xref: /plan9/sys/src/ape/cmd/pdksh/main.c (revision 59cc4ca53493a3c6d2349fe2b7f7c40f7dce7294)
1 /*
2  * startup, main loop, enviroments and error handling
3  */
4 
5 #define	EXTERN				/* define EXTERNs in sh.h */
6 
7 #include "sh.h"
8 #include "ksh_stat.h"
9 #include "ksh_time.h"
10 
11 extern char **environ;
12 
13 /*
14  * global data
15  */
16 
17 static void	reclaim ARGS((void));
18 static void	remove_temps ARGS((struct temp *tp));
19 static int	is_restricted ARGS((char *name));
20 
21 /*
22  * shell initialization
23  */
24 
25 static const char initifs[] = "IFS= \t\n";
26 
27 static const char initsubs[] = "${PS2=> } ${PS3=#? } ${PS4=+ }";
28 
29 static const char version_param[] =
30 #ifdef KSH
31 	"KSH_VERSION"
32 #else /* KSH */
33 	"SH_VERSION"
34 #endif /* KSH */
35 	;
36 
37 static const char *const initcoms [] = {
38 	"typeset", "-x", "SHELL", "PATH", "HOME", NULL,
39 	"typeset", "-r", version_param, NULL,
40 	"typeset", "-i", "PPID", NULL,
41 	"typeset", "-i", "OPTIND=1", NULL,
42 #ifdef KSH
43 	"eval", "typeset -i RANDOM MAILCHECK=\"${MAILCHECK-600}\" SECONDS=\"${SECONDS-0}\" TMOUT=\"${TMOUT-0}\"", NULL,
44 #endif /* KSH */
45 	"alias",
46 	 /* Standard ksh aliases */
47 	  "hash=alias -t",	/* not "alias -t --": hash -r needs to work */
48 	  "type=whence -v",
49 #ifdef JOBS
50 	  "stop=kill -STOP",
51 	  "suspend=kill -STOP $$",
52 #endif
53 #ifdef KSH
54 	  "autoload=typeset -fu",
55 	  "functions=typeset -f",
56 # ifdef HISTORY
57 	  "history=fc -l",
58 # endif /* HISTORY */
59 	  "integer=typeset -i",
60 	  "nohup=nohup ",
61 	  "local=typeset",
62 	  "r=fc -e -",
63 #endif /* KSH */
64 #ifdef KSH
65 	 /* Aliases that are builtin commands in at&t */
66 	  "login=exec login",
67 	  "newgrp=exec newgrp",
68 #endif /* KSH */
69 	  NULL,
70 	/* this is what at&t ksh seems to track, with the addition of emacs */
71 	"alias", "-tU",
72 	  "cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
73 	  "mail", "make", "mv", "pr", "rm", "sed", "sh", "vi", "who",
74 	  NULL,
75 #ifdef EXTRA_INITCOMS
76 	EXTRA_INITCOMS, NULL,
77 #endif /* EXTRA_INITCOMS */
78 	NULL
79 };
80 
81 int
main(argc,argv)82 main(argc, argv)
83 	int argc;
84 	register char **argv;
85 {
86 	register int i;
87 	int argi;
88 	Source *s;
89 	struct block *l;
90 	int restricted, errexit;
91 	char **wp;
92 	struct env env;
93 	pid_t ppid;
94 
95 #ifdef MEM_DEBUG
96 	chmem_set_defaults("ct", 1);
97 	/* chmem_push("+c", 1); */
98 #endif /* MEM_DEBUG */
99 
100 #ifdef OS2
101 	setmode (0, O_BINARY);
102 	setmode (1, O_TEXT);
103 #endif
104 
105 	/* make sure argv[] is sane */
106 	if (!*argv) {
107 		static const char	*empty_argv[] = {
108 					    "pdksh", (char *) 0
109 					};
110 
111 		argv = (char **) empty_argv;
112 		argc = 1;
113 	}
114 	kshname = *argv;
115 
116 	ainit(&aperm);		/* initialize permanent Area */
117 
118 	/* set up base enviroment */
119 	memset(&env, 0, sizeof(env));
120 	env.type = E_NONE;
121 	ainit(&env.area);
122 	e = &env;
123 	newblock();		/* set up global l->vars and l->funs */
124 
125 	/* Do this first so output routines (eg, errorf, shellf) can work */
126 	initio();
127 
128 	initvar();
129 
130 	initctypes();
131 
132 	inittraps();
133 
134 #ifdef KSH
135 	coproc_init();
136 #endif /* KSH */
137 
138 	/* set up variable and command dictionaries */
139 	tinit(&taliases, APERM, 0);
140 	tinit(&aliases, APERM, 0);
141 	tinit(&homedirs, APERM, 0);
142 
143 	/* define shell keywords */
144 	initkeywords();
145 
146 	/* define built-in commands */
147 	tinit(&builtins, APERM, 64); /* must be 2^n (currently 40 builtins) */
