xref: /netbsd/bin/ksh/main.c (revision bf9ec67e)
1 /*	$NetBSD: main.c,v 1.6 1999/10/20 15:09:59 hubertf Exp $	*/
2 
3 /*
4  * startup, main loop, enviroments 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 	  "newgrp=exec newgrp",
70 #endif /* KSH */
71 	  NULL,
72 	/* this is what at&t ksh seems to track, with the addition of emacs */
73 	"alias", "-tU",
74 	  "cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
75 	  "mail", "make", "mv", "pr", "rm", "sed", "sh", "vi", "who",
76 	  NULL,
77 #ifdef EXTRA_INITCOMS
78 	EXTRA_INITCOMS, NULL,
79 #endif /* EXTRA_INITCOMS */
80 	NULL
81 };
82 
83 int main __P((int, char **));
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 enviroment */
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 	/* import enviroment */
209 	if (environ != NULL)
210 		for (wp = environ; *wp != NULL; wp++)
211 			typeset(*wp, IMPORT|EXPORT, 0, 0, 0);
212 
213 	kshpid = procpid = getpid();
214 	typeset(initifs, 0, 0, 0, 0);	/* for security */
215 
216 	/* assign default shell variable values */
217 	substitute(initsubs, 0);
218 
219 	/* Figure out the current working directory and set $PWD */
220 	{
221 		struct stat s_pwd, s_dot;
222 		struct tbl *pwd_v = global("PWD");
223 		char *pwd = str_val(pwd_v);
224 		char *pwdx = pwd;
225 
226 		/* Try to use existing $PWD if it is valid */
227 		if (!ISABSPATH(pwd)
228 		    || stat(pwd, &s_pwd) < 0 || stat(".", &s_dot) < 0
229 		    || s_pwd.st_dev != s_dot.st_dev
230 		    || s_pwd.st_ino != s_dot.st_ino)
231 			pwdx = (char *) 0;
232 		set_current_wd(pwdx);
233 		if (current_wd[0])
234 			simplify_path(current_wd);
235 		/* Only set pwd if we know where we are or if it had a
236 		 * bogus value
237 		 */
238 		if (current_wd[0] || pwd != null)
239 			/* setstr can't fail here */
240 			setstr(pwd_v, current_wd, KSH_RETURN_ERROR);
241 	}
242 	ppid = getppid();
243 	setint(global("PPID"), (long) ppid);
244 #ifdef KSH
245 	setint(global("RANDOM"), (long) (time((time_t *)0) * kshpid * ppid));
246 #endif /* KSH */
247 	/* setstr can't fail here */
248 	setstr(global(version_param), ksh_version, KSH_RETURN_ERROR);
249 
250 	/* execute initialization statements */
251 	for (wp = (char**) initcoms; *wp != NULL; wp++) {
252 		shcomexec(wp);
253 		for (; *wp != NULL; wp++)
254 			;
255 	}
256 
257 
258 	ksheuid = geteuid();
259 	safe_prompt = ksheuid ? "$ " : "# ";
260 	{
261 		struct tbl *vp = global("PS1");
262 
263 		/* Set PS1 if it isn't set, or we are root and prompt doesn't
264 		 * contain a #.
265 		 */
266 		if (!(vp->flag & ISSET)
267 		    || (!ksheuid && !strchr(str_val(vp), '#')))
268 			/* setstr can't fail here */
269 			setstr(vp, safe_prompt, KSH_RETURN_ERROR);
270 	}
271 
272 	/* Set this before parsing arguments */
273 	Flag(FPRIVILEGED) = getuid() != ksheuid || getgid() != getegid();
274 
275 	/* this to note if monitor is set on command line (see below) */
276 	Flag(FMONITOR) = 127;
277 	argi = parse_args(argv, OF_CMDLINE, (int *) 0);
278 	if (argi < 0) {
279 		exit(1);
280 		/* NOTREACHED */
281 	}
282 
283 	if (Flag(FCOMMAND)) {
284 		s = pushs(SSTRING, ATEMP);
285 		if (!(s->start = s->str = argv[argi++]))
286 			errorf("-c requires an argument");
287 		if (argv[argi])
288 			kshname = argv[argi++];
289 	} else if (argi < argc && !Flag(FSTDIN)) {
290 		s = pushs(SFILE, ATEMP);
291 #ifdef OS2
292 		/* a bug in os2 extproc shell processing doesn't
293 		 * pass full pathnames so we have to search for it.
294 		 * This changes the behavior of 'ksh arg' to search
295 		 * the users search path but it can't be helped.
