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Extensions

What are extensions?

Extensions make it possible to filter search results by custom functions. They can be written in C or Python.

Custom functions always return a whole number. The image_width() function from the gdk-pixbuf extension is a good example. You can search for JPEG files wider than 800 pixels with the following command:

$ efind . 'name="*.jpg" and image_width()>800'

efind translates the first part of the expression and runs GNU find with the following arguments:

$ find . -name "*.jpg"

Then each found file is filtered by evaluating the second part of the expression.

A function can have optional arguments. Non-zero values evaluate to true. The artist_matches() function from the taglib extension returns a non-zero value if the specified artist name matches the corresponding ID3 tag:

$ efind . 'name="*.mp3" and artist_matches("the cure")'

To print a list with available functions run

$ efind --print-extensions

Extensions can be installed globally in /usr/lib/efind/extensions or locally in ~/.efind/extensions. You may want to specify wildcard patterns in a personal blacklist (~/.efind/blacklist) to prevent extensions from being loaded. To disable all global Python extensions, for instance, add the following line to your blacklist: