xref: /netbsd-src/bin/ksh/main.c (revision 4b896b232495b7a9b8b94a1cf1e21873296d53b8)
1 /*	$NetBSD: main.c,v 1.10 2003/06/23 11:39:00 agc 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 1.10 2003/06/23 11:39:00 agc 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 main __P((int, char **));
92 
93 int
94 main(argc, argv)
95 	int argc;
96 	register char **argv;
97 {
98 	register int i;
99 	int argi;
100 	Source *s;
101 	struct block *l;
102 	int restricted, errexit;
103 	char **wp;
104 	struct env env;
105 	pid_t ppid;
106 
107 #ifdef MEM_DEBUG
108 	chmem_set_defaults("ct", 1);
109 	/* chmem_push("+c", 1); */
110 #endif /* MEM_DEBUG */
111 
112 #ifdef OS2
113 	setmode (0, O_BINARY);
114 	setmode (1, O_TEXT);
115 #endif
116 
117 	/* make sure argv[] is sane */
118 	if (!*argv) {
119 		static const char	*empty_argv[] = {
120 					    "pdksh", (char *) 0
121 					};
122 
123 		argv = (char **) empty_argv;
124 		argc = 1;
125 	}
126 	kshname = *argv;
127 
128 	ainit(&aperm);		/* initialize permanent Area */
129 
130 	/* set up base environment */
131 	memset(&env, 0, sizeof(env));
132 	env.type = E_NONE;
133 	ainit(&env.area);
134 	e = &env;
135 	newblock();		/* set up global l->vars and l->funs */
136 
137 	/* Do this first so output routines (eg, errorf, shellf) can work */
138 	initio();
139 
140 	initvar();
141 
142 	initctypes();
143 
144 	inittraps();
145 
146 #ifdef KSH
147 	coproc_init();
148 #endif /* KSH */
149 
150 	/* set up variable and command dictionaries */
151 	tinit(&taliases, APERM, 0);
152 	tinit(&aliases, APERM, 0);
153 	tinit(&homedirs, APERM, 0);
154 
155 	/* define shell keywords */
156 	initkeywords();
157 
158 	/* define built-in commands */
159 	tinit(&builtins, APERM, 64); /* must be 2^n (currently 40 builtins) */
160 	for (i = 0; shbuiltins[i].name != NULL; i++)
161 		builtin(shbuiltins[i].name, shbuiltins[i].func);
162 	for (i = 0; kshbuiltins[i].name != NULL; i++)
163 		builtin(kshbuiltins[i].name, kshbuiltins[i].func);
164 
165 	init_histvec();
166 
167 	def_path = DEFAULT__PATH;
168 #if defined(HAVE_CONFSTR) && defined(_CS_PATH)
169 	{
170 		size_t len = confstr(_CS_PATH, (char *) 0, 0);
171 		char *new;
172 
173 		if (len > 0) {
174 			confstr(_CS_PATH, new = alloc(len + 1, APERM), len + 1);
175 			def_path = new;
176 		}
177 	}
178 #endif /* HAVE_CONFSTR && _CS_PATH */
179 
180 	/* Set PATH to def_path (will set the path global variable).
181 	 * (import of environment below will probably change this setting).
182 	 */
183 	{
184 		struct tbl *vp = global("PATH");
185 		/* setstr can't fail here */
186 		setstr(vp, def_path, KSH_RETURN_ERROR);
187 	}
188 
189 
190 	/* Turn on nohup by default for how - will change to off
191 	 * by default once people are aware of its existance
192 	 * (at&t ksh does not have a nohup option - it always sends
193 	 * the hup).
194 	 */
195 	Flag(FNOHUP) = 1;
196 
197 	/* Turn on brace expansion by default.  At&t ksh's that have
198 	 * alternation always have it on.  BUT, posix doesn't have
199 	 * brace expansion, so set this before setting up FPOSIX
200 	 * (change_flag() clears FBRACEEXPAND when FPOSIX is set).
