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mirror of git://sourceware.org/git/newlib-cygwin.git synced 2025-01-15 19:09:58 +08:00
Jeff Johnston f1d439fc64 2005-02-16 Eric Blake <ebb9@byu.net>
* libc/time/time.tex: Improve the documentation.
        * libc/time/strftime.c: Improve the documentation.
        (iso_year_adjust): New helper function.
        (strftime): Simplify '%E' and '%O'. Change '%c' to use
        recursion. Fix '%C', '%y', and '%Y' to deal with years with more
        than 4 characters.  Combine '%d' and '%e'. Implement '%D', '%F',
        '%g', '%G', '%n', '%R', '%t', '%T', '%u', '%V', '%X', and '%z'.
        Avoid core dumps on valid inputs (maxsize == 0, or
        tim_p->tm_isdst > 1).
2005-02-16 21:15:37 +00:00

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TeX

@node Timefns
@chapter Time Functions (@file{time.h})
This chapter groups functions used either for reporting on time
(elapsed, current, or compute time) or to perform calculations based
on time.
The header file @file{time.h} defines three types. @code{clock_t} and
@code{time_t} are both used for representations of time particularly
suitable for arithmetic. (In this implementation, quantities of type
@code{clock_t} have the highest resolution possible on your machine,
and quantities of type @code{time_t} resolve to seconds.) @code{size_t}
is also defined if necessary for quantities representing sizes.
@file{time.h} also defines the structure @code{tm} for the traditional
representation of Gregorian calendar time as a series of numbers, with
the following fields:
@table @code
@item tm_sec
Seconds, between 0 and 60 inclusive (60 allows for leap seconds).
@item tm_min
Minutes, between 0 and 59 inclusive.
@item tm_hour
Hours, between 0 and 23 inclusive.
@item tm_mday
Day of the month, between 1 and 31 inclusive.
@item tm_mon
Month, between 0 (January) and 11 (December).
@item tm_year
Year (since 1900), can be negative for earlier years.
@item tm_wday
Day of week, between 0 (Sunday) and 6 (Saturday).
@item tm_yday
Number of days elapsed since last January 1, between 0 and 365 inclusive.
@item tm_isdst
Daylight Savings Time flag: positive means DST in effect, zero means DST
not in effect, negative means no information about DST is available.
@end table
@menu
* asctime:: Format time as string
* clock:: Cumulative processor time
* ctime:: Convert time to local and format as string
* difftime:: Subtract two times
* gmtime:: Convert time to UTC (GMT) traditional representation
* localtime:: Convert time to local representation
* mktime:: Convert time to arithmetic representation
* strftime:: Flexible calendar time formatter
* time:: Get current calendar time (as single number)
* __tz_lock:: Lock time zone global variables
* tzset:: Set timezone info
@end menu
@page
@include time/asctime.def
@page
@include time/clock.def
@page
@include time/ctime.def
@page
@include time/difftime.def
@page
@include time/gmtime.def
@page
@include time/lcltime.def
@page
@include time/mktime.def
@page
@include time/strftime.def
@page
@include time/time.def
@page
@include time/tzlock.def
@page
@include time/tzset.def