#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <pthread.h>
#include <stdlib.h>

#ifndef ROTATION_CYCLE
#define ROTATION_CYCLE 60
#endif

char*     str = "Quick brown fox jumped over lazy dog %d\n";
char      buf[50] = { 0 };
int       rl=1;
int       rr=1;
pthread_t thr[2];

void* logger_thread ( void* ptr ) {
  int i=0, r, fd;

  fd = open ( "/mnt/nfs/file", O_RDWR|O_CREAT, 00600 );
  printf ( "logger starting, fd %d\n", fd );

  if ( fd <= 0 ) {
    printf ("%s\n", strerror(errno));
    return NULL;
  }
  while ( rl ) {
    r = sprintf ( &buf[0], str, i );
    r = write ( fd, &buf[0], strlen(&buf[0]) );
    if ( r <= 0 ) {
      printf ("\n\n%s\n", strerror(errno));
      goto exit;
    }
    i++;
    usleep ( 10000 );
  }
exit:
  printf ("logger exiting\n");
  close (fd);
  return NULL;
}

void* logrotate_thread ( void* ptr ) {
  int r;

  printf ( "rotater starting\n" );
  while ( rr ) {
    sleep(ROTATION_CYCLE);

    r = system ( "mv /mnt/nfs/file.4 /mnt/nfs/file.5" );
    r = system ( "mv /mnt/nfs/file.3 /mnt/nfs/file.4" );
    r = system ( "mv /mnt/nfs/file.2 /mnt/nfs/file.3" );
    r = system ( "mv /mnt/nfs/file.1 /mnt/nfs/file.2" );
    r = system ( "mv /mnt/nfs/file /mnt/nfs/file.1" );
    rl=0;
    sleep(2);
    rl=1;
    pthread_create ( &thr[1], 0, logger_thread, 0 );
  }
  printf ( "rotater exiting\n" );
  return NULL;
}

int main ( int a, char** b ) {
  pthread_create ( &thr[0], 0, logrotate_thread, 0 );
  pthread_create ( &thr[0], 0, logger_thread, 0 );

  while ( 1 )
    usleep ( 100000 );
  return 0;
}