How to print the time in c/unix with gettimeofday()

Question

I am trying to write the time in format of 21-02-2016 00:50:00 but there are some mistakes that I could not solve. Also in main function I called PrintTime() and I got an undefined reference error in main function which is probably because of this piece of code.

void PrintTime()
{
  struct timeval tv;
  time_t nowtime;
  struct tm *nowtm;
  char tmbuf[64]

  gettimeofday(&tv, NULL);
  nowtime = tv.tv_sec;
  nowtm = localtime(&nowtime);
  strftime(tmbuf, sizeof tmbuf, "%Y-%m-%d %H:%M:%S", nowtm);
  free(tmbuf);
}

I tried to execute this here are the list of errors I get:

Q3.c:67:7: warning: assignment makes pointer from integer without a cast
 nowtm = localtime(&nowtime);
       ^
Q3.c:68:1: warning: incompatible implicit declaration of built-in function ‘strftime’
 strftime(tmbuf, sizeof tmbuf, "%d-%d-%d %d:%d:%d", nowtm);
 ^
/tmp/ccwQwMjE.o: In function `main':
Q3.c:(.text+0x102): undefined reference to `PrintTime'

Answer 1

Your code should have #include <time.h> included in it

/* PrintTime.h */
#ifndef PRINTTIME_H
#define PRINTTIME_H
...
#include <time.h>
...

void PrintTime(){

}

And the main.c

/* main.c */
...
#include <PrintTime.h>
...

int main() {
 ...
 return 0;
}

Compiling

% cc main.c -o main -I_path_to_PrintTime_h_file

Answer 2

You forgot ; after char tmbuf[64] . free(tmbuf); is wrong because tmbuff is declared as Stack not Heap. Revise and compile again. Be sure that you are already included

#include <sys/time.h>
#include <time.h>