xref: /freebsd/usr.bin/mail/lex.c (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
1 /*
2  * Copyright (c) 1980, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 #if 0
36 static char sccsid[] = "@(#)lex.c	8.2 (Berkeley) 4/20/95";
37 #endif
38 #endif /* not lint */
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include "rcv.h"
43 #include <errno.h>
44 #include <fcntl.h>
45 #include "extern.h"
46 
47 /*
48  * Mail -- a mail program
49  *
50  * Lexical processing of commands.
51  */
52 
53 const char	*prompt = "& ";
54 
55 extern const struct cmd cmdtab[];
56 extern const char *version;
57 
58 /*
59  * Set up editing on the given file name.
60  * If the first character of name is %, we are considered to be
61  * editing the file, otherwise we are reading our mail which has
62  * signficance for mbox and so forth.
63  *
64  * If the -e option is being passed to mail, this function has a
65  * tri-state return code: -1 on error, 0 on no mail, 1 if there is
66  * mail.
67  */
68 int
69 setfile(name)
70 	char *name;
71 {
72 	FILE *ibuf;
73 	int checkmode, i, fd;
74 	struct stat stb;
75 	char isedit = *name != '%' || getuserid(myname) != getuid();
76 	char *who = name[1] ? name + 1 : myname;
77 	char tempname[PATHSIZE];
78 	static int shudclob;
79 
80 	checkmode = value("checkmode") != NULL;
81 	if ((name = expand(name)) == NULL)
82 		return (-1);
83 
84 	if ((ibuf = Fopen(name, "r")) == NULL) {
85 		if (!isedit && errno == ENOENT)
86 			goto nomail;
87 		warn("%s", name);
88 		return (-1);
89 	}
90 
91 	if (fstat(fileno(ibuf), &stb) < 0) {
92 		warn("fstat");
93 		(void)Fclose(ibuf);
94 		return (-1);
95 	}
96 
97 	if (S_ISDIR(stb.st_mode) || !S_ISREG(stb.st_mode)) {
98 		(void)Fclose(ibuf);
99 		errno = S_ISDIR(stb.st_mode) ? EISDIR : EINVAL;
100 		warn("%s", name);
101 		return (-1);
102 	}
103 
104 	/*
105 	 * Looks like all will be well.  We must now relinquish our
106 	 * hold on the current set of stuff.  Must hold signals
107 	 * while we are reading the new file, else we will ruin
108 	 * the message[] data structure.
109 	 */
110 
111 	holdsigs();
112 	if (shudclob)
113 		quit();
114 
115 	/*
116 	 * Copy the messages into /tmp
117 	 * and set pointers.
118 	 */
119 
120 	readonly = 0;
121 	if ((i = open(name, 1)) < 0)
122 		readonly++;
123 	else
124 		(void)close(i);
125 	if (shudclob) {
126 		(void)fclose(itf);
127 		(void)fclose(otf);
128 	}
129 	shudclob = 1;
130 	edit = isedit;
131 	strlcpy(prevfile, mailname, sizeof(prevfile));
132 	if (name != mailname)
133 		strlcpy(mailname, name, sizeof(mailname));
134 	mailsize = fsize(ibuf);
135 	(void)snprintf(tempname, sizeof(tempname),
136 	    "%s/mail.RxXXXXXXXXXX", tmpdir);
137 	if ((fd = mkstemp(tempname)) == -1 || (otf = fdopen(fd, "w")) == NULL)
138 		err(1, "%s", tempname);
139 	(void)fcntl(fileno(otf), F_SETFD, 1);
140 	if ((itf = fopen(tempname, "r")) == NULL)
141 		err(1, "%s", tempname);
142 	(void)fcntl(fileno(itf), F_SETFD, 1);
143 	(void)rm(tempname);
144 	setptr(ibuf, 0);
145 	setmsize(msgCount);
146 	/*
147 	 * New mail may have arrived while we were reading
148 	 * the mail file, so reset mailsize to be where
149 	 * we really are in the file...
