xref: /freebsd/usr.bin/mail/lex.c (revision 4c9a0adad18263ec8725d9bfc5f560c6ad1da8bd)
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 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)lex.c	8.2 (Berkeley) 4/20/95";
35 #endif
36 #endif /* not lint */
37 #include <sys/cdefs.h>
38 #include "rcv.h"
39 #include <errno.h>
40 #include <fcntl.h>
41 #include "extern.h"
42 
43 /*
44  * Mail -- a mail program
45  *
46  * Lexical processing of commands.
47  */
48 
49 static const char	*prompt = "& ";
50 
51 extern const struct cmd cmdtab[];
52 extern const char *version;
53 
54 /*
55  * Set up editing on the given file name.
56  * If the first character of name is %, we are considered to be
57  * editing the file, otherwise we are reading our mail which has
58  * signficance for mbox and so forth.
59  *
60  * If the -e option is being passed to mail, this function has a
61  * tri-state return code: -1 on error, 0 on no mail, 1 if there is
62  * mail.
63  */
64 int
65 setfile(char *name)
66 {
67 	FILE *ibuf;
68 	int checkmode, i, fd;
69 	struct stat stb;
70 	char isedit = *name != '%' || getuserid(myname) != getuid();
71 	char *who = name[1] ? name + 1 : myname;
72 	char tempname[PATHSIZE];
73 	static int shudclob;
74 
75 	checkmode = value("checkmode") != NULL;
76 	if ((name = expand(name)) == NULL)
77 		return (-1);
78 
79 	if ((ibuf = Fopen(name, "r")) == NULL) {
80 		if (!isedit && errno == ENOENT)
81 			goto nomail;
82 		warn("%s", name);
83 		return (-1);
84 	}
85 
86 	if (fstat(fileno(ibuf), &stb) < 0) {
87 		warn("fstat");
88 		(void)Fclose(ibuf);
89 		return (-1);
90 	}
91 
92 	if (S_ISDIR(stb.st_mode) || !S_ISREG(stb.st_mode)) {
93 		(void)Fclose(ibuf);
94 		errno = S_ISDIR(stb.st_mode) ? EISDIR : EINVAL;
95 		warn("%s", name);
96 		return (-1);
97 	}
98 
99 	/*
100 	 * Looks like all will be well.  We must now relinquish our
101 	 * hold on the current set of stuff.  Must hold signals
102 	 * while we are reading the new file, else we will ruin
103 	 * the message[] data structure.
104 	 */
105 
106 	holdsigs();
107 	if (shudclob)
108 		quit();
109 
110 	/*
111 	 * Copy the messages into /tmp
112 	 * and set pointers.
113 	 */
114 
115 	readonly = 0;
116 	if ((i = open(name, 1)) < 0)
117 		readonly++;
118 	else
119 		(void)close(i);
120 	if (shudclob) {
121 		(void)fclose(itf);
122 		(void)fclose(otf);
123 	}
124 	shudclob = 1;
125 	edit = isedit;
126 	strlcpy(prevfile, mailname, sizeof(prevfile));
127 	if (name != mailname)
128 		strlcpy(mailname, name, sizeof(mailname));
129 	mailsize = fsize(ibuf);
130 	(void)snprintf(tempname, sizeof(tempname),
131 	    "%s/mail.RxXXXXXXXXXX", tmpdir);
132 	if ((fd = mkstemp(tempname)) == -1 || (otf = fdopen(fd, "w")) == NULL)
133 		err(1, "%s", tempname);
134 	(void)fcntl(fileno(otf), F_SETFD, 1);
135 	if ((itf = fopen(tempname, "r")) == NULL)
136 		err(1, "%s", tempname);
137 	(void)fcntl(fileno(itf), F_SETFD, 1);
138 	(void)rm(tempname);
139 	setptr(ibuf, 0);
140 	setmsize(msgCount);
141 	/*
142 	 * New mail may have arrived while we were reading
143 	 * the mail file, so reset mailsize to be where
144 	 * we really are in the file...
