Multipurpose library with a wide range of useful functions for C language

jka.h

/**
 This file is source code of jkalib
 jkalib (C) 2016-2017 JKA Network <contacto@jkanetwork.com>
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 any later version.
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.

 jkalib is a multipurpose library with a wide range of useful functions for C language

 Some code is from https://davidcapello.com/blog/cpp/medir-el-tiempo-de-una-rutina/
 */

//Standard libraries
#include <stdio.h>
#include <time.h>

#ifdef __linux__
#include <sys/time.h>
typedef struct timeval event ;
#else
#include <windows.h>
typedef LARGE_INTEGER event;
#endif

//Prototypes
void pause(void);
int clean_stdin(void);
void printError(char[]);
double eventDiff(event *,event*);
void setEvent(event *);

/**
 Description: Stop the execution until the user push one key
 IN/ VOID
 /OUT VOID
 */
void pause(void){
  clean_stdin();
  getchar();
}

/**
 Description: Clean the keyboard buffer
 IN/ VOID
 /OUT 1
 */
int clean_stdin(void){
  while(getchar()!='\n');
  return 1;
 }

/**
 Description: calculate a difference into two events
 IN/ first event, last event (timeval)
 /OUT difference into last and first event in milliseconds
 */
double eventDiff(event *first,event *last){
  #ifdef __linux__
  return
  ((double)(last->tv_sec + (double)last->tv_usec/1000000)-
  (double)(first->tv_sec + (double)first->tv_usec/1000000))*1000.0;
  #else
  event freq;
  QueryPerformanceFrequency(&freq);
  return ((double)(last->QuadPart - first->QuadPart) / (double)freq.QuadPart) * 1000.0;
  #endif
}

/**
 Description: return an event
 IN/ event pointer
 /OUT VOID
 */
void setEvent(event *ev){
  #ifdef __linux__
  gettimeofday(ev,NULL);
  #else
  QueryPerformanceCounter(ev);	
  #endif
}

/**
 Description: print an error in stderr
 IN/ String whith the mesage
 /OUT VOID (In stderr the mesage)
 */
void printError(char mesage[]){
  fprintf(stderr,mesage);
}

main.c

#include <stdio.h>
#include "jka.h"

int main(int argc, char const *argv[])
{
	event init,end;

	double secs;
	int i;
	setEvent(&init);
	for(i=0;i<50000;i++){
		printf("%d\n",i);
	}
	setEvent(&end);
	secs = eventDiff(&init,&end);

	printf("\n%.16f milliseconds\n", secs);
	return 0;
}