150 	 */
151 	mailsize = ftello(ibuf);
152 	(void)Fclose(ibuf);
153 	relsesigs();
154 	sawcom = 0;
155 
156 	if ((checkmode || !edit) && msgCount == 0) {
157 nomail:
158 		if (!checkmode) {
159 			fprintf(stderr, "No mail for %s\n", who);
160 			return (-1);
161 		} else
162 			return (0);
163 	}
164 	return (checkmode ? 1 : 0);
165 }
166 
167 /*
168  * Incorporate any new mail that has arrived since we first
169  * started reading mail.
170  */
171 int
172 incfile()
173 {
174 	off_t newsize;
175 	int omsgCount = msgCount;
176 	FILE *ibuf;
177 
178 	ibuf = Fopen(mailname, "r");
179 	if (ibuf == NULL)
180 		return (-1);
181 	holdsigs();
182 	newsize = fsize(ibuf);
183 	if (newsize == 0)
184 		return (-1);		/* mail box is now empty??? */
185 	if (newsize < mailsize)
186 		return (-1);		/* mail box has shrunk??? */
187 	if (newsize == mailsize)
188 		return (0);		/* no new mail */
189 	setptr(ibuf, mailsize);
190 	setmsize(msgCount);
191 	mailsize = ftello(ibuf);
192 	(void)Fclose(ibuf);
193 	relsesigs();
194 	return (msgCount - omsgCount);
195 }
196 
197 int	*msgvec;
198 int	reset_on_stop;			/* do a reset() if stopped */
199 
200 /*
201  * Interpret user commands one by one.  If standard input is not a tty,
202  * print no prompt.
203  */
204 void
205 commands()
206 {
207 	int n, eofloop = 0;
208 	char linebuf[LINESIZE];
209 
210 	if (!sourcing) {
211 		if (signal(SIGINT, SIG_IGN) != SIG_IGN)
212 			(void)signal(SIGINT, intr);
213 		if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
214 			(void)signal(SIGHUP, hangup);
215 		(void)signal(SIGTSTP, stop);
216 		(void)signal(SIGTTOU, stop);
217 		(void)signal(SIGTTIN, stop);
218 	}
219 	setexit();
220 	for (;;) {
221 		/*
222 		 * Print the prompt, if needed.  Clear out
223 		 * string space, and flush the output.
224 		 */
225 		if (!sourcing && value("interactive") != NULL) {
226 			if ((value("autoinc") != NULL) && (incfile() > 0))
227 				printf("New mail has arrived.\n");
228 			reset_on_stop = 1;
229 			printf("%s", prompt);
230 		}
231 		(void)fflush(stdout);
232 		sreset();
233 		/*
234 		 * Read a line of commands from the current input
235 		 * and handle end of file specially.
236 		 */
237 		n = 0;
238 		for (;;) {
239 			if (readline(input, &linebuf[n], LINESIZE - n) < 0) {
240 				if (n == 0)
241 					n = -1;
242 				break;
243 			}
244 			if ((n = strlen(linebuf)) == 0)
245 				break;
246 			n--;
247 			if (linebuf[n] != '\\')
248 				break;
249 			linebuf[n++] = ' ';
250 		}
251 		reset_on_stop = 0;
252 		if (n < 0) {
253 				/* eof */
254 			if (loading)
255 				break;
256 			if (sourcing) {
257 				unstack();
258 				continue;
259 			}
260 			if (value("interactive") != NULL &&
261 			    value("ignoreeof") != NULL &&
262 			    ++eofloop < 25) {
263 				printf("Use \"quit\" to quit.\n");
264 				continue;
265 			}
266 			break;
267 		}
268 		eofloop = 0;
269 		if (execute(linebuf, 0))
270 			break;
271 	}
272 }
273 
274 /*
275  * Execute a single command.
276  * Command functions return 0 for success, 1 for error, and -1
277  * for abort.  A 1 or -1 aborts a load or source.  A -1 aborts
278  * the interactive command loop.
279  * Contxt is non-zero if called while composing mail.
