xref: /original-bsd/bin/csh/csh.c (revision 9374f148)
1 /*-
2  * Copyright (c) 1980, 1991 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 char copyright[] =
10 "@(#) Copyright (c) 1991 The Regents of the University of California.\n\
11  All rights reserved.\n";
12 #endif /* not lint */
13 
14 #ifndef lint
15 static char sccsid[] = "@(#)csh.c	5.25 (Berkeley) 06/08/91";
16 #endif /* not lint */
17 
18 #include <sys/types.h>
19 #include <sys/ioctl.h>
20 #include <sys/stat.h>
21 #include <fcntl.h>
22 #include <errno.h>
23 #include <pwd.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <locale.h>
27 #include <unistd.h>
28 #include "csh.h"
29 #include "extern.h"
30 #include "pathnames.h"
31 
32 extern bool MapsAreInited;
33 extern bool NLSMapsAreInited;
34 
35 /*
36  * C Shell
37  *
38  * Bill Joy, UC Berkeley, California, USA
39  * October 1978, May 1980
40  *
41  * Jim Kulp, IIASA, Laxenburg, Austria
42  * April 1980
43  *
44  * Christos Zoulas, Cornell University
45  * June, 1991
46  */
47 
48 Char   *dumphist[] = {STRhistory, STRmh, 0, 0};
49 Char   *loadhist[] = {STRsource, STRmh, STRhistfile, 0};
50 
51 int     nofile = 0;
52 bool    reenter = 0;
53 bool    nverbose = 0;
54 bool    nexececho = 0;
55 bool    quitit = 0;
56 bool    fast = 0;
57 bool    batch = 0;
58 bool    mflag = 0;
59 bool    prompt = 1;
60 bool    enterhist = 0;
61 bool    tellwhat = 0;
62 
63 extern char **environ;
64 
65 static int	srccat __P((Char *, Char *));
66 static int	srcfile __P((char *, bool, bool));
67 static void	phup __P((int));
68 static void	srcunit __P((int, bool, bool));
69 static void	mailchk __P((void));
70 static Char   **defaultpath __P((void));
71 
72 int
73 main(argc, argv)
74     int     argc;
75     char  **argv;
76 {
77     register Char *cp;
78     register char *tcp;
79     register int f;
80     register char **tempv;
81     struct sigvec osv;
82 
83 
84     settimes();			/* Immed. estab. timing base */
85 
86     /*
87      * Initialize non constant strings
88      */
89 #ifdef _PATH_BSHELL
90     STR_BSHELL = SAVE(_PATH_BSHELL);
91 #endif
92 #ifdef _PATH_CSHELL
93     STR_SHELLPATH = SAVE(_PATH_CSHELL);
94 #endif
95     STR_environ = blk2short(environ);
96     environ = short2blk(STR_environ);	/* So that we can free it */
97     STR_WORD_CHARS = SAVE(WORD_CHARS);
98 
99     HIST = '!';
100     HISTSUB = '^';
101     word_chars = STR_WORD_CHARS;
102 
103     tempv = argv;
104     if (eq(str2short(tempv[0]), STRaout))	/* A.out's are quittable */
105 	quitit = 1;
106     uid = getuid();
107     gid = getgid();
108     /*
109      * We are a login shell if: 1. we were invoked as -<something> and we had
110      * no arguments 2. or we were invoked only with the -l flag
111      */
112     loginsh = (**tempv == '-' && argc == 1) ||
113 	(argc == 2 && tempv[1][0] == '-' && tempv[1][1] == 'l' &&
114 	 tempv[1][2] == '\0');
115 
116     if (loginsh && **tempv != '-') {
117 	/*
118 	 * Mangle the argv space
119 	 */
120 	tempv[1][0] = '\0';
121 	tempv[1][1] = '\0';
122 	tempv[1] = NULL;
123 	for (tcp = *tempv; *tcp++;);
124 	for (tcp--; tcp >= *tempv; tcp--)
125 	    tcp[1] = tcp[0];
126 	*++tcp = '-';
127 	argc--;
128     }
129     if (loginsh)
130 	(void) time(&chktim);
131 
132     AsciiOnly = 1;
133 #ifdef NLS
134     (void) setlocale(LC_ALL, "");
135     {
136 	int     k;
137 
138 	for (k = 0200; k <= 0377 && !Isprint(k); k++);
139 	AsciiOnly = k > 0377;
140     }
141 #else
142     AsciiOnly = getenv("LANG") == NULL && getenv("LC_CTYPE") == NULL;
143 #endif				/* NLS */
144 
145     /*
146      * Move the descriptors to safe places. The variable didfds is 0 while we
147      * have only FSH* to work with. When didfds is true, we have 0,1,2 and
148      * prefer to use these.
