Function l_getFormattedDate

deps/leptonica/src/utils1.c:1103–1141

! * \brief l_getFormattedDate() * * \return formatted date string, or NULL on error * * * Notes: * (1) This is used in pdf, in the form specified in section 3.8.2 of * http://partners.adobe.com/public/developer/en/pdf/PDFReference.pdf * (2) Contributed by Dave Bryan. Works on all platforms. * */

 * </pre>
 */
char *
l_getFormattedDate()
{
char        buf[sizeof "199812231952SS-08'00'"] = "", sep = 'Z';
l_int32     gmt_offset, relh, relm;
time_t      ut, lt;
struct tm  *tptr;

    ut = time(NULL);

        /* This generates a second "time_t" value by calling "gmtime" to
           fill in a "tm" structure expressed as UTC and then calling
           "mktime", which expects a "tm" structure expressed as the
           local time.  The result is a value that is offset from the
           value returned by the "time" function by the local UTC offset.
           "tm_isdst" is set to -1 to tell "mktime" to determine for
           itself whether DST is in effect.  This is necessary because
           "gmtime" always sets "tm_isdst" to 0, which would tell
           "mktime" to presume that DST is not in effect. */
    tptr = gmtime(&ut);
    tptr->tm_isdst = -1;
    lt = mktime(tptr);

        /* Calls "difftime" to obtain the resulting difference in seconds,
         * because "time_t" is an opaque type, per the C standard. */
    gmt_offset = (l_int32) difftime(ut, lt);

    if (gmt_offset > 0)
        sep = '+';
    else if (gmt_offset < 0)
        sep = '-';

    relh = L_ABS(gmt_offset) / 3600;
    relm = (L_ABS(gmt_offset) % 3600) / 60;

    strftime(buf, sizeof(buf), "%Y%m%d%H%M%S", localtime(&ut));
    sprintf(buf + 14, "%c%02d'%02d'", sep, relh, relm);
    return stringNew(buf);
}