usr/src/usr.bin/calendar/calendar.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)calendar.c  4.8 (Berkeley) %G%";
#endif /* not lint */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <pwd.h>
#include <errno.h>
#include <tzfile.h>
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include <string.h>
#include <paths.h>
#include "pathnames.h"

struct passwd *pw;
int doall;

main(argc, argv)
        int argc;
        char **argv;
{
        extern int errno, optind;
        int ch;

        while ((ch = getopt(argc, argv, "-a")) != EOF)
                switch(ch) {
                case '-':               /* backward contemptible */
                case 'a':
                        if (getuid()) {
                                (void)fprintf(stderr,
                                    "calendar: %s\n", strerror(EPERM));
                                exit(1);
                        }
                        doall = 1;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (argc)
                usage();

        settime();
        if (doall)
                while (pw = getpwent()) {
                        (void)setegid(pw->pw_gid);
                        (void)seteuid(pw->pw_uid);
                        if (!chdir(pw->pw_dir))
                                cal();
                        (void)seteuid(0);
                }
        else
                cal();
        exit(0);
}

cal()
{
        register int printing;
        register char *p;
        FILE *fp, *opencal();
        int ch;
        char buf[2048 + 1];

        if (!(fp = opencal()))
                return;
        for (printing = 0; fgets(buf, sizeof(buf), stdin);) {
                if (p = index(buf, '\n'))
                        *p = '\0';
                else
                        while ((ch = getchar()) != '\n' && ch != EOF);
                if (buf[0] == '\0')
                        continue;
                if (buf[0] != '\t')
                        printing = isnow(buf) ? 1 : 0;
                if (printing)
                        (void)fprintf(fp, "%s\n", buf);
        }
        closecal(fp);
}

/* 1-based month, 0-based days, cumulative */
int daytab[][14] = {
        0, 0, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364,
        0, 0, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365,
};
struct tm *tp;
int *cumdays, offset, yrdays;
char dayname[10];

settime()
{
        time_t now, time();

        (void)time(&now);
        tp = localtime(&now);
        if (isleap(tp->tm_year + 1900)) {
                yrdays = DAYSPERLYEAR;
                cumdays = daytab[1];
        } else {
                yrdays = DAYSPERNYEAR;
                cumdays = daytab[0];
        }
        /* Friday displays Monday's events */
        offset = tp->tm_wday == 6 ? 3 : 1;
        (void)strftime(dayname, sizeof(dayname), "%A", tp);
}

/*
 * Possible date formats include any combination of:
 *      3-charmonth                     (January, Jan, Jan)
 *      3-charweekday                   (Friday, Monday, mon.)
 *      numeric month or day            (1, 2, 04)
 *
 * Any character may separate them, or they may not be separated.  Any line,
 * following a line that is matched, that starts with "whitespace", is shown
 * along with the matched line.
 */
isnow(endp)
        char *endp;
{
        int day, flags, month, v1, v2;

#define F_ISMONTH       0x01
#define F_ISDAY         0x02
        flags = 0;
        /* didn't recognize anything, skip it */
        if (!(v1 = getfield(endp, &endp, &flags)))
                return(0);
        if (flags&F_ISDAY || v1 > 12) {
                /* found a day */
                day = v1;
                /* if no recognizable month, assume just a day alone */
                if (!(month = getfield(endp, &endp, &flags)))
                        month = tp->tm_mon;
        } else if (flags&F_ISMONTH) {
                month = v1;
                /* if no recognizable day, assume the first */
                if (!(day = getfield(endp, &endp, &flags)))
                        day = 1;
        } else {
                v2 = getfield(endp, &endp, &flags);
                if (flags&F_ISMONTH) {
                        day = v1;
                        month = v2;
                } else {
                        /* F_ISDAY set, v2 > 12, or no way to tell */
                        month = v1;
                        /* if no recognizable day, assume the first */
                        day = v2 ? v2 : 1;
                }
        }
        day = cumdays[month] + day;