280  */
281 int
282 execute(linebuf, contxt)
283 	char linebuf[];
284 	int contxt;
285 {
286 	char word[LINESIZE];
287 	char *arglist[MAXARGC];
288 	const struct cmd *com;
289 	char *cp, *cp2;
290 	int c, muvec[2];
291 	int e = 1;
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 
302 	for (cp = linebuf; isspace((unsigned char)*cp); cp++)
303 		;
304 	if (*cp == '!') {
305 		if (sourcing) {
306 			printf("Can't \"!\" while sourcing\n");
307 			goto out;
308 		}
309 		shell(cp+1);
310 		return (0);
311 	}
312 	cp2 = word;
313 	while (*cp != '\0' && strchr(" \t0123456789$^.:/-+*'\"", *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 
325 	if (sourcing && *word == '\0')
326 		return (0);
327 	com = lex(word);
328 	if (com == NULL) {
329 		printf("Unknown command: \"%s\"\n", word);
330 		goto out;
331 	}
332 
333 	/*
334 	 * See if we should execute the command -- if a conditional
335 	 * we always execute it, otherwise, check the state of cond.
336 	 */
337 
338 	if ((com->c_argtype & F) == 0)
339 		if ((cond == CRCV && !rcvmode) || (cond == CSEND && rcvmode))
340 			return (0);
341 
342 	/*
343 	 * Process the arguments to the command, depending
344 	 * on the type he expects.  Default to an error.
345 	 * If we are sourcing an interactive command, it's
346 	 * an error.
347 	 */
348 
349 	if (!rcvmode && (com->c_argtype & M) == 0) {
350 		printf("May not execute \"%s\" while sending\n",
351 		    com->c_name);
352 		goto out;
353 	}
354 	if (sourcing && com->c_argtype & I) {
355 		printf("May not execute \"%s\" while sourcing\n",
356 		    com->c_name);
357 		goto out;
358 	}
359 	if (readonly && com->c_argtype & W) {
360 		printf("May not execute \"%s\" -- message file is read only\n",
361 		   com->c_name);
362 		goto out;
363 	}
364 	if (contxt && com->c_argtype & R) {
365 		printf("Cannot recursively invoke \"%s\"\n", com->c_name);
366 		goto out;
367 	}
368 	switch (com->c_argtype & ~(F|P|I|M|T|W|R)) {
369 	case MSGLIST:
370 		/*
371 		 * A message list defaulting to nearest forward
372 		 * legal message.
373 		 */
374 		if (msgvec == 0) {
375 			printf("Illegal use of \"message list\"\n");
376 			break;
377 		}
378 		if ((c = getmsglist(cp, msgvec, com->c_msgflag)) < 0)
379 			break;
380 		if (c  == 0) {
381 			*msgvec = first(com->c_msgflag, com->c_msgmask);
382 			msgvec[1] = 0;
383 		}
384 		if (*msgvec == 0) {
385 			printf("No applicable messages\n");
386 			break;
387 		}
388 		e = (*com->c_func)(msgvec);
389 		break;
390 
391 	case NDMLIST:
392 		/*
393 		 * A message list with no defaults, but no error
394 		 * if none exist.
395 		 */
396 		if (msgvec == 0) {
397 			printf("Illegal use of \"message list\"\n");
398 			break;
399 		}
400 		if (getmsglist(cp, msgvec, com->c_msgflag) < 0)
401 			break;
402 		e = (*com->c_func)(msgvec);
403 		break;
404 
405 	case STRLIST:
406 		/*
407 		 * Just the straight string, with
408 		 * leading blanks removed.
409 		 */
410 		while (isspace((unsigned char)*cp))
411 			cp++;
412 		e = (*com->c_func)(cp);
413 		break;
414 
415 	case RAWLIST:
416 		/*
417 		 * A vector of strings, in shell style.
