xref: /openbsd-src/bin/ksh/main.c (revision fc405d53b73a2d73393cb97f684863d17b583e38)
1 /*	$OpenBSD: main.c,v 1.99 2023/02/08 17:22:10 kn Exp $	*/
2 
3 /*
4  * startup, main loop, environments and error handling
5  */
6 
7 #include <sys/stat.h>
8 
9 #include <errno.h>
10 #include <fcntl.h>
11 #include <paths.h>
12 #include <pwd.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <unistd.h>
17 
18 #include "sh.h"
19 
20 extern char **environ;
21 
22 /*
23  * global data
24  */
25 
26 static void	reclaim(void);
27 static void	remove_temps(struct temp *tp);
28 static int	is_restricted(char *name);
29 static void	init_username(void);
30 
31 const char *kshname;
32 pid_t	kshpid;
33 pid_t	procpid;
34 uid_t	ksheuid;
35 int	exstat;
36 int	subst_exstat;
37 const char *safe_prompt;
38 int	disable_subst;
39 
40 Area	aperm;
41 
42 struct env	*genv;
43 
44 char	shell_flags[FNFLAGS];
45 
46 char	null[] = "";
47 
48 int shl_stdout_ok;
49 
50 unsigned int	ksh_tmout;
51 enum tmout_enum	ksh_tmout_state = TMOUT_EXECUTING;
52 
53 int	really_exit;
54 
55 int ifs0 = ' ';
56 
57 volatile sig_atomic_t	trap;
58 volatile sig_atomic_t	intrsig;
59 volatile sig_atomic_t	fatal_trap;
60 
61 Getopt	builtin_opt;
62 Getopt	user_opt;
63 
64 struct coproc	coproc;
65 sigset_t	sm_default, sm_sigchld;
66 
67 char	*builtin_argv0;
68 int	 builtin_flag;
69 
70 char	*current_wd;
71 int	 current_wd_size;
72 
73 int	x_cols = 80;
74 
75 /*
76  * shell initialization
77  */
78 
79 static const char initifs[] = "IFS= \t\n";
80 
81 static const char initsubs[] = "${PS2=> } ${PS3=#? } ${PS4=+ }";
82 
83 static const char *initcoms [] = {
84 #ifndef SMALL
85 	"typeset", "-r", "KSH_VERSION", NULL,
86 #endif /* SMALL */
87 	"typeset", "-x", "SHELL", "PATH", "HOME", "PWD", "OLDPWD", NULL,
88 	"typeset", "-ir", "PPID", NULL,
89 	"typeset", "-i", "OPTIND=1", NULL,
90 	"eval", "typeset -i RANDOM MAILCHECK=\"${MAILCHECK-600}\" SECONDS=\"${SECONDS-0}\" TMOUT=\"${TMOUT-0}\"", NULL,
91 	"alias",
92 	 /* Standard ksh aliases */
93 	  "hash=alias -t",	/* not "alias -t --": hash -r needs to work */
94 	  "stop=kill -STOP",
95 	  "autoload=typeset -fu",
96 	  "functions=typeset -f",
97 	  "history=fc -l",
98 	  "integer=typeset -i",
99 	  "nohup=nohup ",
100 	  "local=typeset",
101 	  "r=fc -s",
102 	 /* Aliases that are builtin commands in at&t */
103 	  "login=exec login",
104 	  NULL,
105 	/* this is what at&t ksh seems to track, with the addition of emacs */
106 	"alias", "-tU",
107 	  "cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
108 	  "mail", "make", "mv", "pr", "rm", "sed", "sh", "vi", "who",
109 	  NULL,
110 	NULL
111 };
112 
113 char username[_PW_NAME_LEN + 1];
114 
115 #ifndef SMALL
116 #define version_param  (initcoms[2])
117 #endif /* SMALL */
118 
119 /* The shell uses its own variation on argv, to build variables like
120  * $0 and $@.
121  * Allocate a new array since modifying the original argv will modify
122  * ps output.
