xref: /openbsd-src/bin/ksh/main.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: main.c,v 1.20 2000/12/19 21:48:54 markus Exp $	*/
2 
3 /*
4  * startup, main loop, environments and error handling
5  */
6 
7 #define	EXTERN				/* define EXTERNs in sh.h */
8 
9 #include "sh.h"
10 #include "ksh_stat.h"
11 #include "ksh_time.h"
12 
13 extern char **environ;
14 
15 /*
16  * global data
17  */
18 
19 static void	reclaim ARGS((void));
20 static void	remove_temps ARGS((struct temp *tp));
21 static int	is_restricted ARGS((char *name));
22 
23 /*
24  * shell initialization
25  */
26 
27 static const char initifs[] = "IFS= \t\n";
28 
29 static const char initsubs[] = "${PS2=> } ${PS3=#? } ${PS4=+ }";
30 
31 static const char version_param[] =
32 #ifdef KSH
33 	"KSH_VERSION"
34 #else /* KSH */
35 	"SH_VERSION"
36 #endif /* KSH */
37 	;
38 
39 static const char *const initcoms [] = {
40 	"typeset", "-x", "SHELL", "PATH", "HOME", NULL,
41 	"typeset", "-r", version_param, NULL,
42 	"typeset", "-i", "PPID", NULL,
43 	"typeset", "-i", "OPTIND=1", NULL,
44 #ifdef KSH
45 	"eval", "typeset -i RANDOM MAILCHECK=\"${MAILCHECK-600}\" SECONDS=\"${SECONDS-0}\" TMOUT=\"${TMOUT-0}\"", NULL,
46 #endif /* KSH */
47 	"alias",
48 	 /* Standard ksh aliases */
49 	  "hash=alias -t",	/* not "alias -t --": hash -r needs to work */
50 	  "type=whence -v",
51 #ifdef JOBS
52 	  "stop=kill -STOP",
53 	  "suspend=kill -STOP $$",
54 #endif
55 #ifdef KSH
56 	  "autoload=typeset -fu",
57 	  "functions=typeset -f",
58 # ifdef HISTORY
59 	  "history=fc -l",
60 # endif /* HISTORY */
61 	  "integer=typeset -i",
62 	  "nohup=nohup ",
63 	  "local=typeset",
64 	  "r=fc -e -",
65 #endif /* KSH */
66 #ifdef KSH
67 	 /* Aliases that are builtin commands in at&t */
68 	  "login=exec login",
69 #ifndef __OpenBSD__
70 	  "newgrp=exec newgrp",
71 #endif /* __OpenBSD__ */
72 #endif /* KSH */
73 	  NULL,
74 	/* this is what at&t ksh seems to track, with the addition of emacs */
75 	"alias", "-tU",
76 	  "cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
77 	  "mail", "make", "mv", "pr", "rm", "sed", "sh", "vi", "who",
78 	  NULL,
79 #ifdef EXTRA_INITCOMS
80 	EXTRA_INITCOMS, NULL,
81 #endif /* EXTRA_INITCOMS */
82 	NULL
83 };
84 
85 int
86 main(argc, argv)
87 	int argc;
88 	register char **argv;
89 {
90 	register int i;
91 	int argi;
92 	Source *s;
93 	struct block *l;
94 	int restricted, errexit;
95 	char **wp;
96 	struct env env;
97 	pid_t ppid;
98 
99 #ifdef MEM_DEBUG
100 	chmem_set_defaults("ct", 1);
101 	/* chmem_push("+c", 1); */
102 #endif /* MEM_DEBUG */
103 
104 #ifdef OS2
105 	setmode (0, O_BINARY);
106 	setmode (1, O_TEXT);
107 #endif
108 
109 	/* make sure argv[] is sane */
110 	if (!*argv) {
111 		static const char	*empty_argv[] = {
112 					    "pdksh", (char *) 0
113 					};
114 
115 		argv = (char **) empty_argv;
116 		argc = 1;
117 	}
118 	kshname = *argv;
119 
120 	ainit(&aperm);		/* initialize permanent Area */
121 
122 	/* set up base environment */
123 	memset(&env, 0, sizeof(env));
124 	env.type = E_NONE;
125 	ainit(&env.area);
126 	e = &env;
127 	newblock();		/* set up global l->vars and l->funs */
128 
129 	/* Do this first so output routines (eg, errorf, shellf) can work */
130 	initio();
131 
132 	initvar();
133 
134 	initctypes();
135 
136 	inittraps();
137 
138 #ifdef KSH
139 	coproc_init();
140 #endif /* KSH */
141 
142 	/* set up variable and command dictionaries */
143 	tinit(&taliases, APERM, 0);
144 	tinit(&aliases, APERM, 0);
145 	tinit(&homedirs, APERM, 0);
146 
147 	/* define shell keywords */
148 	initkeywords();
