Just say I have a file: \"HelloWorld.pm\" in multiple subdirectories within a Git repository.
I would like to issue a command to find the full paths of all the files
git ls-files will give you a listing of all files in current state of the repository (the cache or index). You can pass a pattern in to get files matching that pattern.
git ls-files HelloWorld.pm '**/HelloWorld.pm'
If you would like to find a set of files and grep through their contents, you can do that with git grep:
git grep some-string -- HelloWorld.pm '**/HelloWorld.pm'