418 		 */
419 		if ((c = getrawlist(cp, arglist,
420 		    sizeof(arglist) / sizeof(*arglist))) < 0)
421 			break;
422 		if (c < com->c_minargs) {
423 			printf("%s requires at least %d arg(s)\n",
424 			    com->c_name, com->c_minargs);
425 			break;
426 		}
427 		if (c > com->c_maxargs) {
428 			printf("%s takes no more than %d arg(s)\n",
429 			    com->c_name, com->c_maxargs);
430 			break;
431 		}
432 		e = (*com->c_func)(arglist);
433 		break;
434 
435 	case NOLIST:
436 		/*
437 		 * Just the constant zero, for exiting,
438 		 * eg.
439 		 */
440 		e = (*com->c_func)(0);
441 		break;
442 
443 	default:
444 		errx(1, "Unknown argtype");
445 	}
446 
447 out:
448 	/*
449 	 * Exit the current source file on
450 	 * error.
451 	 */
452 	if (e) {
453 		if (e < 0)
454 			return (1);
455 		if (loading)
456 			return (1);
457 		if (sourcing)
458 			unstack();
459 		return (0);
460 	}
461 	if (com == NULL)
462 		return (0);
463 	if (value("autoprint") != NULL && com->c_argtype & P)
464 		if ((dot->m_flag & MDELETED) == 0) {
465 			muvec[0] = dot - &message[0] + 1;
466 			muvec[1] = 0;
467 			type(muvec);
468 		}
469 	if (!sourcing && (com->c_argtype & T) == 0)
470 		sawcom = 1;
471 	return (0);
472 }
473 
474 /*
475  * Set the size of the message vector used to construct argument
476  * lists to message list functions.
477  */
478 void
479 setmsize(sz)
480 	int sz;
481 {
482 
483 	if (msgvec != NULL)
484 		(void)free(msgvec);
485 	msgvec = calloc((unsigned)(sz + 1), sizeof(*msgvec));
486 }
487 
488 /*
489  * Find the correct command in the command table corresponding
490  * to the passed command "word"
491  */
492 
493 __const struct cmd *
494 lex(word)
495 	char word[];
496 {
497 	const struct cmd *cp;
498 
499 	/*
500 	 * ignore trailing chars after `#'
501 	 *
502 	 * lines with beginning `#' are comments
503 	 * spaces before `#' are ignored in execute()
504 	 */
505 
506 	if (*word == '#')
507 	    *(word+1) = '\0';
508 
509 
510 	for (cp = &cmdtab[0]; cp->c_name != NULL; cp++)
511 		if (isprefix(word, cp->c_name))
512 			return (cp);
513 	return (NULL);
514 }
515 
516 /*
517  * Determine if as1 is a valid prefix of as2.
518  * Return true if yep.
519  */
520 int
521 isprefix(as1, as2)
522 	const char *as1, *as2;
523 {
524 	const char *s1, *s2;
525 
526 	s1 = as1;
527 	s2 = as2;
528 	while (*s1++ == *s2)
529 		if (*s2++ == '\0')
530 			return (1);
531 	return (*--s1 == '\0');
532 }
533 
534 /*
535  * The following gets called on receipt of an interrupt.  This is
536  * to abort printout of a command, mainly.
537  * Dispatching here when command() is inactive crashes rcv.
538  * Close all open files except 0, 1, 2, and the temporary.
539  * Also, unstack all source files.
540  */
541 
542 int	inithdr;			/* am printing startup headers */
543 
544 /*ARGSUSED*/
545 void
546 intr(s)
547 	int s;
548 {
549 
550 	noreset = 0;
551 	if (!inithdr)
552 		sawcom++;
553 	inithdr = 0;
554 	while (sourcing)
555 		unstack();
556 
557 	close_all_files();
558 
559 	if (image >= 0) {
560 		(void)close(image);
561 		image = -1;
562 	}
563 	fprintf(stderr, "Interrupt\n");
564 	reset(0);
565 }
566 
567 /*
568  * When we wake up after ^Z, reprint the prompt.
