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/*
* time support routines that are easier to do in C than in Lisp
*/
/*
* This software is part of the SBCL system. See the README file for
* more information.
*
* This software is derived from the CMU CL system, which was
* written at Carnegie Mellon University and released into the
* public domain. The software is in the public domain and is
* provided with absolutely no warranty. See the COPYING and CREDITS
* files for more information.
*/
#include <stdio.h>
#include <time.h>
#include "sbcl.h"
#include "runtime.h"
#ifdef LISP_FEATURE_HPUX
struct tm *gmtime_r(const time_t *timer, struct tm *result);
struct tm *localtime_r(const time_t *timer, struct tm *result);
#endif
int get_timezone(time_t when, boolean *dst)
{
struct tm ltm, gtm;
int sw;
#ifdef LISP_FEATURE_WIN32
/* No _r versions on Windows, but the API documentation also
* doesn't warn them about being non-reentrant... So here's
* hoping they actually are -- once Windows grows threads
* this better be checked, though.
*
* The Windows versions also don't support times before the
* epoch, so we kludge it. */
if (when < 0)
when = 0;
ltm = *localtime(&when);
gtm = *gmtime(&when);
#else
ltm = *localtime_r(&when, &ltm);
gtm = *gmtime_r(&when, &gtm);
#endif
sw = (((gtm.tm_hour*60)+gtm.tm_min)*60+gtm.tm_sec) - (((ltm.tm_hour*60)+ltm.tm_min)*60+ltm.tm_sec);
if ((gtm.tm_wday + 1) % 7 == ltm.tm_wday)
sw -= 24*3600;
else if (gtm.tm_wday == (ltm.tm_wday + 1) % 7)
sw += 24*3600;
*dst = ltm.tm_isdst;
return sw;
}