148 	for (i = 0; shbuiltins[i].name != NULL; i++)
149 		builtin(shbuiltins[i].name, shbuiltins[i].func);
150 	for (i = 0; kshbuiltins[i].name != NULL; i++)
151 		builtin(kshbuiltins[i].name, kshbuiltins[i].func);
152 
153 	init_histvec();
154 
155 	def_path = DEFAULT__PATH;
156 #if defined(HAVE_CONFSTR) && defined(_CS_PATH)
157 	{
158 		size_t len = confstr(_CS_PATH, (char *) 0, 0);
159 		char *new;
160 
161 		if (len > 0) {
162 			confstr(_CS_PATH, new = alloc(len + 1, APERM), len + 1);
163 			def_path = new;
164 		}
165 	}
166 #endif /* HAVE_CONFSTR && _CS_PATH */
167 
168 	/* Set PATH to def_path (will set the path global variable).
169 	 * (import of environment below will probably change this setting).
170 	 */
171 	{
172 		struct tbl *vp = global("PATH");
173 		/* setstr can't fail here */
174 		setstr(vp, def_path, KSH_RETURN_ERROR);
175 	}
176 
177 
178 	/* Turn on nohup by default for how - will change to off
179 	 * by default once people are aware of its existance
180 	 * (at&t ksh does not have a nohup option - it always sends
181 	 * the hup).
182 	 */
183 	Flag(FNOHUP) = 1;
184 
185 	/* Turn on brace expansion by default.  At&t ksh's that have
186 	 * alternation always have it on.  BUT, posix doesn't have
187 	 * brace expansion, so set this before setting up FPOSIX
188 	 * (change_flag() clears FBRACEEXPAND when FPOSIX is set).
189 	 */
190 #ifdef BRACE_EXPAND
191 	Flag(FBRACEEXPAND) = 1;
192 #endif /* BRACE_EXPAND */
193 
194 	/* set posix flag just before environment so that it will have
195 	 * exactly the same effect as the POSIXLY_CORRECT environment
196 	 * variable.  If this needs to be done sooner to ensure correct posix
197 	 * operation, an initial scan of the environment will also have
198 	 * done sooner.
199 	 */
200 #ifdef POSIXLY_CORRECT
201 	change_flag(FPOSIX, OF_SPECIAL, 1);
202 #endif /* POSIXLY_CORRECT */
203 
204 	/* import enviroment */
205 	if (environ != NULL)
206 		for (wp = environ; *wp != NULL; wp++)
207 			typeset(*wp, IMPORT|EXPORT, 0, 0, 0);
208 
209 	kshpid = procpid = getpid();
210 	typeset(initifs, 0, 0, 0, 0);	/* for security */
211 
212 	/* assign default shell variable values */
213 	substitute(initsubs, 0);
214 
215 	/* Figure out the current working directory and set $PWD */
216 	{
217 		struct stat s_pwd, s_dot;
218 		struct tbl *pwd_v = global("PWD");
219 		char *pwd = str_val(pwd_v);
220 		char *pwdx = pwd;
221 
222 		/* Try to use existing $PWD if it is valid */
223 		if (!ISABSPATH(pwd)
224 		    || stat(pwd, &s_pwd) < 0 || stat(".", &s_dot) < 0
225 		    || s_pwd.st_dev != s_dot.st_dev
226 		    || s_pwd.st_ino != s_dot.st_ino)
227 			pwdx = (char *) 0;
228 		set_current_wd(pwdx);
229 		if (current_wd[0])
230 			simplify_path(current_wd);
231 		/* Only set pwd if we know where we are or if it had a
232 		 * bogus value
233 		 */
234 		if (current_wd[0] || pwd != null)
235 			/* setstr can't fail here */
236 			setstr(pwd_v, current_wd, KSH_RETURN_ERROR);
237 	}
238 	ppid = getppid();
239 	setint(global("PPID"), (long) ppid);
240 #ifdef KSH
241 	setint(global("RANDOM"), (long) (time((time_t *)0) * kshpid * ppid));
242 #endif /* KSH */
243 	/* setstr can't fail here */
244 	setstr(global(version_param), ksh_version, KSH_RETURN_ERROR);
245 
246 	/* execute initialization statements */
247 	for (wp = (char**) initcoms; *wp != NULL; wp++) {
248 		shcomexec(wp);
249 		for (; *wp != NULL; wp++)
250 			;
251 	}
252 
253 
254 	ksheuid = geteuid();
255 	safe_prompt = ksheuid ? "$ " : "# ";
256 	{
257 		struct tbl *vp = global("PS1");
258 
259 		/* Set PS1 if it isn't set, or we are root and prompt doesn't
260 		 * contain a #.
