hkd/tests/inotify.c

/*This is the sample program to notify us for the file creation and file deletion takes place in “/tmp” directory*/
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/inotify.h>
#include <unistd.h>

#define EVENT_SIZE  ( sizeof (struct inotify_event) )
#define EVENT_BUF_LEN     ( 1024 * ( EVENT_SIZE + 16 ) )

int main( )
{
  int length, i = 0;
  int fd;
  int wd;
  char buffer[EVENT_BUF_LEN];

  /*creating the INOTIFY instance*/
  fd = inotify_init1(IN_NONBLOCK);

  /*checking for error*/
  if ( fd < 0 ) {
    perror( "inotify_init" );
  }

  /*adding the “/tmp” directory into watch list. Here, the suggestion is to validate the existence of the directory before adding into monitoring list.*/
  wd = inotify_add_watch( fd, "/dev/input/", IN_CREATE | IN_DELETE );

  printf("%d\t%d\n", fd, wd);
  /*read to determine the event change happens on “/tmp” directory. Actually this read blocks until the change event occurs*/
  while ((length = read( fd, buffer, EVENT_BUF_LEN )) < 0);

  /*checking for error*/
  if ( length < 0 ) {
    perror( "read" );
  }

  /*actually read return the list of change events happens. Here, read the change event one by one and process it accordingly.*/
  while ( i < length ) {     struct inotify_event *event = ( struct inotify_event * ) &buffer[ i ];     if ( event->len ) {
      if ( event->mask & IN_CREATE ) {
        if ( event->mask & IN_ISDIR ) {
          printf( "New directory %s created.\n", event->name );
        }
        else {
          printf( "New file %s created.\n", event->name );
        }
      }
      else if ( event->mask & IN_DELETE ) {
        if ( event->mask & IN_ISDIR ) {
          printf( "Directory %s deleted.\n", event->name );
        }
        else {
          printf( "File %s deleted.\n", event->name );
        }
      }
    }
    i += EVENT_SIZE + event->len;
  }
  /*removing the “/tmp” directory from the watch list.*/
   inotify_rm_watch( fd, wd );

  /*closing the INOTIFY instance*/
   close( fd );

}