569  */
570 void
571 stop(s)
572 	int s;
573 {
574 	sig_t old_action = signal(s, SIG_DFL);
575 	sigset_t nset;
576 
577 	(void)sigemptyset(&nset);
578 	(void)sigaddset(&nset, s);
579 	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
580 	(void)kill(0, s);
581 	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
582 	(void)signal(s, old_action);
583 	if (reset_on_stop) {
584 		reset_on_stop = 0;
585 		reset(0);
586 	}
587 }
588 
589 /*
590  * Branch here on hangup signal and simulate "exit".
591  */
592 /*ARGSUSED*/
593 void
594 hangup(s)
595 	int s;
596 {
597 
598 	/* nothing to do? */
599 	exit(1);
600 }
601 
602 /*
603  * Announce the presence of the current Mail version,
604  * give the message count, and print a header listing.
605  */
606 void
607 announce()
608 {
609 	int vec[2], mdot;
610 
611 	mdot = newfileinfo(0);
612 	vec[0] = mdot;
613 	vec[1] = 0;
614 	dot = &message[mdot - 1];
615 	if (msgCount > 0 && value("noheader") == NULL) {
616 		inithdr++;
617 		headers(vec);
618 		inithdr = 0;
619 	}
620 }
621 
622 /*
623  * Announce information about the file we are editing.
624  * Return a likely place to set dot.
625  */
626 int
627 newfileinfo(omsgCount)
628 	int omsgCount;
629 {
630 	struct message *mp;
631 	int u, n, mdot, d, s;
632 	char fname[PATHSIZE+1], zname[PATHSIZE+1], *ename;
633 
634 	for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
635 		if (mp->m_flag & MNEW)
636 			break;
637 	if (mp >= &message[msgCount])
638 		for (mp = &message[omsgCount]; mp < &message[msgCount]; mp++)
639 			if ((mp->m_flag & MREAD) == 0)
640 				break;
641 	if (mp < &message[msgCount])
642 		mdot = mp - &message[0] + 1;
643 	else
644 		mdot = omsgCount + 1;
645 	s = d = 0;
646 	for (mp = &message[0], n = 0, u = 0; mp < &message[msgCount]; mp++) {
647 		if (mp->m_flag & MNEW)
648 			n++;
649 		if ((mp->m_flag & MREAD) == 0)
650 			u++;
651 		if (mp->m_flag & MDELETED)
652 			d++;
653 		if (mp->m_flag & MSAVED)
654 			s++;
655 	}
656 	ename = mailname;
657 	if (getfold(fname, sizeof(fname) - 1) >= 0) {
658 		strcat(fname, "/");
659 		if (strncmp(fname, mailname, strlen(fname)) == 0) {
660 			(void)snprintf(zname, sizeof(zname), "+%s",
661 			    mailname + strlen(fname));
662 			ename = zname;
663 		}
664 	}
665 	printf("\"%s\": ", ename);
666 	if (msgCount == 1)
667 		printf("1 message");
668 	else
669 		printf("%d messages", msgCount);
670 	if (n > 0)
671 		printf(" %d new", n);
672 	if (u-n > 0)
673 		printf(" %d unread", u);
674 	if (d > 0)
675 		printf(" %d deleted", d);
676 	if (s > 0)
677 		printf(" %d saved", s);
678 	if (readonly)
679 		printf(" [Read only]");
680 	printf("\n");
681 	return (mdot);
682 }
683 
684 /*
685  * Print the current version number.
686  */
687 
688 /*ARGSUSED*/
689 int
690 pversion(e)
691 	int e;
692 {
693 
694 	printf("Version %s\n", version);
695 	return (0);
696 }
697 
698 /*
699  * Load a file of user definitions.
700  */
701 void
702 load(name)
703 	char *name;
704 {
705 	FILE *in, *oldin;
706 
707 	if ((in = Fopen(name, "r")) == NULL)
708 		return;
709 	oldin = input;
710 	input = in;
711 	loading = 1;
712 	sourcing = 1;
713 	commands();
714 	loading = 0;
715 	sourcing = 0;
716 	input = oldin;
717 	(void)Fclose(in);
718 }
719