git merge-file [-L <current-name> [-L <base-name> [-L <other-name>]]] [--ours|--theirs|--union] [-p|--stdout] [-q|--quiet] [--marker-size=<n>] [--[no-]diff3] <current-file> <base-file> <other-file>
git merge-file incorporates all changes that lead from the <base-file> to <other-file> into <current-file>. The result ordinarily goes into <current-file>. git merge-file is useful for combining separate changes to an original. Suppose <base-file> is the original, and both <current-file> and <other-file> are modifications of <base-file>, then git merge-file combines both changes.
A conflict occurs if both <current-file> and <other-file> have changes in a common segment of lines. If a conflict is found, git merge-file normally outputs a warning and brackets the conflict with lines containing <<<<<<< and >>>>>>> markers. A typical conflict will look like this:
<<<<<<< A lines in file A ======= lines in file B >>>>>>> B
If there are conflicts, the user should edit the result and delete one of the alternatives. When --ours, --theirs, or --union option is in effect, however, these conflicts are resolved favouring lines from <current-file>, lines from <other-file>, or lines from both respectively. The length of the conflict markers can be given with the --marker-size option.
The exit value of this program is negative on error, and the number of conflicts otherwise. If the merge was clean, the exit value is 0.
git merge-file is designed to be a minimal clone of RCS merge; that is, it implements all of RCS merge's functionality which is needed by git(1).
--ours, --theirs, --union
git merge-file README.my README README.upstream
git merge-file -L a -L b -L c tmp/a123 tmp/b234 tmp/c345
Part of the git(1) suite