201 	 */
202 #ifdef BRACE_EXPAND
203 	Flag(FBRACEEXPAND) = 1;
204 #endif /* BRACE_EXPAND */
205 
206 	/* set posix flag just before environment so that it will have
207 	 * exactly the same effect as the POSIXLY_CORRECT environment
208 	 * variable.  If this needs to be done sooner to ensure correct posix
209 	 * operation, an initial scan of the environment will also have
210 	 * done sooner.
211 	 */
212 #ifdef POSIXLY_CORRECT
213 	change_flag(FPOSIX, OF_SPECIAL, 1);
214 #endif /* POSIXLY_CORRECT */
215 
216 	/* Set edit mode to emacs by default, may be overridden
217 	 * by the environment or the user.  Also, we want tab completion
218 	 * on in vi by default. */
219 #if defined(EDIT) && defined(EMACS)
220 	change_flag(FEMACS, OF_SPECIAL, 1);
221 #endif /* EDIT && EMACS */
222 #if defined(EDIT) && defined(VI)
223 	Flag(FVITABCOMPLETE) = 1;
224 #endif /* EDIT && VI */
225 
226 	/* import environment */
227 	if (environ != NULL)
228 		for (wp = environ; *wp != NULL; wp++)
229 			typeset(*wp, IMPORT|EXPORT, 0, 0, 0);
230 
231 	kshpid = procpid = getpid();
232 	typeset(initifs, 0, 0, 0, 0);	/* for security */
233 
234 	/* assign default shell variable values */
235 	substitute(initsubs, 0);
236 
237 	/* Figure out the current working directory and set $PWD */
238 	{
239 		struct stat s_pwd, s_dot;
240 		struct tbl *pwd_v = global("PWD");
241 		char *pwd = str_val(pwd_v);
242 		char *pwdx = pwd;
243 
244 		/* Try to use existing $PWD if it is valid */
245 		if (!ISABSPATH(pwd)
246 		    || stat(pwd, &s_pwd) < 0 || stat(".", &s_dot) < 0
247 		    || s_pwd.st_dev != s_dot.st_dev
248 		    || s_pwd.st_ino != s_dot.st_ino)
249 			pwdx = (char *) 0;
250 		set_current_wd(pwdx);
251 		if (current_wd[0])
252 			simplify_path(current_wd);
253 		/* Only set pwd if we know where we are or if it had a
254 		 * bogus value
255 		 */
256 		if (current_wd[0] || pwd != null)
257 			/* setstr can't fail here */
258 			setstr(pwd_v, current_wd, KSH_RETURN_ERROR);
259 	}
260 	ppid = getppid();
261 	setint(global("PPID"), (long) ppid);
262 #ifdef KSH
263 	setint(global("RANDOM"), (long) (time((time_t *)0) * kshpid * ppid));
264 #endif /* KSH */
265 	/* setstr can't fail here */
266 	setstr(global(version_param), ksh_version, KSH_RETURN_ERROR);
267 
268 	/* execute initialization statements */
269 	for (wp = (char**) initcoms; *wp != NULL; wp++) {
270 		shcomexec(wp);
271 		for (; *wp != NULL; wp++)
272 			;
273 	}
274 
275 
276 	ksheuid = geteuid();
277 	safe_prompt = ksheuid ? "$ " : "# ";
278 	{
279 		struct tbl *vp = global("PS1");
280 
281 		/* Set PS1 if it isn't set, or we are root and prompt doesn't
282 		 * contain a #.
