xref: /openbsd/usr.bin/mail/lex.c (revision d415bd75) 
1 /*	$OpenBSD: lex.c,v 1.43 2023/03/08 04:43:11 guenther Exp $	*/
2 /*	$NetBSD: lex.c,v 1.10 1997/05/17 19:55:13 pk Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "rcv.h"
34 #include <errno.h>
35 #include <fcntl.h>
36 #include "extern.h"
37 
38 /*
39  * Mail -- a mail program
40  *
41  * Lexical processing of commands.
42  */
43 
44 char	*prompt = "& ";
45 
46 const struct cmd *com;	/* command we are running */
47 
48 /*
49  * Set up editing on the given file name.
50  * If the first character of name is %, we are considered to be
51  * editing the file, otherwise we are reading our mail which has
52  * signficance for mbox and so forth.
53  */
54 int
55 setfile(char *name)
56 {
57 	FILE *ibuf;
58 	int i, fd;
59 	struct stat stb;
60 	char isedit = *name != '%';
61 	const char *who = name[1] ? name + 1 : myname;
62 	char tempname[PATHSIZE];
63 	static int shudclob;
64 
65 	if ((name = expand(name)) == NULL)
66 		return(-1);
67 
68 	if ((ibuf = Fopen(name, "r")) == NULL) {
69 		if (!isedit && errno == ENOENT)
70 			goto nomail;
71 		warn("%s", name);
72 		return(-1);
73 	}
74 
75 	if (fstat(fileno(ibuf), &stb) == -1) {
76 		warn("fstat");
77 		(void)Fclose(ibuf);
78 		return(-1);
79 	}
80 
81 	switch (stb.st_mode & S_IFMT) {
82 	case S_IFDIR:
83 		(void)Fclose(ibuf);
84 		warnc(EISDIR, "%s", name);
85 		return(-1);
86 
87 	case S_IFREG:
88 		break;
89 
90 	default:
91 		(void)Fclose(ibuf);
92 		warnc(EINVAL, "%s", name);
93 		return(-1);
94 	}
95 
96 	/*
97 	 * Looks like all will be well.  We must now relinquish our
98 	 * hold on the current set of stuff.  Must hold signals
99 	 * while we are reading the new file, else we will ruin
100 	 * the message[] data structure.
101 	 */
102 	holdsigs();
103 	if (shudclob)
104 		quit();
105 
106 	/*
107 	 * Copy the messages into /tmp
108 	 * and set pointers.
109 	 */
110 	readonly = 0;
111 	if ((i = open(name, O_WRONLY)) == -1)
112 		readonly++;
113 	else
114 		(void)close(i);
115 	if (shudclob) {
116 		(void)fclose(itf);
117 		(void)fclose(otf);
118 	}
119 	shudclob = 1;
120 	edit = isedit;
121 	strlcpy(prevfile, mailname, PATHSIZE);
122 	if (name != mailname)
123 		strlcpy(mailname, name, sizeof(mailname));
124 	mailsize = fsize(ibuf);
125 	(void)snprintf(tempname, sizeof(tempname),
126 	    "%s/mail.RxXXXXXXXXXX", tmpdir);
127 	if ((fd = mkostemp(tempname, O_CLOEXEC)) == -1 ||
128 	    (otf = fdopen(fd, "w")) == NULL)
129 		err(1, "%s", tempname);
130 	if ((itf = fopen(tempname, "re")) == NULL)
131 		err(1, "%s", tempname);
132 	(void)rm(tempname);
133 	setptr(ibuf, (off_t)0);
134 	setmsize(msgCount);
135 	/*
136 	 * New mail may have arrived while we were reading
137 	 * the mail file, so reset mailsize to be where
138 	 * we really are in the file...
139 	 */
140 	mailsize = ftell(ibuf);
141 	(void)Fclose(ibuf);
142 	relsesigs();
143 	sawcom = 0;
144 	if (!edit && msgCount == 0) {
145 nomail:
146 		fprintf(stderr, "No mail for %s\n", who);
147 		return(-1);
148 	}
149 	return(0);
150 }
151 
152 /*
153  * Incorporate any new mail that has arrived since we first
154  * started reading mail.