145 	 */
146 	mailsize = ftello(ibuf);
147 	(void)Fclose(ibuf);
148 	relsesigs();
149 	sawcom = 0;
150 
151 	if ((checkmode || !edit) && msgCount == 0) {
152 nomail:
153 		if (!checkmode) {
154 			fprintf(stderr, "No mail for %s\n", who);
155 			return (-1);
156 		} else
157 			return (0);
158 	}
159 	return (checkmode ? 1 : 0);
160 }
161 
162 /*
163  * Incorporate any new mail that has arrived since we first
164  * started reading mail.
165  */
166 int
167 incfile(void)
168 {
169 	off_t newsize;
170 	int omsgCount = msgCount;
171 	FILE *ibuf;
172 
173 	ibuf = Fopen(mailname, "r");
174 	if (ibuf == NULL)
175 		return (-1);
176 	holdsigs();
177 	newsize = fsize(ibuf);
178 	if (newsize == 0)
179 		return (-1);		/* mail box is now empty??? */
180 	if (newsize < mailsize)
181 		return (-1);		/* mail box has shrunk??? */
182 	if (newsize == mailsize)
183 		return (0);		/* no new mail */
184 	setptr(ibuf, mailsize);
185 	setmsize(msgCount);
186 	mailsize = ftello(ibuf);
187 	(void)Fclose(ibuf);
188 	relsesigs();
189 	return (msgCount - omsgCount);
190 }
191 
192 static int	*msgvec;
193 static int	reset_on_stop;		/* do a reset() if stopped */
194 
195 /*
196  * Interpret user commands one by one.  If standard input is not a tty,
197  * print no prompt.
198  */
199 void
200 commands(void)
201 {
202 	int n, eofloop = 0;
203 	char linebuf[LINESIZE];
204 
205 	if (!sourcing) {
206 		if (signal(SIGINT, SIG_IGN) != SIG_IGN)
207 			(void)signal(SIGINT, intr);
208 		if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
209 			(void)signal(SIGHUP, hangup);
210 		(void)signal(SIGTSTP, stop);
211 		(void)signal(SIGTTOU, stop);
212 		(void)signal(SIGTTIN, stop);
213 	}
214 	setexit();
215 	for (;;) {
216 		/*
217 		 * Print the prompt, if needed.  Clear out
218 		 * string space, and flush the output.
219 		 */
220 		if (!sourcing && value("interactive") != NULL) {
221 			if ((value("autoinc") != NULL) && (incfile() > 0))
222 				printf("New mail has arrived.\n");
223 			reset_on_stop = 1;
224 			printf("%s", prompt);
225 		}
226 		(void)fflush(stdout);
227 		sreset();
228 		/*
229 		 * Read a line of commands from the current input
230 		 * and handle end of file specially.
231 		 */
232 		n = 0;
233 		for (;;) {
234 			if (readline(input, &linebuf[n], LINESIZE - n) < 0) {
235 				if (n == 0)
236 					n = -1;
237 				break;
238 			}
239 			if ((n = strlen(linebuf)) == 0)
240 				break;
241 			n--;
242 			if (linebuf[n] != '\\')
243 				break;
244 			linebuf[n++] = ' ';
245 		}
246 		reset_on_stop = 0;
247 		if (n < 0) {
248 				/* eof */
249 			if (loading)
250 				break;
251 			if (sourcing) {
252 				unstack();
253 				continue;
254 			}
255 			if (value("interactive") != NULL &&
256 			    value("ignoreeof") != NULL &&
257 			    ++eofloop < 25) {
258 				printf("Use \"quit\" to quit.\n");
259 				continue;
260 			}
261 			break;
262 		}
263 		eofloop = 0;
264 		if (execute(linebuf, 0))
265 			break;
266 	}
267 }
268 
269 /*
270  * Execute a single command.
271  * Command functions return 0 for success, 1 for error, and -1
272  * for abort.  A 1 or -1 aborts a load or source.  A -1 aborts
273  * the interactive command loop.
274  * Contxt is non-zero if called while composing mail.