123  */
124 static char **
125 make_argv(int argc, char *argv[])
126 {
127 	int i;
128 	char **nargv;
129 
130 	nargv = areallocarray(NULL, argc + 1, sizeof(char *), &aperm);
131 	nargv[0] = (char *) kshname;
132 	for (i = 1; i < argc; i++)
133 		nargv[i] = argv[i];
134 	nargv[i] = NULL;
135 
136 	return nargv;
137 }
138 
139 int
140 main(int argc, char *argv[])
141 {
142 	int i;
143 	int argi;
144 	Source *s;
145 	struct block *l;
146 	int restricted, errexit;
147 	char **wp;
148 	struct env env;
149 	pid_t ppid;
150 
151 	kshname = argv[0];
152 
153 	if (issetugid()) { /* could later drop privileges */
154 		if (pledge("stdio rpath wpath cpath fattr flock getpw proc "
155 		    "exec tty id", NULL) == -1) {
156 			perror("pledge");
157 			exit(1);
158 		}
159 	} else {
160 		if (pledge("stdio rpath wpath cpath fattr flock getpw proc "
161 		    "exec tty", NULL) == -1) {
162 			perror("pledge");
163 			exit(1);
164 		}
165 	}
166 
167 	ainit(&aperm);		/* initialize permanent Area */
168 
169 	/* set up base environment */
170 	memset(&env, 0, sizeof(env));
171 	env.type = E_NONE;
172 	ainit(&env.area);
173 	genv = &env;
174 	newblock();		/* set up global l->vars and l->funs */
175 
176 	/* Do this first so output routines (eg, errorf, shellf) can work */
177 	initio();
178 
179 	initvar();
180 
181 	initctypes();
182 
183 	inittraps();
184 
185 	coproc_init();
186 
187 	/* set up variable and command dictionaries */
188 	ktinit(&taliases, APERM, 0);
189 	ktinit(&aliases, APERM, 0);
190 	ktinit(&homedirs, APERM, 0);
191 
192 	/* define shell keywords */
193 	initkeywords();
194 
195 	/* define built-in commands */
196 	ktinit(&builtins, APERM, 64); /* must be 2^n (currently 40 builtins) */
197 	for (i = 0; shbuiltins[i].name != NULL; i++)
198 		builtin(shbuiltins[i].name, shbuiltins[i].func);
199 	for (i = 0; kshbuiltins[i].name != NULL; i++)
200 		builtin(kshbuiltins[i].name, kshbuiltins[i].func);
201 
202 	init_histvec();
203 
204 	def_path = _PATH_DEFPATH;
205 	{
206 		size_t len = confstr(_CS_PATH, NULL, 0);
207 		char *new;
208 
209 		if (len > 0) {
210 			confstr(_CS_PATH, new = alloc(len + 1, APERM), len + 1);
211 			def_path = new;
212 		}
213 	}
214 
215 	/* Set PATH to def_path (will set the path global variable).
216 	 * (import of environment below will probably change this setting).
217 	 */
218 	{
219 		struct tbl *vp = global("PATH");
220 		/* setstr can't fail here */
221 		setstr(vp, def_path, KSH_RETURN_ERROR);
222 	}
223 
224 
225 	/* Turn on nohup by default for now - will change to off
226 	 * by default once people are aware of its existence
227 	 * (at&t ksh does not have a nohup option - it always sends
228 	 * the hup).
229 	 */
230 	Flag(FNOHUP) = 1;
231 
232 	/* Turn on brace expansion by default.  At&t ksh's that have
233 	 * alternation always have it on.  BUT, posix doesn't have
234 	 * brace expansion, so set this before setting up FPOSIX
235 	 * (change_flag() clears FBRACEEXPAND when FPOSIX is set).
236 	 */
237 	Flag(FBRACEEXPAND) = 1;
238 
239 	/* set posix flag just before environment so that it will have
240 	 * exactly the same effect as the POSIXLY_CORRECT environment
241 	 * variable.  If this needs to be done sooner to ensure correct posix
242 	 * operation, an initial scan of the environment will also have
243 	 * done sooner.