149 
150 	/* define built-in commands */
151 	tinit(&builtins, APERM, 64); /* must be 2^n (currently 40 builtins) */
152 	for (i = 0; shbuiltins[i].name != NULL; i++)
153 		builtin(shbuiltins[i].name, shbuiltins[i].func);
154 	for (i = 0; kshbuiltins[i].name != NULL; i++)
155 		builtin(kshbuiltins[i].name, kshbuiltins[i].func);
156 
157 	init_histvec();
158 
159 	def_path = DEFAULT__PATH;
160 #if defined(HAVE_CONFSTR) && defined(_CS_PATH)
161 	{
162 		size_t len = confstr(_CS_PATH, (char *) 0, 0);
163 		char *new;
164 
165 		if (len > 0) {
166 			confstr(_CS_PATH, new = alloc(len + 1, APERM), len + 1);
167 			def_path = new;
168 		}
169 	}
170 #endif /* HAVE_CONFSTR && _CS_PATH */
171 
172 	/* Set PATH to def_path (will set the path global variable).
173 	 * (import of environment below will probably change this setting).
174 	 */
175 	{
176 		struct tbl *vp = global("PATH");
177 		/* setstr can't fail here */
178 		setstr(vp, def_path, KSH_RETURN_ERROR);
179 	}
180 
181 
182 	/* Turn on nohup by default for how - will change to off
183 	 * by default once people are aware of its existance
184 	 * (at&t ksh does not have a nohup option - it always sends
185 	 * the hup).
186 	 */
187 	Flag(FNOHUP) = 1;
188 
189 	/* Turn on brace expansion by default.  At&t ksh's that have
190 	 * alternation always have it on.  BUT, posix doesn't have
191 	 * brace expansion, so set this before setting up FPOSIX
192 	 * (change_flag() clears FBRACEEXPAND when FPOSIX is set).
193 	 */
194 #ifdef BRACE_EXPAND
195 	Flag(FBRACEEXPAND) = 1;
196 #endif /* BRACE_EXPAND */
197 
198 	/* set posix flag just before environment so that it will have
199 	 * exactly the same effect as the POSIXLY_CORRECT environment
200 	 * variable.  If this needs to be done sooner to ensure correct posix
201 	 * operation, an initial scan of the environment will also have
202 	 * done sooner.
203 	 */
204 #ifdef POSIXLY_CORRECT
205 	change_flag(FPOSIX, OF_SPECIAL, 1);
206 #endif /* POSIXLY_CORRECT */
207 
208 	/* Check to see if we're /bin/sh. */
209 	if (!strcmp(&kshname[strlen(kshname) - 3], "/sh")
210 	    || !strcmp(kshname, "sh") || !strcmp(kshname, "-sh"))
211 		Flag(FSH) = 1;
212 
213 	/* Set edit mode to emacs by default, may be overridden
214 	 * by the environment or the user.  Also, we want tab completion
215 	 * on in vi by default. */
216 #if defined(EDIT) && defined(EMACS)
217 	change_flag(FEMACS, OF_SPECIAL, 1);
218 #endif /* EDIT && EMACS */
219 #if defined(EDIT) && defined(VI)
220 	Flag(FVITABCOMPLETE) = 1;
221 #endif /* EDIT && VI */
222 
223 	/* import environment */
224 	if (environ != NULL)
225 		for (wp = environ; *wp != NULL; wp++)
226 			typeset(*wp, IMPORT|EXPORT, 0, 0, 0);
227 
228 	kshpid = procpid = getpid();
229 	typeset(initifs, 0, 0, 0, 0);	/* for security */
230 
231 	/* assign default shell variable values */
232 	substitute(initsubs, 0);
233 
234 	/* Figure out the current working directory and set $PWD */
235 	{
236 		struct stat s_pwd, s_dot;
237 		struct tbl *pwd_v = global("PWD");
238 		char *pwd = str_val(pwd_v);
239 		char *pwdx = pwd;
240 
241 		/* Try to use existing $PWD if it is valid */
242 		if (!ISABSPATH(pwd)
243 		    || stat(pwd, &s_pwd) < 0 || stat(".", &s_dot) < 0
244 		    || s_pwd.st_dev != s_dot.st_dev
245 		    || s_pwd.st_ino != s_dot.st_ino)
246 			pwdx = (char *) 0;
247 		set_current_wd(pwdx);
248 		if (current_wd[0])
249 			simplify_path(current_wd);
250 		/* Only set pwd if we know where we are or if it had a
251 		 * bogus value
252 		 */
253 		if (current_wd[0] || pwd != null)