261 		 */
262 		if (!(vp->flag & ISSET)
263 		    || (!ksheuid && !strchr(str_val(vp), '#')))
264 			/* setstr can't fail here */
265 			setstr(vp, safe_prompt, KSH_RETURN_ERROR);
266 	}
267 
268 	/* Set this before parsing arguments */
269 	Flag(FPRIVILEGED) = getuid() != ksheuid || getgid() != getegid();
270 
271 	/* this to note if monitor is set on command line (see below) */
272 	Flag(FMONITOR) = 127;
273 	argi = parse_args(argv, OF_CMDLINE, (int *) 0);
274 	if (argi < 0)
275 		exit(1);
276 
277 	if (Flag(FCOMMAND)) {
278 		s = pushs(SSTRING, ATEMP);
279 		if (!(s->start = s->str = argv[argi++]))
280 			errorf("-c requires an argument");
281 		if (argv[argi])
282 			kshname = argv[argi++];
283 	} else if (argi < argc && !Flag(FSTDIN)) {
284 		s = pushs(SFILE, ATEMP);
285 #ifdef OS2
286 		/* a bug in os2 extproc shell processing doesn't
287 		 * pass full pathnames so we have to search for it.
288 		 * This changes the behavior of 'ksh arg' to search
289 		 * the users search path but it can't be helped.
290 		 */
291 		s->file = search(argv[argi++], path, R_OK, (int *) 0);
292 		if (!s->file || !*s->file)
293 		        s->file = argv[argi - 1];
294 #else
295 		s->file = argv[argi++];
296 #endif /* OS2 */
297 		s->u.shf = shf_open(s->file, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
298 		if (s->u.shf == NULL) {
299 			exstat = 127; /* POSIX */
300 			errorf("%s: %s", s->file, strerror(errno));
301 		}
302 		kshname = s->file;
303 	} else {
304 		Flag(FSTDIN) = 1;
305 		s = pushs(SSTDIN, ATEMP);
306 		s->file = "<stdin>";
307 		s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
308 				      (struct shf *) 0);
309 		if (!Flag(FNOTTALKING) && isatty(0) && isatty(2)) {
310 			Flag(FTALKING) = Flag(FTALKING_I) = 1;
311 			/* The following only if isatty(0) */
312 			s->flags |= SF_TTY;
313 			s->u.shf->flags |= SHF_INTERRUPT;
314 			s->file = (char *) 0;
315 		}
316 	}
317 
318 	/* This bizarreness is mandated by POSIX */
319 	{
320 		struct stat s_stdin;
321 
322 		if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode))
323 			reset_nonblock(0);
324 	}
325 
326 	/* initialize job control */
327 	i = Flag(FMONITOR) != 127;
328 	Flag(FMONITOR) = 0;
329 	j_init(i);
330 #ifdef EDIT
331 	/* Do this after j_init(), as tty_fd is not initialized 'til then */
332 	if (Flag(FTALKING))
333 		x_init();
334 #endif
335 
336 	l = e->loc;
337 	l->argv = &argv[argi - 1];
338 	l->argc = argc - argi;
339 	l->argv[0] = (char *) kshname;
340 	getopts_reset(1);
341 
342 	/* Disable during .profile/ENV reading */
343 	restricted = Flag(FRESTRICTED);
344 	Flag(FRESTRICTED) = 0;
345 	errexit = Flag(FERREXIT);
346 	Flag(FERREXIT) = 0;
347 
348 	/* Do this before profile/$ENV so that if it causes problems in them,
349 	 * user will know why things broke.
