5.3 Ignoring Buffers and Files

Ido is capable of ignoring buffers, directories, files and extensions using regular expression.

User Option: ido-ignore-buffers

This variable takes a list of regular expressions for buffers to ignore in ido-switch-buffer.

User Option: ido-ignore-directories

This variable takes a list of regular expressions for (sub)directories names to ignore in ido-dired and ido-find-file.

User Option: ido-ignore-files

This variable takes a list of regular expressions for files to ignore in ido-find-file.

User Option: ido-ignore-unc-host-regexps

This variable takes a list of regular expressions matching UNC hosts to ignore. The letter case will be ignored if ido-downcase-unc-hosts is non-nil.

To make Ido use completion-ignored-extensions you need to enable it:

(setq ido-ignore-extensions t)

Now you can customize completion-ignored-extensions as well. Go ahead and add all the useless object files, backup files, shared library files and other computing flotsam you don’t want Ido to show.

Please notice: Ido will still complete the ignored elements if it would otherwise not show any other matches. So if you type out the name of an ignored file, Ido will still let you open it just fine.