OAR

RTEMS GNU Tools On-Line Library


Timefns

PREV UP NEXT Bookshelf

Chapter 6: Time Functions (`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 `time.h' defines three types. clock_t and time_t are both used for representations of time particularly suitable for arithmetic. (In this implementation, quantities of type clock_t have the highest resolution possible on your machine, and quantities of type time_t resolve to seconds.) size_t is also defined if necessary for quantities representing sizes.

`time.h' also defines the structure tm for the traditional representation of Gregorian calendar time as a series of numbers, with the following fields:

tm_sec
Seconds.
tm_min
Minutes.
tm_hour
Hours.
tm_mday
Day.
tm_mon
Month.
tm_year
Year (since 1900).
tm_wday
Day of week: the number of days since Sunday.
tm_yday
Number of days elapsed since last January 1.
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.
  • 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)

  • PREV UP NEXT Bookshelf

    Packaging copyright © 1988-2000 OAR Corporation
    Context copyright by each document's author. See Free Software Foundation for information.