350 	 */
351 	if (!current_wd[0] && Flag(FTALKING))
352 		warningf(FALSE, "Cannot determine current working directory");
353 
354 	if (Flag(FLOGIN)) {
355 #ifdef OS2
356 		char *profile;
357 
358 		/* Try to find a profile - first see if $INIT has a value,
359 		 * then try /etc/profile.ksh, then c:/usr/etc/profile.ksh.
360 		 */
361 		if (!Flag(FPRIVILEGED)
362 		    && strcmp(profile = substitute("$INIT/profile.ksh", 0),
363 			      "/profile.ksh"))
364 			include(profile, 0, (char **) 0, 1);
365 		else if (include("/etc/profile.ksh", 0, (char **) 0, 1) < 0)
366 			include("c:/usr/etc/profile.ksh", 0, (char **) 0, 1);
367 		if (!Flag(FPRIVILEGED))
368 			include(substitute("$HOME/profile.ksh", 0), 0,
369 				(char **) 0, 1);
370 #else /* OS2 */
371 		include(KSH_SYSTEM_PROFILE, 0, (char **) 0, 1);
372 		if (!Flag(FPRIVILEGED))
373 			include(substitute("$HOME/.profile", 0), 0,
374 				(char **) 0, 1);
375 #endif /* OS2 */
376 	}
377 
378 	if (Flag(FPRIVILEGED))
379 		include("/etc/suid_profile", 0, (char **) 0, 1);
380 	else {
381 		char *env_file;
382 
383 #ifndef KSH
384 		if (!Flag(FPOSIX))
385 			env_file = null;
386 		else
387 #endif /* !KSH */
388 			/* include $ENV */
389 			env_file = str_val(global("ENV"));
390 
391 #ifdef DEFAULT_ENV
392 		/* If env isn't set, include default environment */
393 		if (env_file == null)
394 			env_file = DEFAULT_ENV;
395 #endif /* DEFAULT_ENV */
396 		env_file = substitute(env_file, DOTILDE);
397 		if (*env_file != '\0')
398 			include(env_file, 0, (char **) 0, 1);
399 #ifdef OS2
400 		else if (Flag(FTALKING))
401 			include(substitute("$HOME/kshrc.ksh", 0), 0,
402 				(char **) 0, 1);
403 #endif /* OS2 */
404 	}
405 
406 	if (is_restricted(argv[0]) || is_restricted(str_val(global("SHELL"))))
407 		restricted = 1;
408 	if (restricted) {
409 		static const char *const restr_com[] = {
410 						"typeset", "-r", "PATH",
411 						    "ENV", "SHELL",
412 						(char *) 0
413 					    };
414 		shcomexec((char **) restr_com);
415 		/* After typeset command... */
416 		Flag(FRESTRICTED) = 1;
417 	}
418 	if (errexit)
419 		Flag(FERREXIT) = 1;
420 
421 	if (Flag(FTALKING)) {
422 		hist_init(s);
423 #ifdef KSH
424 		alarm_init();
425 #endif /* KSH */
426 	} else
427 		Flag(FTRACKALL) = 1;	/* set after ENV */
428 
429 	shell(s, TRUE);	/* doesn't return */
430 	return 0;
431 }
432 
433 int
include(name,argc,argv,intr_ok)434 include(name, argc, argv, intr_ok)
435 	const char *name;
436 	int argc;
437 	char **argv;
438 	int intr_ok;
439 {
440 	register Source *volatile s = NULL;
441 	Source *volatile sold;
442 	struct shf *shf;
443 	char **volatile old_argv;
444 	volatile int old_argc;
445 	int i;
446 
447 	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI|SHF_CLEXEC);
448 	if (shf == NULL)
449 		return -1;
450 
451 	if (argv) {
452 		old_argv = e->loc->argv;
453 		old_argc = e->loc->argc;
454 	} else {
455 		old_argv = (char **) 0;
456 		old_argc = 0;
457 	}
458 	sold = source;
459 	newenv(E_INCL);
460 	i = ksh_sigsetjmp(e->jbuf, 0);
461 	if (i) {
462 		source = sold;
463 		if (s) /* Do this before quitenv(), which frees the memory */
464 			shf_close(s->u.shf);
465 		quitenv();
466 		if (old_argv) {
467 			e->loc->argv = old_argv;
468 			e->loc->argc = old_argc;
469 		}
470 		switch (i) {
471 		  case LRETURN:
472 		  case LERROR:
473 			return exstat & 0xff; /* see below */
474 		  case LINTR:
475 			/* intr_ok is set if we are including .profile or $ENV.