149      */
150     initdesc();
151 
152     /*
153      * Initialize the shell variables. ARGV and PROMPT are initialized later.
154      * STATUS is also munged in several places. CHILD is munged when
155      * forking/waiting
156      */
157     set(STRstatus, Strsave(STR0));
158 
159     if ((tcp = getenv("HOME")) != NULL)
160 	cp = SAVE(tcp);
161     else
162 	cp = NULL;
163 
164     if (cp == NULL)
165 	fast = 1;		/* No home -> can't read scripts */
166     else
167 	set(STRhome, cp);
168     dinit(cp);			/* dinit thinks that HOME == cwd in a login
169 				 * shell */
170     /*
171      * Grab other useful things from the environment. Should we grab
172      * everything??
173      */
174     if ((tcp = getenv("LOGNAME")) != NULL ||
175 	(tcp = getenv("USER")) != NULL)
176 	set(STRuser, SAVE(tcp));
177     if ((tcp = getenv("TERM")) != NULL)
178 	set(STRterm, SAVE(tcp));
179 
180     /*
181      * Re-initialize path if set in environment
182      */
183     if ((tcp = getenv("PATH")) == NULL)
184 	set1(STRpath, defaultpath(), &shvhed);
185     else
186 	importpath(SAVE(tcp));
187 
188     set(STRshell, Strsave(STR_SHELLPATH));
189 
190     doldol = putn((int) getpid());	/* For $$ */
191     shtemp = Strspl(STRtmpsh, doldol);	/* For << */
192 
193     /*
194      * Record the interrupt states from the parent process. If the parent is
195      * non-interruptible our hand must be forced or we (and our children) won't
196      * be either. Our children inherit termination from our parent. We catch it
197      * only if we are the login shell.
198      */
199     /* parents interruptibility */
200     (void) sigvec(SIGINT, NULL, &osv);
201     parintr = (void (*) ()) osv.sv_handler;
202     (void) sigvec(SIGTERM, NULL, &osv);
203     parterm = (void (*) ()) osv.sv_handler;
204 
205     if (loginsh) {
206 	(void) signal(SIGHUP, phup);	/* exit processing on HUP */
207 	(void) signal(SIGXCPU, phup);	/* ...and on XCPU */
208 	(void) signal(SIGXFSZ, phup);	/* ...and on XFSZ */
209     }
210 
211     /*
212      * Process the arguments.
213      *
214      * Note that processing of -v/-x is actually delayed till after script
215      * processing.
216      *
217      * We set the first character of our name to be '-' if we are a shell running
218      * interruptible commands.  Many programs which examine ps'es use this to
219      * filter such shells out.
220      */
221     argc--, tempv++;
222     while (argc > 0 && (tcp = tempv[0])[0] == '-' && *++tcp != '\0' && !batch) {
223 	do
224 	    switch (*tcp++) {
225 
226 	    case 0:		/* -	Interruptible, no prompt */
227 		prompt = 0;
228 		setintr = 1;
229 		nofile = 1;
230 		break;
231 
232 	    case 'b':		/* -b	Next arg is input file */
233 		batch = 1;
234 		break;
235 
236 	    case 'c':		/* -c	Command input from arg */
237 		if (argc == 1)
238 		    xexit(0);
239 		argc--, tempv++;
240 		arginp = SAVE(tempv[0]);
241 		prompt = 0;
242 		nofile = 1;
243 		break;
244 
245 	    case 'e':		/* -e	Exit on any error */
246 		exiterr = 1;
247 		break;
248 
249 	    case 'f':		/* -f	Fast start */
250 		fast = 1;
251 		break;
252 
253 	    case 'i':		/* -i	Interactive, even if !intty */
254 		intact = 1;
255 		nofile = 1;
256 		break;
257 
258 	    case 'm':		/* -m	read .cshrc (from su) */
259 		mflag = 1;
260 		break;
261 
262 	    case 'n':		/* -n	Don't execute */
263 		noexec = 1;
264 		break;
265 
266 	    case 'q':		/* -q	(Undoc'd) ... die on quit */
267 		quitit = 1;
268 		break;
269 
270 	    case 's':		/* -s	Read from std input */
271 		nofile = 1;
272 		break;
273 
274 	    case 't':		/* -t	Read one line from input */
275 		onelflg = 2;
276 		prompt = 0;
277 		nofile = 1;
278 		break;
279 
280 	    case 'v':		/* -v	Echo hist expanded input */
281 		nverbose = 1;	/* ... later */
282 		break;
283 
284 	    case 'x':		/* -x	Echo just before execution */
285 		nexececho = 1;	/* ... later */
286 		break;
287 
288 	    case 'V':		/* -V	Echo hist expanded input */
289 		setNS(STRverbose);	/* NOW! */
290 		break;
291 
292 	    case 'X':		/* -X	Echo just before execution */
293 		setNS(STRecho);	/* NOW! */
294 		break;
295 
296 	} while (*tcp);
297 	tempv++, argc--;
298     }
299 
300     if (quitit)			/* With all due haste, for debugging */
301 	(void) signal(SIGQUIT, SIG_DFL);
302 
303     /*
304      * Unless prevented by -, -c, -i, -s, or -t, if there are remaining
305      * arguments the first of them is the name of a shell file from which to
306      * read commands.