254 			/* setstr can't fail here */
255 			setstr(pwd_v, current_wd, KSH_RETURN_ERROR);
256 	}
257 	ppid = getppid();
258 	setint(global("PPID"), (long) ppid);
259 #ifdef KSH
260 	setint(global("RANDOM"), (long) (time((time_t *)0) * kshpid * ppid));
261 #endif /* KSH */
262 	/* setstr can't fail here */
263 	setstr(global(version_param), ksh_version, KSH_RETURN_ERROR);
264 
265 	/* execute initialization statements */
266 	for (wp = (char**) initcoms; *wp != NULL; wp++) {
267 		shcomexec(wp);
268 		for (; *wp != NULL; wp++)
269 			;
270 	}
271 
272 
273 	ksheuid = geteuid();
274 	safe_prompt = ksheuid ? "$ " : "# ";
275 	{
276 		struct tbl *vp = global("PS1");
277 
278 		/* Set PS1 if it isn't set, or we are root and prompt doesn't
279 		 * contain a #.
280 		 */
281 		if (!(vp->flag & ISSET)
282 		    || (!ksheuid && !strchr(str_val(vp), '#')))
283 			/* setstr can't fail here */
284 			setstr(vp, safe_prompt, KSH_RETURN_ERROR);
285 	}
286 
287 	/* Set this before parsing arguments */
288 	Flag(FPRIVILEGED) = getuid() != ksheuid || getgid() != getegid();
289 
290 	/* this to note if monitor is set on command line (see below) */
291 	Flag(FMONITOR) = 127;
292 	argi = parse_args(argv, OF_CMDLINE, (int *) 0);
293 	if (argi < 0)
294 		exit(1);
295 
296 	if (Flag(FCOMMAND)) {
297 		s = pushs(SSTRING, ATEMP);
298 		if (!(s->start = s->str = argv[argi++]))
299 			errorf("-c requires an argument");
300 		if (argv[argi])
301 			kshname = argv[argi++];
302 	} else if (argi < argc && !Flag(FSTDIN)) {
303 		s = pushs(SFILE, ATEMP);
304 #ifdef OS2
305 		/* a bug in os2 extproc shell processing doesn't
306 		 * pass full pathnames so we have to search for it.
307 		 * This changes the behavior of 'ksh arg' to search
308 		 * the users search path but it can't be helped.
309 		 */
310 		s->file = search(argv[argi++], path, R_OK, (int *) 0);
311 		if (!s->file || !*s->file)
312 		        s->file = argv[argi - 1];
313 #else
314 		s->file = argv[argi++];
315 #endif /* OS2 */
316 		s->u.shf = shf_open(s->file, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
317 		if (s->u.shf == NULL) {
318 			exstat = 127; /* POSIX */
319 			errorf("%s: %s", s->file, strerror(errno));
320 		}
321 		kshname = s->file;
322 	} else {
323 		Flag(FSTDIN) = 1;
324 		s = pushs(SSTDIN, ATEMP);
325 		s->file = "<stdin>";
326 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
327 				      (struct shf *) 0);
328 		if (isatty(0) && isatty(2)) {
329 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
330 			/* The following only if isatty(0) */
331 			s->flags |= SF_TTY;
332 			s->u.shf->flags |= SHF_INTERRUPT;
333 			s->file = (char *) 0;
334 		}
335 	}
336 
337 	/* This bizarreness is mandated by POSIX */
338 	{
339 		struct stat s_stdin;
340 
341 		if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
342 		    Flag(FTALKING))
343 			reset_nonblock(0);
344 	}
345 
346 	/* initialize job control */
347 	i = Flag(FMONITOR) != 127;
348 	Flag(FMONITOR) = 0;
349 	j_init(i);
350 #ifdef EDIT
351 	/* Do this after j_init(), as tty_fd is not initialized 'til then */
352 	if (Flag(FTALKING))
353 		x_init();
354 #endif
355 
356 	l = e->loc;
357 	l->argv = &argv[argi - 1];
358 	l->argc = argc - argi;
359 	l->argv[0] = (char *) kshname;
360 	getopts_reset(1);
361 
362 	/* Disable during .profile/ENV reading */
363 	restricted = Flag(FRESTRICTED);
364 	Flag(FRESTRICTED) = 0;
365 	errexit = Flag(FERREXIT);
366 	Flag(FERREXIT) = 0;
367 
368 	/* Do this before profile/$ENV so that if it causes problems in them,
369 	 * user will know why things broke.