296 		 */
297 		s->file = search(argv[argi++], path, R_OK, (int *) 0);
298 		if (!s->file || !*s->file)
299 		        s->file = argv[argi - 1];
300 #else
301 		s->file = argv[argi++];
302 #endif /* OS2 */
303 		s->u.shf = shf_open(s->file, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
304 		if (s->u.shf == NULL) {
305 			exstat = 127; /* POSIX */
306 			errorf("%s: %s", s->file, strerror(errno));
307 		}
308 		kshname = s->file;
309 	} else {
310 		Flag(FSTDIN) = 1;
311 		s = pushs(SSTDIN, ATEMP);
312 		s->file = "<stdin>";
313 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
314 				      (struct shf *) 0);
315 		if (isatty(0) && isatty(2)) {
316 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
317 			/* The following only if isatty(0) */
318 			s->flags |= SF_TTY;
319 			s->u.shf->flags |= SHF_INTERRUPT;
320 			s->file = (char *) 0;
321 		}
322 	}
323 
324 	/* This bizarreness is mandated by POSIX */
325 	{
326 		struct stat s_stdin;
327 
328 		if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode))
329 			reset_nonblock(0);
330 	}
331 
332 	/* initialize job control */
333 	i = Flag(FMONITOR) != 127;
334 	Flag(FMONITOR) = 0;
335 	j_init(i);
336 #ifdef EDIT
337 	/* Do this after j_init(), as tty_fd is not initialized 'til then */
338 	if (Flag(FTALKING))
339 		x_init();
340 #endif
341 
342 	l = e->loc;
343 	l->argv = &argv[argi - 1];
344 	l->argc = argc - argi;
345 	l->argv[0] = (char *) kshname;
346 	getopts_reset(1);
347 
348 	/* Disable during .profile/ENV reading */
349 	restricted = Flag(FRESTRICTED);
350 	Flag(FRESTRICTED) = 0;
351 	errexit = Flag(FERREXIT);
352 	Flag(FERREXIT) = 0;
353 
354 	/* Do this before profile/$ENV so that if it causes problems in them,
355 	 * user will know why things broke.
356 	 */
357 	if (!current_wd[0] && Flag(FTALKING))
358 		warningf(FALSE, "Cannot determine current working directory");
359 
360 	if (Flag(FLOGIN)) {
361 #ifdef OS2
362 		char *profile;
363 
364 		/* Try to find a profile - first see if $INIT has a value,
365 		 * then try /etc/profile.ksh, then c:/usr/etc/profile.ksh.
366 		 */
367 		if (!Flag(FPRIVILEGED)
368 		    && strcmp(profile = substitute("$INIT/profile.ksh", 0),
369 			      "/profile.ksh"))
370 			include(profile, 0, (char **) 0, 1);
371 		else if (include("/etc/profile.ksh", 0, (char **) 0, 1) < 0)
372 			include("c:/usr/etc/profile.ksh", 0, (char **) 0, 1);
373 		if (!Flag(FPRIVILEGED))
374 			include(substitute("$HOME/profile.ksh", 0), 0,
375 				(char **) 0, 1);
376 #else /* OS2 */
377 		include(KSH_SYSTEM_PROFILE, 0, (char **) 0, 1);
378 		if (!Flag(FPRIVILEGED))
379 			include(substitute("$HOME/.profile", 0), 0,
380 				(char **) 0, 1);
381 #endif /* OS2 */
382 	}
383 
384 	if (Flag(FPRIVILEGED))
385 		include("/etc/suid_profile", 0, (char **) 0, 1);
386 	else {
387 		char *env_file;
388 
389 #ifndef KSH
390 		if (!Flag(FPOSIX))
391 			env_file = null;
392 		else
393 #endif /* !KSH */
394 			/* include $ENV */
395 			env_file = str_val(global("ENV"));
396 
397 #ifdef DEFAULT_ENV
398 		/* If env isn't set, include default environment */
399 		if (env_file == null)
400 			env_file = DEFAULT_ENV;
401 #endif /* DEFAULT_ENV */
402 		env_file = substitute(env_file, DOTILDE);
403 		if (*env_file != '\0')
404 			include(env_file, 0, (char **) 0, 1);
405 #ifdef OS2
406 		else if (Flag(FTALKING))
407 			include(substitute("$HOME/kshrc.ksh", 0), 0,
408 				(char **) 0, 1);
409 #endif /* OS2 */
410 	}
411 
412 	if (is_restricted(argv[0]) || is_restricted(str_val(global("SHELL"))))
413 		restricted = 1;
414 	if (restricted) {
415 		static const char *const restr_com[] = {
416 						"typeset", "-r", "PATH",