476 			 * If user ^C's out, we don't want to kill the shell...
477 			 */
478 			if (intr_ok && (exstat - 128) != SIGTERM)
479 				return 1;
480 			/* fall through... */
481 		  case LEXIT:
482 		  case LLEAVE:
483 		  case LSHELL:
484 			unwind(i);
485 			/*NOREACHED*/
486 		  default:
487 			internal_errorf(1, "include: %d", i);
488 			/*NOREACHED*/
489 		}
490 	}
491 	if (argv) {
492 		e->loc->argv = argv;
493 		e->loc->argc = argc;
494 	}
495 	s = pushs(SFILE, ATEMP);
496 	s->u.shf = shf;
497 	s->file = str_save(name, ATEMP);
498 	i = shell(s, FALSE);
499 	source = sold;
500 	shf_close(s->u.shf);
501 	quitenv();
502 	if (old_argv) {
503 		e->loc->argv = old_argv;
504 		e->loc->argc = old_argc;
505 	}
506 	return i & 0xff;	/* & 0xff to ensure value not -1 */
507 }
508 
509 int
command(comm)510 command(comm)
511 	const char *comm;
512 {
513 	register Source *s;
514 
515 	s = pushs(SSTRING, ATEMP);
516 	s->start = s->str = comm;
517 	return shell(s, FALSE);
518 }
519 
520 /*
521  * run the commands from the input source, returning status.
522  */
523 int
shell(s,toplevel)524 shell(s, toplevel)
525 	Source *volatile s;		/* input source */
526 	int volatile toplevel;
527 {
528 	struct op *t;
529 	volatile int wastty = s->flags & SF_TTY;
530 	volatile int attempts = 13;
531 	volatile int interactive = Flag(FTALKING) && toplevel;
532 	int i;
533 
534 	newenv(E_PARSE);
535 	if (interactive)
536 		really_exit = 0;
537 	i = ksh_sigsetjmp(e->jbuf, 0);
538 	if (i) {
539 		s->start = s->str = null;
540 		switch (i) {
541 		  case LINTR: /* we get here if SIGINT not caught or ignored */
542 		  case LERROR:
543 		  case LSHELL:
544 			if (interactive) {
545 				if (i == LINTR)
546 					shellf(newline);
547 				/* Reset any eof that was read as part of a
548 				 * multiline command.
549 				 */
550 				if (Flag(FIGNOREEOF) && s->type == SEOF
551 				    && wastty)
552 					s->type = SSTDIN;
553 				/* Used by exit command to get back to
554 				 * top level shell.  Kind of strange since
555 				 * interactive is set if we are reading from
556 				 * a tty, but to have stopped jobs, one only
557 				 * needs FMONITOR set (not FTALKING/SF_TTY)...
558 				 */
559 				break;
560 			}
561 			/* fall through... */
562 		  case LEXIT:
563 		  case LLEAVE:
564 		  case LRETURN:
565 			quitenv();
566 			unwind(i);	/* keep on going */
567 			/*NOREACHED*/
568 		  default:
569 			quitenv();
570 			internal_errorf(1, "shell: %d", i);
571 			/*NOREACHED*/
572 		}
573 	}
574 
575 	while (1) {
576 		if (trap)
577 			runtraps(0);
578 
579 		if (s->next == NULL)
580 			if (Flag(FVERBOSE))
581 				s->flags |= SF_ECHO;
582 			else
583 				s->flags &= ~SF_ECHO;
584 
585 		if (interactive) {
586 			j_notify();
587 #ifdef KSH
588 			mcheck();
589 #endif /* KSH */
590 			set_prompt(PS1, s);
591 		}
592 
593 		t = compile(s);
594 		if (t != NULL && t->type == TEOF) {
595 			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
596 				shellf("Use `exit' to leave ksh\n");
597 				s->type = SSTDIN;
598 			} else if (wastty && !really_exit
599 				   && j_stopped_running())
600 			{
601 				really_exit = 1;
602 				s->type = SSTDIN;
603 			} else {
604 				/* this for POSIX, which says EXIT traps
605 				 * shall be taken in the environment
606 				 * immediately after the last command
607 				 * executed.