244 	 */
245 #ifdef POSIXLY_CORRECT
246 	change_flag(FPOSIX, OF_SPECIAL, 1);
247 #endif /* POSIXLY_CORRECT */
248 
249 	/* Check to see if we're /bin/sh. */
250 	if (!strcmp(kshname, "sh") || !strcmp(kshname, "-sh") ||
251 	    (strlen(kshname) >= 3 &&
252 	    !strcmp(&kshname[strlen(kshname) - 3], "/sh"))) {
253 		Flag(FSH) = 1;
254 #ifndef SMALL
255 		version_param = "SH_VERSION";
256 #endif /* SMALL */
257 	}
258 
259 	/* Set edit mode to emacs by default, may be overridden
260 	 * by the environment or the user.  Also, we want tab completion
261 	 * on in vi by default. */
262 #if defined(EMACS)
263 	change_flag(FEMACS, OF_SPECIAL, 1);
264 #endif /* EMACS */
265 #if defined(VI)
266 	Flag(FVITABCOMPLETE) = 1;
267 #endif /* VI */
268 
269 	/* import environment */
270 	if (environ != NULL)
271 		for (wp = environ; *wp != NULL; wp++)
272 			typeset(*wp, IMPORT|EXPORT, 0, 0, 0);
273 
274 	kshpid = procpid = getpid();
275 	typeset(initifs, 0, 0, 0, 0);	/* for security */
276 
277 	/* assign default shell variable values */
278 	substitute(initsubs, 0);
279 
280 	/* Figure out the current working directory and set $PWD */
281 	{
282 		struct stat s_pwd, s_dot;
283 		struct tbl *pwd_v = global("PWD");
284 		char *pwd = str_val(pwd_v);
285 		char *pwdx = pwd;
286 
287 		/* Try to use existing $PWD if it is valid */
288 		if (pwd[0] != '/' ||
289 		    stat(pwd, &s_pwd) == -1 || stat(".", &s_dot) == -1 ||
290 		    s_pwd.st_dev != s_dot.st_dev ||
291 		    s_pwd.st_ino != s_dot.st_ino)
292 			pwdx = NULL;
293 		set_current_wd(pwdx);
294 		if (current_wd[0])
295 			simplify_path(current_wd);
296 		/* Only set pwd if we know where we are or if it had a
297 		 * bogus value
298 		 */
299 		if (current_wd[0] || pwd != null)
300 			/* setstr can't fail here */
301 			setstr(pwd_v, current_wd, KSH_RETURN_ERROR);
302 	}
303 	ppid = getppid();
304 	setint(global("PPID"), (int64_t) ppid);
305 #ifndef SMALL
306 	/* setstr can't fail here */
307 	setstr(global(version_param), ksh_version, KSH_RETURN_ERROR);
308 #endif /* SMALL */
309 
310 	/* execute initialization statements */
311 	for (wp = (char**) initcoms; *wp != NULL; wp++) {
312 		shcomexec(wp);
313 		for (; *wp != NULL; wp++)
314 			;
315 	}
316 
317 
318 	ksheuid = geteuid();
319 	init_username();
320 	safe_prompt = ksheuid ? "$ " : "# ";
321 	{
322 		struct tbl *vp = global("PS1");
323 
324 		/* Set PS1 if it isn't set */
325 		if (!(vp->flag & ISSET)) {
326 			/* setstr can't fail here */
327 			setstr(vp, "\\h\\$ ", KSH_RETURN_ERROR);
328 		}
329 	}
330 
331 	/* Set this before parsing arguments */
332 	Flag(FPRIVILEGED) = getuid() != ksheuid || getgid() != getegid();
333 
334 	/* this to note if monitor is set on command line (see below) */
335 	Flag(FMONITOR) = 127;
336 	argi = parse_args(argv, OF_CMDLINE, NULL);
337 	if (argi < 0)
338 		exit(1);
339 
340 	if (Flag(FCOMMAND)) {
341 		s = pushs(SSTRING, ATEMP);
342 		if (!(s->start = s->str = argv[argi++]))
343 			errorf("-c requires an argument");
344 		if (argv[argi])
345 			kshname = argv[argi++];
346 	} else if (argi < argc && !Flag(FSTDIN)) {
347 		s = pushs(SFILE, ATEMP);
348 		s->file = argv[argi++];
349 		s->u.shf = shf_open(s->file, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
350 		if (s->u.shf == NULL) {
351 			exstat = 127; /* POSIX */
352 			errorf("%s: %s", s->file, strerror(errno));
353 		}
354 		kshname = s->file;
355 	} else {
356 		Flag(FSTDIN) = 1;
357 		s = pushs(SSTDIN, ATEMP);
358 		s->file = "<stdin>";
359 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0), NULL);
360 		if (isatty(0) && isatty(2)) {
361 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
362 			/* The following only if isatty(0) */
363 			s->flags |= SF_TTY;
364 			s->u.shf->flags |= SHF_INTERRUPT;
365 			s->file = NULL;
366 		}
367 	}
368 
369 	/* This bizarreness is mandated by POSIX */
370 	{
371 		struct stat s_stdin;
372 
373 		if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
374 		    Flag(FTALKING))
375 			reset_nonblock(0);
376 	}
377 
378 	/* initialize job control */
379 	i = Flag(FMONITOR) != 127;
380 	Flag(FMONITOR) = 0;
381 	j_init(i);
382 	/* Do this after j_init(), as tty_fd is not initialized 'til then */
383 	if (Flag(FTALKING))
384 		x_init();
385 
386 	l = genv->loc;
387 	l->argv = make_argv(argc - (argi - 1), &argv[argi - 1]);
388 	l->argc = argc - argi;
389 	getopts_reset(1);
390 
391 	/* Disable during .profile/ENV reading */
392 	restricted = Flag(FRESTRICTED);
393 	Flag(FRESTRICTED) = 0;
394 	errexit = Flag(FERREXIT);
395 	Flag(FERREXIT) = 0;
396 
397 	/* Do this before profile/$ENV so that if it causes problems in them,
398 	 * user will know why things broke.