155  */
156 int
157 incfile(void)
158 {
159 	int newsize;
160 	int omsgCount = msgCount;
161 	FILE *ibuf;
162 
163 	ibuf = Fopen(mailname, "r");
164 	if (ibuf == NULL)
165 		return(-1);
166 	holdsigs();
167 	if (!spool_lock()) {
168 		(void)Fclose(ibuf);
169 		relsesigs();
170 		return(-1);
171 	}
172 	newsize = fsize(ibuf);
173 	/* make sure mail box has grown and is non-empty */
174 	if (newsize == 0 || newsize <= mailsize) {
175 		(void)Fclose(ibuf);
176 		spool_unlock();
177 		relsesigs();
178 		return(newsize == mailsize ? 0 : -1);
179 	}
180 	setptr(ibuf, mailsize);
181 	setmsize(msgCount);
182 	mailsize = ftell(ibuf);
183 	(void)Fclose(ibuf);
184 	spool_unlock();
185 	relsesigs();
186 	return(msgCount - omsgCount);
187 }
188 
189 
190 int	*msgvec;
191 int	reset_on_stop;			/* reset prompt if stopped */
192 
193 /*
194  * Interpret user commands one by one.  If standard input is not a tty,
195  * print no prompt.
196  */
197 void
198 commands(void)
199 {
200 	int n, sig, *sigp;
201 	int eofloop = 0;
202 	char linebuf[LINESIZE];
203 
204 	prompt:
205 	for (;;) {
206 		/*
207 		 * Print the prompt, if needed.  Clear out
208 		 * string space, and flush the output.
209 		 */
210 		if (!sourcing && value("interactive") != NULL) {
211 			if ((value("autoinc") != NULL) && (incfile() > 0))
212 				puts("New mail has arrived.");
213 			reset_on_stop = 1;
214 			printf("%s", prompt);
215 		}
216 		fflush(stdout);
217 		sreset();
218 		/*
219 		 * Read a line of commands from the current input
220 		 * and handle end of file specially.
221 		 */
222 		n = 0;
223 		sig = 0;
224 		sigp = sourcing ? NULL : &sig;
225 		for (;;) {
226 			if (readline(input, &linebuf[n], LINESIZE - n, sigp) < 0) {
227 				if (sig) {
228 					if (sig == SIGINT)
229 						dointr();
230 					else if (sig == SIGHUP)
231 						/* nothing to do? */
232 						exit(1);
233 					else {
234 						/* Stopped by job control */
235 						(void)kill(0, sig);
236 						if (reset_on_stop)
237 							reset_on_stop = 0;
238 					}
239 					goto prompt;
240 				}
241 				if (n == 0)
242 					n = -1;
243 				break;
244 			}
245 			if ((n = strlen(linebuf)) == 0)
246 				break;
247 			n--;
248 			if (linebuf[n] != '\\')
249 				break;
250 			linebuf[n++] = ' ';
251 		}
252 		reset_on_stop = 0;
253 		if (n < 0) {
254 				/* eof */
255 			if (loading)
256 				break;
257 			if (sourcing) {
258 				unstack();
259 				continue;
260 			}
261 			if (value("interactive") != NULL &&
262 			    value("ignoreeof") != NULL &&
263 			    ++eofloop < 25) {
264 				puts("Use \"quit\" to quit.");
265 				continue;
266 			}
267 			break;
268 		}
269 		eofloop = 0;
270 		if (execute(linebuf, 0))
271 			break;
272 	}
273 }
274 
275 /*
276  * Execute a single command.
277  * Command functions return 0 for success, 1 for error, and -1
278  * for abort.  A 1 or -1 aborts a load or source.  A -1 aborts
279  * the interactive command loop.
280  * Contxt is non-zero if called while composing mail.
281  */
282 int
283 execute(char *linebuf, int contxt)
284 {
285 	char word[LINESIZE];
286 	char *arglist[MAXARGC];
287 	char *cp, *cp2;
288 	int c, muvec[2];
289 	int e = 1;
290 
291 	com = NULL;
292 
293 	/*
294 	 * Strip the white space away from the beginning
295 	 * of the command, then scan out a word, which
296 	 * consists of anything except digits and white space.