275  */
276 int
277 execute(char linebuf[], int contxt)
278 {
279 	char word[LINESIZE];
280 	char *arglist[MAXARGC];
281 	const struct cmd *com;
282 	char *cp, *cp2;
283 	int c, muvec[2];
284 	int e = 1;
285 
286 	/*
287 	 * Strip the white space away from the beginning
288 	 * of the command, then scan out a word, which
289 	 * consists of anything except digits and white space.
290 	 *
291 	 * Handle ! escapes differently to get the correct
292 	 * lexical conventions.
293 	 */
294 
295 	for (cp = linebuf; isspace((unsigned char)*cp); cp++)
296 		;
297 	if (*cp == '!') {
298 		if (sourcing) {
299 			printf("Can't \"!\" while sourcing\n");
300 			goto out;
301 		}
302 		shell(cp+1);
303 		return (0);
304 	}
305 	cp2 = word;
306 	while (*cp != '\0' && strchr(" \t0123456789$^.:/-+*'\"", *cp) == NULL)
307 		*cp2++ = *cp++;
308 	*cp2 = '\0';
309 
310 	/*
311 	 * Look up the command; if not found, bitch.
312 	 * Normally, a blank command would map to the
313 	 * first command in the table; while sourcing,
314 	 * however, we ignore blank lines to eliminate
315 	 * confusion.
316 	 */
317 
318 	if (sourcing && *word == '\0')
319 		return (0);
320 	com = lex(word);
321 	if (com == NULL) {
322 		printf("Unknown command: \"%s\"\n", word);
323 		goto out;
324 	}
325 
326 	/*
327 	 * See if we should execute the command -- if a conditional
328 	 * we always execute it, otherwise, check the state of cond.
329 	 */
330 
331 	if ((com->c_argtype & F) == 0)
332 		if ((cond == CRCV && !rcvmode) || (cond == CSEND && rcvmode))
333 			return (0);
334 
335 	/*
336 	 * Process the arguments to the command, depending
337 	 * on the type he expects.  Default to an error.
338 	 * If we are sourcing an interactive command, it's
339 	 * an error.
340 	 */
341 
342 	if (!rcvmode && (com->c_argtype & M) == 0) {
343 		printf("May not execute \"%s\" while sending\n",
344 		    com->c_name);
345 		goto out;
346 	}
347 	if (sourcing && com->c_argtype & I) {
348 		printf("May not execute \"%s\" while sourcing\n",
349 		    com->c_name);
350 		goto out;
351 	}
352 	if (readonly && com->c_argtype & W) {
353 		printf("May not execute \"%s\" -- message file is read only\n",
354 		   com->c_name);
355 		goto out;
356 	}
357 	if (contxt && com->c_argtype & R) {
358 		printf("Cannot recursively invoke \"%s\"\n", com->c_name);
359 		goto out;
360 	}
361 	switch (com->c_argtype & ~(F|P|I|M|T|W|R)) {
362 	case MSGLIST:
363 		/*
364 		 * A message list defaulting to nearest forward
365 		 * legal message.
366 		 */
367 		if (msgvec == 0) {
368 			printf("Illegal use of \"message list\"\n");
369 			break;
370 		}
371 		if ((c = getmsglist(cp, msgvec, com->c_msgflag)) < 0)
372 			break;
373 		if (c  == 0) {
374 			*msgvec = first(com->c_msgflag, com->c_msgmask);
375 			msgvec[1] = 0;
376 		}
377 		if (*msgvec == 0) {
378 			printf("No applicable messages\n");
379 			break;
380 		}
381 		e = (*com->c_func)(msgvec);
382 		break;
383 
384 	case NDMLIST:
385 		/*
386 		 * A message list with no defaults, but no error
387 		 * if none exist.
388 		 */
389 		if (msgvec == 0) {
390 			printf("Illegal use of \"message list\"\n");
391 			break;
392 		}
393 		if (getmsglist(cp, msgvec, com->c_msgflag) < 0)
394 			break;
395 		e = (*com->c_func)(msgvec);
396 		break;
397 
398 	case STRLIST:
399 		/*
400 		 * Just the straight string, with
401 		 * leading blanks removed.
