usr/src/bin/date/date.c

/*
 * Copyright (c) 1985, 1987, 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1985, 1987, 1988, 1993\n\
        The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)date.c      8.1 (Berkeley) 5/31/93";
#endif /* not lint */

#include <sys/param.h>
#include <sys/time.h>

#include <ctype.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include "extern.h"

time_t tval;
int retval, nflag;

static void setthetime __P((char *));
static void badformat __P((void));
static void usage __P((void));

int logwtmp __P((char *, char *, char *));

int
main(argc, argv)
        int argc;
        char **argv;
{
        extern int optind;
        extern char *optarg;
        struct timezone tz;
        int ch, rflag;
        char *format, buf[1024];

        tz.tz_dsttime = tz.tz_minuteswest = 0;
        rflag = 0;
        while ((ch = getopt(argc, argv, "d:nr:ut:")) != EOF)
                switch((char)ch) {
                case 'd':               /* daylight savings time */
                        tz.tz_dsttime = atoi(optarg) ? 1 : 0;
                        break;
                case 'n':               /* don't set network */
                        nflag = 1;
                        break;
                case 'r':               /* user specified seconds */
                        rflag = 1;
                        tval = atol(optarg);
                        break;
                case 'u':               /* do everything in GMT */
                        (void)setenv("TZ", "GMT0", 1);
                        break;
                case 't':               /* minutes west of GMT */
                                        /* error check; don't allow "PST" */
                        if (isdigit(*optarg)) {
                                tz.tz_minuteswest = atoi(optarg);
                                break;
                        }
                        /* FALLTHROUGH */
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        /*
         * If -d or -t, set the timezone or daylight savings time; this
         * doesn't belong here, there kernel should not know about either.
         */
        if ((tz.tz_minuteswest || tz.tz_dsttime) &&
            settimeofday(NULL, &tz))
                err(1, "settimeofday");

        if (!rflag && time(&tval) == -1)
                err(1, "time");

        format = "%a %b %e %H:%M:%S %Z %Y\n";

        /* allow the operands in any order */
        if (*argv && **argv == '+') {
                format = *argv + 1;
                ++argv;
        }

        if (*argv) {
                setthetime(*argv);
                ++argv;
        }

        if (*argv && **argv == '+')
                format = *argv + 1;

        (void)strftime(buf, sizeof(buf), format, localtime(&tval));
        (void)printf("%s", buf);
        exit(retval);
}

#define ATOI2(ar)       ((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
void
setthetime(p)
        register char *p;
{
        register struct tm *lt;
        struct timeval tv;
        char *dot, *t;

        for (t = p, dot = NULL; *t; ++t) {
                if (isdigit(*t))
                        continue;
                if (*t == '.' && dot == NULL) {
                        dot = t;
                        continue;
                }
                badformat();
        }

        lt = localtime(&tval);

        if (dot != NULL) {                      /* .ss */
                *dot++ = '\0';
                if (strlen(dot) != 2)
                        badformat();
                lt->tm_sec = ATOI2(dot);
                if (lt->tm_sec > 61)
                        badformat();
        } else
                lt->tm_sec = 0;

        switch (strlen(p)) {
        case 10:                                /* yy */
                lt->tm_year = ATOI2(p);
                if (lt->tm_year < 69)           /* hack for 2000 ;-} */
                        lt->tm_year += 100;
                /* FALLTHROUGH */
        case 8:                                 /* mm */
                lt->tm_mon = ATOI2(p);
                if (lt->tm_mon > 12)
                        badformat();
                --lt->tm_mon;                   /* time struct is 0 - 11 */
                /* FALLTHROUGH */
        case 6:                                 /* dd */
                lt->tm_mday = ATOI2(p);
                if (lt->tm_mday > 31)
                        badformat();
                /* FALLTHROUGH */
        case 4:                                 /* hh */
                lt->tm_hour = ATOI2(p);
                if (lt->tm_hour > 23)
                        badformat();
                /* FALLTHROUGH */
        case 2:                                 /* mm */
                lt->tm_min = ATOI2(p);
                if (lt->tm_min > 59)
                        badformat();
                break;
        default:
                badformat();
        }

        /* convert broken-down time to GMT clock time */
        if ((tval = mktime(lt)) == -1)
                badformat();

        /* set the time */
        if (nflag || netsettime(tval)) {
                logwtmp("|", "date", "");
                tv.tv_sec = tval;
                tv.tv_usec = 0;
                if (settimeofday(&tv, NULL)) {
                        perror("date: settimeofday");
                        exit(1);
                }
                logwtmp("{", "date", "");
        }

        if ((p = getlogin()) == NULL)
                p = "???";
        syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
}

static void
badformat()
{
        warnx("illegal time format");
        usage();
}

static void
usage()
{
        (void)fprintf(stderr,
            "usage: date [-nu] [-d dst] [-r seconds] [-t west] [+format]\n");
        (void)fprintf(stderr, "            [yy[mm[dd[hh]]]]mm[.ss]]\n");
        exit(1);
}