399 	 */
400 	if (!current_wd[0] && Flag(FTALKING))
401 		warningf(false, "Cannot determine current working directory");
402 
403 	if (Flag(FLOGIN)) {
404 		include(KSH_SYSTEM_PROFILE, 0, NULL, 1);
405 		if (!Flag(FPRIVILEGED))
406 			include(substitute("$HOME/.profile", 0), 0, NULL, 1);
407 	}
408 
409 	if (Flag(FPRIVILEGED))
410 		include("/etc/suid_profile", 0, NULL, 1);
411 	else if (Flag(FTALKING)) {
412 		char *env_file;
413 
414 		/* include $ENV */
415 		env_file = str_val(global("ENV"));
416 
417 #ifdef DEFAULT_ENV
418 		/* If env isn't set, include default environment */
419 		if (env_file == null)
420 			env_file = DEFAULT_ENV;
421 #endif /* DEFAULT_ENV */
422 		env_file = substitute(env_file, DOTILDE);
423 		if (*env_file != '\0')
424 			include(env_file, 0, NULL, 1);
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 			NULL
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 		alarm_init();
445 	} else
446 		Flag(FTRACKALL) = 1;	/* set after ENV */
447 
448 	shell(s, true);	/* doesn't return */
449 	return 0;
450 }
451 
452 static void
453 init_username(void)
454 {
455 	char *p;
456 	struct tbl *vp = global("USER");
457 
458 	if (vp->flag & ISSET)
459 		p = ksheuid == 0 ? "root" : str_val(vp);
460 	else
461 		p = getlogin();
462 
463 	strlcpy(username, p != NULL ? p : "?", sizeof username);
464 }
465 
466 int
467 include(const char *name, int argc, char **argv, int intr_ok)
468 {
469 	Source *volatile s = NULL;
470 	struct shf *shf;
471 	char **volatile old_argv;
472 	volatile int old_argc;
473 	int i;
474 
475 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
476 	if (shf == NULL)
477 		return -1;
478 
479 	if (argv) {
480 		old_argv = genv->loc->argv;
481 		old_argc = genv->loc->argc;
482 	} else {
483 		old_argv = NULL;
484 		old_argc = 0;
485 	}
486 	newenv(E_INCL);
487 	i = sigsetjmp(genv->jbuf, 0);
488 	if (i) {
489 		quitenv(s ? s->u.shf : NULL);
490 		if (old_argv) {
491 			genv->loc->argv = old_argv;
492 			genv->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 			/* FALLTHROUGH */
505 		case LEXIT:
506 		case LLEAVE:
507 		case LSHELL:
508 			unwind(i);
509 			/* NOTREACHED */
510 		default:
511 			internal_errorf("%s: %d", __func__, i);
512 			/* NOTREACHED */
513 		}
514 	}
515 	if (argv) {
516 		genv->loc->argv = argv;
517 		genv->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 	quitenv(s->u.shf);
524 	if (old_argv) {
525 		genv->loc->argv = old_argv;
526 		genv->loc->argc = old_argc;
527 	}
528 	return i & 0xff;	/* & 0xff to ensure value not -1 */
529 }
530 
531 /*
532  * spawn a command into a shell optionally keeping track of line
533  * number.
534  */
535 int
536 command(const char *comm, int line)
537 {
538 	Source *s;
539 
540 	s = pushs(SSTRING, ATEMP);
541 	s->start = s->str = comm;
542 	s->line = line;
543 	return shell(s, false);
544 }
545 
546 /*
547  * run the commands from the input source, returning status.
