From Electron Cloud
cp
can be added as a "merge tool" which you can use selectively to accept one side or the other of merge conflicts automatically, without having to run a visual diff. (But it's a good idea to run visual diff or regular diff first to make sure whether you want the "local" or "remote" version!) Seems that so far in such cases I always want the "remote" version (in other words, the second version in the diff, or the non-HEAD version), so I just add cp in that direction as a "merge tool":
git config --global mergetool.accept-remote.cmd 'cp $REMOTE $MERGED' git config --global mergetool.accept-remote.trustExitCode true
Usage:
git mergetool --tool=accept-remote [file ...]
and it will interact with you, something like this:
# git mergetool --tool=accept-remote Merging: file1.c file2.h Normal merge conflict for 'file1.c': {local}: modified {remote}: modified Hit return to start merge resolution tool (accept-remote): ...
and so on for each file to be merged.