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time

From cppreference.com
< c‎ | chrono
Defined in header <time.h>
time_t time( time_t *arg );

Returns the current calendar time encoded as a time_t object, and also stores it in the time_t object pointed to by arg (unless arg is a null pointer)

Contents

[edit] Parameters

arg - pointer to a time_t object where the time will be stored, or a null pointer

[edit] Return value

Current calendar time encoded as time_t object on success, (time_t)(-1) on error. If arg is not a null pointer, the return value is also stored in the object pointed to by arg.

[edit] Notes

The encoding of calendar time in time_t is unspecified, but most systems conform to POSIX specification and return a value of integral type holding the number of seconds since the Epoch. Implementations in which time_t is a 32-bit signed integer (many historical implementations) fail in the year 2038.

[edit] Example

#include <stdio.h>
#include <time.h>
#include <stdint.h>
 
int main(void)
{
    time_t result = time(NULL);
    if(result != (time_t)(-1))
        printf("The current time is %s(%jd seconds since the Epoch)\n",
               asctime(gmtime(&result)), (intmax_t)result);
}

Possible output:

The current time is Fri Apr 24 15:05:25 2015
(1429887925 seconds since the Epoch)

[edit] References

  • C17 standard (ISO/IEC 9899:2018):
  • 7.27.2.4 The time function (p: 286)
  • C11 standard (ISO/IEC 9899:2011):
  • 7.27.2.4 The time function (p: 391)
  • C99 standard (ISO/IEC 9899:1999):
  • 7.23.2.4 The time function (p: 341)
  • C89/C90 standard (ISO/IEC 9899:1990):
  • 4.12.2.4 The time function

[edit] See also

converts time since epoch to calendar time expressed as local time
(function) [edit]
converts time since epoch to calendar time expressed as Coordinated Universal Time (UTC)
(function) [edit]
returns the calendar time in seconds and nanoseconds based on a given time base
(function) [edit]