	tinit(&builtins, APERM, 64); /* must be 2^n (currently 40 builtins) */
156 	for (i = 0; shbuiltins[i].name != NULL; i++)
157 		builtin(shbuiltins[i].name, shbuiltins[i].func);
158 	for (i = 0; kshbuiltins[i].name != NULL; i++)
159 		builtin(kshbuiltins[i].name, kshbuiltins[i].func);
160 
161 	init_histvec();
162 
163 	def_path = DEFAULT__PATH;
164 #if defined(HAVE_CONFSTR) && defined(_CS_PATH)
165 	{
166 		size_t len = confstr(_CS_PATH, (char *) 0, 0);
167 		char *new;
168 
169 		if (len > 0) {
170 			confstr(_CS_PATH, new = alloc(len + 1, APERM), len + 1);
171 			def_path = new;
172 		}
173 	}
174 #endif /* HAVE_CONFSTR && _CS_PATH */
175 
176 	/* Set PATH to def_path (will set the path global variable).
177 	 * (import of environment below will probably change this setting).
178 	 */
179 	{
180 		struct tbl *vp = global("PATH");
181 		/* setstr can't fail here */
182 		setstr(vp, def_path, KSH_RETURN_ERROR);
183 	}
184 
185 
186 	/* Turn on nohup by default for now - will change to off
187 	 * by default once people are aware of its existence
188 	 * (at&t ksh does not have a nohup option - it always sends
189 	 * the hup).
190 	 */
191 	Flag(FNOHUP) = 1;
192 
193 	/* Turn on brace expansion by default.  At&t ksh's that have
194 	 * alternation always have it on.  BUT, posix doesn't have
195 	 * brace expansion, so set this before setting up FPOSIX
196 	 * (change_flag() clears FBRACEEXPAND when FPOSIX is set).
197 	 */
198 #ifdef BRACE_EXPAND
199 	Flag(FBRACEEXPAND) = 1;
200 #endif /* BRACE_EXPAND */
201 
202 	/* set posix flag just before environment so that it will have
203 	 * exactly the same effect as the POSIXLY_CORRECT environment
204 	 * variable.  If this needs to be done sooner to ensure correct posix
205 	 * operation, an initial scan of the environment will also have
206 	 * done sooner.
207 	 */
208 #ifdef POSIXLY_CORRECT
209 	change_flag(FPOSIX, OF_SPECIAL, 1);
210 #endif /* POSIXLY_CORRECT */
211 
212 	/* Set edit mode to emacs by default, may be overridden
213 	 * by the environment or the user.  Also, we want tab completion
214 	 * on in vi by default. */
215 #if defined(EDIT) && defined(EMACS)
216 	change_flag(FEMACS, OF_SPECIAL, 1);
217 #endif /* EDIT && EMACS */
218 #if defined(EDIT) && defined(VI)
219 	Flag(FVITABCOMPLETE) = 1;
220 #endif /* EDIT && VI */
221 
222 	/* import environment */
223 	if (environ != NULL)
224 		for (wp = environ; *wp != NULL; wp++)
225 			typeset(*wp, IMPORT|EXPORT, 0, 0, 0);
226 
227 	kshpid = procpid = getpid();
228 	typeset(initifs, 0, 0, 0, 0);	/* for security */
229 
230 	/* assign default shell variable values */
231 	substitute(initsubs, 0);
232 
233 	/* Figure out the current working directory and set $PWD */
234 	{
235 		struct stat s_pwd, s_dot;
236 		struct tbl *pwd_v = global("PWD");
237 		char *pwd = str_val(pwd_v);
238 		char *pwdx = pwd;
239 
240 		/* Try to use existing $PWD if it is valid */
241 		if (!ISABSPATH(pwd)
242 		    || stat(pwd, &s_pwd) < 0 || stat(".", &s_dot) < 0
243 		    || s_pwd.st_dev != s_dot.st_dev
244 		    || s_pwd.st_ino != s_dot.st_ino)
245 			pwdx = (char *) 0;
246 		set_current_wd(pwdx);
247 		if (current_wd[0])
248 			simplify_path(current_wd);
249 		/* Only set pwd if we know where we are or if it had a
250 		 * bogus value
251 		 */
252 		if (current_wd[0] || pwd != null)
253 			/* setstr can't fail here */
254 			setstr(pwd_v, current_wd, KSH_RETURN_ERROR);
255 	}
256 	ppid = getppid();
257 	setint(global("PPID"), (long) ppid);
258 #ifdef KSH
259 	setint(global("RANDOM"), (long) (time((time_t *)0) * kshpid * ppid));
260 #endif /* KSH */
261 	/* setstr can't fail here */
262 	setstr(global(version_param), ksh_version, KSH_RETURN_ERROR);
263 
264 	/* execute initialization statements */
265 	for (wp = (char**) initcoms; *wp != NULL; wp++) {
266 		shcomexec(wp);
267 		for (; *wp != NULL; wp++)
268 			;
269 	}
270 
271 
272 	ksheuid = geteuid();
273 	safe_prompt = ksheuid ? "$ " : "# ";
274 	{
275 		struct tbl *vp = global("PS1");
276 
277 		/* Set PS1 if it isn't set, or we are root and prompt doesn't
278 		 * contain a #.
