xref: /freebsd/usr.bin/mail/lex.c (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1980, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include "rcv.h"
33 #include <errno.h>
34 #include <fcntl.h>
35 #include "extern.h"
36 
37 /*
38  * Mail -- a mail program
39  *
40  * Lexical processing of commands.
41  */
42 
43 static const char	*prompt = "& ";
44 
45 extern const struct cmd cmdtab[];
46 extern const char *version;
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  * If the -e option is being passed to mail, this function has a
55  * tri-state return code: -1 on error, 0 on no mail, 1 if there is
56  * mail.
57  */
58 int
59 setfile(char *name)
60 {
61 	FILE *ibuf;
62 	int checkmode, i, fd;
63 	struct stat stb;
64 	char isedit = *name != '%' || getuserid(myname) != getuid();
65 	char *who = name[1] ? name + 1 : myname;
66 	char tempname[PATHSIZE];
67 	static int shudclob;
68 
69 	checkmode = value("checkmode") != NULL;
70 	if ((name = expand(name)) == NULL)
71 		return (-1);
72 
73 	if ((ibuf = Fopen(name, "r")) == NULL) {
74 		if (!isedit && errno == ENOENT)
75 			goto nomail;
76 		warn("%s", name);
77 		return (-1);
78 	}
79 
80 	if (fstat(fileno(ibuf), &stb) < 0) {
81 		warn("fstat");
82 		(void)Fclose(ibuf);
83 		return (-1);
84 	}
85 
86 	if (S_ISDIR(stb.st_mode) || !S_ISREG(stb.st_mode)) {
87 		(void)Fclose(ibuf);
88 		errno = S_ISDIR(stb.st_mode) ? EISDIR : EINVAL;
89 		warn("%s", name);
90 		return (-1);
91 	}
92 
93 	/*
94 	 * Looks like all will be well.  We must now relinquish our
95 	 * hold on the current set of stuff.  Must hold signals
96 	 * while we are reading the new file, else we will ruin
97 	 * the message[] data structure.
98 	 */
99 
100 	holdsigs();
101 	if (shudclob)
102 		quit();
103 
104 	/*
105 	 * Copy the messages into /tmp
106 	 * and set pointers.
107 	 */
108 
109 	readonly = 0;
110 	if ((i = open(name, 1)) < 0)
111 		readonly++;
112 	else
113 		(void)close(i);
114 	if (shudclob) {
115 		(void)fclose(itf);
116 		(void)fclose(otf);
117 	}
118 	shudclob = 1;
119 	edit = isedit;
120 	strlcpy(prevfile, mailname, sizeof(prevfile));
121 	if (name != mailname)
122 		strlcpy(mailname, name, sizeof(mailname));
123 	mailsize = fsize(ibuf);
124 	(void)snprintf(tempname, sizeof(tempname),
125 	    "%s/mail.RxXXXXXXXXXX", tmpdir);
126 	if ((fd = mkstemp(tempname)) == -1 || (otf = fdopen(fd, "w")) == NULL)
127 		err(1, "%s", tempname);
128 	(void)fcntl(fileno(otf), F_SETFD, 1);
129 	if ((itf = fopen(tempname, "r")) == NULL)
130 		err(1, "%s", tempname);
131 	(void)fcntl(fileno(itf), F_SETFD, 1);
132 	(void)rm(tempname);
133 	setptr(ibuf, 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 = ftello(ibuf);
141 	(void)Fclose(ibuf);
142 	relsesigs();
143 	sawcom = 0;
144 
145 	if ((checkmode || !edit) && msgCount == 0) {
146 nomail:
147 		if (!checkmode) {
148 			fprintf(stderr, "No mail for %s\n", who);
149 			return (-1);
150 		} else
151 			return (0);
152 	}
153 	return (checkmode ? 1 : 0);
154 }
155 
156 /*
157  * Incorporate any new mail that has arrived since we first
158  * started reading mail.