307      */
308     if (nofile == 0 && argc > 0) {
309 	nofile = open(tempv[0], O_RDONLY);
310 	if (nofile < 0) {
311 	    child = 1;		/* So this doesn't return */
312 	    stderror(ERR_SYSTEM, tempv[0], strerror(errno));
313 	}
314 	ffile = SAVE(tempv[0]);
315 	/*
316 	 * Replace FSHIN. Handle /dev/std{in,out,err} specially
317 	 * since once they are closed we cannot open them again.
318 	 * In that case we use our own saved descriptors
319 	 */
320 	if ((SHIN = dmove(nofile, FSHIN)) < 0)
321 	    switch(nofile) {
322 	    case 0:
323 		SHIN = FSHIN;
324 		break;
325 	    case 1:
326 		SHIN = FSHOUT;
327 		break;
328 	    case 2:
329 		SHIN = FSHDIAG;
330 		break;
331 	    default:
332 		stderror(ERR_SYSTEM, tempv[0], strerror(errno));
333 		break;
334 	    }
335 	(void) ioctl(SHIN, FIOCLEX, NULL);
336 	prompt = 0;
337 	 /* argc not used any more */ tempv++;
338     }
339     intty = isatty(SHIN);
340     intty |= intact;
341     if (intty || (intact && isatty(SHOUT))) {
342 	if (!batch && (uid != geteuid() || gid != getegid())) {
343 	    errno = EACCES;
344 	    child = 1;		/* So this doesn't return */
345 	    stderror(ERR_SYSTEM, "csh", strerror(errno));
346 	}
347     }
348     /*
349      * Decide whether we should play with signals or not. If we are explicitly
350      * told (via -i, or -) or we are a login shell (arg0 starts with -) or the
351      * input and output are both the ttys("csh", or "csh</dev/ttyx>/dev/ttyx")
352      * Note that in only the login shell is it likely that parent may have set
353      * signals to be ignored
354      */
355     if (loginsh || intact || intty && isatty(SHOUT))
356 	setintr = 1;
357     settell();
358     /*
359      * Save the remaining arguments in argv.
360      */
361     setq(STRargv, blk2short(tempv), &shvhed);
362 
363     /*
364      * Set up the prompt.
365      */
366     if (prompt) {
367 	set(STRprompt, Strsave(uid == 0 ? STRsymhash : STRsymcent));
368 	/* that's a meta-questionmark */
369 	set(STRprompt2, Strsave(STRmquestion));
370     }
371 
372     /*
373      * If we are an interactive shell, then start fiddling with the signals;
374      * this is a tricky game.
375      */
376     shpgrp = getpgrp();
377     opgrp = tpgrp = -1;
378     if (setintr) {
379 	**argv = '-';
380 	if (!quitit)		/* Wary! */
381 	    (void) signal(SIGQUIT, SIG_IGN);
382 	(void) signal(SIGINT, pintr);
383 	(void) sigblock(sigmask(SIGINT));
384 	(void) signal(SIGTERM, SIG_IGN);
385 	if (quitit == 0 && arginp == 0) {
386 	    (void) signal(SIGTSTP, SIG_IGN);
387 	    (void) signal(SIGTTIN, SIG_IGN);
388 	    (void) signal(SIGTTOU, SIG_IGN);
389 	    /*
390 	     * Wait till in foreground, in case someone stupidly runs csh &
391 	     * dont want to try to grab away the tty.
392 	     */
393 	    if (isatty(FSHDIAG))
394 		f = FSHDIAG;
395 	    else if (isatty(FSHOUT))
396 		f = FSHOUT;
397 	    else if (isatty(OLDSTD))
398 		f = OLDSTD;
399 	    else
400 		f = -1;
401     retry:
402 	    if ((tpgrp = tcgetpgrp(f)) != -1) {
403 		if (tpgrp != shpgrp) {
404 		    sig_t old = signal(SIGTTIN, SIG_DFL);
405 		    (void) kill(0, SIGTTIN);
406 		    (void) signal(SIGTTIN, old);
407 		    goto retry;
408 		}
409 		opgrp = shpgrp;
410 		shpgrp = getpid();
411 		tpgrp = shpgrp;
412 		/*
413 		 * Setpgid will fail if we are a session leader and
414 		 * mypid == mypgrp (POSIX 4.3.3)
415 		 */
416 		if (opgrp != shpgrp)
417 		    if (setpgid(0, shpgrp) == -1)
418 			goto notty;
419 		/*
420 		 * We do that after we set our process group, to make sure
421 		 * that the process group belongs to a process in the same
422 		 * session as the tty (our process and our group) (POSIX 7.2.4)
423 		 */
424 		if (tcsetpgrp(f, shpgrp) == -1)
425 		    goto notty;
426 		(void) ioctl(dcopy(f, FSHTTY), FIOCLEX, NULL);
427 	    }
428 	    if (tpgrp == -1) {
429 notty:
430 		xprintf("Warning: no access to tty (%s).\n", strerror(errno));
431 		xprintf("Thus no job control in this shell.\n");
432 	    }
433 	}
434     }
435     if ((setintr == 0) && (parintr == SIG_DFL))
436 	setintr = 1;
437     (void) signal(SIGCHLD, pchild);	/* while signals not ready */
438 
439     /*
440      * Set an exit here in case of an interrupt or error reading the shell
441      * start-up scripts.
442      */
443     reenter = setexit();	/* PWP */
444     haderr = 0;			/* In case second time through */
445     if (!fast && reenter == 0) {
446 	/* Will have value(STRhome) here because set fast if don't */
447 	{
448 	    int     osetintr = setintr;
449 	    sigset_t omask = sigblock(sigmask(SIGINT));
450 
451 	    setintr = 0;
452 #ifdef _PATH_DOTCSHRC
453 	    (void) srcfile(_PATH_DOTCSHRC, 0, 0);
454 #endif
455 	    if (!fast && !arginp && !onelflg)
456 		dohash();
457 #ifdef _PATH_DOTLOGIN
458 	    if (loginsh)
459 		(void) srcfile(_PATH_DOTLOGIN, 0, 0);
460 #endif
461 	    (void) sigsetmask(omask);
462 	    setintr = osetintr;
463 	}
464 	(void) srccat(value(STRhome), STRsldotcshrc);
465 
466 	if (!fast && !arginp && !onelflg && !havhash)
467 	    dohash();
468         if (loginsh)
469 	      (void) srccat(value(STRhome), STRsldotlogin);
470 	dosource(loadhist);
471     }
472 
473     /*
474      * Now are ready for the -v and -x flags
475      */
476     if (nverbose)
477 	setNS(STRverbose);
478     if (nexececho)
479 	setNS(STRecho);
480 
481     /*
482      * All the rest of the world is inside this call. The argument to process
483      * indicates whether it should catch "error unwinds".  Thus if we are a
484      * interactive shell our call here will never return by being blown past on
485      * an error.
486      */
487     process(setintr);
488 
489     /*
490      * Mop-up.
491      */
492     if (intty) {
493 	if (loginsh) {
494 	    xprintf("logout\n");
495 	    (void) close(SHIN);
496 	    child = 1;
497 	    goodbye();
498 	}
499 	else {
500 	    xprintf("exit\n");
501 	}
502     }
503     rechist();
504     exitstat();
505     return (0);
506 }
507 
508 void
509 untty()
510 {
511     if (tpgrp > 0) {
512 	(void) setpgid(0, opgrp);
513 	(void) tcsetpgrp(FSHTTY, opgrp);
514     }
515 }
516 
517 void
518 importpath(cp)
519     Char   *cp;
520 {
521     register int i = 0;
522     register Char *dp;
523     register Char **pv;
524     int     c;
525 
526     for (dp = cp; *dp; dp++)
527 	if (*dp == ':')
528 	    i++;
529     /*
530      * i+2 where i is the number of colons in the path. There are i+1
531      * directories in the path plus we need room for a zero terminator.
532      */
533     pv = (Char **) xcalloc((size_t) (i + 2), sizeof(Char **));
534     dp = cp;
535     i = 0;
536     if (*dp)
537 	for (;;) {
538 	    if ((c = *dp) == ':' || c == 0) {
539 		*dp = 0;
540 		pv[i++] = Strsave(*cp ? cp : STRdot);
541 		if (c) {
542 		    cp = dp + 1;
543 		    *dp = ':';
544 		}
545 		else
546 		    break;
547 	    }
548 	    dp++;
549 	}
550     pv[i] = 0;
551     set1(STRpath, pv, &shvhed);
552 }
553 
554 /*
555  * Source to the file which is the catenation of the argument names.
556  */
557 static int
558 srccat(cp, dp)
559     Char   *cp, *dp;
560 {
561     register Char *ep = Strspl(cp, dp);
562     char   *ptr = short2str(ep);
563 
564     xfree((ptr_t) ep);
565     return srcfile(ptr, mflag ? 0 : 1, 0);
566 }
567 
568 /*
569  * Source to a file putting the file descriptor in a safe place (> 2).
570  */
571 static int
572 srcfile(f, onlyown, flag)
573     char   *f;
574     bool    onlyown, flag;
575 {
576     register int unit;
577 
578     if ((unit = open(f, O_RDONLY)) == -1)
579 	return 0;
580     unit = dmove(unit, -1);
581 
582     (void) ioctl(unit, FIOCLEX, NULL);
583     srcunit(unit, onlyown, flag);
584     return 1;
585 }
586 
587 /*
588  * Source to a unit.  If onlyown it must be our file or our group or
589  * we don't chance it.	This occurs on ".cshrc"s and the like.
590  */
591 int     insource;
592 static void
593 srcunit(unit, onlyown, hflg)
594     register int unit;
595     bool    onlyown, hflg;
596 {
597     /* We have to push down a lot of state here */
598     /* All this could go into a structure */
599     int     oSHIN = -1, oldintty = intty, oinsource = insource;
600     struct whyle *oldwhyl = whyles;
601     Char   *ogointr = gointr, *oarginp = arginp;
602     Char   *oevalp = evalp, **oevalvec = evalvec;
603     int     oonelflg = onelflg;
604     bool    oenterhist = enterhist;
605     char    OHIST = HIST;
606     bool    otell = cantell;
607 
608     struct Bin saveB;
609     sigset_t omask;
610     jmp_buf oldexit;
611 
612     /* The (few) real local variables */
613     int     my_reenter;
614 
615     if (unit < 0)
616 	return;
617     if (didfds)
618 	donefds();
619     if (onlyown) {
620 	struct stat stb;
621 
622 	if (fstat(unit, &stb) < 0) {
623 	    (void) close(unit);
624 	    return;
625 	}
626     }
627 
628     /*
629      * There is a critical section here while we are pushing down the input
630      * stream since we have stuff in different structures. If we weren't
631      * careful an interrupt could corrupt SHIN's Bin structure and kill the
632      * shell.
633      *
634      * We could avoid the critical region by grouping all the stuff in a single
635      * structure and pointing at it to move it all at once.  This is less
636      * efficient globally on many variable references however.
637      */
638     insource = 1;
639     getexit(oldexit);
640     omask = 0;
641 
642     if (setintr)
643 	omask = sigblock(sigmask(SIGINT));
644     /* Setup the new values of the state stuff saved above */
645     bcopy((char *) &B, (char *) &(saveB), sizeof(B));
646     fbuf = NULL;
647     fseekp = feobp = fblocks = 0;
648     oSHIN = SHIN, SHIN = unit, arginp = 0, onelflg = 0;
649     intty = isatty(SHIN), whyles = 0, gointr = 0;
650     evalvec = 0;
651     evalp = 0;
652     enterhist = hflg;
653     if (enterhist)
654 	HIST = '\0';
655 
656     /*
657      * Now if we are allowing commands to be interrupted, we let ourselves be
658      * interrupted.
659      */
660     if (setintr)
661 	(void) sigsetmask(omask);
662     settell();
663 
664     if ((my_reenter = setexit()) == 0)
665 	process(0);		/* 0 -> blow away on errors */
666 
667     if (setintr)
668 	(void) sigsetmask(omask);
669     if (oSHIN >= 0) {
670 	register int i;
671 
672 	/* We made it to the new state... free up its storage */
673 	/* This code could get run twice but xfree doesn't care */
674 	for (i = 0; i < fblocks; i++)
675 	    xfree((ptr_t) fbuf[i]);
676 	xfree((ptr_t) fbuf);
677 
678 	/* Reset input arena */
679 	bcopy((char *) &(saveB), (char *) &B, sizeof(B));
680 
681 	(void) close(SHIN), SHIN = oSHIN;
682 	arginp = oarginp, onelflg = oonelflg;
683 	evalp = oevalp, evalvec = oevalvec;
684 	intty = oldintty, whyles = oldwhyl, gointr = ogointr;
685 	if (enterhist)
686 	    HIST = OHIST;
687 	enterhist = oenterhist;
688 	cantell = otell;
689     }
690 
691     resexit(oldexit);
692     /*
693      * If process reset() (effectively an unwind) then we must also unwind.