297 	 *
298 	 * Handle ! escapes differently to get the correct
299 	 * lexical conventions.
300 	 */
301 	for (cp = linebuf; isspace((unsigned char)*cp); cp++)
302 		;
303 	if (*cp == '!') {
304 		if (sourcing) {
305 			puts("Can't \"!\" while sourcing");
306 			goto out;
307 		}
308 		shell(cp+1);
309 		return(0);
310 	}
311 	cp2 = word;
312 	while (*cp &&
313 	        strchr(" \t0123456789$^.:/-+*'\"", (unsigned char)*cp) == NULL)
314 		*cp2++ = *cp++;
315 	*cp2 = '\0';
316 
317 	/*
318 	 * Look up the command; if not found, bitch.
319 	 * Normally, a blank command would map to the
320 	 * first command in the table; while sourcing,
321 	 * however, we ignore blank lines to eliminate
322 	 * confusion.
323 	 */
324 	if (sourcing && *word == '\0')
325 		return(0);
326 	com = lex(word);
327 	if (com == NULL) {
328 		printf("Unknown command: \"%s\"\n", word);
329 		goto out;
330 	}
331 
332 	/*
333 	 * See if we should execute the command -- if a conditional
334 	 * we always execute it, otherwise, check the state of cond.
335 	 */
336 	if ((com->c_argtype & F) == 0)
337 		if ((cond == CRCV && !rcvmode) || (cond == CSEND && rcvmode))
338 			return(0);
339 
340 	/*
341 	 * Process the arguments to the command, depending
342 	 * on the type he expects.  Default to an error.
343 	 * If we are sourcing an interactive command, it's
344 	 * an error.
345 	 */
346 	if (!rcvmode && (com->c_argtype & M) == 0) {
347 		printf("May not execute \"%s\" while sending\n",
348 		    com->c_name);
349 		goto out;
350 	}
351 	if (sourcing && com->c_argtype & I) {
352 		printf("May not execute \"%s\" while sourcing\n",
353 		    com->c_name);
354 		goto out;
355 	}
356 	if (readonly && com->c_argtype & W) {
357 		printf("May not execute \"%s\" -- message file is read only\n",
358 		   com->c_name);
359 		goto out;
360 	}
361 	if (contxt && com->c_argtype & R) {
362 		printf("Cannot recursively invoke \"%s\"\n", com->c_name);
363 		goto out;
364 	}
365 	switch (com->c_argtype & ~(F|P|I|M|T|W|R)) {
366 	case MSGLIST|STRLIST:
367 		/*
368 		 * A message list defaulting to nearest forward
369 		 * legal message.
370 		 */
371 		if (msgvec == 0) {
372 			puts("Illegal use of \"message list\"");
373 			break;
374 		}
375 		/*
376 		 * remove leading blanks.
377 		 */
378 		while (isspace((unsigned char)*cp))
379 			cp++;
380 
381 		if (isdigit((unsigned char)*cp) || *cp == ':') {
382 			if ((c = getmsglist(cp, msgvec, com->c_msgflag)) < 0)
383 				break;
384 			/* position to next space - past the message list */
385 			while (!isspace((unsigned char)*cp))
386 				cp++;
387 			/* position to next non-space */
388 			while (isspace((unsigned char)*cp))
389 				cp++;
390 		} else {
391 			c = 0; /* no message list */
392 		}
393 
394 		if (c  == 0) {
395 			*msgvec = first(com->c_msgflag,
396 				com->c_msgmask);
397 			msgvec[1] = 0;
398 		}
399 		if (*msgvec == 0) {
400 			puts("No applicable messages");
401 			break;
402 		}
403 		/*
404 		 * Just the straight string, with
405 		 * leading blanks removed.
406 		 */
407 		while (isspace((unsigned char)*cp))
408 			cp++;
409 
410 		e = (*com->c_func2)(msgvec, cp);
411 		break;
412 
413 	case MSGLIST:
414 		/*
415 		 * A message list defaulting to nearest forward
416 		 * legal message.
417 		 */
418 		if (msgvec == NULL) {
419 			puts("Illegal use of \"message list\"");
420 			break;
421 		}
422 		if ((c = getmsglist(cp, msgvec, com->c_msgflag)) < 0)
423 			break;
424 		if (c  == 0) {
425 			*msgvec = first(com->c_msgflag,
426 				com->c_msgmask);
427 			msgvec[1] = 0;
428 		}
429 		if (*msgvec == 0) {
430 			puts("No applicable messages");
431 			break;
432 		}
433 		e = (*com->c_func)(msgvec);
434 		break;
435 
436 	case NDMLIST:
437 		/*
438 		 * A message list with no defaults, but no error
439 		 * if none exist.
440 		 */
441 		if (msgvec == 0) {
442 			puts("Illegal use of \"message list\"");
443 			break;
444 		}
445 		if (getmsglist(cp, msgvec, com->c_msgflag) < 0)
446 			break;
447 		e = (*com->c_func)(msgvec);
448 		break;
449 
450 	case STRLIST:
451 		/*
452 		 * Just the straight string, with
453 		 * leading blanks removed.
454 		 */
455 		while (isspace((unsigned char)*cp))
456 			cp++;
457 		e = (*com->c_func)(cp);
458 		break;
459 
460 	case RAWLIST:
461 		/*
462 		 * A vector of strings, in shell style.
463 		 */
464 		if ((c = getrawlist(cp, arglist,
465 				sizeof(arglist) / sizeof(*arglist))) < 0)
466 			break;
467 		if (c < com->c_minargs) {
468 			printf("%s requires at least %d arg(s)\n",
469 				com->c_name, com->c_minargs);
470 			break;
471 		}
472 		if (c > com->c_maxargs) {
473 			printf("%s takes no more than %d arg(s)\n",
474 				com->c_name, com->c_maxargs);
475 			break;
476 		}
477 		e = (*com->c_func)(arglist);
478 		break;
479 
480 	case NOLIST:
481 		/*
482 		 * Just the constant zero, for exiting,
483 		 * eg.
484 		 */
485 		e = (*com->c_func)(0);
486 		break;
487 
488 	default:
489 		errx(1, "Unknown argtype");
490 	}
491 
492 out:
493 	/*
494 	 * Exit the current source file on
495 	 * error.
496 	 */
497 	if (e) {
498 		if (e < 0)
499 			return(1);
500 		if (loading)
501 			return(1);
502 		if (sourcing)
503 			unstack();
504 		return(0);
505 	}
506 	if (com == NULL)
507 		return(0);
508 	if (value("autoprint") != NULL && com->c_argtype & P)
509 		if ((dot->m_flag & MDELETED) == 0) {
510 			muvec[0] = dot - &message[0] + 1;
511 			muvec[1] = 0;
512 			type(muvec);
513 		}
514 	if (!sourcing && (com->c_argtype & T) == 0)
515 		sawcom = 1;
516 	return(0);
517 }
518 
519 /*
520  * Set the size of the message vector used to construct argument
521  * lists to message list functions.
522  */
523 void
524 setmsize(int n)
525 {
526 	int *msgvec2;
527 	size_t msize;
528 
529 	msize = (n + 1) * sizeof(*msgvec);
530 	if ((msgvec2 = realloc(msgvec, msize)) == NULL)
531 		err(1, "realloc");
532 	msgvec = msgvec2;
533 	memset(msgvec, 0, msize);
534 }
535 
536 /*
537  * Find the correct command in the command table corresponding
538  * to the passed command "word"
539  */
540 
541 const struct cmd *
542 lex(char *word)
543 {
544 	extern const struct cmd cmdtab[];
545 	const struct cmd *cp;
546 
547 	if (word[0] == '#')
548 		word = "#";
549 	for (cp = &cmdtab[0]; cp->c_name != NULL; cp++)
550 		if (isprefix(word, cp->c_name))
551 			return(cp);
552 	return(NULL);
553 }
554 
555 /*
556  * Determine if as1 is a valid prefix of as2.
557  * Return true if yep.