548  */
549 int
550 shell(Source *volatile s, volatile int 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 	Source *volatile old_source = source;
557 	int i;
558 
559 	newenv(E_PARSE);
560 	if (interactive)
561 		really_exit = 0;
562 	i = sigsetjmp(genv->jbuf, 0);
563 	if (i) {
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 				c_fc_reset();
570 				if (i == LINTR)
571 					shellf("\n");
572 				/* Reset any eof that was read as part of a
573 				 * multiline command.
574 				 */
575 				if (Flag(FIGNOREEOF) && s->type == SEOF &&
576 				    wastty)
577 					s->type = SSTDIN;
578 				/* Used by exit command to get back to
579 				 * top level shell.  Kind of strange since
580 				 * interactive is set if we are reading from
581 				 * a tty, but to have stopped jobs, one only
582 				 * needs FMONITOR set (not FTALKING/SF_TTY)...
583 				 */
584 				/* toss any input we have so far */
585 				s->start = s->str = null;
586 				break;
587 			}
588 			/* FALLTHROUGH */
589 		case LEXIT:
590 		case LLEAVE:
591 		case LRETURN:
592 			source = old_source;
593 			quitenv(NULL);
594 			unwind(i);	/* keep on going */
595 			/* NOTREACHED */
596 		default:
597 			source = old_source;
598 			quitenv(NULL);
599 			internal_errorf("%s: %d", __func__, i);
600 			/* NOTREACHED */
601 		}
602 	}
603 
604 	while (1) {
605 		if (trap)
606 			runtraps(0);
607 
608 		if (s->next == NULL) {
609 			if (Flag(FVERBOSE))
610 				s->flags |= SF_ECHO;
611 			else
612 				s->flags &= ~SF_ECHO;
613 		}
614 
615 		if (interactive) {
616 			got_sigwinch = 1;
617 			j_notify();
618 			mcheck();
619 			set_prompt(PS1);
620 		}
621 
622 		t = compile(s);
623 		if (t != NULL && t->type == TEOF) {
624 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
625 				shellf("Use `exit' to leave ksh\n");
626 				s->type = SSTDIN;
627 			} else if (wastty && !really_exit &&
628 			    j_stopped_running()) {
629 				really_exit = 1;
630 				s->type = SSTDIN;
631 			} else {
632 				/* this for POSIX, which says EXIT traps
633 				 * shall be taken in the environment
634 				 * immediately after the last command
635 				 * executed.
636 				 */
637 				if (toplevel)
638 					unwind(LEXIT);
639 				break;
640 			}
641 		}
642 
643 		if (t && (!Flag(FNOEXEC) || (s->flags & SF_TTY)))
644 			exstat = execute(t, 0, NULL);
645 
646 		if (t != NULL && t->type != TEOF && interactive && really_exit)
647 			really_exit = 0;
648 
649 		reclaim();
650 	}
651 	quitenv(NULL);
652 	source = old_source;
653 	return exstat;
654 }
655 
656 /* return to closest error handler or shell(), exit if none found */
657 void
658 unwind(int i)
659 {
660 	/* ordering for EXIT vs ERR is a bit odd (this is what at&t ksh does) */
661 	if (i == LEXIT || (Flag(FERREXIT) && (i == LERROR || i == LINTR) &&
662 	    sigtraps[SIGEXIT_].trap)) {
663 		if (trap)
664 			runtraps(0);
665 		runtrap(&sigtraps[SIGEXIT_]);
666 		i = LLEAVE;
667 	} else if (Flag(FERREXIT) && (i == LERROR || i == LINTR)) {
668 		if (trap)
669 			runtraps(0);
670 		runtrap(&sigtraps[SIGERR_]);
671 		i = LLEAVE;
672 	}
673 	while (1) {
674 		switch (genv->type) {
675 		case E_PARSE:
676 		case E_FUNC:
677 		case E_INCL:
678 		case E_LOOP:
679 		case E_ERRH:
680 			siglongjmp(genv->jbuf, i);
681 			/* NOTREACHED */
682 
683 		case E_NONE:
684 			if (i == LINTR)
685 				genv->flags |= EF_FAKE_SIGDIE;
686 			/* FALLTHROUGH */
687 
688 		default:
689 			quitenv(NULL);
690 			/*
691 			 * quitenv() may have reclaimed the memory
692 			 * used by source which will end badly when
693 			 * we jump to a function that expects it to
694 			 * be valid
695 			 */
696 			source = NULL;
697 		}
698 	}
699 }
700 
701 void
702 newenv(int type)
703 {
704 	struct env *ep;
705 
706 	ep = alloc(sizeof(*ep), ATEMP);
707 	ep->type = type;
708 	ep->flags = 0;
709 	ainit(&ep->area);
710 	ep->loc = genv->loc;
711 	ep->savefd = NULL;
712 	ep->oenv = genv;
713 	ep->temps = NULL;
714 	genv = ep;
715 }
716 
717 void
718 quitenv(struct shf *shf)
719 {
720 	struct env *ep = genv;
721 	int fd;
722 
723 	if (ep->oenv && ep->oenv->loc != ep->loc)
724 		popblock();
725 	if (ep->savefd != NULL) {
726 		for (fd = 0; fd < NUFILE; fd++)
727 			/* if ep->savefd[fd] < 0, means fd was closed */
728 			if (ep->savefd[fd])
729 				restfd(fd, ep->savefd[fd]);
730 		if (ep->savefd[2]) /* Clear any write errors */
731 			shf_reopen(2, SHF_WR, shl_out);
732 	}
733 
734 	/* Bottom of the stack.
