C program to define macro PRINTF for printf , where in PRINTF takes same arguments as printf and also prints timestamp

neelkanth_surekha# cat printf.c

#include <time.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#define LOG_INIT()              time_t ltime; /* calendar time */ \

                                char *ptr;\

#define PRINTF(...)     ltime = time(NULL); /* get current cal time */ \

                                ptr = asctime( localtime(&ltime));\

                                ptr[strlen(ptr)-1] = '\0';\

                                printf("%s: ", ptr); \

                                printf(__VA_ARGS__); printf("\n");

void print_logs()

{

   LOG_INIT();

   PRINTF("%s", "neelu");

   sleep(2);

   PRINTF("%s", "peelu");

   sleep(2);

   PRINTF("%s", "meelu");

}

void main()

{

    print_logs();

}

Output:

neelkanth_surekha#./a.out 

Thu Nov 23 00:29:32 2017: neelu

Thu Nov 23 00:29:34 2017: peelu

Thu Nov 23 00:29:36 2017: meelu