417 						    "ENV", "SHELL",
418 						(char *) 0
419 					    };
420 		shcomexec((char **) restr_com);
421 		/* After typeset command... */
422 		Flag(FRESTRICTED) = 1;
423 	}
424 	if (errexit)
425 		Flag(FERREXIT) = 1;
426 
427 	if (Flag(FTALKING)) {
428 		hist_init(s);
429 #ifdef KSH
430 		alarm_init();
431 #endif /* KSH */
432 	} else
433 		Flag(FTRACKALL) = 1;	/* set after ENV */
434 
435 	shell(s, TRUE);	/* doesn't return */
436 	return 0;
437 }
438 
439 int
440 include(name, argc, argv, intr_ok)
441 	const char *name;
442 	int argc;
443 	char **argv;
444 	int intr_ok;
445 {
446 	register Source *volatile s = NULL;
447 	Source *volatile sold;
448 	struct shf *shf;
449 	char **volatile old_argv;
450 	volatile int old_argc;
451 	int i;
452 
453 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
454 	if (shf == NULL)
455 		return -1;
456 
457 	if (argv) {
458 		old_argv = e->loc->argv;
459 		old_argc = e->loc->argc;
460 	} else {
461 		old_argv = (char **) 0;
462 		old_argc = 0;
463 	}
464 	sold = source;
465 	newenv(E_INCL);
466 	i = ksh_sigsetjmp(e->jbuf, 0);
467 	if (i) {
468 		source = sold;
469 		if (s) /* Do this before quitenv(), which frees the memory */
470 			shf_close(s->u.shf);
471 		quitenv();
472 		if (old_argv) {
473 			e->loc->argv = old_argv;
474 			e->loc->argc = old_argc;
475 		}
476 		switch (i) {
477 		  case LRETURN:
478 		  case LERROR:
479 			return exstat & 0xff; /* see below */
480 		  case LINTR:
481 			/* intr_ok is set if we are including .profile or $ENV.
482 			 * If user ^C's out, we don't want to kill the shell...
483 			 */
484 			if (intr_ok && (exstat - 128) != SIGTERM)
485 				return 1;
486 			/* fall through... */
487 		  case LEXIT:
488 		  case LLEAVE:
489 		  case LSHELL:
490 			unwind(i);
491 			/*NOREACHED*/
492 		  default:
493 			internal_errorf(1, "include: %d", i);
494 			/*NOREACHED*/
495 		}
496 	}
497 	if (argv) {
498 		e->loc->argv = argv;
499 		e->loc->argc = argc;
500 	}
501 	s = pushs(SFILE, ATEMP);
502 	s->u.shf = shf;
503 	s->file = str_save(name, ATEMP);
504 	i = shell(s, FALSE);
505 	source = sold;
506 	shf_close(s->u.shf);
507 	quitenv();
508 	if (old_argv) {
509 		e->loc->argv = old_argv;
510 		e->loc->argc = old_argc;
511 	}
512 	return i & 0xff;	/* & 0xff to ensure value not -1 */
513 }
514 
515 int
516 command(comm)
517 	const char *comm;
518 {
519 	register Source *s;
520 
521 	s = pushs(SSTRING, ATEMP);
522 	s->start = s->str = comm;
523 	return shell(s, FALSE);
524 }
525 
526 /*
527  * run the commands from the input source, returning status.
528  */
529 int
530 shell(s, toplevel)
531 	Source *volatile s;		/* input source */
532 	int volatile toplevel;
533 {
534 	struct op *t;
535 	volatile int wastty = s->flags & SF_TTY;
536 	volatile int attempts = 13;
537 	volatile int interactive = Flag(FTALKING) && toplevel;
538 	int i;
539 
540 	newenv(E_PARSE);
541 	if (interactive)
542 		really_exit = 0;
543 	i = ksh_sigsetjmp(e->jbuf, 0);
544 	if (i) {
545 		s->start = s->str = null;
546 		switch (i) {
547 		  case LINTR: /* we get here if SIGINT not caught or ignored */
548 		  case LERROR:
549 		  case LSHELL:
550 			if (interactive) {
551 				if (i == LINTR)
552 					shellf(newline);
553 				/* Reset any eof that was read as part of a
554 				 * multiline command.
555 				 */
556 				if (Flag(FIGNOREEOF) && s->type == SEOF
557 				    && wastty)
558 					s->type = SSTDIN;
559 				/* Used by exit command to get back to
560 				 * top level shell.  Kind of strange since
561 				 * interactive is set if we are reading from
562 				 * a tty, but to have stopped jobs, one only
563 				 * needs FMONITOR set (not FTALKING/SF_TTY)...
