32 comment

1. Awesome man! I liked the most about rndc reload. Now no need to keep running rndc reload every hour or so.

   1. Why reload named every hour? Do you make any automated changes to zone file?

      1. No I don’t. Just gave a thought. I know XName.org reloads it every hour. I don’t have too many zones.

2. Hi, to resolve one of my biggest problem, i wrote a python program with inotify:
   http://ebalaskas.gr./blog/?page=PIrsyncD

3. Hi, nice article.

   I’ve written a program based on inotify:

   http://ebalaskas.gr./blog/?page=PIrsyncD

   to resolve one of my biggest problems

4. None of my machines using the default CentOS repos seem to have incron available to install. Which repos are you using? My machines are Centos 5.5 ones (one 32-bit, one 64-bit).

   1. It is from Fedora Project – EPEL repo. Install epel repo and you will get access to tons of binary packages.

      rpm -qi incron | grep -i vendor
      Version     : 0.5.5                             Vendor: Fedora Project
      

      HTH

      1. After adding EPEL per the tutorial you linked, I was able to add incron onto my machine. Thanks for the quick response and very useful information you’ve provided.

5. Silly, this can be done with a simple 4 or 5 line script in python.

   hints
   os.path.exists
   os.unlink
   popen

   1. Ya sure, but you need to run it as a daemon, it would be slow/cpuhog. incron is in C, so works much faster. There may be some python-inotify library which can be used instead of the above suggestion.
      Also, using this method, you could write a bash daemon! (I have one on my local system to check that if pidgin runs, ensure skype runs, if pidgin doesn’t kill skype).

      1. And wohoo, here’s the python-inotify library- http://trac.dbzteam.org/pyinotify

   2. Try that on tons of thousandths of files and you will see that your Python will perform in tens of seconds rather than milliseconds. You will say that there is no big difference but this will translate in disk reads a the physical level rather than operating system level triggers.

      I speak from experience. I am not using incrond but something similar in production and it performs way faster that the similar Python code.

      Use the right tool for the job.

      1. That’s one of the libraries, there’s a C extension also available which directly handles with the kernel, i.e. responds to kernel events. Just google it out.

6. I don’t suppose we have similar version of this for Mac OS X ? Can’t seem to find one.

   1. May be this will help. Edit: It appers that it is a work in progress software. If you know coding than you can always use knotify API.

7. From what I’m seeing online, the FreeBSD and Mac OS X implementation is called kqueue rather than inotify.

   1. Something else I wanted to bring up about using inotify after having looked more into it. There’s a handy option lsyncd that will work better than incrond for rsyncing directories. The project’s home page is at http://code.google.com/p/lsyncd/

      Is there a consideration of bring up lsync for either this tutorial or another one? It appears to possibly work better due to handling recursion in a directory for rsyncing using inotify based on what I’m seeing.

      (If this ends up double posting, apologies, but it didn’t appear to post or even be in moderation after I initially submitted it so re-adding it.)

      1. DRBD is much better solution if you need to mirror entire partition in real time. It is like network based RAID-1.

8. Something else I wanted to bring up about using inotify after having looked more into it. There’s a handy option lsyncd that will work better than incrond for rsyncing directories. The project’s home page is at http://code.google.com/p/lsyncd/

   There’s a how-to on using it at Link

   Is there a consideration of bring up lsync for either this tutorial or another one? It appears to possibly work better due to handling recursion in a directory for rsyncing using inotify based on what I’m seeing.

9. Hi all,

   Is it possible to set incrontab in bash script? I tried to set normal crontab and it works without any problem but not “incrontab” :(

   Any idea?

   R

10. This is easily the best website to check for new ideas. I was struggling with inotify for this kind of job and I wouldn’t have find this incron tool by myself.

