Format
#include <time.h>
char *asctime_r(const struct tm *tm, char *buf);Language Level: XPG4
Threadsafe: Yes.
Description
This function is the restartable version of the asctime() function.
The asctime_r() function converts time, stored as a structure pointed to by tm, to a character string. You can obtain the tm value from a call to gmtime_r(), gmtime64_r(), localtime_r(), or localtime64_r().
The string result that asctime_r() produces contains exactly 26 characters and has the format:
"%.3s %.3s%3d %.2d:%.2d:%.2d %d\n"The following are examples of the string returned:
Sat Jul 16 02:03:55 1994\n\0
or
Sat Jul 16 2:03:55 1994\n\0The asctime_r() function uses a 24-hour-clock format. The days are abbreviated to: Sun, Mon, Tue, Wed, Thu, Fri, and Sat. The months are abbreviated to: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, and Dec. All fields have constant width. Dates with only one digit are preceded either with a zero or a blank space. The new-line character (\n) and the null character (\0) occupy the last two positions of the string.
The time and date functions begin at 00:00:00 Universal Time, January 1, 1970.
Return Value
The asctime_r() function returns a pointer to the resulting character string. If the function is unsuccessful, it returns NULL.
Example that uses asctime_r()
This example polls the system clock and prints a message giving the current time.
#include <time.h>
#include <stdio.h>
int main(void)
{
struct tm *newtime;
time_t ltime;
char mybuf[50];
/* Get the time in seconds */
time(<ime);
/* Convert it to the structure tm */
newtime = localtime_r(<ime());
/* Print the local time as a string */
printf("The current date and time are %s",
asctime_r(newtime, mybuf));
}
/**************** Output should be similar to ******************
The current date and time are Fri Sep 16 132951 1994
*/Related Information