rsync copy over only certain types of files using include option

I think --include is used to include a subset of files that are otherwise excluded by --exclude, rather than including only those files.In other words: you have to think about include meaning don't exclude.

Try instead:

rsync -zarv  --include "*/" --exclude="*" --include="*.sh" "$from" "$to"

For rsync version 3.0.6 or higher, the order needs to be modified as follows (see comments):

rsync -zarv --include="*/" --include="*.sh" --exclude="*" "$from" "$to"

Adding the -m flag will avoid creating empty directory structures in the destination. Tested in version 3.1.2.

So if we only want *.sh files we have to exclude all files --exclude="*", include all directories --include="*/" and include all *.sh files --include="*.sh".

You can find some good examples in the section Include/Exclude Pattern Rules of the man page

The answer by @chepner will copy all the sub-directories irrespective of the fact if it contains the file or not. If you need to exclude the sub-directories that dont contain the file and still retain the directory structure, use

rsync -zarv  --prune-empty-dirs --include "*/"  --include="*.sh" --exclude="*" "$from" "$to"

Here's the important part from the man page:

As the list of files/directories to transfer is built, rsync checks each name to be transferred against the list of include/exclude patterns in turn, and the first matching pattern is acted on: if it is an exclude pattern, then that file is skipped; if it is an include pattern then that filename is not skipped; if no matching pattern is found, then the filename is not skipped.

To summarize:

• Not matching any pattern means a file will be copied!
• The algorithm quits once any pattern matches

Also, something ending with a slash is matching directories (like find -type d would).

Let's pull apart this answer from above.

rsync -zarv  --prune-empty-dirs --include "*/"  --include="*.sh" --exclude="*" "$from" "$to"

1. Don't skip any directories
2. Don't skip any .sh files
3. Skip everything
4. (Implicitly, don't skip anything, but the rule above prevents the default rule from ever happening.)

Finally, the --prune-empty-directories keeps the first rule from making empty directories all over the place.