KNF, ANSI C

[unix-history] / usr / src / usr.bin / calendar / calendar.c

/*
* Copyright (c) 1989, 1993, 1994
*      The Regents of the University of California.  All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
       The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)calendar.c  8.3 (Berkeley) %G%";
#endif /* not lint */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/wait.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <tzfile.h>
#include <unistd.h>

#include "pathnames.h"

struct passwd *pw;
int doall;

void     cal __P((void));
void     closecal __P((FILE *));
int      getday __P((char *));
int      getfield __P((char *, char **, int *));
int      getmonth __P((char *));
int      isnow __P((char *));
FILE    *opencal __P((void));
void     settime __P((void));
void     usage __P((void));

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

       while ((ch = getopt(argc, argv, "-a")) != EOF)
               switch (ch) {
               case '-':               /* backward contemptible */
               case 'a':
                       if (getuid()) {
                               errno = EPERM;
                               err(1, NULL);
                       }
                       doall = 1;
                       break;
               case '?':
               default:
                       usage();
               }
       argc -= optind;
       argv += optind;

       if (argc)
               usage();

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

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

       if ((fp = opencal()) == NULL)
               return;
       for (printing = 0; fgets(buf, sizeof(buf), stdin) != NULL;) {
               if ((p = strchr(buf, '\n')) != NULL)
                       *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);
}

struct iovec header[] = {
       "From: ", 6,
       NULL, 0,
       " (Reminder Service)\nTo: ", 24,
       NULL, 0,
       "\nSubject: ", 10,
       NULL, 0,
       "'s Calendar\nPrecedence: bulk\n\n",  30,
};

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

void
settime()
{
       time_t now;

       (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 == 5 ? 3 : 1;
       header[5].iov_base = dayname;
       header[5].iov_len = 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.
*/
int
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 + 1;
       } 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;
               }
       }
       if (flags & F_ISDAY)
               day = tp->tm_mday + (((day - 1) - tp->tm_wday + 7) % 7);
       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);
}

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

       for (; !isdigit(*p) && !isalpha(*p) && *p != '*'; ++p);
       if (*p == '*') {                        /* `*' is current month */
               *flags |= F_ISMONTH;
               *endp = p+1;
               return (tp->tm_mon + 1);
       }
       if (isdigit(*p)) {
               val = strtol(p, &p, 10);        /* if 0, it's failure */
               for (; !isdigit(*p) && !isalpha(*p) && *p != '*'; ++p);
               *endp = p;
               return (val);
       }
       for (start = p; isalpha(*++p););
       savech = *p;
       *p = '\0';
       if ((val = getmonth(start)) != 0)
               *flags |= F_ISMONTH;
       else if ((val = getday(start)) != 0)
               *flags |= F_ISDAY;
       else {
               *p = savech;
               return (0);
       }
       for (*p = savech; !isdigit(*p) && !isalpha(*p) && *p != '*'; ++p);
       *endp = p;
       return (val);
}

char path[MAXPATHLEN + 1];

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

       /* open up calendar file as stdin */
       if (!freopen("calendar", "r", stdin)) {
               if (doall)
                       return (NULL);
               errx(1, "no calendar file.");
       }
       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);
               (void)fprintf(stderr,
                   "calendar: execl: %s: %s.\n", _PATH_CPP, strerror(errno));
               _exit(1);
       }
       /* parent -- set stdin to pipe output */
       (void)dup2(pdes[0], STDIN_FILENO);
       (void)close(pdes[0]);
       (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)snprintf(path, sizeof(path), "%s/_calXXXXXX", _PATH_TMP);
       if ((fd = mkstemp(path)) < 0)
               return (NULL);
       return (fdopen(fd, "w+"));
}

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

       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, "sendmail", "-i", "-t", "-F",
                   "\"Reminder Service\"", "-f", "root", NULL);
               (void)fprintf(stderr,
                   "calendar: %s: %s.\n", _PATH_SENDMAIL, strerror(errno));
               _exit(1);
       }
       /* parent -- write to pipe input */
       (void)close(pdes[0]);

       header[1].iov_base = header[3].iov_base = pw->pw_name;
       header[1].iov_len = header[3].iov_len = strlen(pw->pw_name);
       writev(pdes[1], header, 7);
       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,
};

int
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,
};

int
getday(s)
       register char *s;
{
       register char **p;

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

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