735 	 * Either main shell is exiting or cleanup_parents_env() was called.
736 	 */
737 	if (ep->oenv == NULL) {
738 		if (ep->type == E_NONE) {	/* Main shell exiting? */
739 			if (Flag(FTALKING))
740 				hist_finish();
741 			j_exit();
742 			if (ep->flags & EF_FAKE_SIGDIE) {
743 				int sig = exstat - 128;
744 
745 				/* ham up our death a bit (at&t ksh
746 				 * only seems to do this for SIGTERM)
747 				 * Don't do it for SIGQUIT, since we'd
748 				 * dump a core..
749 				 */
750 				if ((sig == SIGINT || sig == SIGTERM) &&
751 				    getpgrp() == kshpid) {
752 					setsig(&sigtraps[sig], SIG_DFL,
753 					    SS_RESTORE_CURR|SS_FORCE);
754 					kill(0, sig);
755 				}
756 			}
757 		}
758 		if (shf)
759 			shf_close(shf);
760 		reclaim();
761 		exit(exstat);
762 	}
763 	if (shf)
764 		shf_close(shf);
765 	reclaim();
766 
767 	genv = genv->oenv;
768 	afree(ep, ATEMP);
769 }
770 
771 /* Called after a fork to cleanup stuff left over from parents environment */
772 void
773 cleanup_parents_env(void)
774 {
775 	struct env *ep;
776 	int fd;
777 
778 	/* Don't clean up temporary files - parent will probably need them.
779 	 * Also, can't easily reclaim memory since variables, etc. could be
780 	 * anywhere.
781 	 */
782 
783 	/* close all file descriptors hiding in savefd */
784 	for (ep = genv; ep; ep = ep->oenv) {
785 		if (ep->savefd) {
786 			for (fd = 0; fd < NUFILE; fd++)
787 				if (ep->savefd[fd] > 0)
788 					close(ep->savefd[fd]);
789 			afree(ep->savefd, &ep->area);
790 			ep->savefd = NULL;
791 		}
792 	}
793 	genv->oenv = NULL;
794 }
795 
796 /* Called just before an execve cleanup stuff temporary files */
797 void
798 cleanup_proc_env(void)
799 {
800 	struct env *ep;
801 
802 	for (ep = genv; ep; ep = ep->oenv)
803 		remove_temps(ep->temps);
804 }
805 
806 /* remove temp files and free ATEMP Area */
807 static void
808 reclaim(void)
809 {
810 	remove_temps(genv->temps);
811 	genv->temps = NULL;
812 	afreeall(&genv->area);
813 }
814 
815 static void
816 remove_temps(struct temp *tp)
817 {
818 
819 	for (; tp != NULL; tp = tp->next)
820 		if (tp->pid == procpid) {
821 			unlink(tp->name);
822 		}
823 }
824 
825 /* Returns true if name refers to a restricted shell */
826 static int
827 is_restricted(char *name)
828 {
829 	char *p;
830 
831 	if ((p = strrchr(name, '/')))
832 		name = p + 1;
833 	/* accepts rsh, rksh, rpdksh, pdrksh */
834 	if (strcmp(name, "rsh") && \
835 		strcmp(name, "rksh") && \
836 		strcmp(name, "rpdksh") && \
837 		strcmp(name, "pdrksh"))
838 		return(0);
839 	else
840 		return(1);
841 
842 }
843