how to move and merge folders in OSX Mavericks?

Solution 1:

1 Quick answer

Enter this command in Terminal:

cp -r -n ./srcFolder/ ./targetFolder/
Remove the -n if you want to overwrite duplicates.

Update:
ditto source target will also do the trick.

Files in source folder overwrite any duplicates in target folder.

Add -v for details (ditto -v source target)

via How to Merge Folders on Mac OS X Without Losing All Your Files (Seriously)

2 Use Finder (surprisingly more complex)

Possibly a duplicate of Where did folder "merge" or "keep both" go in OS X 10.9 Mavericks?, but I'll sum up:

The weird thing is, the folders can't have any duplicate files if you want to merge.

If you're merging two folders that don't have any duplicate files between them, you will see the merge option if you hold the option key.

However, if the folders you're merging contain any files with the same name, the merge option won't show up.

In that case, you basically have two options:

1. use the command line or
2. manually remove duplicates, then click & drag + hold option to merge.