370 	 */
371 	if (!current_wd[0] && Flag(FTALKING))
372 		warningf(FALSE, "Cannot determine current working directory");
373 
374 	if (Flag(FLOGIN)) {
375 #ifdef OS2
376 		char *profile;
377 
378 		/* Try to find a profile - first see if $INIT has a value,
379 		 * then try /etc/profile.ksh, then c:/usr/etc/profile.ksh.
380 		 */
381 		if (!Flag(FPRIVILEGED)
382 		    && strcmp(profile = substitute("$INIT/profile.ksh", 0),
383 			      "/profile.ksh"))
384 			include(profile, 0, (char **) 0, 1);
385 		else if (include("/etc/profile.ksh", 0, (char **) 0, 1) < 0)
386 			include("c:/usr/etc/profile.ksh", 0, (char **) 0, 1);
387 		if (!Flag(FPRIVILEGED))
388 			include(substitute("$HOME/profile.ksh", 0), 0,
389 				(char **) 0, 1);
390 #else /* OS2 */
391 		include(KSH_SYSTEM_PROFILE, 0, (char **) 0, 1);
392 		if (!Flag(FPRIVILEGED))
393 			include(substitute("$HOME/.profile", 0), 0,
394 				(char **) 0, 1);
395 #endif /* OS2 */
396 	}
397 
398 	if (Flag(FPRIVILEGED))
399 		include("/etc/suid_profile", 0, (char **) 0, 1);
400 	else {
401 		char *env_file;
402 
403 #ifndef KSH
404 		if (!Flag(FPOSIX))
405 			env_file = null;
406 		else
407 #endif /* !KSH */
408 			/* include $ENV */
409 			env_file = str_val(global("ENV"));
410 
411 #ifdef DEFAULT_ENV
412 		/* If env isn't set, include default environment */
413 		if (env_file == null)
414 			env_file = DEFAULT_ENV;
415 #endif /* DEFAULT_ENV */
416 		env_file = substitute(env_file, DOTILDE);
417 		if (*env_file != '\0')
418 			include(env_file, 0, (char **) 0, 1);
419 #ifdef OS2
420 		else if (Flag(FTALKING))
421 			include(substitute("$HOME/kshrc.ksh", 0), 0,
422 				(char **) 0, 1);
423 #endif /* OS2 */
424 	}
425 
426 	if (is_restricted(argv[0]) || is_restricted(str_val(global("SHELL"))))
427 		restricted = 1;
428 	if (restricted) {
429 		static const char *const restr_com[] = {
430 						"typeset", "-r", "PATH",
431 						    "ENV", "SHELL",
432 						(char *) 0
433 					    };
434 		shcomexec((char **) restr_com);
435 		/* After typeset command... */
436 		Flag(FRESTRICTED) = 1;
437 	}
438 	if (errexit)
439 		Flag(FERREXIT) = 1;
440 
441 	if (Flag(FTALKING)) {
442 		hist_init(s);
443 #ifdef KSH
444 		alarm_init();
445 #endif /* KSH */
446 	} else
447 		Flag(FTRACKALL) = 1;	/* set after ENV */
448 
449 	shell(s, TRUE);	/* doesn't return */
450 	return 0;
451 }
452 
453 int
454 include(name, argc, argv, intr_ok)
455 	const char *name;
456 	int argc;
457 	char **argv;
458 	int intr_ok;
459 {
460 	register Source *volatile s = NULL;
461 	struct shf *shf;
462 	char **volatile old_argv;
463 	volatile int old_argc;
464 	int i;
465 
466 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
467 	if (shf == NULL)
468 		return -1;
469 
470 	if (argv) {
471 		old_argv = e->loc->argv;
472 		old_argc = e->loc->argc;
473 	} else {
474 		old_argv = (char **) 0;
475 		old_argc = 0;
476 	}
477 	newenv(E_INCL);
478 	i = ksh_sigsetjmp(e->jbuf, 0);
479 	if (i) {
480 		if (s) /* Do this before quitenv(), which frees the memory */
481 			shf_close(s->u.shf);
482 		quitenv();
483 		if (old_argv) {
484 			e->loc->argv = old_argv;
485 			e->loc->argc = old_argc;
486 		}
487 		switch (i) {
488 		  case LRETURN:
489 		  case LERROR:
490 			return exstat & 0xff; /* see below */
491 		  case LINTR:
492 			/* intr_ok is set if we are including .profile or $ENV.
