How to rename files as they are added to a folder? - macos

Question

I created an Automator workflow that renames iOS Simulator Screenshots as they are added to the Desktop folder. But for the workflow to work, I need to run it myself manually. Is there a way to make the workflow watches the Desktop folder continuously and renames screenshots as they are added like a background service?
This is the workflow I created :
Screenshot of the Workflow

Answer 1

I find automator to be a a bit clunky at times, so I suggest you do this with a standard AppleScript Folder Action. Copy the following script into Script Editor.app, modify the prefixes as needed, then save it in ~/Library/Scripts/Folder Action Scripts.
property old_prefix : "Simulator Screen Shot - "
property new_prefix : "some text "
on adding folder items to this_folder after receiving these_items
repeat with this_item in these_items
set item_path to POSIX path of this_item
tell application "System Events"
set this_disk_item to disk item item_path
tell this_disk_item
if its name begins with old_prefix then
set its_extention to its name extension
set its_name to its displayed name
set new_file_name to new_prefix & (text ((length of old_prefix) + 1) through -1 of its_name)
if new_file_name ≠ its displayed name and new_file_name ≠ "" then
set name of this_disk_item to new_file_name & "." & its_extention
end if
end if
end tell
end tell
end repeat
end adding folder items to
Use Spotlight to open the app "Folder Actions Setup", add your desktop as a folder on the left side, and on the right, select and attach the script you just saved to that folder. It should 'just work'.

Answer 2

The way I would do it is to use an application called launchd to open the automator script how ever often you need (e.g. every few seconds). This website describes how to set it up. Basically you have to first save your automator script as an application into a certain folder (e.g. Documents), then write a short xml script which tells launchd which file to open and how often to do it.
Below is a sample script:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>com.NAME.test</string>
<key>Program</key>
<string>/Users/USERNAME/Documents/test.app/Contents/MacOS/Application Stub</string>
<key>StartInterval</key>
<integer>5</integer>
<key>RunAtLoad</key>
<true/>
</dict>
</plist>
Open a new "Plain text" TextEdit document and paste in the above. Replace the Label (com.NAME.test) with whatever you want; I usually just put my name in there, followed by the name of the script. Next change the line under Program to the location of your ".app" file you saved earlier, remembering to change USERNAME to your username. Keep in mind that the /Contents/MacOS/Application Stub needs to be right after the ".app" part so that the script will start your application. Then change the line under StartInterval to the number of seconds you want the script to wait before it runs again.
After you're done editing the script, save it to "/Users/USERNAME/Library/LaunchAgents/com.NAME.test.plist," of course changing USERNAME to your username and com.NAME.test to the Label used in the xml script. If it asks if you want to save it with the ".plist" extension, choose yes. Once the file's saved, open up Terminal (/Applications/Utilities/Terminal.app) and type in the command launchctl load /Users/USERNAME/Library/LaunchAgents/com.NAME.test.plist, changing the file name to the filepath of your ".plist" file. Use unload instead of load to stop the script from running.
For me a gear icon kept appearing in the menu bar every time the script ran, so I found on this and this website that you can stop it by adding "Run Shell Script" to the very top of your Automator script, then typing in the box killall ScriptMonitor || true.