cmd/date/date.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright 2012 Nexenta Systems, Inc. All rights reserved.
 */
/*
 * Copyright (c) 2012, Joyent, Inc.  All rights reserved.
 */
/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 *  date - with format capabilities and international flair
 */

#include    <locale.h>
#include    <fcntl.h>
#include    <langinfo.h>
#include    <stdio.h>
#include    <stdlib.h>
#include    <string.h>
#include    <time.h>
#include    <unistd.h>
#include    <sys/time.h>
#include    <sys/types.h>
#include    <ctype.h>
#include    <utmpx.h>
#include    <tzfile.h>

#define year_size(A)    ((isleap(A)) ? 366 : 365)
static  char    buf[BUFSIZ];
static  time_t  clock_val;
static  short   month_size[12] =
    { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
static  struct  utmpx wtmpx[2] = {
    {"", "", OTIME_MSG, 0, OLD_TIME, 0, 0, 0},
    {"", "", NTIME_MSG, 0, NEW_TIME, 0, 0, 0}
    };
static char *usage =
    "usage:\tdate [-u] mmddHHMM[[cc]yy][.SS]\n\tdate [-Ru] [+format]\n"
    "\tdate -a [-]sss[.fff]\n";
static int uflag = 0;
static int Rflag = 0;

static int get_adj(char *, struct timeval *);
static int setdate(struct tm *, char *);
static void fmt_extensions(char *, size_t,
    const char *, const struct timespec *);

int
main(int argc, char **argv)
{
    struct tm *tp, tm;
    struct timeval tv;
    char *fmt;
    char fmtbuf[BUFSIZ];
    int c, aflag = 0, illflag = 0;
    struct timespec ts;

    (void) setlocale(LC_ALL, "");

#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
    (void) textdomain(TEXT_DOMAIN);

    while ((c = getopt(argc, argv, "a:uR")) != EOF)
        switch (c) {
        case 'a':
            aflag++;
            if (get_adj(optarg, &tv) < 0) {
                (void) fprintf(stderr,
                    gettext("date: invalid argument -- %s\n"),
                    optarg);
                illflag++;
            }
            break;
        case 'u':
            uflag++;
            break;
        case 'R':
            Rflag++;
            break;
        default:
            illflag++;
        }

    argc -= optind;
    argv  = &argv[optind];

    /* -a is mutually exclusive with -u and -R */
    if (uflag && aflag)
        illflag++;
    if (Rflag && aflag)
        illflag++;

    if (illflag) {
        (void) fprintf(stderr, gettext(usage));
        exit(1);
    }

    if (clock_gettime(CLOCK_REALTIME, &ts) != 0) {
        perror(gettext("date: Failed to obtain system time"));
        exit(1);
    }
    clock_val = ts.tv_sec;

    if (aflag) {
        if (adjtime(&tv, 0) < 0) {
            perror(gettext("date: Failed to adjust date"));
            exit(1);
        }
        exit(0);
    }

    if (argc > 0) {
        if (*argv[0] == '+')
            fmt = &argv[0][1];
        else {
            if (setdate(localtime(&clock_val), argv[0])) {
                (void) fprintf(stderr, gettext(usage));
                exit(1);
            }
            fmt = nl_langinfo(_DATE_FMT);
        }
    } else if (Rflag) {
        fmt = "%a, %d %h %Y %H:%M:%S %z";
    } else
        fmt = nl_langinfo(_DATE_FMT);

    fmt_extensions(fmtbuf, sizeof (fmtbuf), fmt, &ts);

    if (uflag) {
        (void) putenv("TZ=GMT0");
        tzset();
        tp = gmtime(&clock_val);
    } else
        tp = localtime(&clock_val);
    (void) memcpy(&tm, tp, sizeof (struct tm));
    (void) strftime(buf, BUFSIZ, fmtbuf, &tm);

    (void) puts(buf);

    return (0);
}

int
setdate(struct tm *current_date, char *date)
{
    int i;
    int mm;
    int hh;
    int min;
    int sec = 0;
    char    *secptr;
    int yy;
    int dd  = 0;
    int minidx  = 6;
    int len;
    int dd_check;

    /*  Parse date string  */
    if ((secptr = strchr(date, '.')) != NULL && strlen(&secptr[1]) == 2 &&
        isdigit(secptr[1]) && isdigit(secptr[2]) &&
        (sec = atoi(&secptr[1])) >= 0 && sec < 60)
        secptr[0] = '\0';   /* eat decimal point only on success */

    len = strlen(date);

    for (i = 0; i < len; i++) {
        if (!isdigit(date[i])) {
            (void) fprintf(stderr,
            gettext("date: bad conversion\n"));
            exit(1);
        }
    }
    switch (strlen(date)) {
    case 12:
        yy = atoi(&date[8]);
        date[8] = '\0';
        break;
    case 10:
        /*
         * The YY format has the following representation:
         * 00-68 = 2000 thru 2068
         * 69-99 = 1969 thru 1999
         */
        if (atoi(&date[8]) <= 68) {
            yy = 1900 + (atoi(&date[8]) + 100);
        } else {
            yy = 1900 + atoi(&date[8]);
        }
        date[8] = '\0';
        break;
    case 8:
        yy = 1900 + current_date->tm_year;
        break;
    case 4:
        yy = 1900 + current_date->tm_year;
        mm = current_date->tm_mon + 1;  /* tm_mon goes from 1 to 11 */
        dd = current_date->tm_mday;
        minidx = 2;
        break;
    default:
        (void) fprintf(stderr, gettext("date: bad conversion\n"));
        return (1);
    }

    min = atoi(&date[minidx]);
    date[minidx] = '\0';
    hh = atoi(&date[minidx-2]);
    date[minidx-2] = '\0';

    if (!dd) {
        /*
         * if dd is 0 (not between 1 and 31), then
         * read the value supplied by the user.
         */
        dd = atoi(&date[2]);
        date[2] = '\0';
        mm = atoi(&date[0]);
    }

    if (hh == 24)
        hh = 0, dd++;

    /*  Validate date elements  */
    dd_check = 0;
    if (mm >= 1 && mm <= 12) {
        dd_check = month_size[mm - 1];  /* get days in this month */
        if (mm == 2 && isleap(yy))  /* adjust for leap year */
            dd_check++;
    }
    if (!((mm >= 1 && mm <= 12) && (dd >= 1 && dd <= dd_check) &&
        (hh >= 0 && hh <= 23) && (min >= 0 && min <= 59))) {
        (void) fprintf(stderr, gettext("date: bad conversion\n"));
        return (1);
    }

    /*  Build date and time number  */
    for (clock_val = 0, i = 1970; i < yy; i++)
        clock_val += year_size(i);
    /*  Adjust for leap year  */
    if (isleap(yy) && mm >= 3)
        clock_val += 1;
    /*  Adjust for different month lengths  */
    while (--mm)
        clock_val += (time_t)month_size[mm - 1];
    /*  Load up the rest  */
    clock_val += (time_t)(dd - 1);
    clock_val *= 24;
    clock_val += (time_t)hh;
    clock_val *= 60;
    clock_val += (time_t)min;
    clock_val *= 60;
    clock_val += sec;

    if (!uflag) {
        /* convert to GMT assuming standard time */
        /* correction is made in localtime(3C) */

        /*
         * call localtime to set up "timezone" variable applicable
         * for clock_val time, to support Olson timezones which
         * can allow timezone rules to change.
         */
        (void) localtime(&clock_val);

        clock_val += (time_t)timezone;

        /* correct if daylight savings time in effect */

        if (localtime(&clock_val)->tm_isdst)
            clock_val = clock_val - (time_t)(timezone - altzone);
    }

    (void) time(&wtmpx[0].ut_xtime);
    if (stime(&clock_val) < 0) {
        perror("date");
        return (1);
    }
#if defined(i386)
    /* correct the kernel's "gmt_lag" and the PC's RTC */
    (void) system("/usr/sbin/rtc -c > /dev/null 2>&1");
#endif
    (void) time(&wtmpx[1].ut_xtime);
    (void) pututxline(&wtmpx[0]);
    (void) pututxline(&wtmpx[1]);
    (void) updwtmpx(WTMPX_FILE, &wtmpx[0]);
    (void) updwtmpx(WTMPX_FILE, &wtmpx[1]);
    return (0);
}

int
get_adj(char *cp, struct timeval *tp)
{
    register int mult;
    int sign;

    /* arg must be [-]sss[.fff] */

    tp->tv_sec = tp->tv_usec = 0;
    if (*cp == '-') {
        sign = -1;
        cp++;
    } else {
        sign = 1;
    }

    while (*cp >= '0' && *cp <= '9') {
        tp->tv_sec *= 10;
        tp->tv_sec += *cp++ - '0';
    }
    if (*cp == '.') {
        cp++;
        mult = 100000;
        while (*cp >= '0' && *cp <= '9') {
            tp->tv_usec += (*cp++ - '0') * mult;
            mult /= 10;
        }
    }
    /*
     * if there's anything left in the string,
     * the input was invalid.
     */
    if (*cp) {
        return (-1);
    } else {
        tp->tv_sec *= sign;
        tp->tv_usec *= sign;
        return (0);
    }
}

/*
 * Extensions that cannot be interpreted by strftime are interpreted here.
 */
void
fmt_extensions(char *fmtbuf, size_t len,
    const char *fmt, const struct timespec *tsp)
{
    const char *p;
    char *q;

    for (p = fmt, q = fmtbuf; *p != '\0' && q < fmtbuf + len; ++p) {
        if (*p == '%') {
            switch (*(p + 1)) {
            case 'N':
                ++p;
                q += snprintf(q, len - (q - fmtbuf),
                    "%09lu", tsp->tv_nsec);
                continue;
            }
        }
        *q++ = *p;
    }

    if (q < fmtbuf + len)
        *q = '\0';
    else
        fmtbuf[len - 1] = '\0';
}