Make emacs autocomplete cpp files over binary files

Question

My question is similar to this one, except for emacs instead of vim. The issue is that I have a cpp file that I want to open and when I type f[TAB] it autocompletes to foo the binary file foo instead of foo.cpp. Is there a way to turn of autocomplete for files with certain (or no) extension? Or is there a way to prioritize certain extensions?

EDIT: I've used this solution for autocompletion in the minibuffer, but I want a solution for Bash autocompletion.

EDIT: I've found that I can do export FIGNORE=.bin to ignore all files with the .bin extension in Bash autocomplete. The issue with this solution is that this doesn't work for a file with no extension, and also there's no way to make this occur only when there are no .cpp files in the same directory.

Answer 1

If you give it some extension (e.g. .bin) then you can ignore it with completion-ignored-extensions:

When completing file names, Emacs usually omits certain alternatives that are considered unlikely to be chosen, as determined by the list variable completion-ignored-extensions. Each element in the list should be a string; any file name ending in such a string is ignored as a completion alternative. Any element ending in a slash (/) represents a subdirectory name. The standard value of completion-ignored-extensions has several elements including ".o", ".elc", and "~". For example, if a directory contains ‘foo.c’ and ‘foo.elc’, ‘foo’ completes to ‘foo.c’. However, if all possible completions end in “ignored” strings, they are not ignored: in the previous example, ‘foo.e’ completes to ‘foo.elc’. Emacs disregards completion-ignored-extensions when showing completion alternatives in the completion list.

http://www.gnu.org/software/emacs/manual/html_node/emacs/Completion-Options.html