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time

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

Returns the current calendar time encoded as a time_t object.

Contents

[edit] Parameters

time - pointer to a time_t object to store the time in or NULL

[edit] Return value

Current calendar time encoded as time_t object on success, (time_t)(-1) on error. If the argument is not NULL, the return value is equal to the value stored in the object pointed to by the argument.

[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 <stdlib.h>
 
int main(void)
{
    time_t result = time(NULL);
    if (result == ((time_t)-1))
    {
       fprintf(stderr,"time() failed in file %s at line # %d\n", __FILE__,__LINE__-3);
       exit(EXIT_FAILURE);
    }
 
    printf("%s", asctime(localtime(&result)));
    printf("%d seconds since the Epoch", (int)result);
    return EXIT_SUCCESS;
}

Possible output:

Wed Oct  9 10:49:31 2013
1381315771 seconds since the Epoch

[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]