How to skip "Hit return to start merge resolution tool" and open mergetool automatically

Question

Git asking to hit return button to open the mergetool for each conflict file one by one:

> git mergetool 
Normal merge conflict for '...':
  {local}: modified file
  {remote}: modified file
Hit return to start merge resolution tool (opendiff):

How can I avoid the hitting return step for my project and just open the configured merge tool automatically?

Answer 1

Use the -y flag. From the documentation:

-y
--no-prompt
Don’t prompt before each invocation of the merge resolution program.

Answer 2

To permanently skip the prompt, run:

git config --global mergetool.prompt false

To skip it for a single run of git mergetool, pass -y or --no-prompt:

git mergetool -y

Answer 3

Note: GIt 2.0.x (Q3 2014) won't display that message if you have explicitely defined your merge.tool.
No need for a -y anymore.

See commit 4ecc63d by Felipe Contreras (felipec):

mergetool: run prompt only if guessed tool

It's annoying to see the prompt:

Hit return to start merge resolution tool (foo):

Every time the user does 'git mergetool' even if the user already configured 'foo' as the wanted tool.

Display this prompt only when the user hasn't explicitly configured a tool.

See git-mergetool--lib.sh#L323-L339 for the "explicitly defined" part: git config merge.tool

---

This is clarified by commit c15bb0c:

-y::
--no-prompt::

Don't prompt before each invocation of the merge resolution program.

This is the default if the merge resolution program is explicitly specified with the --tool option or with the merge.tool configuration variable.

--prompt::

Prompt before each invocation of the merge resolution program to give the user a chance to skip the path.