Il CD di internet/CD.iso/SOURCE/N/TCPIP/NNTP-1.000/NNTP-1/nntp.1.5.11t/server/time.c

C/C++ Source or Header | 1993-10-17 | 4.2 KB | 221 lines

#ifndef lint
static char    *sccsid = "@(#)$Header: time.c,v 1.13 91/01/13 03:27:14 sob Exp $";
#endif

/*
 * Collection of routines for dealing with ASCII time strings.
 * These may actually be useful in their own right.
 */

#include "common.h"
#ifdef USG
#include <time.h>
#else not USG
#include <sys/time.h>
#endif not USG

/*
 * dtol -- convert date to long integer.  This is not implicitly
 * local time, or any other kind of time, for that matter.  If you
 * pass it a date you think is GMT, you wind up with that number of
 * seconds...
 *
 *    Parameters:        "date_ascii" is in the form "yymmddhhmmss".
 *
 *    Returns:        Long integer containing number
 *                of seconds since 000000 Jan 1, 1970,
 *                and "date".  -1 on error.
 *
 *    Side effects:        None.
 */

#define twodigtoi(x)    (((x[0]) - '0') + (x[1] - '0')*10)
#define    dysize(y)    ((y % 4 ? 365 : 366))

static    int    dmsize[12] =
    { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

long
dtol(date_ascii)
    char    *date_ascii;
{
    char    date[32], *date_str;
    char    *lhs, *rhs;
    char    temp;
    long    seconds;
    int    year, month, day, hour, mins, secs;
    int    len, i;

    len = strlen(date_ascii);
    if (len != sizeof("yymmddhhmmss")-1)
        return (-1);

    (void) strcpy(date, date_ascii);
    date_str = date;

#ifdef DEBUG
    if (debug > 1)
        syslog(LOG_DEBUG, "(1) date_str = \"%s\"", date_str);
#endif
    rhs = date_str + len - 1;
    lhs = date_str;

    for (; lhs < rhs; ++lhs, --rhs) {
        temp = *lhs;
        *lhs = *rhs;
        *rhs = temp;
        if (!isdigit(temp) || !isdigit(*lhs))
            return (-1);
    }

    lhs = date_str;
#ifdef DEBUG
    if (debug > 1)
        syslog(LOG_DEBUG, "(2) date_str = \"%s\"", date_str);
#endif

    secs = twodigtoi(lhs);
    lhs += 2;
    mins = twodigtoi(lhs);
    lhs += 2;
    hour = twodigtoi(lhs);
    lhs += 2;
    day = twodigtoi(lhs);
    lhs += 2;
    month = twodigtoi(lhs);
    lhs += 2;
    year = twodigtoi(lhs);

    if (month < 1 || month > 12 ||
        day < 1 || day > 31 ||
        mins < 0 || mins > 59 ||
        secs < 0 || secs > 59)
        return (-1);
    if (hour == 24) {
        hour = 0;
        day++;
    }
    if (hour < 0 || hour > 23)
        return (-1);
    seconds = 0;
    year += 1900;
    for (i = 1970; i < year; i++)
        seconds += dysize(i);
    /* Leap year */
    if (dysize(year) == 366 && month >= 3)
        seconds++;
    while (--month)
        seconds += dmsize[month-1];
    seconds += day-1;
    seconds = 24 * seconds + hour;
    seconds = 60 * seconds + mins;
    seconds = 60 * seconds + secs;

    return (seconds);
}


/*
 * ltod -- convert long integer to date string.
 *
 *    Parameters:        "date" is in the number of seconds
 *                since the epoch.
 *
 *    Returns:        Pointer to static data in the form
 *                yymmddhhmmss\0.
 *
 *    Side effects:        None.
 */

char *
ltod(date)
    long        date;
{
    static char    timebuf[32];
    struct tm    *tp;

    tp = gmtime(&date);

    (void) sprintf(timebuf, "%02d%02d%02d%02d%02d%02d",
        tp->tm_year,
        tp->tm_mon + 1,        /* 0 to 11??? How silly. */
        tp->tm_mday,
        tp->tm_hour,
        tp->tm_min,
        tp->tm_sec);

    return (timebuf);
}


/*
 * local_to_gmt -- convert a local time (in form of number of
 * seconds since you-know-when) to GMT.
 *
 *    Parameters:    "date" is date we want converted, in
 *            seconds since 000000 1 Jan 1970.
 *
 *    Returns:    Number of seconds corrected for local
 *            and dst.
 */

long
local_to_gmt(date)
    long    date;
{
#ifdef USG
#if !defined(dgux) && !defined(M_XENIX)
    extern    long    timezone;
#endif
    tzset();
    date += timezone;
#else /* not USG */
    struct    timeval    tv;
    struct    timezone tz;

    (void) gettimeofday(&tv, &tz);
    date += (long) tz.tz_minuteswest * 60;
#endif /* not USG */

    /* now fix up local daylight time */
    if (localtime((time_t *)&date)->tm_isdst)
        date -= 60*60;

    return (date);
}

/*
 * gmt_to_local -- take a GMT time expressed in seconds since
 * the epoch, and convert it to local time.
 *
 *    Parameters:    "date" is the number of seconds...
 *
 *    Returns:    Number of seconds corrected to reflect
 *            local time and dst.
 */

long
gmt_to_local(date)
    long    date;
{
#ifdef USG
#if !defined(dgux) && !defined(M_XENIX)
    extern    long    timezone;
#endif
    tzset();
    date -= timezone;
#else /* not USG */
    struct    timeval    tv;
    struct    timezone tz;

    (void) gettimeofday(&tv, &tz);
    date -= (long) tz.tz_minuteswest * 60;
#endif /* not USG */

    /* now fix up local daylight time */
    if (localtime((time_t *)&date)->tm_isdst)
        date += 60*60;

    return (date);
}