564 				 */
565 				break;
566 			}
567 			/* fall through... */
568 		  case LEXIT:
569 		  case LLEAVE:
570 		  case LRETURN:
571 			quitenv();
572 			unwind(i);	/* keep on going */
573 			/*NOREACHED*/
574 		  default:
575 			quitenv();
576 			internal_errorf(1, "shell: %d", i);
577 			/*NOREACHED*/
578 		}
579 	}
580 
581 	while (1) {
582 		if (trap)
583 			runtraps(0);
584 
585 		if (s->next == NULL) {
586 			if (Flag(FVERBOSE))
587 				s->flags |= SF_ECHO;
588 			else
589 				s->flags &= ~SF_ECHO;
590 		}
591 
592 		if (interactive) {
593 			j_notify();
594 #ifdef KSH
595 			mcheck();
596 #endif /* KSH */
597 			set_prompt(PS1, s);
598 		}
599 
600 		t = compile(s);
601 		if (t != NULL && t->type == TEOF) {
602 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
603 				shellf("Use `exit' to leave ksh\n");
604 				s->type = SSTDIN;
605 			} else if (wastty && !really_exit
606 				   && j_stopped_running())
607 			{
608 				really_exit = 1;
609 				s->type = SSTDIN;
610 			} else {
611 				/* this for POSIX, which says EXIT traps
612 				 * shall be taken in the environment
613 				 * immediately after the last command
614 				 * executed.
615 				 */
616 				if (toplevel)
617 					unwind(LEXIT);
618 				break;
619 			}
620 		}
621 
622 		if (t && (!Flag(FNOEXEC) || (s->flags & SF_TTY)))
623 			exstat = execute(t, 0);
624 
625 		if (t != NULL && t->type != TEOF && interactive && really_exit)
626 			really_exit = 0;
627 
628 		reclaim();
629 	}
630 	quitenv();
631 	return exstat;
632 }
633 
634 /* return to closest error handler or shell(), exit if none found */
635 void
636 unwind(i)
637 	int i;
638 {
639 	/* ordering for EXIT vs ERR is a bit odd (this is what at&t ksh does) */
640 	if (i == LEXIT || (Flag(FERREXIT) && (i == LERROR || i == LINTR)
641 			   && sigtraps[SIGEXIT_].trap))
642 	{
643 		runtrap(&sigtraps[SIGEXIT_]);
644 		i = LLEAVE;
645 	} else if (Flag(FERREXIT) && (i == LERROR || i == LINTR)) {
646 		runtrap(&sigtraps[SIGERR_]);
647 		i = LLEAVE;
648 	}
649 	while (1) {
650 		switch (e->type) {
651 		  case E_PARSE:
652 		  case E_FUNC:
653 		  case E_INCL:
654 		  case E_LOOP:
655 		  case E_ERRH:
656 			ksh_siglongjmp(e->jbuf, i);
657 			/*NOTREACHED*/
658 
659 		  case E_NONE:
660 			if (i == LINTR)
661 				e->flags |= EF_FAKE_SIGDIE;
662 			/* Fall through... */
663 
664 		  default:
665 			quitenv();
666 		}
667 	}
668 }
669 
670 void
671 newenv(type)
672 	int type;
673 {
674 	register struct env *ep;
675 
676 	ep = (struct env *) alloc(sizeof(*ep), ATEMP);
677 	ep->type = type;
678 	ep->flags = 0;
679 	ainit(&ep->area);
680 	ep->loc = e->loc;
681 	ep->savefd = NULL;
682 	ep->oenv = e;
683 	ep->temps = NULL;
684 	e = ep;
685 }
686 
687 void
688 quitenv()
689 {
690 	register struct env *ep = e;
691 	register int fd;
692 
693 	if (ep->oenv && ep->oenv->loc != ep->loc)
694 		popblock();
695 	if (ep->savefd != NULL) {
696 		for (fd = 0; fd < NUFILE; fd++)
697 			/* if ep->savefd[fd] < 0, means fd was closed */
698 			if (ep->savefd[fd])
699 				restfd(fd, ep->savefd[fd]);
700 		if (ep->savefd[2]) /* Clear any write errors */
701 			shf_reopen(2, SHF_WR, shl_out);
702 	}
703 	reclaim();
704 
705 	/* Bottom of the stack.
706 	 * Either main shell is exiting or cleanup_parents_env() was called.
