When building a disk image software distribution, it's nice to make a certain directory (usually the root directory of the volume) automatically open a Finder window when the disk image is
mounted. In years past, one could do that using the command line tool bless with the --openfolder option. But now, the --openfolder option is deprecated, and does not seem to work.
This command line tool attempts to do the equivalent, by modifying a field in the Finder info of the volume. It works with volumes using the HFS+ (Mac OS Extended) file system, but
not volumes using other file systems such as APFS.
Usage:
SetDmgOpenFolder [--verbose] path-to-folder-on-mounted-writable-disk-image
There is a different way to create a read-only disk image that automatically opens a particular folder:
sudo hdiutil makehybrid -hfs -hfs-openfolder open-path -o output-path source-path