283 		 */
284 		if (!(vp->flag & ISSET)
285 		    || (!ksheuid && !strchr(str_val(vp), '#')))
286 			/* setstr can't fail here */
287 			setstr(vp, safe_prompt, KSH_RETURN_ERROR);
288 	}
289 
290 	/* Set this before parsing arguments */
291 	Flag(FPRIVILEGED) = getuid() != ksheuid || getgid() != getegid();
292 
293 	/* this to note if monitor is set on command line (see below) */
294 	Flag(FMONITOR) = 127;
295 	argi = parse_args(argv, OF_CMDLINE, (int *) 0);
296 	if (argi < 0) {
297 		exit(1);
298 		/* NOTREACHED */
299 	}
300 
301 	if (Flag(FCOMMAND)) {
302 		s = pushs(SSTRING, ATEMP);
303 		if (!(s->start = s->str = argv[argi++]))
304 			errorf("-c requires an argument");
305 		if (argv[argi])
306 			kshname = argv[argi++];
307 	} else if (argi < argc && !Flag(FSTDIN)) {
308 		s = pushs(SFILE, ATEMP);
309 #ifdef OS2
310 		/* a bug in os2 extproc shell processing doesn't
311 		 * pass full pathnames so we have to search for it.
312 		 * This changes the behavior of 'ksh arg' to search
313 		 * the users search path but it can't be helped.
314 		 */
315 		s->file = search(argv[argi++], path, R_OK, (int *) 0);
316 		if (!s->file || !*s->file)
317 		        s->file = argv[argi - 1];
318 #else
319 		s->file = argv[argi++];
320 #endif /* OS2 */
321 		s->u.shf = shf_open(s->file, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
322 		if (s->u.shf == NULL) {
323 			exstat = 127; /* POSIX */
324 			errorf("%s: %s", s->file, strerror(errno));
325 		}
326 		kshname = s->file;
327 	} else {
328 		Flag(FSTDIN) = 1;
329 		s = pushs(SSTDIN, ATEMP);
330 		s->file = "<stdin>";
331 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
332 				      (struct shf *) 0);
333 		if (isatty(0) && isatty(2)) {
334 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
335 			/* The following only if isatty(0) */
336 			s->flags |= SF_TTY;
337 			s->u.shf->flags |= SHF_INTERRUPT;
338 			s->file = (char *) 0;
339 		}
340 	}
341 
342 	/* This bizarreness is mandated by POSIX */
343 	{
344 		struct stat s_stdin;
345 
346 		if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode))
347 			reset_nonblock(0);
348 	}
349 
350 	/* initialize job control */
351 	i = Flag(FMONITOR) != 127;
352 	Flag(FMONITOR) = 0;
353 	j_init(i);
354 #ifdef EDIT
355 	/* Do this after j_init(), as tty_fd is not initialized 'til then */
356 	if (Flag(FTALKING))
357 		x_init();
358 #endif
359 
360 	l = e->loc;
361 	l->argv = &argv[argi - 1];
362 	l->argc = argc - argi;
363 	l->argv[0] = (char *) kshname;
364 	getopts_reset(1);
365 
366 	/* Disable during .profile/ENV reading */
367 	restricted = Flag(FRESTRICTED);
368 	Flag(FRESTRICTED) = 0;
369 	errexit = Flag(FERREXIT);
370 	Flag(FERREXIT) = 0;
371 
372 	/* Do this before profile/$ENV so that if it causes problems in them,
373 	 * user will know why things broke.
374 	 */
375 	if (!current_wd[0] && Flag(FTALKING))
376 		warningf(FALSE, "Cannot determine current working directory");
377 
378 	if (Flag(FLOGIN)) {
379 #ifdef OS2
380 		char *profile;
381 
382 		/* Try to find a profile - first see if $INIT has a value,
383 		 * then try /etc/profile.ksh, then c:/usr/etc/profile.ksh.
