calendar.c revision 11334 
1/*
2 * Copyright (c) 1989, 1993, 1994
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
35static char copyright[] =
36"@(#) Copyright (c) 1989, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41static char sccsid[] = "@(#)calendar.c	8.3 (Berkeley) 3/25/94";
42#endif /* not lint */
43
44#include <sys/param.h>
45#include <sys/time.h>
46#include <sys/stat.h>
47#include <sys/uio.h>
48#include <sys/wait.h>
49
50#include <ctype.h>
51#include <err.h>
52#include <errno.h>
53#include <fcntl.h>
54#include <pwd.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <unistd.h>
59
60#include "pathnames.h"
61
62struct passwd *pw;
63int doall;
64
65void	 cal __P((void));
66void	 closecal __P((FILE *));
67int	 getday __P((char *));
68int	 getfield __P((char *, char **, int *));
69int	 getmonth __P((char *));
70int	 isnow __P((char *));
71FILE	*opencal __P((void));
72void	 settime __P((void));
73void	 usage __P((void));
74#define isleap(y) (((y) % 4) == 0 && ((y) % 100) != 0 || ((y) % 400) == 0)
75
76int
77main(argc, argv)
78	int argc;
79	char *argv[];
80{
81	extern int optind;
82	int ch;
83
84	while ((ch = getopt(argc, argv, "-a")) != EOF)
85		switch (ch) {
86		case '-':		/* backward contemptible */
87		case 'a':
88			if (getuid()) {
89				errno = EPERM;
90				err(1, NULL);
91			}
92			doall = 1;
93			break;
94		case '?':
95		default:
96			usage();
97		}
98	argc -= optind;
99	argv += optind;
100
101	if (argc)
102		usage();
103
104	settime();
105	if (doall)
106		while ((pw = getpwent()) != NULL) {
107			(void)setegid(pw->pw_gid);
108			(void)seteuid(pw->pw_uid);
109			if (!chdir(pw->pw_dir))
110				cal();
111			(void)seteuid(0);
112		}
113	else
114		cal();
115	exit(0);
116}
117
118void
119cal()
120{
121	register int printing;
122	register char *p;
123	FILE *fp;
124	int ch;
125	char buf[2048 + 1];
126
127	if ((fp = opencal()) == NULL)
128		return;
129	for (printing = 0; fgets(buf, sizeof(buf), stdin) != NULL;) {
130		if ((p = strchr(buf, '\n')) != NULL)
131			*p = '\0';
132		else
133			while ((ch = getchar()) != '\n' && ch != EOF);
134		if (buf[0] == '\0')
135			continue;
136		if (buf[0] != '\t')
137			printing = isnow(buf) ? 1 : 0;
138		if (printing)
139			(void)fprintf(fp, "%s\n", buf);
140	}
141	closecal(fp);
142}
143
144struct iovec header[] = {
145	"From: ", 6,
146	NULL, 0,
147	" (Reminder Service)\nTo: ", 24,
148	NULL, 0,
149	"\nSubject: ", 10,
150	NULL, 0,
151	"'s Calendar\nPrecedence: bulk\n\n",  30,
152};
153
154/* 1-based month, 0-based days, cumulative */
155int daytab[][14] = {
156	0, -1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364,
157	0, -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365,
158};
159struct tm *tp;
160int *cumdays, offset, yrdays;
161char dayname[10];
162
163void
164settime()
165{
166	time_t now;
167
168	(void)time(&now);
169	tp = localtime(&now);
170	if (isleap(tp->tm_year + 1900)) {
171		yrdays = 366;
172		cumdays = daytab[1];
173	} else {
174		yrdays = 365;
175		cumdays = daytab[0];
176	}
177	/* Friday displays Monday's events */
178	offset = tp->tm_wday == 5 ? 3 : 1;
179	header[5].iov_base = dayname;
180	header[5].iov_len = strftime(dayname, sizeof(dayname), "%A", tp);
181}
182
183/*
184 * Possible date formats include any combination of:
185 *	3-charmonth			(January, Jan, Jan)
186 *	3-charweekday			(Friday, Monday, mon.)
187 *	numeric month or day		(1, 2, 04)
188 *
189 * Any character may separate them, or they may not be separated.  Any line,
190 * following a line that is matched, that starts with "whitespace", is shown
191 * along with the matched line.
