Unmount a volume as soon as its inserted if its name is "XYZ"

Question

I have a USB modem which is mounted as say XYZ(which contains the Dialer Software and Readme) when its inserted. In order to connect using it, I have to eject it and then connect it using ppp dialer.

Let us say that it mounts under the name /Volumes/XYZ

I want to do something like if I insert a USB device and it mounts under the name XYZ, I want it to be ejected immediately.

How do I do that?

Answer 1

I did something similar once upon a time, where whenever a drive named a certain way was mounted, a script immediately fired off to sync the contents of a set of folders to the drive.

To do something similar here, the script would need to look like this:

#!/bin/bash

if [ -d /Volumes/XYZ ];
    then
    echo “Ejecting XYZ!”;
    umount /Volumes/XYZ
    exit;
fi

Save it somewhere, your ~/bin/ directory if you have one, or maybe ~/Library/Scripts/, just remember where.

The second piece of the puzzle is the LaunchAgent that will actually handle the event whenever a drive is mounted:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.superuser.226504.example</string>
    <key>ProgramArguments</key>
    <array>
        <string>/Path/To/Script/unmount-modem.sh</string>
    </array>
    <key>QueueDirectories</key>
    <array/>
    <key>StartOnMount</key>
    <true/>
    <key>WatchPaths</key>
    <array/>
</dict>
</plist>

That needs to be saved as a .plist (named similar to the string used in place of “com.superuser.226504.example”) and saved to ~/Library/LaunchAgents. You can either load it from the terminal via launchctl load ~/Library/LaunchAgents/pathtoplist or log out / log back in and it should get loaded if everything is configured properly.

Answer 2

You can use the following AppleScript:

on adding folder items to this_folder after receiving added_items
    set the item_count to the number of items in the added_items

    if the item_count is greater than 1 then
        display dialog "Multiple additions, I can't handle that!"
    else
        set the volume_name_raw to (item 1 of the items in the added_items as text)
        set AppleScript's text item delimiters to ":"
        set volume_name to text item 1 of volume_name_raw as text
        if volume_name is "Carbon Copy Cloner" then
            do shell script "hdiutil detach '/Volumes/" & volume_name & "'"
        end if
    end if
end adding folder items to

^{Based on the folder action "new item alert" by Apple}

Change the name of the volume you want to eject in the following line:

if volume_name is "Carbon Copy Cloner" then

---

To activate it:

1. Open /Applications/Utilities/AppleScript Editor and paste the script above.
2. Save it as a script (e.g. eject.scpt) in ~/Library/Scripts/Folder Action Scripts/.
3. Close AppleScript Editor.
4. Right-click any folder in Finder, select Services » Folder Actions Setup
5. Dismiss the sheet dialog.
6. Check Enable Folder Actions
7. Click the + button to the lower left, and press Command-Shift-G in the resulting file dialog. Enter /Volumes. Don't select an item, just press OK.
8. Select the list entry Volumes and click the + button below the right side list.
9. Select eject.scpt in the sheet dialog and click Attach
10. Close Folder Actions Setup.

Done!