707 	 */
708 	if (ep->oenv == NULL) {
709 		if (ep->type == E_NONE) {	/* Main shell exiting? */
710 			if (Flag(FTALKING))
711 				hist_finish();
712 			j_exit();
713 			if (ep->flags & EF_FAKE_SIGDIE) {
714 				int sig = exstat - 128;
715 
716 				/* ham up our death a bit (at&t ksh
717 				 * only seems to do this for SIGTERM)
718 				 * Don't do it for SIGQUIT, since we'd
719 				 * dump a core..
720 				 */
721 				if (sig == SIGINT || sig == SIGTERM) {
722 					setsig(&sigtraps[sig], SIG_DFL,
723 						SS_RESTORE_CURR|SS_FORCE);
724 					kill(0, sig);
725 				}
726 			}
727 #ifdef MEM_DEBUG
728 			chmem_allfree();
729 #endif /* MEM_DEBUG */
730 		}
731 		exit(exstat);
732 	}
733 
734 	e = e->oenv;
735 	afree(ep, ATEMP);
736 }
737 
738 /* Called after a fork to cleanup stuff left over from parents environment */
739 void
740 cleanup_parents_env()
741 {
742 	struct env *ep;
743 	int fd;
744 
745 	/* Don't clean up temporary files - parent will probably need them.
746 	 * Also, can't easily reclaim memory since variables, etc. could be
747 	 * anywyere.
748 	 */
749 
750 	/* close all file descriptors hiding in savefd */
751 	for (ep = e; ep; ep = ep->oenv) {
752 		if (ep->savefd) {
753 			for (fd = 0; fd < NUFILE; fd++)
754 				if (ep->savefd[fd] > 0)
755 					close(ep->savefd[fd]);
756 			afree(ep->savefd, &ep->area);
757 			ep->savefd = (short *) 0;
758 		}
759 	}
760 	e->oenv = (struct env *) 0;
761 }
762 
763 /* Called just before an execve cleanup stuff temporary files */
764 void
765 cleanup_proc_env()
766 {
767 	struct env *ep;
768 
769 	for (ep = e; ep; ep = ep->oenv)
770 		remove_temps(ep->temps);
771 }
772 
773 /* remove temp files and free ATEMP Area */
774 static void
775 reclaim()
776 {
777 	remove_temps(e->temps);
778 	e->temps = NULL;
779 	afreeall(&e->area);
780 }
781 
782 static void
783 remove_temps(tp)
784 	struct temp *tp;
785 {
786 #ifdef OS2
787 	static struct temp *delayed_remove;
788 	struct temp *t, **tprev;
789 
790 	if (delayed_remove) {
791 		for (tprev = &delayed_remove, t = delayed_remove; t; t = *tprev)
792 			/* No need to check t->pid here... */
793 			if (unlink(t->name) >= 0 || errno == ENOENT) {
794 				*tprev = t->next;
795 				afree(t, APERM);
796 			} else
797 				tprev = &t->next;
798 	}
799 #endif /* OS2 */
800 
801 	for (; tp != NULL; tp = tp->next)
802 		if (tp->pid == procpid) {
803 #ifdef OS2
804 			/* OS/2 (and dos) do not allow files that are currently
805 			 * open to be removed, so we cache it away for future
806 			 * removal.
807 			 * XXX should only do this if errno
808 			 *     is Efile-still-open-can't-remove
809 			 *     (but I don't know what that is...)
810 			 */
811 			if (unlink(tp->name) < 0 && errno != ENOENT) {
812 				t = (struct temp *) alloc(
813 				    sizeof(struct temp) + strlen(tp->name) + 1,
814 				    APERM);
815 				memset(t, 0, sizeof(struct temp));
816 				t->name = (char *) &t[1];
817 				strcpy(t->name, tp->name);
818 				t->next = delayed_remove;
819 				delayed_remove = t;
820 			}
821 #else /* OS2 */
822 			unlink(tp->name);
823 #endif /* OS2 */
824 		}
825 }
826 
827 /* Returns true if name refers to a restricted shell */
828 static int
829 is_restricted(name)
830 	char *name;
831 {
832 	char *p;
833 
834 	if ((p = ksh_strrchr_dirsep(name)))
835 		name = p;
836 	/* accepts rsh, rksh, rpdksh, pdrksh, etc. */
837 	return (p = strchr(name, 'r')) && strstr(p, "sh");
838 }
839 
840 void
841 aerror(ap, msg)
842 	Area *ap;
843 	const char *msg;
844 {
845 	internal_errorf(1, "alloc: %s", msg);
846 	errorf(null); /* this is never executed - keeps gcc quiet */
847 	/*NOTREACHED*/
848 }
849