How to list files ignored by git that are currently staged or committed?

How does one get a list of those files that match a rule in .gitignore file, but that have been staged or committed in the past?

The documentation to ls-files is not exactly clearly written, but it appears that the following simple alias does the job:

git config --global alias.showtrackedignored "ls-files -i --exclude-standard"

The above command creates an alias called showtrackedignored. To use, run:

git showtrackedignored

and it will list all of the files in the current directory and subdirectories that are tracked but would be ignored if they weren't tracked.

Bug in git ls-files

Unfortunately, this doesn't work 100% reliably. Apparently Git does a good job of finding files that should not be ignored, but when searching for files that are ignored (the -i option to git ls-files), it doesn't list ignored files inside a directory if it's the directory that matches the ignore rules.

To work around this bug, try converting your ignore rules so that only files are matched, not directories (this isn't always possible).

(Thank you Christoph for discovering this bug and reporting it to the Git mailing list! Edit: A patch is in the works now and will make it into git 1.7.11.2 or later)

Alternative approach

Here's a different approach. It's far more complicated and might have broken corner cases.

git config --global alias.showtrackedignored '!
cd "${GIT_PREFIX}" &&
untracked_list=$(git rev-parse --git-dir)/ignored-untracked.txt &&
git ls-files -o -i --exclude-standard >"${untracked_list}" &&
GIT_INDEX_FILE="" git ls-files -o -i --exclude-standard | grep -Fvxf "${untracked_list}" &&
rm -rf "${untracked_list}"'

The alias does the following:

• cd back to the directory where git showtrackedignored was run from (Git runs shell-based aliases from the toplevel directory, not the current directory; see the section on alias.* in git help config)
• Define a variable called untracked_list. This variable holds the path to a temporary file that will contain the list of currently ignored files. This temporary file is in the .git directory.
• Write the list of ignored files to ${untracked_list}.
• Tell Git to act as if the index is empty and list all the ignored files.
• Pipe that output to grep, which filters out the files that were written to ${untracked_list}.
• Delete the temporary file ${untracked_list}.

Drawbacks to this approach:

• It creates a temporary file in your .git directory.
• It assumes you have a POSIX-compatible shell.
• It assumes you have a POSIX-compatible implementation of grep.

It also suffers from the same bug as the former alias.

Just going to leave this one here, based on Richard's answer:

git ls-files --cached -i --exclude-standard | xargs git rm --cached

This will delete every tracked file that is ignored by .gitignore.

The other answers only show files that are currently ignored but exist in the working-tree/index.

To see files that are currently ignored but checked in in the past (and possibly now deleted)

git log --pretty=format: --name-only --diff-filter=A `# all files ever` \
| sed '/^$/d' `# skip git-logs empty lines` \
| sort -u `# sort + unique` \
| tr '\n' '\0' `# null separate for xargs` \
| xargs -0 git check-ignore # check if they are ignored

Not sure if renamed files are displayed multiple times or not.

edit:

Fix formatting and skip git-log empty lines

This question was answered well by https://stackoverflow.com/a/467053. Basically, git clean -ndX will tell you what can be safely ignored.