192 */
193int
194isnow(endp)
195	char *endp;
196{
197	int day, flags, month, v1, v2;
198
199#define	F_ISMONTH	0x01
200#define	F_ISDAY		0x02
201	flags = 0;
202	/* didn't recognize anything, skip it */
203	if (!(v1 = getfield(endp, &endp, &flags)))
204		return (0);
205	if (flags & F_ISDAY || v1 > 12) {
206		/* found a day */
207		day = v1;
208		/* if no recognizable month, assume just a day alone */
209		if (!(month = getfield(endp, &endp, &flags)))
210			month = tp->tm_mon + 1;
211	} else if (flags & F_ISMONTH) {
212		month = v1;
213		/* if no recognizable day, assume the first */
214		if (!(day = getfield(endp, &endp, &flags)))
215			day = 1;
216	} else {
217		v2 = getfield(endp, &endp, &flags);
218		if (flags & F_ISMONTH) {
219			day = v1;
220			month = v2;
221		} else {
222			/* F_ISDAY set, v2 > 12, or no way to tell */
223			month = v1;
224			/* if no recognizable day, assume the first */
225			day = v2 ? v2 : 1;
226		}
227	}
228	if (flags & F_ISDAY)
229		day = tp->tm_mday + (((day - 1) - tp->tm_wday + 7) % 7);
230	day = cumdays[month] + day;
231
232	/* if today or today + offset days */
233	if (day >= tp->tm_yday && day <= tp->tm_yday + offset)
234		return (1);
235	/* if number of days left in this year + days to event in next year */
236	if (yrdays - tp->tm_yday + day <= offset)
237		return (1);
238	return (0);
239}
240
241int
242getfield(p, endp, flags)
243	char *p, **endp;
244	int *flags;
245{
246	int val;
247	char *start, savech;
248
249	for (; !isdigit(*p) && !isalpha(*p) && *p != '*'; ++p);
250	if (*p == '*') {			/* `*' is current month */
251		*flags |= F_ISMONTH;
252		*endp = p+1;
253		return (tp->tm_mon + 1);
254	}
255	if (isdigit(*p)) {
256		val = strtol(p, &p, 10);	/* if 0, it's failure */
257		for (; !isdigit(*p) && !isalpha(*p) && *p != '*'; ++p);
258		*endp = p;
259		return (val);
260	}
261	for (start = p; isalpha(*++p););
262	savech = *p;
263	*p = '\0';
264	if ((val = getmonth(start)) != 0)
265		*flags |= F_ISMONTH;
266	else if ((val = getday(start)) != 0)
267		*flags |= F_ISDAY;
268	else {
269		*p = savech;
270		return (0);
271	}
272	for (*p = savech; !isdigit(*p) && !isalpha(*p) && *p != '*'; ++p);
273	*endp = p;
274	return (val);
275}
276
277char path[MAXPATHLEN + 1];
278
279FILE *
280opencal()
281{
282	int fd, pdes[2];
283
284	/* open up calendar file as stdin */
285	if (!freopen("calendar", "r", stdin)) {
286		if (doall)
287			return (NULL);
288		errx(1, "no calendar file.");
289	}
290	if (pipe(pdes) < 0)
291		return (NULL);
292	switch (vfork()) {
293	case -1:			/* error */
294		(void)close(pdes[0]);
295		(void)close(pdes[1]);
296		return (NULL);
297	case 0:
298		/* child -- stdin already setup, set stdout to pipe input */
299		if (pdes[1] != STDOUT_FILENO) {
300			(void)dup2(pdes[1], STDOUT_FILENO);
301			(void)close(pdes[1]);
302		}
303		(void)close(pdes[0]);
304		execl(_PATH_CPP, "cpp", "-P", "-I.", _PATH_INCLUDE, NULL);
305		(void)fprintf(stderr,
306		    "calendar: execl: %s: %s.\n", _PATH_CPP, strerror(errno));
307		_exit(1);
308	}
309	/* parent -- set stdin to pipe output */
310	(void)dup2(pdes[0], STDIN_FILENO);
311	(void)close(pdes[0]);
312	(void)close(pdes[1]);
313
314	/* not reading all calendar files, just set output to stdout */
315	if (!doall)
316		return (stdout);
317
318	/* set output to a temporary file, so if no output don't send mail */
319	(void)snprintf(path, sizeof(path), "%s/_calXXXXXX", _PATH_TMP);
320	if ((fd = mkstemp(path)) < 0)
321		return (NULL);
322	return (fdopen(fd, "w+"));
323}
324
325void
326closecal(fp)
327	FILE *fp;
328{
329	struct stat sbuf;
330	int nread, pdes[2], status;
331	char buf[1024];
332
333	if (!doall)
334		return;
335
336	(void)rewind(fp);
337	if (fstat(fileno(fp), &sbuf) || !sbuf.st_size)
338		goto done;
339	if (pipe(pdes) < 0)
340		goto done;
341	switch (vfork()) {
342	case -1:			/* error */
343		(void)close(pdes[0]);
344		(void)close(pdes[1]);
345		goto done;
346	case 0:
347		/* child -- set stdin to pipe output */
348		if (pdes[0] != STDIN_FILENO) {
349			(void)dup2(pdes[0], STDIN_FILENO);
350			(void)close(pdes[0]);
351		}
352		(void)close(pdes[1]);
353		execl(_PATH_SENDMAIL, "sendmail", "-i", "-t", "-F",
354		    "\"Reminder Service\"", "-f", "root", NULL);
355		(void)fprintf(stderr,
356		    "calendar: %s: %s.\n", _PATH_SENDMAIL, strerror(errno));
357		_exit(1);
358	}
359	/* parent -- write to pipe input */
360	(void)close(pdes[0]);
361
362	header[1].iov_base = header[3].iov_base = pw->pw_name;
363	header[1].iov_len = header[3].iov_len = strlen(pw->pw_name);
364	writev(pdes[1], header, 7);
365	while ((nread = read(fileno(fp), buf, sizeof(buf))) > 0)
366		(void)write(pdes[1], buf, nread);
367	(void)close(pdes[1]);
368done:	(void)fclose(fp);
369	(void)unlink(path);
370	while (wait(&status) >= 0);
371}
372
373static char *months[] = {
374	"jan", "feb", "mar", "apr", "may", "jun",
375	"jul", "aug", "sep", "oct", "nov", "dec", NULL,
376};
377
378int
379getmonth(s)
380	register char *s;
381{
382	register char **p;
383
384	for (p = months; *p; ++p)
385		if (!strncasecmp(s, *p, 3))
386			return ((p - months) + 1);
387	return (0);
388}
389
390static char *days[] = {
391	"sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL,
392};
393
394int
395getday(s)
396	register char *s;
397{
398	register char **p;
399
400	for (p = days; *p; ++p)
401		if (!strncasecmp(s, *p, 3))
402			return ((p - days) + 1);
403	return (0);
404}
405
406void
407usage()
408{
409	(void)fprintf(stderr, "usage: calendar [-a]\n");
410	exit(1);
411}
412