archie/tcl7.6/unix/tclUnixTime.c
2024-05-27 16:40:40 +02:00

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/*
* tclUnixTime.c --
*
* Contains Unix specific versions of Tcl functions that
* obtain time values from the operating system.
*
* Copyright (c) 1995 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) tclUnixTime.c 1.11 96/07/23 16:17:21
*/
#include "tclInt.h"
#include "tclPort.h"
/*
*-----------------------------------------------------------------------------
*
* TclpGetSeconds --
*
* This procedure returns the number of seconds from the epoch. On
* most Unix systems the epoch is Midnight Jan 1, 1970 GMT.
*
* Results:
* Number of seconds from the epoch.
*
* Side effects:
* None.
*
*-----------------------------------------------------------------------------
*/
unsigned long
TclpGetSeconds()
{
return time((time_t *) NULL);
}
/*
*-----------------------------------------------------------------------------
*
* TclpGetClicks --
*
* This procedure returns a value that represents the highest resolution
* clock available on the system. There are no garantees on what the
* resolution will be. In Tcl we will call this value a "click". The
* start time is also system dependant.
*
* Results:
* Number of clicks from some start time.
*
* Side effects:
* None.
*
*-----------------------------------------------------------------------------
*/
unsigned long
TclpGetClicks()
{
unsigned long now;
#ifdef NO_GETTOD
struct tms dummy;
#else
struct timeval date;
struct timezone tz;
#endif
#ifdef NO_GETTOD
now = (unsigned long) times(&dummy);
#else
gettimeofday(&date, &tz);
now = date.tv_sec*1000000 + date.tv_usec;
#endif
return now;
}
/*
*----------------------------------------------------------------------
*
* TclpGetTimeZone --
*
* Determines the current timezone. The method varies wildly
* between different platform implementations, so its hidden in
* this function.
*
* Results:
* Hours east of GMT.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
int
TclpGetTimeZone (currentTime)
unsigned long currentTime;
{
/*
* Determine how a timezone is obtained from "struct tm". If there is no
* time zone in this struct (very lame) then use the timezone variable.
* This is done in a way to make the timezone variable the method of last
* resort, as some systems have it in addition to a field in "struct tm".
* The gettimeofday system call can also be used to determine the time
* zone.
*/
#if defined(HAVE_TM_TZADJ)
# define TCL_GOT_TIMEZONE
time_t curTime = (time_t) currentTime;
struct tm *timeDataPtr = localtime(&curTime);
int timeZone;
timeZone = timeDataPtr->tm_tzadj / 60;
if (timeDataPtr->tm_isdst) {
timeZone += 60;
}
return timeZone;
#endif
#if defined(HAVE_TM_GMTOFF) && !defined (TCL_GOT_TIMEZONE)
# define TCL_GOT_TIMEZONE
time_t curTime = (time_t) currentTime;
struct tm *timeDataPtr = localtime(&currentTime);
int timeZone;
timeZone = -(timeDataPtr->tm_gmtoff / 60);
if (timeDataPtr->tm_isdst) {
timeZone += 60;
}
return timeZone;
#endif
/*
* Must prefer timezone variable over gettimeofday, as gettimeofday does
* not return timezone information on many systems that have moved this
* information outside of the kernel.
*/
#if defined(HAVE_TIMEZONE_VAR) && !defined (TCL_GOT_TIMEZONE)
# define TCL_GOT_TIMEZONE
static int setTZ = 0;
int timeZone;
if (!setTZ) {
tzset();
setTZ = 1;
}
/*
* Note: this is not a typo in "timezone" below! See tzset
* documentation for details.
*/
timeZone = timezone / 60;
return timeZone;
#endif
#if defined(HAVE_GETTIMEOFDAY) && !defined (TCL_GOT_TIMEZONE)
# define TCL_GOT_TIMEZONE
struct timeval tv;
struct timezone tz;
int timeZone;
gettimeofday(&tv, &tz);
timeZone = tz.tz_minuteswest;
if (tz.tz_dsttime) {
timeZone += 60;
}
return timeZone;
#endif
#ifndef TCL_GOT_TIMEZONE
/*
* Cause compile error, we don't know how to get timezone.
*/
error: autoconf did not figure out how to determine the timezone.
#endif
}
/*
*----------------------------------------------------------------------
*
* TclpGetTime --
*
* Gets the current system time in seconds and microseconds
* since the beginning of the epoch: 00:00 UCT, January 1, 1970.
*
* Results:
* Returns the current time in timePtr.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
void
TclpGetTime(timePtr)
Tcl_Time *timePtr; /* Location to store time information. */
{
struct timeval tv;
struct timezone tz;
(void) gettimeofday(&tv, &tz);
timePtr->sec = tv.tv_sec;
timePtr->usec = tv.tv_usec;
}