11. Thanks for the tutorial. I was exactly looking for a tool like this one – thanks to this blog it even comes with a complete tutorial! :)

12. Check out the script mentioned in the url pasted below. It uses inotifywait to recursively monitor and record file creation events.

    http://jackal777.wordpress.com/2013/05/11/script-to-monitor-file-creation-under-all-cpanel-users-documentroot/

13. HI Nix craft,

    when i use incrontab out of the box, i mean no changes,

    i have no result, as if the cmd was not executed.

    my incron line is :

    /crrae IN_CREATE,IN_CLOSE_WRITE,IN_MOVED_TO /usr/bin/unix2dos $#

    the log give information as if everything was ok but no actually

    when i change my incron to :

    /crrae IN_CREATE,IN_CLOSE_WRITE,IN_MOVED_TO /usr/bin/unix2dos /crrae/$#

    the log give me this:

    May  4 18:15:10 srvovs incrond[20859]: (root) CMD (/usr/bin/unix2dos /crrae/u2dtmpPbqoFd)
    May  4 18:15:10 srvovs incrond[20859]: (root) CMD (/usr/bin/unix2dos /crrae/u2dtmpN2Odxf)
    May  4 18:15:10 srvovs incrond[20859]: (root) CMD (/usr/bin/unix2dos /crrae/u2dtmpN2Odxf)
    

    multiple times

    here is the incron.conf:

    [root@srvovs ~]# cat /etc/incron.conf
    #
    # *** incron example configuration file ***
    #
    # (c) Lukas Jelinek, 2007, 2008
    #
    
    
    # Parameter:   system_table_dir
    # Meaning:     system table directory
    # Description: This directory is examined by incrond for system table files.
    # Default:     /etc/incron.d
    #
    # Example:
    # system_table_dir = /var/spool/incron.systables
    
    
    # Parameter:   user_table_dir
    # Meaning:     user table directory
    # Description: This directory is examined by incrond for user table files.
    # Default:     /var/spool/incron
    #
    # Example:
    # user_table_dir = /var/spool/incron.usertables
    
    
    # Parameter:   allowed_users
    # Meaning:     allowed users list file
    # Description: This file contains users allowed to use incron.
    # Default:     /etc/incron.allow
    #
    # Example:
    # allowed_users = /etc/incron/allow
    
    
    # Parameter:   denied_users
    # Meaning:     denied users list file
    # Description: This file contains users denied to use incron.
    # Default:     /etc/incron.deny
    #
    # Example:
    # denied_users = /etc/incron/deny
    
    
    # Parameter:   lockfile_dir
    # Meaning:     application lock file directory
    # Description: This directory is used for creating a lock avoiding to run
    #              multiple instances of incrond.
    # Default:     /var/run
    #
    # Example:
    # lockfile_dir = /tmp
    
    
    # Parameter:   lockfile_name
    # Meaning:     application lock file name base
    # Description: This name (appended by '.pid') is used for creating a lock
    #              avoiding to run multiple instances of incrond.
    # Default:     incrond
    #
    # Example:
    # lockfile_name = incron.lock
    
    
    # Parameter:   editor
    # Meaning:     editor executable
    # Description: This name or path is used to run as an editor for editting
    #              user tables.
    # Default:     vim
    #
    # Example:
    # editor = nano
    
    

    any idea ?

14. Hi Nix craft,
    This is helpful I appended an email notification whenever a file is being copied but when there’s a lot of file being transferred its spamming my email because it is monitoring every event.. Any suggestion to send email per batch not per files.

15. i have a question,

    im running cuckoo sandbox,
    and i want to make a folder, that whenever i put a sample there, this script will perform the next action

    python submit.py

    how could i do that?

16. Has anyone got incron & unison successfully working together to sync remote servers, all on CentOS 6? If so, can you explain, please?

    Thanks

    1. We use this line for “incrontab -e”:

       /home/user-to-be-replicated/base-directory IN_CREATE,IN_DELETE,IN_CLOSE_WRITE unison -batch -group -owner /home/user-to-be-replicated/base-directory ssh://otherhost//home/user-to-be-replicated/base-directory

       Additionally we configured password-less auth for root (private/public-key pair) and enabled incron for root:
       echo ‘root’ >> /etc/incron.allow

       I hope this helps.

17. I have a situation where we receive 2 or more small files of say 2k thru an FTP at the same time.
    incron only fires once for both files and passes only one file name.

    Anyone know the reason for this, and what I can do to resolve this.

18. Awesome, exactly what I needed. I use it with cups and avahi to print PDFs on my iPhone and automatically email them to myself. Many thanks.

19. Thanks for this write-up!

20. This probably sounds stupid, but I’m trying to save after I enter my command. But I can’t figure out how.
    I incron -e enter my command and can’t get back out to the command line. How do I save my changes?

    Have a question? Post it on our forum!