How do I get the number of seconds since 1970, within a script, for the previous day at 23:59? I need this value to pass into a sql statement to cleanup records older than the previous day at midnight. It will be automated via cron so no hard coding allowed.
Thanks! (2 Replies)
Hi All,
We are running the HP-UX 11.11 and Linux AS 3.0. so, shall we need to make any changes for leap second i.e. insert the leap second on 1st Jan 2006 or does the system have some setup which would take care of this automatically.
Please advise.
Regards,
Inder (2 Replies)
Hi All,
We are running the HP-UX 11.11 and Linux AS 3.0. so, shall we need to make any changes for leap second i.e. insert the leap second on 1st Jan 2006 or does the system have some setup which would take care of this automatically.
Please advise.
Regards,
Inder (1 Reply)
I understand the NTP protocol, so keeping system time updated is not a problem.
Standard C library routines like localtime() take a number of UTC seconds elapsed since the start of the epoch (Jan 1, 1970). These times in seconds can be a filetime, system time, or some other time in the past or... (1 Reply)
Have anybody heard about the Leap second problem
Leap second :A leap second is a one-second adjustment that is occasionally applied to Coordinated Universal Time (UTC) in order to keep its time of day close to the mean solar time.
How could i avoid such thing in my script which i deal with... (6 Replies)
Hi friends,
I have a file with contents below:
01.m4a 00:14:45.82, 01.mp4 00:03:46.05, -659.770000
05.m4a 00:27:43.51, 05.mp4 00:27:45.10, 1.590000
06.m4a 00:11:39.73, 06.mp4 00:11:44.60, 4.870000
If 5th column value more than 3 or less than -3 then I should get its name (from first... (2 Replies)
I hear the Leap second for 2015 will occur on June 30 at 23:59:60 according to the wild rumours from internet the expected impact ranges from crashing to hanging servers.
Can anybody share their preparations what they have done for solaris servers? are there any patches to install or workaround?... (1 Reply)
Discussion started by: sparcguy
1 Replies
LEARN ABOUT OSX
posix2time
TIME2POSIX(3) BSD Library Functions Manual TIME2POSIX(3)NAME
time2posix, posix2time -- convert seconds since the Epoch
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <time.h>
time_t
time2posix(time_t t);
time_t
posix2time(time_t t);
DESCRIPTION
IEEE Std 1003.1-1988 (``POSIX.1'') legislates that a time_t value of 536457599 shall correspond to "Wed Dec 31 23:59:59 GMT 1986." This
effectively implies that POSIX time_t's cannot include leap seconds and, therefore, that the system time must be adjusted as each leap
occurs.
If the time package is configured with leap-second support enabled, however, no such adjustment is needed and time_t values continue to
increase over leap events (as a true `seconds since...' value). This means that these values will differ from those required by POSIX by the
net number of leap seconds inserted since the Epoch.
Typically this is not a problem as the type time_t is intended to be (mostly) opaque--time_t values should only be obtained-from and passed-
to functions such as time(3), localtime(3), mktime(3) and difftime(3). However, IEEE Std 1003.1-1988 (``POSIX.1'') gives an arithmetic
expression for directly computing a time_t value from a given date/time, and the same relationship is assumed by some (usually older) appli-
cations. Any programs creating/dissecting time_t's using such a relationship will typically not handle intervals over leap seconds cor-
rectly.
The time2posix() and posix2time() functions are provided to address this time_t mismatch by converting between local time_t values and their
POSIX equivalents. This is done by accounting for the number of time-base changes that would have taken place on a POSIX system as leap sec-
onds were inserted or deleted. These converted values can then be used in lieu of correcting the older applications, or when communicating
with POSIX-compliant systems.
The time2posix() function is single-valued. That is, every local time_t corresponds to a single POSIX time_t. The posix2time() function is
less well-behaved: for a positive leap second hit the result is not unique, and for a negative leap second hit the corresponding POSIX time_t
does not exist so an adjacent value is returned. Both of these are good indicators of the inferiority of the POSIX representation.
The following table summarizes the relationship between time_t and its conversion to, and back from, the POSIX representation over the leap
second inserted at the end of June, 1993.
DATE TIME T X=time2posix(T) posix2time(X)
93/06/30 23:59:59 A+0 B+0 A+0
93/06/30 23:59:60 A+1 B+1 A+1 or A+2
93/07/01 00:00:00 A+2 B+1 A+1 or A+2
93/07/01 00:00:01 A+3 B+2 A+3
A leap second deletion would look like...
DATE TIME T X=time2posix(T) posix2time(X)
??/06/30 23:59:58 A+0 B+0 A+0
??/07/01 00:00:00 A+1 B+2 A+1
??/07/01 00:00:01 A+2 B+3 A+2
[Note: posix2time(B+1) => A+0 or A+1]
If leap-second support is not enabled, local time_t's and POSIX time_t's are equivalent, and both time2posix() and posix2time() degenerate to
the identity function.
SEE ALSO difftime(3), localtime(3), mktime(3), time(3)BSD September 11, 2005 BSD