Batch copy multiple folders and their subfolders into a merge folder

Question

I have a folder X:\Export that has several folders:

X:\Export
+---Export1
|   \---various files …
+---Export2
|   \---… and subfolders
+---Export3
|   \---etc.
\---etc.            (names vary widely)

Each “Export” folder has the same subdirectory structure, but they have different files (with possibly some name collisions). I would like to copy all the subfolders and the files of X:\Export\Export1, X:\Export\Export2, X:\Export\Export3, etc., to a folder X:\Export\merged, keeping the subdirectory structure.

Pseudocode of what I would like to do but cannot get working properly:

create new folder "merged"
for (every folder X in a given directory Y (i.e., X:\Export)
    copy every file in X keeping directory structure to "merged"
If conflict then overwrite

Answer 1

How about

@echo off
md merged
for /f "delims=" %%f in ('dir /b /ad') do (
    if not %%f==merged xcopy "%%f" merged /s /y
)

The /y option causes files to be overwritten without asking for confirmation.  Replace /s with /e if you want to copy empty subdirectories.

---

Additional explanation: for /f "options"(optional) variable in ('command') runs command, captures the output, assigns tokens (strings) from that output to the variable, and then runs the command(s) after the do.  dir /b means show only filenames (no attributes, no . and ..); dir /ad means list only directories (no files).

The default behavior for for /f is to create a token from each line of output by taking all characters up to the first space.  The "delims=" option tells it to take the entire line.  This bit of paranoia makes the script work even if you have directory names with spaces in them.  I probably could have gotten away with saying xcopy %%f merged; but I need the double quotes around %%f (xcopy "%%f" merged) to handle the case where %%f contains spaces.