inotify.c

/* A simple inotify example from https://www.ibm.com/developerworks/linux/library/l-ubuntu-inotify/ */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/inotify.h>

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

int main( int argc, char **argv ) 
{
  int length;
  int fd;
  int wd;
  char buffer[BUF_LEN];

  fd = inotify_init();

  if ( fd < 0 ) {
    perror( "inotify_init" );
  }

  wd = inotify_add_watch( fd, "/home/wh5a", 
                         IN_MODIFY | IN_CREATE | IN_DELETE );

  while (1) {
    int i = 0;
    length = read( fd, buffer, BUF_LEN );

    if ( length < 0 ) {
      perror( "read" );
    }  

    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( "The directory %s was created.\n", event->name );       
          }
          else {
            printf( "The file %s was created.\n", event->name );
          }
        }
        else if ( event->mask & IN_DELETE ) {
          if ( event->mask & IN_ISDIR ) {
            printf( "The directory %s was deleted.\n", event->name );       
          }
          else {
            printf( "The file %s was deleted.\n", event->name );
          }
        }
        else if ( event->mask & IN_MODIFY ) {
          if ( event->mask & IN_ISDIR ) {
            printf( "The directory %s was modified.\n", event->name );
          }
          else {
            printf( "The file %s was modified.\n", event->name );
          }
        }
      }
      i += EVENT_SIZE + event->len;
    }
  }
  ( void ) inotify_rm_watch( fd, wd );
  ( void ) close( fd );

  exit( 0 );
}