384 		 */
385 		if (!Flag(FPRIVILEGED)
386 		    && strcmp(profile = substitute("$INIT/profile.ksh", 0),
387 			      "/profile.ksh"))
388 			include(profile, 0, (char **) 0, 1);
389 		else if (include("/etc/profile.ksh", 0, (char **) 0, 1) < 0)
390 			include("c:/usr/etc/profile.ksh", 0, (char **) 0, 1);
391 		if (!Flag(FPRIVILEGED))
392 			include(substitute("$HOME/profile.ksh", 0), 0,
393 				(char **) 0, 1);
394 #else /* OS2 */
395 		include(KSH_SYSTEM_PROFILE, 0, (char **) 0, 1);
396 		if (!Flag(FPRIVILEGED))
397 			include(substitute("$HOME/.profile", 0), 0,
398 				(char **) 0, 1);
399 #endif /* OS2 */
400 	}
401 
402 	if (Flag(FPRIVILEGED))
403 		include("/etc/suid_profile", 0, (char **) 0, 1);
404 	else {
405 		char *env_file;
406 
407 #ifndef KSH
408 		if (!Flag(FPOSIX))
409 			env_file = null;
410 		else
411 #endif /* !KSH */
412 			/* include $ENV */
413 			env_file = str_val(global("ENV"));
414 
415 #ifdef DEFAULT_ENV
416 		/* If env isn't set, include default environment */
417 		if (env_file == null)
418 			env_file = DEFAULT_ENV;
419 #endif /* DEFAULT_ENV */
420 		env_file = substitute(env_file, DOTILDE);
421 		if (*env_file != '\0')
422 			include(env_file, 0, (char **) 0, 1);
423 #ifdef OS2
424 		else if (Flag(FTALKING))
425 			include(substitute("$HOME/kshrc.ksh", 0), 0,
426 				(char **) 0, 1);
427 #endif /* OS2 */
428 	}
429 
430 	if (is_restricted(argv[0]) || is_restricted(str_val(global("SHELL"))))
431 		restricted = 1;
432 	if (restricted) {
433 		static const char *const restr_com[] = {
434 						"typeset", "-r", "PATH",
435 						    "ENV", "SHELL",
436 						(char *) 0
437 					    };
438 		shcomexec((char **) restr_com);
439 		/* After typeset command... */
440 		Flag(FRESTRICTED) = 1;
441 	}
442 	if (errexit)
443 		Flag(FERREXIT) = 1;
444 
445 	if (Flag(FTALKING)) {
446 		hist_init(s);
447 #ifdef KSH
448 		alarm_init();
449 #endif /* KSH */
450 	} else
451 		Flag(FTRACKALL) = 1;	/* set after ENV */
452 
453 	shell(s, TRUE);	/* doesn't return */
454 	return 0;
455 }
456 
457 int
458 include(name, argc, argv, intr_ok)
459 	const char *name;
460 	int argc;
461 	char **argv;
462 	int intr_ok;
463 {
464 	register Source *volatile s = NULL;
465 	Source *volatile sold;
466 	struct shf *shf;
467 	char **volatile old_argv;
468 	volatile int old_argc;
469 	int i;
470 
471 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
472 	if (shf == NULL)
473 		return -1;
474 
475 	if (argv) {
476 		old_argv = e->loc->argv;
477 		old_argc = e->loc->argc;
478 	} else {
479 		old_argv = (char **) 0;
480 		old_argc = 0;
481 	}
482 	sold = source;
483 	newenv(E_INCL);
484 	i = ksh_sigsetjmp(e->jbuf, 0);
485 	if (i) {
486 		source = sold;
487 		if (s) /* Do this before quitenv(), which frees the memory */
488 			shf_close(s->u.shf);
489 		quitenv();
490 		if (old_argv) {
491 			e->loc->argv = old_argv;
492 			e->loc->argc = old_argc;
493 		}
494 		switch (i) {
495 		  case LRETURN:
496 		  case LERROR:
497 			return exstat & 0xff; /* see below */
498 		  case LINTR:
499 			/* intr_ok is set if we are including .profile or $ENV.
500 			 * If user ^C's out, we don't want to kill the shell...