608 				 */
609 				if (toplevel)
610 					unwind(LEXIT);
611 				break;
612 			}
613 		}
614 
615 		if (t && (!Flag(FNOEXEC) || (s->flags & SF_TTY)))
616 			exstat = execute(t, 0);
617 
618 		if (t != NULL && t->type != TEOF && interactive && really_exit)
619 			really_exit = 0;
620 
621 		reclaim();
622 	}
623 	quitenv();
624 	return exstat;
625 }
626 
627 /* return to closest error handler or shell(), exit if none found */
628 void
unwind(i)629 unwind(i)
630 	int i;
631 {
632 	/* ordering for EXIT vs ERR is a bit odd (this is what at&t ksh does) */
633 	if (i == LEXIT || (Flag(FERREXIT) && (i == LERROR || i == LINTR)
634 			   && sigtraps[SIGEXIT_].trap))
635 	{
636 		runtrap(&sigtraps[SIGEXIT_]);
637 		i = LLEAVE;
638 	} else if (Flag(FERREXIT) && (i == LERROR || i == LINTR)) {
639 		runtrap(&sigtraps[SIGERR_]);
640 		i = LLEAVE;
641 	}
642 	while (1) {
643 		switch (e->type) {
644 		  case E_PARSE:
645 		  case E_FUNC:
646 		  case E_INCL:
647 		  case E_LOOP:
648 		  case E_ERRH:
649 			ksh_siglongjmp(e->jbuf, i);
650 			/*NOTREACHED*/
651 
652 		  case E_NONE:
653 			if (i == LINTR)
654 				e->flags |= EF_FAKE_SIGDIE;
655 			/* Fall through... */
656 
657 		  default:
658 			quitenv();
659 		}
660 	}
661 }
662 
663 void
newenv(type)664 newenv(type)
665 	int type;
666 {
667 	register struct env *ep;
668 
669 	ep = (struct env *) alloc(sizeof(*ep), ATEMP);
670 	ep->type = type;
671 	ep->flags = 0;
672 	ainit(&ep->area);
673 	ep->loc = e->loc;
674 	ep->savefd = NULL;
675 	ep->oenv = e;
676 	ep->temps = NULL;
677 	e = ep;
678 }
679 
680 void
quitenv()681 quitenv()
682 {
683 	register struct env *ep = e;
684 	register int fd;
685 
686 	if (ep->oenv && ep->oenv->loc != ep->loc)
687 		popblock();
688 	if (ep->savefd != NULL) {
689 		for (fd = 0; fd < NUFILE; fd++)
690 			/* if ep->savefd[fd] < 0, means fd was closed */
691 			if (ep->savefd[fd])
692 				restfd(fd, ep->savefd[fd]);
693 		if (ep->savefd[2]) /* Clear any write errors */
694 			shf_reopen(2, SHF_WR, shl_out);
695 	}
696 	reclaim();
697 
698 	/* Bottom of the stack.
699 	 * Either main shell is exiting or cleanup_parents_env() was called.
700 	 */
701 	if (ep->oenv == NULL) {
702 		if (ep->type == E_NONE) {	/* Main shell exiting? */
703 			if (Flag(FTALKING))
704 				hist_finish();
705 			j_exit();
706 			if (ep->flags & EF_FAKE_SIGDIE) {
707 				int sig = exstat - 128;
708 
709 				/* ham up our death a bit (at&t ksh
710 				 * only seems to do this for SIGTERM)
711 				 * Don't do it for SIGQUIT, since we'd
712 				 * dump a core..