493 			 * If user ^C's out, we don't want to kill the shell...
494 			 */
495 			if (intr_ok && (exstat - 128) != SIGTERM)
496 				return 1;
497 			/* fall through... */
498 		  case LEXIT:
499 		  case LLEAVE:
500 		  case LSHELL:
501 			unwind(i);
502 			/*NOREACHED*/
503 		  default:
504 			internal_errorf(1, "include: %d", i);
505 			/*NOREACHED*/
506 		}
507 	}
508 	if (argv) {
509 		e->loc->argv = argv;
510 		e->loc->argc = argc;
511 	}
512 	s = pushs(SFILE, ATEMP);
513 	s->u.shf = shf;
514 	s->file = str_save(name, ATEMP);
515 	i = shell(s, FALSE);
516 	shf_close(s->u.shf);
517 	quitenv();
518 	if (old_argv) {
519 		e->loc->argv = old_argv;
520 		e->loc->argc = old_argc;
521 	}
522 	return i & 0xff;	/* & 0xff to ensure value not -1 */
523 }
524 
525 int
526 command(comm)
527 	const char *comm;
528 {
529 	register Source *s;
530 
531 	s = pushs(SSTRING, ATEMP);
532 	s->start = s->str = comm;
533 	return shell(s, FALSE);
534 }
535 
536 /*
537  * run the commands from the input source, returning status.
538  */
539 int
540 shell(s, toplevel)
541 	Source *volatile s;		/* input source */
542 	int volatile toplevel;
543 {
544 	struct op *t;
545 	volatile int wastty = s->flags & SF_TTY;
546 	volatile int attempts = 13;
547 	volatile int interactive = Flag(FTALKING) && toplevel;
548 	Source *volatile old_source = source;
549 	int i;
550 
551 	newenv(E_PARSE);
552 	if (interactive)
553 		really_exit = 0;
554 	i = ksh_sigsetjmp(e->jbuf, 0);
555 	if (i) {
556 		switch (i) {
557 		  case LINTR: /* we get here if SIGINT not caught or ignored */
558 		  case LERROR:
559 		  case LSHELL:
560 			if (interactive) {
561 				if (i == LINTR)
562 					shellf(newline);
563 				/* Reset any eof that was read as part of a
564 				 * multiline command.
565 				 */
566 				if (Flag(FIGNOREEOF) && s->type == SEOF
567 				    && wastty)
568 					s->type = SSTDIN;
569 				/* Used by exit command to get back to
570 				 * top level shell.  Kind of strange since
571 				 * interactive is set if we are reading from
572 				 * a tty, but to have stopped jobs, one only
573 				 * needs FMONITOR set (not FTALKING/SF_TTY)...