501 			 */
502 			if (intr_ok && (exstat - 128) != SIGTERM)
503 				return 1;
504 			/* fall through... */
505 		  case LEXIT:
506 		  case LLEAVE:
507 		  case LSHELL:
508 			unwind(i);
509 			/*NOREACHED*/
510 		  default:
511 			internal_errorf(1, "include: %d", i);
512 			/*NOREACHED*/
513 		}
514 	}
515 	if (argv) {
516 		e->loc->argv = argv;
517 		e->loc->argc = argc;
518 	}
519 	s = pushs(SFILE, ATEMP);
520 	s->u.shf = shf;
521 	s->file = str_save(name, ATEMP);
522 	i = shell(s, FALSE);
523 	source = sold;
524 	shf_close(s->u.shf);
525 	quitenv();
526 	if (old_argv) {
527 		e->loc->argv = old_argv;
528 		e->loc->argc = old_argc;
529 	}
530 	return i & 0xff;	/* & 0xff to ensure value not -1 */
531 }
532 
533 int
534 command(comm)
535 	const char *comm;
536 {
537 	register Source *s;
538 
539 	s = pushs(SSTRING, ATEMP);
540 	s->start = s->str = comm;
541 	return shell(s, FALSE);
542 }
543 
544 /*
545  * run the commands from the input source, returning status.
546  */
547 int
548 shell(s, toplevel)
549 	Source *volatile s;		/* input source */
550 	int volatile toplevel;
551 {
552 	struct op *t;
553 	volatile int wastty = s->flags & SF_TTY;
554 	volatile int attempts = 13;
555 	volatile int interactive = Flag(FTALKING) && toplevel;
556 	int i;
557 
558 	newenv(E_PARSE);
559 	if (interactive)
560 		really_exit = 0;
561 	i = ksh_sigsetjmp(e->jbuf, 0);
562 	if (i) {
563 		s->start = s->str = null;
564 		switch (i) {
565 		  case LINTR: /* we get here if SIGINT not caught or ignored */
566 		  case LERROR:
567 		  case LSHELL:
568 			if (interactive) {
569 				if (i == LINTR)
570 					shellf(newline);
571 				/* Reset any eof that was read as part of a
572 				 * multiline command.
573 				 */
574 				if (Flag(FIGNOREEOF) && s->type == SEOF
575 				    && wastty)
576 					s->type = SSTDIN;
577 				/* Used by exit command to get back to
578 				 * top level shell.  Kind of strange since
579 				 * interactive is set if we are reading from
580 				 * a tty, but to have stopped jobs, one only
581 				 * needs FMONITOR set (not FTALKING/SF_TTY)...
582 				 */
583 				break;
584 			}
585 			/* fall through... */
586 		  case LEXIT:
587 		  case LLEAVE:
588 		  case LRETURN:
589 			quitenv();
590 			unwind(i);	/* keep on going */
591 			/*NOREACHED*/
592 		  default:
593 			quitenv();
594 			internal_errorf(1, "shell: %d", i);
595 			/*NOREACHED*/
596 		}
597 	}
598 
599 	while (1) {
600 		if (trap)
601 			runtraps(0);
602 
603 		if (s->next == NULL) {
604 			if (Flag(FVERBOSE))
605 				s->flags |= SF_ECHO;
606 			else
607 				s->flags &= ~SF_ECHO;
608 		}
609 
610 		if (interactive) {
611 			j_notify();
612 #ifdef KSH
613 			mcheck();
614 #endif /* KSH */
615 			set_prompt(PS1, s);
616 		}
617 
618 		t = compile(s);
619 		if (t != NULL && t->type == TEOF) {
620 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
621 				shellf("Use `exit' to leave ksh\n");
622 				s->type = SSTDIN;
623 			} else if (wastty && !really_exit
624 				   && j_stopped_running())
625 			{
626 				really_exit = 1;
627 				s->type = SSTDIN;
628 			} else {
629 				/* this for POSIX, which says EXIT traps
630 				 * shall be taken in the environment
631 				 * immediately after the last command
632 				 * executed.