694      */
695     if (my_reenter)
696 	stderror(ERR_SILENT);
697     insource = oinsource;
698 }
699 
700 void
701 rechist()
702 {
703     Char    buf[BUFSIZ];
704     int     fp, ftmp, oldidfds;
705 
706     if (!fast) {
707 	if (value(STRsavehist)[0] == '\0')
708 	    return;
709 	(void) Strcpy(buf, value(STRhome));
710 	(void) Strcat(buf, STRsldthist);
711 	fp = creat(short2str(buf), 0600);
712 	if (fp == -1)
713 	    return;
714 	oldidfds = didfds;
715 	didfds = 0;
716 	ftmp = SHOUT;
717 	SHOUT = fp;
718 	(void) Strcpy(buf, value(STRsavehist));
719 	dumphist[2] = buf;
720 	dohist(dumphist);
721 	(void) close(fp);
722 	SHOUT = ftmp;
723 	didfds = oldidfds;
724     }
725 }
726 
727 void
728 goodbye()
729 {
730     rechist();
731 
732     if (loginsh) {
733 	(void) signal(SIGQUIT, SIG_IGN);
734 	(void) signal(SIGINT, SIG_IGN);
735 	(void) signal(SIGTERM, SIG_IGN);
736 	setintr = 0;		/* No interrupts after "logout" */
737 	if (!(adrof(STRlogout)))
738 	    set(STRlogout, STRnormal);
739 #ifdef _PATH_DOTLOGOUT
740 	(void) srcfile(_PATH_DOTLOGOUT, 0, 0);
741 #endif
742 	if (adrof(STRhome))
743 	    (void) srccat(value(STRhome), STRsldtlogout);
744     }
745     exitstat();
746 }
747 
748 void
749 exitstat()
750 {
751 
752 #ifdef PROF
753     monitor(0);
754 #endif
755     /*
756      * Note that if STATUS is corrupted (i.e. getn bombs) then error will exit
757      * directly because we poke child here. Otherwise we might continue
758      * unwarrantedly (sic).
759      */
760     child = 1;
761     xexit(getn(value(STRstatus)));
762 }
763 
764 /*
765  * in the event of a HUP we want to save the history
766  */
767 static void
768 phup(sig)
769 int sig;
770 {
771     rechist();
772     xexit(sig);
773 }
774 
775 Char   *jobargv[2] = {STRjobs, 0};
776 
777 /*
778  * Catch an interrupt, e.g. during lexical input.
779  * If we are an interactive shell, we reset the interrupt catch
780  * immediately.  In any case we drain the shell output,
781  * and finally go through the normal error mechanism, which
782  * gets a chance to make the shell go away.
783  */
784 /* ARGSUSED */
785 void
786 pintr(notused)
787 	int notused;
788 {
789     pintr1(1);
790 }
791 
792 void
793 pintr1(wantnl)
794     bool    wantnl;
795 {
796     register Char **v;
797     sigset_t omask;
798 
799     omask = sigblock((sigset_t) 0);
800     if (setintr) {
801 	(void) sigsetmask(omask & ~sigmask(SIGINT));
802 	if (pjobs) {
803 	    pjobs = 0;
804 	    xprintf("\n");
805 	    dojobs(jobargv);
806 	    stderror(ERR_NAME | ERR_INTR);
807 	}
808     }
809     (void) sigsetmask(omask & ~sigmask(SIGCHLD));
810     draino();
811     (void) endpwent();
812 
813     /*
814      * If we have an active "onintr" then we search for the label. Note that if
815      * one does "onintr -" then we shan't be interruptible so we needn't worry
816      * about that here.
817      */
818     if (gointr) {
819 	search(T_GOTO, 0, gointr);
820 	timflg = 0;
821 	if (v = pargv)
822 	    pargv = 0, blkfree(v);
823 	if (v = gargv)
824 	    gargv = 0, blkfree(v);
825 	reset();
826     }
827     else if (intty && wantnl) {
828 	(void) putraw('\r');
829 	(void) putraw('\n');
830     }
831     stderror(ERR_SILENT);
832 }
833 
834 /*
835  * Process is the main driving routine for the shell.
836  * It runs all command processing, except for those within { ... }
837  * in expressions (which is run by a routine evalav in sh.exp.c which
838  * is a stripped down process), and `...` evaluation which is run
839  * also by a subset of this code in sh.glob.c in the routine backeval.
840  *
841  * The code here is a little strange because part of it is interruptible
842  * and hence freeing of structures appears to occur when none is necessary
843  * if this is ignored.
844  *
845  * Note that if catch is not set then we will unwind on any error.
846  * If an end-of-file occurs, we return.