279 		 */
280 		if (!(vp->flag & ISSET)
281 		    || (!ksheuid && !strchr(str_val(vp), '#')))
282 			/* setstr can't fail here */
283 			setstr(vp, safe_prompt, KSH_RETURN_ERROR);
284 	}
285 
286 	/* Set this before parsing arguments */
287 	Flag(FPRIVILEGED) = getuid() != ksheuid || getgid() != getegid();
288 
289 	/* this to note if monitor is set on command line (see below) */
290 	Flag(FMONITOR) = 127;
291 	argi = parse_args(argv, OF_CMDLINE, (int *) 0);
292 	if (argi < 0) {
293 		exit(1);
294 		/* NOTREACHED */
295 	}
296 
297 	if (Flag(FCOMMAND)) {
298 		s = pushs(SSTRING, ATEMP);
299 		if (!(s->start = s->str = argv[argi++]))
300 			errorf("-c requires an argument");
301 		if (argv[argi])
302 			kshname = argv[argi++];
303 	} else if (argi < argc && !Flag(FSTDIN)) {
304 		s = pushs(SFILE, ATEMP);
305 #ifdef OS2
306 		/* a bug in os2 extproc shell processing doesn't
307 		 * pass full pathnames so we have to search for it.
308 		 * This changes the behavior of 'ksh arg' to search
309 		 * the users search path but it can't be helped.
310 		 */
311 		s->file = search(argv[argi++], path, R_OK, (int *) 0);
312 		if (!s->file || !*s->file)
313 		        s->file = argv[argi - 1];
314 #else
315 		s->file = argv[argi++];
316 #endif /* OS2 */
317 		s->u.shf = shf_open(s->file, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
318 		if (s->u.shf == NULL) {
319 			exstat = 127; /* POSIX */
320 			errorf("%s: %s", s->file, strerror(errno));
321 		}
322 		kshname = s->file;
323 	} else {
324 		Flag(FSTDIN) = 1;
325 		s = pushs(SSTDIN, ATEMP);
326 		s->file = "<stdin>";
327 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
328 				      (struct shf *) 0);
329 		if (isatty(0) && isatty(2)) {
330 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
331 			/* The following only if isatty(0) */
332 			s->flags |= SF_TTY;
333 			s->u.shf->flags |= SHF_INTERRUPT;
334 			s->file = (char *) 0;
335 		}
336 	}
337 
338 	/* This bizarreness is mandated by POSIX */
339 	{
340 		struct stat s_stdin;
341 
342 		if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
343 		    Flag(FTALKING))
344 			reset_nonblock(0);
345 	}
346 
347 	/* initialize job control */
348 	i = Flag(FMONITOR) != 127;
349 	Flag(FMONITOR) = 0;
350 	j_init(i);
351 #ifdef EDIT
352 	/* Do this after j_init(), as tty_fd is not initialized 'til then */
353 	if (Flag(FTALKING))
354 		x_init();
355 #endif
356 
357 	l = e->loc;
358 	l->argv = &argv[argi - 1];
359 	l->argc = argc - argi;
360 	l->argv[0] = (char *) kshname;
361 	getopts_reset(1);
362 
363 	/* Disable during .profile/ENV reading */
364 	restricted = Flag(FRESTRICTED);
365 	Flag(FRESTRICTED) = 0;
366 	errexit = Flag(FERREXIT);
367 	Flag(FERREXIT) = 0;
368 
369 	/* Do this before profile/$ENV so that if it causes problems in them,
370 	 * user will know why things broke.
