Git Extract modification in one string line

Question

Any good combination of Bash + git diff to get in one line the only change that I made in my file?

I'm using form Jenkins DSL, and the best that I get so far is this

"${sh(script: "git diff --shortstat", returnStdout: true)}".trim() == "1 file changed, 1 insertion(+), 1 deletion(-)"

But what I would love to have is the "hello world" text that I just add into one of the files.

Answer 1

If you've got just one hunk,

git diff -U0 | sed 1,/^@@/d

and strip the leading character off.