633 				 */
634 				if (toplevel)
635 					unwind(LEXIT);
636 				break;
637 			}
638 		}
639 
640 		if (t && (!Flag(FNOEXEC) || (s->flags & SF_TTY)))
641 			exstat = execute(t, 0);
642 
643 		if (t != NULL && t->type != TEOF && interactive && really_exit)
644 			really_exit = 0;
645 
646 		reclaim();
647 	}
648 	quitenv();
649 	return exstat;
650 }
651 
652 /* return to closest error handler or shell(), exit if none found */
653 void
654 unwind(i)
655 	int i;
656 {
657 	/* ordering for EXIT vs ERR is a bit odd (this is what at&t ksh does) */
658 	if (i == LEXIT || (Flag(FERREXIT) && (i == LERROR || i == LINTR)
659 			   && sigtraps[SIGEXIT_].trap))
660 	{
661 		runtrap(&sigtraps[SIGEXIT_]);
662 		i = LLEAVE;
663 	} else if (Flag(FERREXIT) && (i == LERROR || i == LINTR)) {
664 		runtrap(&sigtraps[SIGERR_]);
665 		i = LLEAVE;
666 	}
667 	while (1) {
668 		switch (e->type) {
669 		  case E_PARSE:
670 		  case E_FUNC:
671 		  case E_INCL:
672 		  case E_LOOP:
673 		  case E_ERRH:
674 			ksh_siglongjmp(e->jbuf, i);
675 			/*NOTREACHED*/
676 
677 		  case E_NONE:
678 			if (i == LINTR)
679 				e->flags |= EF_FAKE_SIGDIE;
680 			/* Fall through... */
681 
682 		  default:
683 			quitenv();
684 		}
685 	}
686 }
687 
688 void
689 newenv(type)
690 	int type;
691 {
692 	register struct env *ep;
693 
694 	ep = (struct env *) alloc(sizeof(*ep), ATEMP);
695 	ep->type = type;
696 	ep->flags = 0;
697 	ainit(&ep->area);
698 	ep->loc = e->loc;
699 	ep->savefd = NULL;
700 	ep->oenv = e;
701 	ep->temps = NULL;
702 	e = ep;
703 }
704 
705 void
706 quitenv()
707 {
708 	register struct env *ep = e;
709 	register int fd;
710 
711 	if (ep->oenv && ep->oenv->loc != ep->loc)
712 		popblock();
713 	if (ep->savefd != NULL) {
714 		for (fd = 0; fd < NUFILE; fd++)
715 			/* if ep->savefd[fd] < 0, means fd was closed */
716 			if (ep->savefd[fd])
717 				restfd(fd, ep->savefd[fd]);
718 		if (ep->savefd[2]) /* Clear any write errors */
719 			shf_reopen(2, SHF_WR, shl_out);
720 	}
721 	reclaim();
722 
723 	/* Bottom of the stack.
724 	 * Either main shell is exiting or cleanup_parents_env() was called.
725 	 */
726 	if (ep->oenv == NULL) {
727 		if (ep->type == E_NONE) {	/* Main shell exiting? */
728 			if (Flag(FTALKING))
729 				hist_finish();
730 			j_exit();
731 			if (ep->flags & EF_FAKE_SIGDIE) {
732 				int sig = exstat - 128;
733 
734 				/* ham up our death a bit (at&t ksh
735 				 * only seems to do this for SIGTERM)
736 				 * Don't do it for SIGQUIT, since we'd
737 				 * dump a core..