402 		 */
403 		while (isspace((unsigned char)*cp))
404 			cp++;
405 		e = (*com->c_func)(cp);
406 		break;
407 
408 	case RAWLIST:
409 		/*
410 		 * A vector of strings, in shell style.
411 		 */
412 		if ((c = getrawlist(cp, arglist,
413 		    sizeof(arglist) / sizeof(*arglist))) < 0)
414 			break;
415 		if (c < com->c_minargs) {
416 			printf("%s requires at least %d arg(s)\n",
417 			    com->c_name, com->c_minargs);
418 			break;
419 		}
420 		if (c > com->c_maxargs) {
421 			printf("%s takes no more than %d arg(s)\n",
422 			    com->c_name, com->c_maxargs);
423 			break;
424 		}
425 		e = (*com->c_func)(arglist);
426 		break;
427 
428 	case NOLIST:
429 		/*
430 		 * Just the constant zero, for exiting,
431 		 * eg.
432 		 */
433 		e = (*com->c_func)(0);
434 		break;
435 
436 	default:
437 		errx(1, "Unknown argtype");
438 	}
439 
440 out:
441 	/*
442 	 * Exit the current source file on
443 	 * error.
444 	 */
445 	if (e) {
446 		if (e < 0)
447 			return (1);
448 		if (loading)
449 			return (1);
450 		if (sourcing)
451 			unstack();
452 		return (0);
453 	}
454 	if (com == NULL)
455 		return (0);
456 	if (value("autoprint") != NULL && com->c_argtype & P)
457 		if ((dot->m_flag & MDELETED) == 0) {
458 			muvec[0] = dot - &message[0] + 1;
459 			muvec[1] = 0;
460 			type(muvec);
461 		}
462 	if (!sourcing && (com->c_argtype & T) == 0)
463 		sawcom = 1;
464 	return (0);
465 }
466 
467 /*
468  * Set the size of the message vector used to construct argument
469  * lists to message list functions.
470  */
471 void
472 setmsize(int sz)
473 {
474 
475 	if (msgvec != NULL)
476 		(void)free(msgvec);
477 	msgvec = calloc((unsigned)(sz + 1), sizeof(*msgvec));
478 }
479 
480 /*
481  * Find the correct command in the command table corresponding
482  * to the passed command "word"
483  */
484 
485 const struct cmd *
486 lex(char word[])
487 {
488 	const struct cmd *cp;
489 
490 	/*
491 	 * ignore trailing chars after `#'
492 	 *
493 	 * lines with beginning `#' are comments
494 	 * spaces before `#' are ignored in execute()
495 	 */
496 
497 	if (*word == '#')
498 	    *(word+1) = '\0';
499 
500 
501 	for (cp = &cmdtab[0]; cp->c_name != NULL; cp++)
502 		if (isprefix(word, cp->c_name))
503 			return (cp);
504 	return (NULL);
505 }
506 
507 /*
508  * Determine if as1 is a valid prefix of as2.
509  * Return true if yep.
510  */
511 int
512 isprefix(const char *as1, const char *as2)
513 {
514 	const char *s1, *s2;
515 
516 	s1 = as1;
517 	s2 = as2;
518 	while (*s1++ == *s2)
519 		if (*s2++ == '\0')
520 			return (1);
521 	return (*--s1 == '\0');
522 }
523 
524 /*
525  * The following gets called on receipt of an interrupt.  This is
526  * to abort printout of a command, mainly.
527  * Dispatching here when command() is inactive crashes rcv.
528  * Close all open files except 0, 1, 2, and the temporary.
529  * Also, unstack all source files.
530  */
531 
532 static int	inithdr;		/* am printing startup headers */
533 
534 void
535 intr(int s __unused)
536 {
537 
538 	noreset = 0;
539 	if (!inithdr)
540 		sawcom++;
541 	inithdr = 0;
542 	while (sourcing)
543 		unstack();
544 
545 	close_all_files();
546 
547 	if (image >= 0) {
548 		(void)close(image);
549 		image = -1;
550 	}
551 	fprintf(stderr, "Interrupt\n");
552 	reset(0);
553 }
554 
555 /*
556  * When we wake up after ^Z, reprint the prompt.
