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deb-mbse/lib/gmtoffset.c
2004-02-21 14:24:03 +00:00

168 lines
3.3 KiB
C

/*****************************************************************************
*
* $Id$
* Purpose ...............: Calculate UTC offset
* Source ................: Eugene G. Crosser's ifmail package.
*
*****************************************************************************
* Copyright (C) 1997-2004
*
* Michiel Broek FIDO: 2:280/2802
* Beekmansbos 10
* 1971 BV IJmuiden
* the Netherlands
*
* This file is part of MBSE BBS.
*
* This BBS is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* MBSE BBS is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MBSE BBS; see the file COPYING. If not, write to the Free
* Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*****************************************************************************/
#include "../config.h"
#include "mbselib.h"
/*
* Returns the offset from your location to UTC. So in the MET timezone
* this returns -60 (wintertime). People in the USA get positive results.
*/
long gmt_offset(time_t now)
{
struct tm ptm;
struct tm gtm;
long offset;
if (!now)
now = time(NULL);
ptm = *localtime(&now);
/*
* To get the timezone, compare localtime with GMT.
*/
gtm = *gmtime(&now);
/*
* Assume we are never more than 24 hours away.
*/
offset = gtm.tm_yday - ptm.tm_yday;
if (offset > 1)
offset = -24;
else if (offset < -1)
offset = 24;
else
offset *= 24;
/*
* Scale in the hours and minutes; ignore seconds.
*/
offset += gtm.tm_hour - ptm.tm_hour;
offset *= 60;
offset += gtm.tm_min - ptm.tm_min;
return offset;
}
/*
* Returns the TZUTC string, note that the sign is opposite from the
* function above.
*/
char *gmtoffset(time_t now)
{
static char buf[6]="+0000";
char sign;
int hr, min;
long offset;
offset = gmt_offset(now);
if (offset <= 0) {
sign = '+';
offset = -offset;
} else
sign = '-';
hr = offset / 60L;
min = offset % 60L;
if (sign == '-')
sprintf(buf, "%c%02d%02d", sign, hr, min);
else
sprintf(buf, "%02d%02d", hr, min);
return(buf);
}
char *str_time(time_t total)
{
static char buf[10];
int h, m;
memset(&buf, 0, sizeof(buf));
/*
* 0 .. 59 seconds
*/
if (total < (time_t)60) {
sprintf(buf, "%2d.00s", (int)total);
return buf;
}
/*
* 1:00 .. 59:59 minutes:seconds
*/
if (total < (time_t)3600) {
h = total / 60;
m = total % 60;
sprintf(buf, "%2d:%02d ", h, m);
return buf;
}
/*
* 1:00 .. 23:59 hours:minutes
*/
if (total < (time_t)86400) {
h = (total / 60) / 60;
m = (total / 60) % 60;
sprintf(buf, "%2d:%02dm", h, m);
return buf;
}
/*
* 1/00 .. 30/23 days/hours
*/
if (total < (time_t)2592000) {
h = (total / 3600) / 24;
m = (total / 3600) % 24;
sprintf(buf, "%2d/%02dh", h, m);
return buf;
}
sprintf(buf, "N/A ");
return buf;
}
char *t_elapsed(time_t start, time_t end)
{
return str_time(end - start);
}