159  */
160 int
161 incfile(void)
162 {
163 	off_t newsize;
164 	int omsgCount = msgCount;
165 	FILE *ibuf;
166 
167 	ibuf = Fopen(mailname, "r");
168 	if (ibuf == NULL)
169 		return (-1);
170 	holdsigs();
171 	newsize = fsize(ibuf);
172 	if (newsize == 0)
173 		return (-1);		/* mail box is now empty??? */
174 	if (newsize < mailsize)
175 		return (-1);		/* mail box has shrunk??? */
176 	if (newsize == mailsize)
177 		return (0);		/* no new mail */
178 	setptr(ibuf, mailsize);
179 	setmsize(msgCount);
180 	mailsize = ftello(ibuf);
181 	(void)Fclose(ibuf);
182 	relsesigs();
183 	return (msgCount - omsgCount);
184 }
185 
186 static int	*msgvec;
187 static int	reset_on_stop;		/* do a reset() if stopped */
188 
189 /*
190  * Interpret user commands one by one.  If standard input is not a tty,
191  * print no prompt.
192  */
193 void
194 commands(void)
195 {
196 	int n, eofloop = 0;
197 	char linebuf[LINESIZE];
198 
199 	if (!sourcing) {
200 		if (signal(SIGINT, SIG_IGN) != SIG_IGN)
201 			(void)signal(SIGINT, intr);
202 		if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
203 			(void)signal(SIGHUP, hangup);
204 		(void)signal(SIGTSTP, stop);
205 		(void)signal(SIGTTOU, stop);
206 		(void)signal(SIGTTIN, stop);
207 	}
208 	setexit();
209 	for (;;) {
210 		/*
211 		 * Print the prompt, if needed.  Clear out
212 		 * string space, and flush the output.
213 		 */
214 		if (!sourcing && value("interactive") != NULL) {
215 			if ((value("autoinc") != NULL) && (incfile() > 0))
216 				printf("New mail has arrived.\n");
217 			reset_on_stop = 1;
218 			printf("%s", prompt);
219 		}
220 		(void)fflush(stdout);
221 		sreset();
222 		/*
223 		 * Read a line of commands from the current input
224 		 * and handle end of file specially.
225 		 */
226 		n = 0;
227 		for (;;) {
228 			if (readline(input, &linebuf[n], LINESIZE - n) < 0) {
229 				if (n == 0)
230 					n = -1;
231 				break;
232 			}
233 			if ((n = strlen(linebuf)) == 0)
234 				break;
235 			n--;
236 			if (linebuf[n] != '\\')
237 				break;
238 			linebuf[n++] = ' ';
239 		}
240 		reset_on_stop = 0;
241 		if (n < 0) {
242 				/* eof */
243 			if (loading)
244 				break;
245 			if (sourcing) {
246 				unstack();
247 				continue;
248 			}
249 			if (value("interactive") != NULL &&
250 			    value("ignoreeof") != NULL &&
251 			    ++eofloop < 25) {
252 				printf("Use \"quit\" to quit.\n");
253 				continue;
254 			}
255 			break;
256 		}
257 		eofloop = 0;
258 		if (execute(linebuf, 0))
259 			break;
260 	}
261 }
262 
263 /*
264  * Execute a single command.
265  * Command functions return 0 for success, 1 for error, and -1
266  * for abort.  A 1 or -1 aborts a load or source.  A -1 aborts
267  * the interactive command loop.
268  * Contxt is non-zero if called while composing mail.
269  */
270 int
271 execute(char linebuf[], int contxt)
272 {
273 	char word[LINESIZE];
274 	char *arglist[MAXARGC];
275 	const struct cmd *com;
276 	char *cp, *cp2;
277 	int c, muvec[2];
278 	int e = 1;
279 
280 	/*
281 	 * Strip the white space away from the beginning
282 	 * of the command, then scan out a word, which
283 	 * consists of anything except digits and white space.
284 	 *
285 	 * Handle ! escapes differently to get the correct
286 	 * lexical conventions.