847  */
848 void
849 process(catch)
850     bool    catch;
851 {
852     jmp_buf osetexit;
853     struct command *t;
854 
855     getexit(osetexit);
856     for (;;) {
857 	pendjob();
858 	paraml.next = paraml.prev = &paraml;
859 	paraml.word = STRNULL;
860 	t = 0;
861 	(void) setexit();
862 	justpr = enterhist;	/* execute if not entering history */
863 
864 	/*
865 	 * Interruptible during interactive reads
866 	 */
867 	if (setintr)
868 	    (void) sigsetmask(sigblock((sigset_t) 0) & ~sigmask(SIGINT));
869 
870 	/*
871 	 * For the sake of reset()
872 	 */
873 	freelex(&paraml);
874 	freesyn(t);
875 	t = 0;
876 
877 	if (haderr) {
878 	    if (!catch) {
879 		/* unwind */
880 		doneinp = 0;
881 		resexit(osetexit);
882 		reset();
883 	    }
884 	    haderr = 0;
885 	    /*
886 	     * Every error is eventually caught here or the shell dies.  It is
887 	     * at this point that we clean up any left-over open files, by
888 	     * closing all but a fixed number of pre-defined files.  Thus
889 	     * routines don't have to worry about leaving files open due to
890 	     * deeper errors... they will get closed here.
891 	     */
892 	    closem();
893 	    continue;
894 	}
895 	if (doneinp) {
896 	    doneinp = 0;
897 	    break;
898 	}
899 	if (chkstop)
900 	    chkstop--;
901 	if (neednote)
902 	    pnote();
903 	if (intty && prompt && evalvec == 0) {
904 	    mailchk();
905 	    /*
906 	     * If we are at the end of the input buffer then we are going to
907 	     * read fresh stuff. Otherwise, we are rereading input and don't
908 	     * need or want to prompt.
909 	     */
910 	    if (fseekp == feobp)
911 		printprompt();
912 	    flush();
913 	}
914 	if (seterr) {
915 	    xfree((ptr_t) seterr);
916 	    seterr = NULL;
917 	}
918 
919 	/*
920 	 * Echo not only on VERBOSE, but also with history expansion. If there
921 	 * is a lexical error then we forego history echo.
922 	 */
923 	if (lex(&paraml) && !seterr && intty || adrof(STRverbose)) {
924 	    haderr = 1;
925 	    prlex(&paraml);
926 	    haderr = 0;
927 	}
928 
929 	/*
930 	 * The parser may lose space if interrupted.
931 	 */
932 	if (setintr)
933 	    (void) sigblock(sigmask(SIGINT));
934 
935 	/*
936 	 * Save input text on the history list if reading in old history, or it
937 	 * is from the terminal at the top level and not in a loop.
938 	 *
939 	 * PWP: entry of items in the history list while in a while loop is done
940 	 * elsewhere...
941 	 */
942 	if (enterhist || catch && intty && !whyles)
943 	    savehist(&paraml);
944 
945 	/*
946 	 * Print lexical error messages, except when sourcing history lists.
947 	 */
948 	if (!enterhist && seterr)
949 	    stderror(ERR_OLD);
950 
951 	/*
952 	 * If had a history command :p modifier then this is as far as we
953 	 * should go
954 	 */
955 	if (justpr)
956 	    reset();
957 
958 	alias(&paraml);
959 
960 	/*
961 	 * Parse the words of the input into a parse tree.
962 	 */
963 	t = syntax(paraml.next, &paraml, 0);
964 	if (seterr)
965 	    stderror(ERR_OLD);
966 
967 	execute(t, (tpgrp > 0 ? tpgrp : -1), NULL, NULL);
968 
969 	/*
970 	 * Made it!
971 	 */
972 	freelex(&paraml);
973 	freesyn(t);
974     }
975     resexit(osetexit);
976 }
977 
978 void
979 dosource(t)
980     register Char **t;
981 {
982     register Char *f;
983     bool    hflg = 0;
984     Char    buf[BUFSIZ];
985 
986     t++;
987     if (*t && eq(*t, STRmh)) {
988 	if (*++t == NULL)
989 	    stderror(ERR_NAME | ERR_HFLAG);
990 	hflg++;
991     }
992     (void) Strcpy(buf, *t);
993     f = globone(buf, G_ERROR);
994     (void) strcpy((char *) buf, short2str(f));
995     xfree((ptr_t) f);
996     if (!srcfile((char *) buf, 0, hflg) && !hflg)
997 	stderror(ERR_SYSTEM, (char *) buf, strerror(errno));
998 }
999 
1000 /*
1001  * Check for mail.
1002  * If we are a login shell, then we don't want to tell
1003  * about any mail file unless its been modified
1004  * after the time we started.
1005  * This prevents us from telling the user things he already
1006  * knows, since the login program insists on saying
1007  * "You have mail."