371 	 */
372 	if (!current_wd[0] && Flag(FTALKING))
373 		warningf(FALSE, "Cannot determine current working directory");
374 
375 	if (Flag(FLOGIN)) {
376 #ifdef OS2
377 		char *profile;
378 
379 		/* Try to find a profile - first see if $INIT has a value,
380 		 * then try /etc/profile.ksh, then c:/usr/etc/profile.ksh.
381 		 */
382 		if (!Flag(FPRIVILEGED)
383 		    && strcmp(profile = substitute("$INIT/profile.ksh", 0),
384 			      "/profile.ksh"))
385 			include(profile, 0, (char **) 0, 1);
386 		else if (include("/etc/profile.ksh", 0, (char **) 0, 1) < 0)
387 			include("c:/usr/etc/profile.ksh", 0, (char **) 0, 1);
388 		if (!Flag(FPRIVILEGED))
389 			include(substitute("$HOME/profile.ksh", 0), 0,
390 				(char **) 0, 1);
391 #else /* OS2 */
392 		include(KSH_SYSTEM_PROFILE, 0, (char **) 0, 1);
393 		if (!Flag(FPRIVILEGED))
394 			include(substitute("$HOME/.profile", 0), 0,
395 				(char **) 0, 1);
396 #endif /* OS2 */
397 	}
398 
399 	if (Flag(FPRIVILEGED))
400 		include("/etc/suid_profile", 0, (char **) 0, 1);
401 	else {
402 		char *env_file;
403 
404 #ifndef KSH
405 		if (!Flag(FPOSIX))
406 			env_file = null;
407 		else
408 #endif /* !KSH */
409 			/* include $ENV */
410 			env_file = str_val(global("ENV"));
411 
412 #ifdef DEFAULT_ENV
413 		/* If env isn't set, include default environment */
414 		if (env_file == null)
415 			env_file = DEFAULT_ENV;
416 #endif /* DEFAULT_ENV */
417 		env_file = substitute(env_file, DOTILDE);
418 		if (*env_file != '\0')
419 			include(env_file, 0, (char **) 0, 1);
420 #ifdef OS2
421 		else if (Flag(FTALKING))
422 			include(substitute("$HOME/kshrc.ksh", 0), 0,
423 				(char **) 0, 1);
424 #endif /* OS2 */
425 	}
426 
427 	if (is_restricted(argv[0]) || is_restricted(str_val(global("SHELL"))))
428 		restricted = 1;
429 	if (restricted) {
430 		static const char *const restr_com[] = {
431 						"typeset", "-r", "PATH",
432 						    "ENV", "SHELL",
433 						(char *) 0
434 					    };
435 		shcomexec((char **) restr_com);
436 		/* After typeset command... */
437 		Flag(FRESTRICTED) = 1;
438 	}
439 	if (errexit)
440 		Flag(FERREXIT) = 1;
441 
442 	if (Flag(FTALKING)) {
443 		hist_init(s);
444 #ifdef KSH
445 		alarm_init();
446 #endif /* KSH */
447 	} else
448 		Flag(FTRACKALL) = 1;	/* set after ENV */
449 
450 	shell(s, TRUE);	/* doesn't return */
451 	return 0;
452 }
453 
454 int
455 include(name, argc, argv, intr_ok)
456 	const char *name;
457 	int argc;
458 	char **argv;
459 	int intr_ok;
460 {
461 	register Source *volatile s = NULL;
462 	struct shf *shf;
463 	char **volatile old_argv;
464 	volatile int old_argc;
465 	int i;
466 
467 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
468 	if (shf == NULL)
469 		return -1;
470 
471 	if (argv) {
472 		old_argv = e->loc->argv;
473 		old_argc = e->loc->argc;
474 	} else {
475 		old_argv = (char **) 0;
476 		old_argc = 0;
477 	}
478 	newenv(E_INCL);
479 	i = ksh_sigsetjmp(e->jbuf, 0);
480 	if (i) {
481 		if (s) /* Do this before quitenv(), which frees the memory */
482 			shf_close(s->u.shf);
483 		quitenv();
484 		if (old_argv) {
485 			e->loc->argv = old_argv;
486 			e->loc->argc = old_argc;
487 		}
488 		switch (i) {
489 		  case LRETURN:
490 		  case LERROR:
491 			return exstat & 0xff; /* see below */
492 		  case LINTR:
493 			/* intr_ok is set if we are including .profile or $ENV.
