![]() ![]() A process group is created to prevent shell scripts from masking signals. SIGTERM is used to terminate the utility before it is restarted. As with the standard mode of operation, a utility which terminates is not executed again until a file system or keyboard event is processed. In this mode entr does not attempt to read from the TTY or change its properties. Files with names beginning with ‘.’ are ignored. This option also enables directories to be specified explicitly. -d Track the directories of regular files provided as input and exit if a new file is added.my_watch_dir | entr -dnr echo "Running trigger."Įcho. You can track a directory for new additions using while $(true) do You can install it with apt-get install entr entr was written to make rapid feedback and automated testing natural and completely ordinary. Uses kqueue(2) or inotify(7) to avoid polling. Note entr doesn't use polling giving it a huge advantage over many of the alternatives. Using entr is the new way to do this (it's cross platform). var/www/html IN_CREATE /root/scripts/backup.sh Essentially it's a service that leverages inotify and you can setup configurations to take action based on file change operations. I prefer incron, as its easier to manage. It's not bullet proof, but it serves some purposes without external tools like inotify. You could also background the activities. If your file processing doesn't take too long, you should not miss any new file. I just cooked up this, and see no huge problems with it, other than a tiny chance of missing files in between checks. Not real time, so if a file was created and deleted in less than 0.1 second, then this would not work, watch only supports minimum of 0.1 seconds. Non-scriptable (For scripting options, have a look at other answers) ![]() Monitors your folder and lists you everything in it every 0.1 seconds In case you came here for a simple, fast, handy solution reading the title, you could use watch watch -n 0.1 ls There is no need to use grep/sed/awk to preprocess the output. Also, your read command can assign the positional output into multiple variables that you can choose to use or ignore. What is important to note is that the -e option to inotifywait is the best way to do event filtering. As of version 3.13 (current in Ubuntu 12.04) inotifywait will include the filename without the -f option. In Ubuntu inotifywait is provided by the inotify-tools package. # find the path to the desktop folder: $desktop = :: GetFolderPath ( 'Desktop' ) # specify the path to the folder you want to monitor: $Path = $desktop # specify which files you want to monitor $FileFilter = '*' # specify whether you want to monitor subfolders as well: $IncludeSubfolders = $true # specify the file or folder properties you want to monitor: $AttributeFilter = :: FileName, :: LastWrite # specify the type of changes you want to monitor: $ChangeTypes = :: Created, :: Deleted # specify the maximum time (in milliseconds) you want to wait for changes: $Timeout = 1000 # define a function that gets called for every change: function Invoke-SomeAction # subscribe your event handler to all event types that are # important to you.You should consider using inotifywait, as an example: inotifywait -m /path -e create -e moved_to |Įcho "The file '$file' appeared in directory '$dir' via '$action'" Whenever a change is detected, Invoke-SomeAction is called. This is straight-forward: the script below monitors your desktop and all of its subfolders for new files and for deletion of files. However, responding to events is not trivial in a single-threaded environment like PowerShell. This way, you cannot miss change events because the FileSystemWatcher is constantly monitoring. Instead, whenever a change occurs, an event is fired, and your script can respond to the events. Advanced Mode: In asynchronous mode, the FileSystemWatcher does not block PowerShell.This approachis very simple to implement however there is a chance to miss change events when they occur in rapid succession. ![]() This blocks PowerShell until either the change occurs or a timeout is reached.
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