How can I view all the git repositories on my machine?

ORIGINAL ANSWER: This works pretty well from Windows Powershell:

Get-ChildItem . -Attributes Directory+Hidden -ErrorAction SilentlyContinue -Include ".git" -Recurse

EDIT #1: -Filter is twice as fast as -Include. Here is that solution:

Get-ChildItem . -Attributes Directory+Hidden -ErrorAction SilentlyContinue -Filter ".git" -Recurse

EDIT #2: Keith E. Truesdell mentioned sending the output to a file. See his comment for that solution. I prefer console output. But his comment got me thinking that I prefer just the full path, not the whole mess that is returned by default. If you want that just the full path, use the following:

Get-ChildItem . -Attributes Directory+Hidden -ErrorAction SilentlyContinue -Filter ".git" -Recurse | % { Write-Host $_.FullName }

FINAL NOTE: The above solutions only return Git repositories under the current directory. If you want ALL repositories on a drive, you should run the command once from the root of each drive.

On *nix, this will also find any --bare repositories.

find / -name "*.git" -type d

Git repositories all have HEAD, refs and objects entries.

on GNU/anything,

find -name HEAD -execdir test -e refs -a -e objects \; -printf %h\\n

Just checking for .git will miss many bare repos and submodules.

To go full-paranoid on the checking you can ask git to do all its own checks before printing,

find -name HEAD -execdir test -e refs -a -e objects \; \
      -execdir sh -ec 'GIT_DIR=$PWD git rev-parse --absolute-git-dir 2>&-' \;

(edit: I thought the .git/config file was necessary, turns out it's not, so the absolute minimum git init newrepo is

mkdir -p newrepo/.git/{objects,refs}
echo ref: refs/heads/master >newrepo/.git/HEAD

)

If you are in Linux find / -name ".git", otherwise there is no way, they are standard directories, just use your OS file/folder find program to find .git named folders.