738 				 */
739 				if (sig == SIGINT || sig == SIGTERM) {
740 					setsig(&sigtraps[sig], SIG_DFL,
741 						SS_RESTORE_CURR|SS_FORCE);
742 					kill(0, sig);
743 				}
744 			}
745 #ifdef MEM_DEBUG
746 			chmem_allfree();
747 #endif /* MEM_DEBUG */
748 		}
749 		exit(exstat);
750 	}
751 
752 	e = e->oenv;
753 	afree(ep, ATEMP);
754 }
755 
756 /* Called after a fork to cleanup stuff left over from parents environment */
757 void
758 cleanup_parents_env()
759 {
760 	struct env *ep;
761 	int fd;
762 
763 	/* Don't clean up temporary files - parent will probably need them.
764 	 * Also, can't easily reclaim memory since variables, etc. could be
765 	 * anywyere.
766 	 */
767 
768 	/* close all file descriptors hiding in savefd */
769 	for (ep = e; ep; ep = ep->oenv) {
770 		if (ep->savefd) {
771 			for (fd = 0; fd < NUFILE; fd++)
772 				if (ep->savefd[fd] > 0)
773 					close(ep->savefd[fd]);
774 			afree(ep->savefd, &ep->area);
775 			ep->savefd = (short *) 0;
776 		}
777 	}
778 	e->oenv = (struct env *) 0;
779 }
780 
781 /* Called just before an execve cleanup stuff temporary files */
782 void
783 cleanup_proc_env()
784 {
785 	struct env *ep;
786 
787 	for (ep = e; ep; ep = ep->oenv)
788 		remove_temps(ep->temps);
789 }
790 
791 /* remove temp files and free ATEMP Area */
792 static void
793 reclaim()
794 {
795 	remove_temps(e->temps);
796 	e->temps = NULL;
797 	afreeall(&e->area);
798 }
799 
800 static void
801 remove_temps(tp)
802 	struct temp *tp;
803 {
804 #ifdef OS2
805 	static struct temp *delayed_remove;
806 	struct temp *t, **tprev;
807 
808 	if (delayed_remove) {
809 		for (tprev = &delayed_remove, t = delayed_remove; t; t = *tprev)
810 			/* No need to check t->pid here... */
811 			if (unlink(t->name) >= 0 || errno == ENOENT) {
812 				*tprev = t->next;
813 				afree(t, APERM);
814 			} else
815 				tprev = &t->next;
816 	}
817 #endif /* OS2 */
818 
819 	for (; tp != NULL; tp = tp->next)
820 		if (tp->pid == procpid) {
821 #ifdef OS2
822 			/* OS/2 (and dos) do not allow files that are currently
823 			 * open to be removed, so we cache it away for future
824 			 * removal.
825 			 * XXX should only do this if errno
826 			 *     is Efile-still-open-can't-remove
827 			 *     (but I don't know what that is...)
828 			 */
829 			if (unlink(tp->name) < 0 && errno != ENOENT) {
830 				t = (struct temp *) alloc(
831 				    sizeof(struct temp) + strlen(tp->name) + 1,
832 				    APERM);
833 				memset(t, 0, sizeof(struct temp));
834 				t->name = (char *) &t[1];
835 				strcpy(t->name, tp->name);
836 				t->next = delayed_remove;
837 				delayed_remove = t;
838 			}
839 #else /* OS2 */
840 			unlink(tp->name);
841 #endif /* OS2 */
842 		}
843 }
844 
845 /* Returns true if name refers to a restricted shell */
846 static int
847 is_restricted(name)
848 	char *name;
849 {
850 	char *p;
851 
852 	if ((p = ksh_strrchr_dirsep(name)))
853 		name = p;
854 	/* accepts rsh, rksh, rpdksh, pdrksh, etc. */
855 	return (p = strchr(name, 'r')) && strstr(p, "sh");
856 }
857 
858 void
859 aerror(ap, msg)
860 	Area *ap;
861 	const char *msg;
862 {
863 	internal_errorf(1, "alloc: %s", msg);
864 	errorf(null); /* this is never executed - keeps gcc quiet */
865 	/*NOTREACHED*/
866 }
867