Книга: Fedora™ Unleashed, 2008 edition

Finding Files from an Index with locate

Finding Files from an Index with locate

When you use the find command, it searches recursively through each directory each time you request a file. This is slow, as you can imagine. Fortunately, Fedora ships with a cron job that creates an index of all the files on your system every night. Searching this index is extremely fast, which means that, if the file you are looking for has been around since the last index, this is the preferable way of searching.

To look for a file in your index, use the command locate followed by the names of the files you want to find, like this:

$ locate myfile.txt

On a relatively modern computer (1.5GHz or higher), locate should be able to return all the matching files in less than a second. The trade-off for this speed is lack of flexibility. You can search for matching filenames, but, unlike with find, you cannot search for sizes, owners, access permissions, or other attributes. The one thing you can change is case sensitivity; use the -i parameter to do a search that is not case sensitive.

Although Fedora rebuilds the filename index nightly, you can force a rebuild whenever you want by running the command updatedb as root. This usually takes a few minutes, but when it's done the new database is immediately available.

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