574 				 */
575 				/* toss any input we have so far */
576 				s->start = s->str = null;
577 				break;
578 			}
579 			/* fall through... */
580 		  case LEXIT:
581 		  case LLEAVE:
582 		  case LRETURN:
583 			source = old_source;
584 			quitenv();
585 			unwind(i);	/* keep on going */
586 			/*NOREACHED*/
587 		  default:
588 			source = old_source;
589 			quitenv();
590 			internal_errorf(1, "shell: %d", i);
591 			/*NOREACHED*/
592 		}
593 	}
594 
595 	while (1) {
596 		if (trap)
597 			runtraps(0);
598 
599 		if (s->next == NULL) {
600 			if (Flag(FVERBOSE))
601 				s->flags |= SF_ECHO;
602 			else
603 				s->flags &= ~SF_ECHO;
604 		}
605 
606 		if (interactive) {
607 			j_notify();
608 #ifdef KSH
609 			mcheck();
610 #endif /* KSH */
611 			set_prompt(PS1, s);
612 		}
613 
614 		t = compile(s);
615 		if (t != NULL && t->type == TEOF) {
616 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
617 				shellf("Use `exit' to leave ksh\n");
618 				s->type = SSTDIN;
619 			} else if (wastty && !really_exit
620 				   && j_stopped_running())
621 			{
622 				really_exit = 1;
623 				s->type = SSTDIN;
624 			} else {
625 				/* this for POSIX, which says EXIT traps
626 				 * shall be taken in the environment
627 				 * immediately after the last command
628 				 * executed.
629 				 */
630 				if (toplevel)
631 					unwind(LEXIT);
632 				break;
633 			}
634 		}
635 
636 		if (t && (!Flag(FNOEXEC) || (s->flags & SF_TTY)))
637 			exstat = execute(t, 0);
638 
639 		if (t != NULL && t->type != TEOF && interactive && really_exit)
640 			really_exit = 0;
641 
642 		reclaim();
643 	}
644 	quitenv();
645 	source = old_source;
646 	return exstat;
647 }
648 
649 /* return to closest error handler or shell(), exit if none found */
650 void
651 unwind(i)
652 	int i;
653 {
654 	/* ordering for EXIT vs ERR is a bit odd (this is what at&t ksh does) */
655 	if (i == LEXIT || (Flag(FERREXIT) && (i == LERROR || i == LINTR)
656 			   && sigtraps[SIGEXIT_].trap))
657 	{
658 		runtrap(&sigtraps[SIGEXIT_]);
659 		i = LLEAVE;
660 	} else if (Flag(FERREXIT) && (i == LERROR || i == LINTR)) {
661 		runtrap(&sigtraps[SIGERR_]);
662 		i = LLEAVE;
663 	}
664 	while (1) {
665 		switch (e->type) {
666 		  case E_PARSE:
667 		  case E_FUNC:
668 		  case E_INCL:
669 		  case E_LOOP:
670 		  case E_ERRH:
671 			ksh_siglongjmp(e->jbuf, i);
672 			/*NOTREACHED*/
673 
674 		  case E_NONE:
675 			if (i == LINTR)
676 				e->flags |= EF_FAKE_SIGDIE;
677 			/* Fall through... */
678 
679 		  default:
680 			quitenv();
681 		}
682 	}
683 }
684 
685 void
686 newenv(type)
687 	int type;
688 {
689 	register struct env *ep;
690 
691 	ep = (struct env *) alloc(sizeof(*ep), ATEMP);
692 	ep->type = type;
693 	ep->flags = 0;
694 	ainit(&ep->area);
695 	ep->loc = e->loc;
696 	ep->savefd = NULL;
697 	ep->oenv = e;
698 	ep->temps = NULL;
699 	e = ep;
700 }
701 
702 void
703 quitenv()
704 {
705 	register struct env *ep = e;
706 	register int fd;
707 
708 	if (ep->oenv && ep->oenv->loc != ep->loc)
709 		popblock();
710 	if (ep->savefd != NULL) {
711 		for (fd = 0; fd < NUFILE; fd++)
712 			/* if ep->savefd[fd] < 0, means fd was closed */
713 			if (ep->savefd[fd])
714 				restfd(fd, ep->savefd[fd]);
715 		if (ep->savefd[2]) /* Clear any write errors */
716 			shf_reopen(2, SHF_WR, shl_out);
717 	}
718 	reclaim();
719 
720 	/* Bottom of the stack.
721 	 * Either main shell is exiting or cleanup_parents_env() was called.
722 	 */
723 	if (ep->oenv == NULL) {
724 		if (ep->type == E_NONE) {	/* Main shell exiting? */
725 			if (Flag(FTALKING))
726 				hist_finish();
727 			j_exit();
728 			if (ep->flags & EF_FAKE_SIGDIE) {
729 				int sig = exstat - 128;
730 
731 				/* ham up our death a bit (at&t ksh
732 				 * only seems to do this for SIGTERM)
733 				 * Don't do it for SIGQUIT, since we'd
734 				 * dump a core..