287 	 */
288 
289 	for (cp = linebuf; isspace((unsigned char)*cp); cp++)
290 		;
291 	if (*cp == '!') {
292 		if (sourcing) {
293 			printf("Can't \"!\" while sourcing\n");
294 			goto out;
295 		}
296 		shell(cp+1);
297 		return (0);
298 	}
299 	cp2 = word;
300 	while (*cp != '\0' && strchr(" \t0123456789$^.:/-+*'\"", *cp) == NULL)
301 		*cp2++ = *cp++;
302 	*cp2 = '\0';
303 
304 	/*
305 	 * Look up the command; if not found, bitch.
306 	 * Normally, a blank command would map to the
307 	 * first command in the table; while sourcing,
308 	 * however, we ignore blank lines to eliminate
309 	 * confusion.
310 	 */
311 
312 	if (sourcing && *word == '\0')
313 		return (0);
314 	com = lex(word);
315 	if (com == NULL) {
316 		printf("Unknown command: \"%s\"\n", word);
317 		goto out;
318 	}
319 
320 	/*
321 	 * See if we should execute the command -- if a conditional
322 	 * we always execute it, otherwise, check the state of cond.
323 	 */
324 
325 	if ((com->c_argtype & F) == 0)
326 		if ((cond == CRCV && !rcvmode) || (cond == CSEND && rcvmode))
327 			return (0);
328 
329 	/*
330 	 * Process the arguments to the command, depending
331 	 * on the type he expects.  Default to an error.
332 	 * If we are sourcing an interactive command, it's
333 	 * an error.
334 	 */
335 
336 	if (!rcvmode && (com->c_argtype & M) == 0) {
337 		printf("May not execute \"%s\" while sending\n",
338 		    com->c_name);
339 		goto out;
340 	}
341 	if (sourcing && com->c_argtype & I) {
342 		printf("May not execute \"%s\" while sourcing\n",
343 		    com->c_name);
344 		goto out;
345 	}
346 	if (readonly && com->c_argtype & W) {
347 		printf("May not execute \"%s\" -- message file is read only\n",
348 		   com->c_name);
349 		goto out;
350 	}
351 	if (contxt && com->c_argtype & R) {
352 		printf("Cannot recursively invoke \"%s\"\n", com->c_name);
353 		goto out;
354 	}
355 	switch (com->c_argtype & ~(F|P|I|M|T|W|R)) {
356 	case MSGLIST:
357 		/*
358 		 * A message list defaulting to nearest forward
359 		 * legal message.
360 		 */
361 		if (msgvec == 0) {
362 			printf("Illegal use of \"message list\"\n");
363 			break;
364 		}
365 		if ((c = getmsglist(cp, msgvec, com->c_msgflag)) < 0)
366 			break;
367 		if (c  == 0) {
368 			*msgvec = first(com->c_msgflag, com->c_msgmask);
369 			msgvec[1] = 0;
370 		}
371 		if (*msgvec == 0) {
372 			printf("No applicable messages\n");
373 			break;
374 		}
375 		e = (*com->c_func)(msgvec);
376 		break;
377 
378 	case NDMLIST:
379 		/*
380 		 * A message list with no defaults, but no error
381 		 * if none exist.
382 		 */
383 		if (msgvec == 0) {
384 			printf("Illegal use of \"message list\"\n");
385 			break;
386 		}
387 		if (getmsglist(cp, msgvec, com->c_msgflag) < 0)
388 			break;
389 		e = (*com->c_func)(msgvec);
390 		break;
391 
392 	case STRLIST:
393 		/*
394 		 * Just the straight string, with
395 		 * leading blanks removed.
396 		 */
397 		while (isspace((unsigned char)*cp))
398 			cp++;
399 		e = (*com->c_func)(cp);
400 		break;
401 
402 	case RAWLIST:
403 		/*
404 		 * A vector of strings, in shell style.