494 			 * If user ^C's out, we don't want to kill the shell...
495 			 */
496 			if (intr_ok && (exstat - 128) != SIGTERM)
497 				return 1;
498 			/* fall through... */
499 		  case LEXIT:
500 		  case LLEAVE:
501 		  case LSHELL:
502 			unwind(i);
503 			/*NOREACHED*/
504 		  default:
505 			internal_errorf(1, "include: %d", i);
506 			/*NOREACHED*/
507 		}
508 	}
509 	if (argv) {
510 		e->loc->argv = argv;
511 		e->loc->argc = argc;
512 	}
513 	s = pushs(SFILE, ATEMP);
514 	s->u.shf = shf;
515 	s->file = str_save(name, ATEMP);
516 	i = shell(s, FALSE);
517 	shf_close(s->u.shf);
518 	quitenv();
519 	if (old_argv) {
520 		e->loc->argv = old_argv;
521 		e->loc->argc = old_argc;
522 	}
523 	return i & 0xff;	/* & 0xff to ensure value not -1 */
524 }
525 
526 int
527 command(comm)
528 	const char *comm;
529 {
530 	register Source *s;
531 
532 	s = pushs(SSTRING, ATEMP);
533 	s->start = s->str = comm;
534 	return shell(s, FALSE);
535 }
536 
537 /*
538  * run the commands from the input source, returning status.
539  */
540 int
541 shell(s, toplevel)
542 	Source *volatile s;		/* input source */
543 	int volatile toplevel;
544 {
545 	struct op *t;
546 	volatile int wastty = s->flags & SF_TTY;
547 	volatile int attempts = 13;
548 	volatile int interactive = Flag(FTALKING) && toplevel;
549 	Source *volatile old_source = source;
550 	int i;
551 
552 	newenv(E_PARSE);
553 	if (interactive)
554 		really_exit = 0;
555 	i = ksh_sigsetjmp(e->jbuf, 0);
556 	if (i) {
557 		switch (i) {
558 		  case LINTR: /* we get here if SIGINT not caught or ignored */
559 		  case LERROR:
560 		  case LSHELL:
561 			if (interactive) {
562 				if (i == LINTR)
563 					shellf(newline);
564 				/* Reset any eof that was read as part of a
565 				 * multiline command.
566 				 */
567 				if (Flag(FIGNOREEOF) && s->type == SEOF
568 				    && wastty)
569 					s->type = SSTDIN;
570 				/* Used by exit command to get back to
571 				 * top level shell.  Kind of strange since
572 				 * interactive is set if we are reading from
573 				 * a tty, but to have stopped jobs, one only
574 				 * needs FMONITOR set (not FTALKING/SF_TTY)...
575 				 */
576 				/* toss any input we have so far */
577 				s->start = s->str = null;
578 				break;
579 			}
580 			/* fall through... */
581 		  case LEXIT:
582 		  case LLEAVE:
583 		  case LRETURN:
584 			source = old_source;
585 			quitenv();
586 			unwind(i);	/* keep on going */
587 			/*NOREACHED*/
588 		  default:
589 			source = old_source;
590 			quitenv();
591 			internal_errorf(1, "shell: %d", i);
592 			/*NOREACHED*/
593 		}
594 	}
595 
596 	while (1) {
597 		if (trap)
598 			runtraps(0);
599 
600 		if (s->next == NULL) {
601 			if (Flag(FVERBOSE))
602 				s->flags |= SF_ECHO;
603 			else
604 				s->flags &= ~SF_ECHO;
605 		}
606 
607 		if (interactive) {
608 			j_notify();
609 #ifdef KSH
610 			mcheck();
611 #endif /* KSH */
612 			set_prompt(PS1, s);
613 		}
614 
615 		t = compile(s);
616 		if (t != NULL && t->type == TEOF) {
617 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
618 				shellf("Use `exit' to leave ksh\n");
619 				s->type = SSTDIN;
620 			} else if (wastty && !really_exit
621 				   && j_stopped_running())
622 			{
623 				really_exit = 1;
624 				s->type = SSTDIN;
625 			} else {
626 				/* this for POSIX, which says EXIT traps
627 				 * shall be taken in the environment
628 				 * immediately after the last command
629 				 * executed.
