Using git diff with xargs -0, spaces in file names

Question

What I'm attempting to do is extract a list of 'projects' which have changed since a given commit. For this I'm approximating a project to a folder containing a changed file.

The problem I'm having is getting this to work with files which have spaces in their names:

$ git diff --name-only TREEISH.. | xargs -n 1 dirname

I've looked at the -0 option for xargs, and the -z option for diff, but this gives me:

$ git diff --name-only -z TREEISH.. | xargs -0 dirname
dirname: too many arguments

What am I missing?

Answer 1

Try this:

git diff --name-only -z TREEISH.. | while IFS= read -r n; do dirname "$n"; done 

• IFS is the input field separator, needed to avoid trimming leading/trailing whitespace
• -r is needed to avoid backslash processing.
• The quotes around "$n" make it deal with spaces.

See here for more information.