405 		 */
406 		if ((c = getrawlist(cp, arglist,
407 		    sizeof(arglist) / sizeof(*arglist))) < 0)
408 			break;
409 		if (c < com->c_minargs) {
410 			printf("%s requires at least %d arg(s)\n",
411 			    com->c_name, com->c_minargs);
412 			break;
413 		}
414 		if (c > com->c_maxargs) {
415 			printf("%s takes no more than %d arg(s)\n",
416 			    com->c_name, com->c_maxargs);
417 			break;
418 		}
419 		e = (*com->c_func)(arglist);
420 		break;
421 
422 	case NOLIST:
423 		/*
424 		 * Just the constant zero, for exiting,
425 		 * eg.
426 		 */
427 		e = (*com->c_func)(0);
428 		break;
429 
430 	default:
431 		errx(1, "Unknown argtype");
432 	}
433 
434 out:
435 	/*
436 	 * Exit the current source file on
437 	 * error.
438 	 */
439 	if (e) {
440 		if (e < 0)
441 			return (1);
442 		if (loading)
443 			return (1);
444 		if (sourcing)
445 			unstack();
446 		return (0);
447 	}
448 	if (com == NULL)
449 		return (0);
450 	if (value("autoprint") != NULL && com->c_argtype & P)
451 		if ((dot->m_flag & MDELETED) == 0) {
452 			muvec[0] = dot - &message[0] + 1;
453 			muvec[1] = 0;
454 			type(muvec);
455 		}
456 	if (!sourcing && (com->c_argtype & T) == 0)
457 		sawcom = 1;
458 	return (0);
459 }
460 
461 /*
462  * Set the size of the message vector used to construct argument
463  * lists to message list functions.
464  */
465 void
466 setmsize(int sz)
467 {
468 
469 	if (msgvec != NULL)
470 		(void)free(msgvec);
471 	msgvec = calloc((unsigned)(sz + 1), sizeof(*msgvec));
472 }
473 
474 /*
475  * Find the correct command in the command table corresponding
476  * to the passed command "word"
477  */
478 
479 const struct cmd *
480 lex(char word[])
481 {
482 	const struct cmd *cp;
483 
484 	/*
485 	 * ignore trailing chars after `#'
486 	 *
487 	 * lines with beginning `#' are comments
488 	 * spaces before `#' are ignored in execute()
489 	 */
490 
491 	if (*word == '#')
492 	    *(word+1) = '\0';
493 
494 
495 	for (cp = &cmdtab[0]; cp->c_name != NULL; cp++)
496 		if (isprefix(word, cp->c_name))
497 			return (cp);
498 	return (NULL);
499 }
500 
501 /*
502  * Determine if as1 is a valid prefix of as2.
503  * Return true if yep.
504  */
505 int
506 isprefix(const char *as1, const char *as2)
507 {
508 	const char *s1, *s2;
509 
510 	s1 = as1;
511 	s2 = as2;
512 	while (*s1++ == *s2)
513 		if (*s2++ == '\0')
514 			return (1);
515 	return (*--s1 == '\0');
516 }
517 
518 /*
519  * The following gets called on receipt of an interrupt.  This is
520  * to abort printout of a command, mainly.
521  * Dispatching here when command() is inactive crashes rcv.
522  * Close all open files except 0, 1, 2, and the temporary.
523  * Also, unstack all source files.
524  */
525 
526 static int	inithdr;		/* am printing startup headers */
527 
528 void
529 intr(int s __unused)
530 {
531 
532 	noreset = 0;
533 	if (!inithdr)
534 		sawcom++;
535 	inithdr = 0;
536 	while (sourcing)
537 		unstack();
538 
539 	close_all_files();
540 
541 	if (image >= 0) {
542 		(void)close(image);
543 		image = -1;
544 	}
545 	fprintf(stderr, "Interrupt\n");
546 	reset(0);
547 }
548 
549 /*
550  * When we wake up after ^Z, reprint the prompt.