630 				 */
631 				if (toplevel)
632 					unwind(LEXIT);
633 				break;
634 			}
635 		}
636 
637 		if (t && (!Flag(FNOEXEC) || (s->flags & SF_TTY)))
638 			exstat = execute(t, 0);
639 
640 		if (t != NULL && t->type != TEOF && interactive && really_exit)
641 			really_exit = 0;
642 
643 		reclaim();
644 	}
645 	quitenv();
646 	source = old_source;
647 	return exstat;
648 }
649 
650 /* return to closest error handler or shell(), exit if none found */
651 void
652 unwind(i)
653 	int i;
654 {
655 	/* ordering for EXIT vs ERR is a bit odd (this is what at&t ksh does) */
656 	if (i == LEXIT || (Flag(FERREXIT) && (i == LERROR || i == LINTR)
657 			   && sigtraps[SIGEXIT_].trap))
658 	{
659 		runtrap(&sigtraps[SIGEXIT_]);
660 		i = LLEAVE;
661 	} else if (Flag(FERREXIT) && (i == LERROR || i == LINTR)) {
662 		runtrap(&sigtraps[SIGERR_]);
663 		i = LLEAVE;
664 	}
665 	while (1) {
666 		switch (e->type) {
667 		  case E_PARSE:
668 		  case E_FUNC:
669 		  case E_INCL:
670 		  case E_LOOP:
671 		  case E_ERRH:
672 			ksh_siglongjmp(e->jbuf, i);
673 			/*NOTREACHED*/
674 
675 		  case E_NONE:
676 			if (i == LINTR)
677 				e->flags |= EF_FAKE_SIGDIE;
678 			/* Fall through... */
679 
680 		  default:
681 			quitenv();
682 		}
683 	}
684 }
685 
686 void
687 newenv(type)
688 	int type;
689 {
690 	register struct env *ep;
691 
692 	ep = (struct env *) alloc(sizeof(*ep), ATEMP);
693 	ep->type = type;
694 	ep->flags = 0;
695 	ainit(&ep->area);
696 	ep->loc = e->loc;
697 	ep->savefd = NULL;
698 	ep->oenv = e;
699 	ep->temps = NULL;
700 	e = ep;
701 }
702 
703 void
704 quitenv()
705 {
706 	register struct env *ep = e;
707 	register int fd;
708 
709 	if (ep->oenv && ep->oenv->loc != ep->loc)
710 		popblock();
711 	if (ep->savefd != NULL) {
712 		for (fd = 0; fd < NUFILE; fd++)
713 			/* if ep->savefd[fd] < 0, means fd was closed */
714 			if (ep->savefd[fd])
715 				restfd(fd, ep->savefd[fd]);
716 		if (ep->savefd[2]) /* Clear any write errors */
717 			shf_reopen(2, SHF_WR, shl_out);
718 	}
719 	reclaim();
720 
721 	/* Bottom of the stack.
722 	 * Either main shell is exiting or cleanup_parents_env() was called.
723 	 */
724 	if (ep->oenv == NULL) {
725 		if (ep->type == E_NONE) {	/* Main shell exiting? */
726 			if (Flag(FTALKING))
727 				hist_finish();
728 			j_exit();
729 			if (ep->flags & EF_FAKE_SIGDIE) {
730 				int sig = exstat - 128;
731 
732 				/* ham up our death a bit (at&t ksh
733 				 * only seems to do this for SIGTERM)
734 				 * Don't do it for SIGQUIT, since we'd
735 				 * dump a core..
