Ubuntu – Remove all files within directory older than the most recently added ten files

As @Jos pointed out you missed a space between name and '*.gz'; also for speeding up the command use -type f option to running the command on files only.

So the fixed command would be:

find /path/to/ -type f -mtime +7 -name '*.gz' -execdir rm -- '{}' \;

Explanation:

• find: the unix command for finding files/directories/links and etc.
• /path/to/: the directory to start your search in.
• -type f: only find files.
• -name '*.gz': list files that ends with .gz.
• -mtime +7: only consider the ones with modification time older than 7 days.
• -execdir ... \;: for each such result found, do the following command in ....
• rm -- '{}': remove the file; the {} part is where the find result gets substituted into from the previous part. -- means end of command parameters avoid prompting error for those files starting with hyphen.

Alternatively, use:

find /path/to/ -type f -mtime +7 -name '*.gz' -print0 | xargs -r0 rm --

From man find:

-print0 
      True; print the full file name on the standard output, followed by a null character 
  (instead of the newline character that -print uses). This allows file names that contain
  newlines or other types of white space to be correctly interpreted by programs that process
  the find output. This option corresponds to the -0 option of xargs.

Which is a bit more efficient, because it amounts to:

rm file1 file2 file3 ...

as opposed to:

rm file1; rm file2; rm file3; ...

as in the -exec method.

An alternative and also faster command is using exec's + terminator instead of \;:

find /path/to/ -type f -mtime +7 -name '*.gz' -execdir rm -- '{}' +

This command will run rm only once at the end instead of each time a file is found and this command is almost as fast as using -delete option as following in modern find:

find /path/to/ -type f -mtime +7 -name '*.gz' -delete

Using inoticoming:

You can put a script in /etc/init.d/ that runs inoticoming at boot time.

1. Create a new folder to hold the inoticoming log / last pid for the watched folder: sudo mkdir -p /var/log/inoticoming/watched/

2. Create a script inoticoming_watched in /etc/init.d/:

_{* Remember to change <path_to_folder> and <path_to_script> to match the full path of the watched folder and the full path of the script to execute}

#!/bin/sh

case "${1}" in
    start)
        inoticoming --logfile '/var/log/inoticoming/watched/inoticoming.log' --pid-file '/var/log/inoticoming/watched/inoticoming_last_pid.txt' <path_to_folder> <path_to_script> \;
    ;;

    stop)
        kill -15 $(< /var/log/inoticoming/watched/inoticoming_last_pid.txt tee)
    ;;

    restart)
        ${0} stop
        sleep 1
        ${0} start
    ;;

    *)
    echo "Usage: ${0} {start|stop|restart}"
    exit 1
    ;;
esac

3. Mark the script as executable: sudo chmod u+x /etc/init.d/inoticoming_watched

4. Make sure that the script called by inoticoming_watched is executable.

5. Update rc.d to make the service inoticoming_watched start at boot time: sudo update-rc.d inoticoming_watched defaults

You can check the inoticoming log in /var/log/inoticoming/watched.