557  */
558 void
559 stop(int s)
560 {
561 	sig_t old_action = signal(s, SIG_DFL);
562 	sigset_t nset;
563 
564 	(void)sigemptyset(&nset);
565 	(void)sigaddset(&nset, s);
566 	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
567 	(void)kill(0, s);
568 	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
569 	(void)signal(s, old_action);
570 	if (reset_on_stop) {
571 		reset_on_stop = 0;
572 		reset(0);
573 	}
574 }
575 
576 /*
577  * Branch here on hangup signal and simulate "exit".
578  */
579 void
580 hangup(int s __unused)
581 {
582 
583 	/* nothing to do? */
584 	exit(1);
585 }
586 
587 /*
588  * Announce the presence of the current Mail version,
589  * give the message count, and print a header listing.
590  */
591 void
592 announce(void)
593 {
594 	int vec[2], mdot;
595 
596 	mdot = newfileinfo(0);
597 	vec[0] = mdot;
598 	vec[1] = 0;
599 	dot = &message[mdot - 1];
600 	if (msgCount > 0 && value("noheader") == NULL) {
601 		inithdr++;
602 		headers(vec);
603 		inithdr = 0;
604 	}
605 }
606 
607 /*
608  * Announce information about the file we are editing.
609  * Return a likely place to set dot.
610  */
611 int
612 newfileinfo(int omsgCount)
613 {
614 	struct message *mp;
615 	int u, n, mdot, d, s;
616 	char fname[PATHSIZE+1], zname[PATHSIZE+1], *ename;
617 
618 	for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
619 		if (mp->m_flag & MNEW)
620 			break;
621 	if (mp >= &message[msgCount])
622 		for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
623 			if ((mp->m_flag & MREAD) == 0)
624 				break;
625 	if (mp < &message[msgCount])
626 		mdot = mp - &message[0] + 1;
627 	else
628 		mdot = omsgCount + 1;
629 	s = d = 0;
630 	for (mp = &message[0], n = 0, u = 0; mp < &message[msgCount]; mp++) {
631 		if (mp->m_flag & MNEW)
632 			n++;
633 		if ((mp->m_flag & MREAD) == 0)
634 			u++;
635 		if (mp->m_flag & MDELETED)
636 			d++;
637 		if (mp->m_flag & MSAVED)
638 			s++;
639 	}
640 	ename = mailname;
641 	if (getfold(fname, sizeof(fname) - 1) >= 0) {
642 		strcat(fname, "/");
643 		if (strncmp(fname, mailname, strlen(fname)) == 0) {
644 			(void)snprintf(zname, sizeof(zname), "+%s",
645 			    mailname + strlen(fname));
646 			ename = zname;
647 		}
648 	}
649 	printf("\"%s\": ", ename);
650 	if (msgCount == 1)
651 		printf("1 message");
652 	else
653 		printf("%d messages", msgCount);
654 	if (n > 0)
655 		printf(" %d new", n);
656 	if (u-n > 0)
657 		printf(" %d unread", u);
658 	if (d > 0)
659 		printf(" %d deleted", d);
660 	if (s > 0)
661 		printf(" %d saved", s);
662 	if (readonly)
663 		printf(" [Read only]");
664 	printf("\n");
665 	return (mdot);
666 }
667 
668 /*
669  * Print the current version number.
670  */
671 
672 int
673 pversion(void *arg __unused)
674 {
675 
676 	printf("Version %s\n", version);
677 	return (0);
678 }
679 
680 /*
681  * Load a file of user definitions.
682  */
683 void
684 load(char *name)
685 {
686 	FILE *in, *oldin;
687 
688 	if ((in = Fopen(name, "r")) == NULL)
689 		return;
690 	oldin = input;
691 	input = in;
692 	loading = 1;
693 	sourcing = 1;
694 	commands();
695 	loading = 0;
696 	sourcing = 0;
697 	input = oldin;
698 	(void)Fclose(in);
699 }
700