function
<ctime>
ctime
char* ctime (const time_t * timer);
Convert time_t value to string
Interprets the value pointed by timer as a calendar time and converts it to a C-string containing a human-readable version of the corresponding time and date, in terms of local time.
The returned string has the following format:
Where Www is the weekday, Mmm the month (in letters), dd the day of the month, hh:mm:ss the time, and yyyy the year.
The string is followed by a new-line character ('\n') and terminated with a null-character.
This function is equivalent to:
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asctime(localtime(timer))
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For an alternative with custom date formatting, see strftime.
Parameters
- timer
- Pointer to an object of type time_t that contains a time value.
time_t is an alias of a fundamental arithmetic type capable of representing times as returned by function time.
Return Value
A C-string containing the date and time information in a human-readable format.
The returned value points to an internal array whose validity or value may be altered by any subsequent call to asctime or ctime.
Example
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/* ctime example */
#include <stdio.h> /* printf */
#include <time.h> /* time_t, time, ctime */
int main ()
{
time_t rawtime;
time (&rawtime);
printf ("The current local time is: %s", ctime (&rawtime));
return 0;
}
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Output:
The current local time is: Wed Feb 13 16:06:10 2013
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Data races
The function accesses the object pointed by timer.
The function also accesses and modifies a shared internal buffer, which may cause data races on concurrent calls to asctime or ctime. Some libraries provide an alternative function that avoids this data race: ctime_r (non-portable).
Exceptions (C++)
No-throw guarantee: this function never throws exceptions.
See also
- asctime
- Convert tm structure to string (function
)
- gmtime
- Convert time_t to tm as UTC time (function
)
- localtime
- Convert time_t to tm as local time (function
)
- time
- Get current time (function
)