1008  */
1009 static void
1010 mailchk()
1011 {
1012     register struct varent *v;
1013     register Char **vp;
1014     time_t  t;
1015     int     intvl, cnt;
1016     struct stat stb;
1017     bool    new;
1018 
1019     v = adrof(STRmail);
1020     if (v == 0)
1021 	return;
1022     (void) time(&t);
1023     vp = v->vec;
1024     cnt = blklen(vp);
1025     intvl = (cnt && number(*vp)) ? (--cnt, getn(*vp++)) : MAILINTVL;
1026     if (intvl < 1)
1027 	intvl = 1;
1028     if (chktim + intvl > t)
1029 	return;
1030     for (; *vp; vp++) {
1031 	if (stat(short2str(*vp), &stb) < 0)
1032 	    continue;
1033 	new = stb.st_mtime > time0.tv_sec;
1034 	if (stb.st_size == 0 || stb.st_atime > stb.st_mtime ||
1035 	    (stb.st_atime < chktim && stb.st_mtime < chktim) ||
1036 	    loginsh && !new)
1037 	    continue;
1038 	if (cnt == 1)
1039 	    xprintf("You have %smail.\n", new ? "new " : "");
1040 	else
1041 	    xprintf("%s in %s.\n", new ? "New mail" : "Mail", short2str(*vp));
1042     }
1043     chktim = t;
1044 }
1045 
1046 /*
1047  * Extract a home directory from the password file
1048  * The argument points to a buffer where the name of the
1049  * user whose home directory is sought is currently.
1050  * We write the home directory of the user back there.
1051  */
1052 int
1053 gethdir(home)
1054     Char   *home;
1055 {
1056     Char   *h;
1057     struct passwd *pw;
1058 
1059     /*
1060      * Is it us?
1061      */
1062     if (*home == '\0') {
1063 	if (h = value(STRhome)) {
1064 	    (void) Strcpy(home, h);
1065 	    return 0;
1066 	}
1067 	else
1068 	    return 1;
1069     }
1070 
1071     if (pw = getpwnam(short2str(home))) {
1072 	(void) Strcpy(home, str2short(pw->pw_dir));
1073 	return 0;
1074     }
1075     else
1076 	return 1;
1077 }
1078 
1079 /*
1080  * Move the initial descriptors to their eventual
1081  * resting places, closin all other units.
1082  */
1083 void
1084 initdesc()
1085 {
1086 
1087     didfds = 0;			/* 0, 1, 2 aren't set up */
1088     (void) ioctl(SHIN = dcopy(0, FSHIN), FIOCLEX, NULL);
1089     (void) ioctl(SHOUT = dcopy(1, FSHOUT), FIOCLEX, NULL);
1090     (void) ioctl(SHDIAG = dcopy(2, FSHDIAG), FIOCLEX, NULL);
1091     (void) ioctl(OLDSTD = dcopy(SHIN, FOLDSTD), FIOCLEX, NULL);
1092     closem();
1093 }
1094 
1095 
1096 void
1097 #ifdef PROF
1098 done(i)
1099 #else
1100 xexit(i)
1101 #endif
1102     int     i;
1103 {
1104     untty();
1105     _exit(i);
1106 }
1107 
1108 static Char **
1109 defaultpath()
1110 {
1111     char   *ptr;
1112     Char  **blk, **blkp;
1113     struct stat stb;
1114 
1115     blkp = blk = (Char **) xmalloc((size_t) sizeof(Char *) * 10);
1116 
1117 #define DIRAPPEND(a)  \
1118 	if (stat(ptr = a, &stb) == 0 && (stb.st_mode & S_IFMT) == S_IFDIR) \
1119 		*blkp++ = SAVE(ptr)
1120 
1121     DIRAPPEND(_PATH_BIN);
1122     DIRAPPEND(_PATH_USRBIN);
1123 
1124 #undef DIRAPPEND
1125 
1126     *blkp++ = Strsave(STRdot);
1127     *blkp = NULL;
1128     return (blk);
1129 }
1130 
1131 void
1132 printprompt()
1133 {
1134     register Char *cp;
1135 
1136     if (!whyles) {
1137 	for (cp = value(STRprompt); *cp; cp++)
1138 	    if (*cp == HIST)
1139 		xprintf("%d", eventno + 1);
1140 	    else {
1141 		if (*cp == '\\' && cp[1] == HIST)
1142 		    cp++;
1143 		xputchar(*cp | QUOTE);
1144 	    }
1145     }
1146     else
1147 	/*
1148 	 * Prompt for forward reading loop body content.
1149 	 */
1150 	xprintf("? ");
1151     flush();
1152 }
1153