736 				 */
737 				if (sig == SIGINT || sig == SIGTERM) {
738 					setsig(&sigtraps[sig], SIG_DFL,
739 						SS_RESTORE_CURR|SS_FORCE);
740 					kill(0, sig);
741 				}
742 			}
743 #ifdef MEM_DEBUG
744 			chmem_allfree();
745 #endif /* MEM_DEBUG */
746 		}
747 		exit(exstat);
748 	}
749 
750 	e = e->oenv;
751 	afree(ep, ATEMP);
752 }
753 
754 /* Called after a fork to cleanup stuff left over from parents environment */
755 void
756 cleanup_parents_env()
757 {
758 	struct env *ep;
759 	int fd;
760 
761 	/* Don't clean up temporary files - parent will probably need them.
762 	 * Also, can't easily reclaim memory since variables, etc. could be
763 	 * anywhere.
764 	 */
765 
766 	/* close all file descriptors hiding in savefd */
767 	for (ep = e; ep; ep = ep->oenv) {
768 		if (ep->savefd) {
769 			for (fd = 0; fd < NUFILE; fd++)
770 				if (ep->savefd[fd] > 0)
771 					close(ep->savefd[fd]);
772 			afree(ep->savefd, &ep->area);
773 			ep->savefd = (short *) 0;
774 		}
775 	}
776 	e->oenv = (struct env *) 0;
777 }
778 
779 /* Called just before an execve cleanup stuff temporary files */
780 void
781 cleanup_proc_env()
782 {
783 	struct env *ep;
784 
785 	for (ep = e; ep; ep = ep->oenv)
786 		remove_temps(ep->temps);
787 }
788 
789 /* remove temp files and free ATEMP Area */
790 static void
791 reclaim()
792 {
793 	remove_temps(e->temps);
794 	e->temps = NULL;
795 	afreeall(&e->area);
796 }
797 
798 static void
799 remove_temps(tp)
800 	struct temp *tp;
801 {
802 #ifdef OS2
803 	static struct temp *delayed_remove;
804 	struct temp *t, **tprev;
805 
806 	if (delayed_remove) {
807 		for (tprev = &delayed_remove, t = delayed_remove; t; t = *tprev)
808 			/* No need to check t->pid here... */
809 			if (unlink(t->name) >= 0 || errno == ENOENT) {
810 				*tprev = t->next;
811 				afree(t, APERM);
812 			} else
813 				tprev = &t->next;
814 	}
815 #endif /* OS2 */
816 
817 	for (; tp != NULL; tp = tp->next)
818 		if (tp->pid == procpid) {
819 #ifdef OS2
820 			/* OS/2 (and dos) do not allow files that are currently
821 			 * open to be removed, so we cache it away for future
822 			 * removal.
823 			 * XXX should only do this if errno
824 			 *     is Efile-still-open-can't-remove
825 			 *     (but I don't know what that is...)
826 			 */
827 			if (unlink(tp->name) < 0 && errno != ENOENT) {
828 				t = (struct temp *) alloc(
829 				    sizeof(struct temp) + strlen(tp->name) + 1,
830 				    APERM);
831 				memset(t, 0, sizeof(struct temp));
832 				t->name = (char *) &t[1];
833 				strlcpy(t->name, tp->name, strlen(tp->name) + 1);
834 				t->next = delayed_remove;
835 				delayed_remove = t;
836 			}
837 #else /* OS2 */
838 			unlink(tp->name);
839 #endif /* OS2 */
840 		}
841 }
842 
843 /* Returns true if name refers to a restricted shell */
844 static int
845 is_restricted(name)
846 	char *name;
847 {
848 	char *p;
849 
850 	if ((p = ksh_strrchr_dirsep(name)))
851 		name = p;
852 	/* accepts rsh, rksh, rpdksh, pdrksh, etc. */
853 	return (p = strchr(name, 'r')) && strstr(p, "sh");
854 }
855 
856 void
857 aerror(ap, msg)
858 	Area *ap;
859 	const char *msg;
860 {
861 	internal_errorf(1, "alloc: %s", msg);
862 	errorf(null); /* this is never executed - keeps gcc quiet */
863 	/*NOTREACHED*/
864 }
865