713 				 */
714 				if (sig == SIGINT || sig == SIGTERM) {
715 					setsig(&sigtraps[sig], SIG_DFL,
716 						SS_RESTORE_CURR|SS_FORCE);
717 					kill(0, sig);
718 				}
719 			}
720 #ifdef MEM_DEBUG
721 			chmem_allfree();
722 #endif /* MEM_DEBUG */
723 		}
724 		exit(exstat);
725 	}
726 
727 	e = e->oenv;
728 	afree(ep, ATEMP);
729 }
730 
731 /* Called after a fork to cleanup stuff left over from parents environment */
732 void
cleanup_parents_env()733 cleanup_parents_env()
734 {
735 	struct env *ep;
736 	int fd;
737 
738 	/* Don't clean up temporary files - parent will probably need them.
739 	 * Also, can't easily reclaim memory since variables, etc. could be
740 	 * anywyere.
741 	 */
742 
743 	/* close all file descriptors hiding in savefd */
744 	for (ep = e; ep; ep = ep->oenv) {
745 		if (ep->savefd) {
746 			for (fd = 0; fd < NUFILE; fd++)
747 				if (ep->savefd[fd] > 0)
748 					close(ep->savefd[fd]);
749 			afree(ep->savefd, &ep->area);
750 			ep->savefd = (short *) 0;
751 		}
752 	}
753 	e->oenv = (struct env *) 0;
754 }
755 
756 /* Called just before an execve cleanup stuff temporary files */
757 void
cleanup_proc_env()758 cleanup_proc_env()
759 {
760 	struct env *ep;
761 
762 	for (ep = e; ep; ep = ep->oenv)
763 		remove_temps(ep->temps);
764 }
765 
766 /* remove temp files and free ATEMP Area */
767 static void
reclaim()768 reclaim()
769 {
770 	remove_temps(e->temps);
771 	e->temps = NULL;
772 	afreeall(&e->area);
773 }
774 
775 static void
remove_temps(tp)776 remove_temps(tp)
777 	struct temp *tp;
778 {
779 #ifdef OS2
780 	static struct temp *delayed_remove;
781 	struct temp *t, **tprev;
782 
783 	if (delayed_remove) {
784 		for (tprev = &delayed_remove, t = delayed_remove; t; t = *tprev)
785 			/* No need to check t->pid here... */
786 			if (unlink(t->name) >= 0 || errno == ENOENT) {
787 				*tprev = t->next;
788 				afree(t, APERM);
789 			} else
790 				tprev = &t->next;
791 	}
792 #endif /* OS2 */
793 
794 	for (; tp != NULL; tp = tp->next)
795 		if (tp->pid == procpid) {
796 #ifdef OS2
797 			/* OS/2 (and dos) do not allow files that are currently
798 			 * open to be removed, so we cache it away for future
799 			 * removal.
800 			 * XXX should only do this if errno
801 			 *     is Efile-still-open-can't-remove
802 			 *     (but I don't know what that is...)
803 			 */
804 			if (unlink(tp->name) < 0 && errno != ENOENT) {
805 				t = (struct temp *) alloc(
806 				    sizeof(struct temp) + strlen(tp->name) + 1,
807 				    APERM);
808 				memset(t, 0, sizeof(struct temp));
809 				t->name = (char *) &t[1];
810 				strcpy(t->name, tp->name);
811 				t->next = delayed_remove;
812 				delayed_remove = t;
813 			}
814 #else /* OS2 */
815 			unlink(tp->name);
816 #endif /* OS2 */
817 		}
818 }
819 
820 /* Returns true if name refers to a restricted shell */
821 static int
is_restricted(name)822 is_restricted(name)
823 	char *name;
824 {
825 	char *p;
826 
827 	/* this silly function prevents you running a command called runconf.sh. */
828 	/* we don't care about restricted shells, which aren't very restricted anyway */
829 	/* and introduce a false sense of security */
830 	return 0;
831 #ifdef dumbidea
832 	if ((p = ksh_strrchr_dirsep(name)))
833 		name = p;
834 	/* accepts rsh, rksh, rpdksh, pdrksh, etc. */
835 	return (p = strchr(name, 'r')) && strstr(p, "sh");
836 #endif
837 }
838 
839 void
aerror(ap,msg)840 aerror(ap, msg)
841 	Area *ap;
842 	const char *msg;
843 {
844 	internal_errorf(1, "alloc: %s", msg);
845 	errorf(null); /* this is never executed - keeps gcc quiet */
846 	/*NOTREACHED*/
847 }
848