Recoll Desktop Search
To help me locate an item of interest amongst the ever growing collection of documents, emails, photographs and other data files I have on my computer, I use a desktop search program. Desktop search programs create and maintain an index of the contents of your files. You can specify a word or phrase that you know is in the file and the program will display the list of files that match your search clue. You can preview or open the file from the list of matches.
A good desktop search program will go further. You should be able to specify the file types to include or exclude from a search, and which files and folders to ignore when indexing.
To be really useful the desktop search program needs to be able to burrow through the databases of other applications, such as the email store of Thunderbird, and index the data it finds there. (Actually the search in Thunderbird is very good on its own, but sometimes I need to search for something and see all matching images, documents and emails in one place.)
The program I’ve settled on in Ubuntu is called Recoll. It is very flexible, it indexes all sorts of files – and the search is fast. Recoll needs to have its index updated periodically to keep it in synch with the changing content of your files. There is a program called recollindex which updates the Recoll index. I didn’t want to have to remember to manually run recollindex, I wanted to find a way to have recollindex started automatically for me.
The answer to that was Cron.