558  */
559 int
560 isprefix(char *as1, char *as2)
561 {
562 	char *s1, *s2;
563 
564 	s1 = as1;
565 	s2 = as2;
566 	while (*s1++ == *s2)
567 		if (*s2++ == '\0')
568 			return(1);
569 	return(*--s1 == '\0');
570 }
571 
572 /*
573  * The following gets called on receipt of an interrupt.  This is
574  * to abort printout of a command, mainly.
575  * Dispatching here when command() is inactive crashes rcv.
576  * Close all open files except 0, 1, 2, and the temporary.
577  * Also, unstack all source files.
578  */
579 int	inithdr;			/* am printing startup headers */
580 
581 void
582 dointr(void)
583 {
584 
585 	noreset = 0;
586 	if (!inithdr)
587 		sawcom++;
588 	inithdr = 0;
589 	while (sourcing)
590 		unstack();
591 
592 	close_all_files();
593 
594 	if (image >= 0) {
595 		(void)close(image);
596 		image = -1;
597 	}
598 	fputs("Interrupt\n", stderr);
599 }
600 
601 /*
602  * Announce the presence of the current Mail version,
603  * give the message count, and print a header listing.
604  */
605 void
606 announce(void)
607 {
608 	int vec[2], mdot;
609 
610 	mdot = newfileinfo(0);
611 	vec[0] = mdot;
612 	vec[1] = 0;
613 	dot = &message[mdot - 1];
614 	if (msgCount > 0 && value("noheader") == NULL) {
615 		inithdr++;
616 		headers(vec);
617 		inithdr = 0;
618 	}
619 }
620 
621 /*
622  * Announce information about the file we are editing.
623  * Return a likely place to set dot.
624  */
625 int
626 newfileinfo(int omsgCount)
627 {
628 	struct message *mp;
629 	int u, n, mdot, d, s;
630 	char fname[PATHSIZE], zname[PATHSIZE], *ename;
631 
632 	for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
633 		if (mp->m_flag & MNEW)
634 			break;
635 	if (mp >= &message[msgCount])
636 		for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
637 			if ((mp->m_flag & MREAD) == 0)
638 				break;
639 	if (mp < &message[msgCount])
640 		mdot = mp - &message[0] + 1;
641 	else
642 		mdot = omsgCount + 1;
643 	s = d = 0;
644 	for (mp = &message[0], n = 0, u = 0; mp < &message[msgCount]; mp++) {
645 		if (mp->m_flag & MNEW)
646 			n++;
647 		if ((mp->m_flag & MREAD) == 0)
648 			u++;
649 		if (mp->m_flag & MDELETED)
650 			d++;
651 		if (mp->m_flag & MSAVED)
652 			s++;
653 	}
654 	ename = mailname;
655 	if (getfold(fname, sizeof(fname)) >= 0) {
656 		strlcat(fname, "/", sizeof(fname));
657 		if (strncmp(fname, mailname, strlen(fname)) == 0) {
658 			(void)snprintf(zname, sizeof(zname), "+%s",
659 			    mailname + strlen(fname));
660 			ename = zname;
661 		}
662 	}
663 	printf("\"%s\": ", ename);
664 	if (msgCount == 1)
665 		fputs("1 message", stdout);
666 	else
667 		printf("%d messages", msgCount);
668 	if (n > 0)
669 		printf(" %d new", n);
670 	if (u-n > 0)
671 		printf(" %d unread", u);
672 	if (d > 0)
673 		printf(" %d deleted", d);
674 	if (s > 0)
675 		printf(" %d saved", s);
676 	if (readonly)
677 		fputs(" [Read only]", stdout);
678 	putchar('\n');
679 	return(mdot);
680 }
681 
682 /*
683  * Print the current version number.
684  */
685 int
686 pversion(void *v)
687 {
688 	extern const char version[];
689 
690 	printf("Version %s\n", version);
691 	return(0);
692 }
693 
694 /*
695  * Load a file of user definitions.
696  */
697 void
698 load(char *name)
699 {
700 	FILE *in, *oldin;
701 
702 	if ((in = Fopen(name, "r")) == NULL)
703 		return;
704 	oldin = input;
705 	input = in;
706 	loading = 1;
707 	sourcing = 1;
708 	commands();
709 	loading = 0;
710 	sourcing = 0;
711 	input = oldin;
712 	(void)Fclose(in);
713 }
714