Skim the clipboard от FrançoisR

This add-on use regular expression templates to filter a text when it is pasted or copied.
You may paste & filter when you paste text modified by a regular expression in a form field in Firefox.
To change an url, you may use the replace in clipboard menu that appears when the page is right clicked outside a field or a link:
he modified clipboard content is replace in the clipboard, ready to be pasted outside the page.

You may also copy & filter to copy some text from a web page and want to use it modified by a regular expression in another application.

Example: Suppose I want to paste the host url address in the address bar, when you have copied any link location from a page any where on the same site.

Open the Filtered Clipboard options, Click on Add a row (text field)
and enter the following in the table:

1. name: host,
2. Regular expression template enter a regular expression: (^http.?:\/\/[^\/]+)(.*$)
3. Regular expression modifier: i
4. keep machtes or substitute: $1
5. Upercase(U) Lowercase(L): no value
6. keep in clipboard: checked
7. Shortcut: one

Click outside the table and checked that the corresponding JSON data contains the new row.
Close the option page and navigate to a random page,
copy (Ctrl+c) the link location from the address bar.

Now, you may call the new filter with the mouse. Right click anywhere on the page and select Replace in Clipboard > Host.
Go to the address bar and paste (Ctrl+V) to see the changed url.

This extension exists also for Opera and Chrome:

• Opera
• Chrome