        /* if today or today + offset days */
        if (day >= tp->tm_yday && day <= tp->tm_yday + offset)
                return(1);
        /* if number of days left in this year + days to event in next year */
        if (yrdays - tp->tm_yday + day <= offset)
                return(1);
        return(0);
}

getfield(p, endp, flags)
        char *p, **endp;
        int *flags;
{
        int val;
        char *start, savech;

        if (*p == '*') {                        /* `*' is current month */
                *flags |= F_ISMONTH;
                return(tp->tm_mon);
        }
        if (isdigit(*p)) {
                val = strtol(p, &p, 10);        /* if 0, it's failure */
                for (; !isdigit(*p) && !isalpha(*p); ++p);
                *endp = p;
                return(val);
        }
        for (start = p; isalpha(*++p););
        savech = *p;
        *p = '\0';
        if (val = getmonth(start))
                *flags |= F_ISMONTH;
        else if (val = getday(start))
                *flags |= F_ISDAY;
        else
                return(0);
        for (*p = savech; !isdigit(*p) && !isalpha(*p); ++p);
        *endp = p;
        return(val);
}

char path[MAXPATHLEN + 1];

FILE *
opencal()
{
        int fd, pdes[2];
        char *mktemp();

        /* open up calendar file as stdin */
        if (!freopen("calendar", "r", stdin)) {
                if (doall)
                        return((FILE *)NULL);
                (void)fprintf(stderr, "calendar: no calendar file.\n");
                exit(1);
        }
        if (pipe(pdes) < 0)
                return(NULL);
        switch (vfork()) {
        case -1:                        /* error */
                (void)close(pdes[0]);
                (void)close(pdes[1]);
                return(NULL);
        case 0:
                /* child -- stdin already setup, set stdout to pipe input */
                if (pdes[1] != STDOUT_FILENO) {
                        (void)dup2(pdes[1], STDOUT_FILENO);
                        (void)close(pdes[1]);
                }
                (void)close(pdes[0]);
                execl(_PATH_CPP, "cpp", "-I.", _PATH_INCLUDE, NULL);
                _exit(1);
        }
        /* parent -- set stdin to pipe output */
        (void)dup2(pdes[0], STDIN_FILENO);
        (void)close(pdes[1]);

        /* not reading all calendar files, just set output to stdout */
        if (!doall)
                return(stdout);

        /* set output to a temporary file, so if no output don't send mail */
        (void)sprintf(path, "%s/_calXXXXXX", _PATH_TMP);
        if ((fd = mkstemp(path)) < 0)
                return(NULL);
        return(fdopen(fd, "w+"));
}

closecal(fp)
        FILE *fp;
{
        struct stat sbuf;
        FILE *iop;
        int nread, pdes[2], status;
        char buf[1024], *mktemp();

        if (!doall)
                return;

        (void)rewind(fp);
        if (fstat(fileno(fp), &sbuf) || !sbuf.st_size)
                goto done;
        if (pipe(pdes) < 0)
                goto done;
        switch (vfork()) {
        case -1:                        /* error */
                (void)close(pdes[0]);
                (void)close(pdes[1]);
                goto done;
        case 0:
                /* child -- set stdin to pipe output */
                if (pdes[0] != STDIN_FILENO) {
                        (void)dup2(pdes[0], STDIN_FILENO);
                        (void)close(pdes[0]);
                }
                (void)close(pdes[1]);
                execl(_PATH_SENDMAIL, "-i", "-t", "-F",
                    "\"Reminder Service\"", "-f", "root");
                _exit(1);
        }
        /* parent -- rewind file, write to pipe input */
        (void)close(pdes[0]);

        iop = fdopen(pdes[1], "w");
        (void)fprintf(iop,
"From: %s (Reminder Service)\nTo: %s\nSubject: %s's Calendar\nPrecedence: bulk\n\n",
            pw->pw_name, pw->pw_name, dayname);
        (void)fflush(iop);
        while ((nread = read(fileno(fp), buf, sizeof(buf))) > 0)
                (void)write(pdes[1], buf, nread);
        (void)close(pdes[1]);
done:   (void)fclose(fp);
        (void)unlink(path);
        while (wait(&status) >= 0);
}

static char *months[] = {
        "jan", "feb", "mar", "apr", "may", "jun",
        "jul", "aug", "sep", "oct", "nov", "dec", NULL,
};
getmonth(s)
        register char *s;
{
        register char **p;

        for (p = months; *p; ++p)
                if (!strncasecmp(s, *p, 3))
                        return((p - months) + 1);
        return(0);
}

static char *days[] = {
        "sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL,
};
getday(s)
        register char *s;
{
        register char **p;

        for (p = days; *p; ++p)
                if (!strncasecmp(s, *p, 3))
                        return((p - days) + 1);
        return(0);
}

usage()
{
        (void)fprintf(stderr, "usage: calendar [-a]\n");
        exit(1);
}