735 				 */
736 				if (sig == SIGINT || sig == SIGTERM) {
737 					setsig(&sigtraps[sig], SIG_DFL,
738 						SS_RESTORE_CURR|SS_FORCE);
739 					kill(0, sig);
740 				}
741 			}
742 #ifdef MEM_DEBUG
743 			chmem_allfree();
744 #endif /* MEM_DEBUG */
745 		}
746 		exit(exstat);
747 	}
748 
749 	e = e->oenv;
750 	afree(ep, ATEMP);
751 }
752 
753 /* Called after a fork to cleanup stuff left over from parents environment */
754 void
755 cleanup_parents_env()
756 {
757 	struct env *ep;
758 	int fd;
759 
760 	/* Don't clean up temporary files - parent will probably need them.
761 	 * Also, can't easily reclaim memory since variables, etc. could be
762 	 * anywyere.
763 	 */
764 
765 	/* close all file descriptors hiding in savefd */
766 	for (ep = e; ep; ep = ep->oenv) {
767 		if (ep->savefd) {
768 			for (fd = 0; fd < NUFILE; fd++)
769 				if (ep->savefd[fd] > 0)
770 					close(ep->savefd[fd]);
771 			afree(ep->savefd, &ep->area);
772 			ep->savefd = (short *) 0;
773 		}
774 	}
775 	e->oenv = (struct env *) 0;
776 }
777 
778 /* Called just before an execve cleanup stuff temporary files */
779 void
780 cleanup_proc_env()
781 {
782 	struct env *ep;
783 
784 	for (ep = e; ep; ep = ep->oenv)
785 		remove_temps(ep->temps);
786 }
787 
788 /* remove temp files and free ATEMP Area */
789 static void
790 reclaim()
791 {
792 	remove_temps(e->temps);
793 	e->temps = NULL;
794 	afreeall(&e->area);
795 }
796 
797 static void
798 remove_temps(tp)
799 	struct temp *tp;
800 {
801 #ifdef OS2
802 	static struct temp *delayed_remove;
803 	struct temp *t, **tprev;
804 
805 	if (delayed_remove) {
806 		for (tprev = &delayed_remove, t = delayed_remove; t; t = *tprev)
807 			/* No need to check t->pid here... */
808 			if (unlink(t->name) >= 0 || errno == ENOENT) {
809 				*tprev = t->next;
810 				afree(t, APERM);
811 			} else
812 				tprev = &t->next;
813 	}
814 #endif /* OS2 */
815 
816 	for (; tp != NULL; tp = tp->next)
817 		if (tp->pid == procpid) {
818 #ifdef OS2
819 			/* OS/2 (and dos) do not allow files that are currently
820 			 * open to be removed, so we cache it away for future
821 			 * removal.
822 			 * XXX should only do this if errno
823 			 *     is Efile-still-open-can't-remove
824 			 *     (but I don't know what that is...)
825 			 */
826 			if (unlink(tp->name) < 0 && errno != ENOENT) {
827 				t = (struct temp *) alloc(
828 				    sizeof(struct temp) + strlen(tp->name) + 1,
829 				    APERM);
830 				memset(t, 0, sizeof(struct temp));
831 				t->name = (char *) &t[1];
832 				strcpy(t->name, tp->name);
833 				t->next = delayed_remove;
834 				delayed_remove = t;
835 			}
836 #else /* OS2 */
837 			unlink(tp->name);
838 #endif /* OS2 */
839 		}
840 }
841 
842 /* Returns true if name refers to a restricted shell */
843 static int
844 is_restricted(name)
845 	char *name;
846 {
847 	char *p;
848 
849 	if ((p = ksh_strrchr_dirsep(name)))
850 		name = p;
851 	/* accepts rsh, rksh, rpdksh, pdrksh, etc. */
852 	return (p = strchr(name, 'r')) && strstr(p, "sh");
853 }
854 
855 void
856 aerror(ap, msg)
857 	Area *ap;
858 	const char *msg;
859 {
860 	internal_errorf(1, "alloc: %s", msg);
861 	errorf(null); /* this is never executed - keeps gcc quiet */
862 	/*NOTREACHED*/
863 }
864