551  */
552 void
553 stop(int s)
554 {
555 	sig_t old_action = signal(s, SIG_DFL);
556 	sigset_t nset;
557 
558 	(void)sigemptyset(&nset);
559 	(void)sigaddset(&nset, s);
560 	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
561 	(void)kill(0, s);
562 	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
563 	(void)signal(s, old_action);
564 	if (reset_on_stop) {
565 		reset_on_stop = 0;
566 		reset(0);
567 	}
568 }
569 
570 /*
571  * Branch here on hangup signal and simulate "exit".
572  */
573 void
574 hangup(int s __unused)
575 {
576 
577 	/* nothing to do? */
578 	exit(1);
579 }
580 
581 /*
582  * Announce the presence of the current Mail version,
583  * give the message count, and print a header listing.
584  */
585 void
586 announce(void)
587 {
588 	int vec[2], mdot;
589 
590 	mdot = newfileinfo(0);
591 	vec[0] = mdot;
592 	vec[1] = 0;
593 	dot = &message[mdot - 1];
594 	if (msgCount > 0 && value("noheader") == NULL) {
595 		inithdr++;
596 		headers(vec);
597 		inithdr = 0;
598 	}
599 }
600 
601 /*
602  * Announce information about the file we are editing.
603  * Return a likely place to set dot.
604  */
605 int
606 newfileinfo(int omsgCount)
607 {
608 	struct message *mp;
609 	int u, n, mdot, d, s;
610 	char fname[PATHSIZE+1], zname[PATHSIZE+1], *ename;
611 
612 	for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
613 		if (mp->m_flag & MNEW)
614 			break;
615 	if (mp >= &message[msgCount])
616 		for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
617 			if ((mp->m_flag & MREAD) == 0)
618 				break;
619 	if (mp < &message[msgCount])
620 		mdot = mp - &message[0] + 1;
621 	else
622 		mdot = omsgCount + 1;
623 	s = d = 0;
624 	for (mp = &message[0], n = 0, u = 0; mp < &message[msgCount]; mp++) {
625 		if (mp->m_flag & MNEW)
626 			n++;
627 		if ((mp->m_flag & MREAD) == 0)
628 			u++;
629 		if (mp->m_flag & MDELETED)
630 			d++;
631 		if (mp->m_flag & MSAVED)
632 			s++;
633 	}
634 	ename = mailname;
635 	if (getfold(fname, sizeof(fname) - 1) >= 0) {
636 		strcat(fname, "/");
637 		if (strncmp(fname, mailname, strlen(fname)) == 0) {
638 			(void)snprintf(zname, sizeof(zname), "+%s",
639 			    mailname + strlen(fname));
640 			ename = zname;
641 		}
642 	}
643 	printf("\"%s\": ", ename);
644 	if (msgCount == 1)
645 		printf("1 message");
646 	else
647 		printf("%d messages", msgCount);
648 	if (n > 0)
649 		printf(" %d new", n);
650 	if (u-n > 0)
651 		printf(" %d unread", u);
652 	if (d > 0)
653 		printf(" %d deleted", d);
654 	if (s > 0)
655 		printf(" %d saved", s);
656 	if (readonly)
657 		printf(" [Read only]");
658 	printf("\n");
659 	return (mdot);
660 }
661 
662 /*
663  * Print the current version number.
664  */
665 
666 int
667 pversion(void *arg __unused)
668 {
669 
670 	printf("Version %s\n", version);
671 	return (0);
672 }
673 
674 /*
675  * Load a file of user definitions.
676  */
677 void
678 load(char *name)
679 {
680 	FILE *in, *oldin;
681 
682 	if ((in = Fopen(name, "r")) == NULL)
683 		return;
684 	oldin = input;
685 	input = in;
686 	loading = 1;
687 	sourcing = 1;
688 	commands();
689 	loading = 0;
690 	sourcing = 0;
691 	input = oldin;
692 	(void)Fclose(in);
693 }
694