OSX, which is BSD, uses UID and GID along with ACL to manage file access permissions.
OK, that was letter soup so let me clear it up:
UID = User ID number.
GID = Group ID number
ACL = Access Control List.
You CAN do what you are trying with a little work, which I will detail, but let me reiterate that KB has suggested NOT using external drives. I do, but I am willing to take the risk as I am pretty sure I can recover.
Lets talk ACL. In its simplest form (the form we will be using) the system uses the UID and GID to determine if you are allowed to access a file, and what type of access you are allowed to had. When the file is created the OS assigns the creators UID and GID (primary as you can be part of more than one group) to the file. The users umask is used to set the default permissions. You can see this by opening a terminal window and typing the following
This will give you a file listing from the OS using the long format. All those r, w, x, and - mean something. More on that in a minute. You can also get this information from the finder by selecting a file and doing a cmd-i. This will bring up the file information pane.
The permission ACL has three sections, owner permissions, group permissions, and everyone else permission. These are represented by the last six r/w/x/- characters in the long listing. The first character is a “type” representation and is not an ACL component. Each set of 3 are the read, write and execute/extended permission bit respectively. The first set of three is for the owner, the second for the group, the last for everyone else. What we are going to do is what I like to think of as “a bad idea” for servers, but a “handy trick” for situations like yours. We are going to make your file "readable by everyone.
- note * This point is where I tell you that you are proceeding at your own risk. There is a chance of messing up your project so BACK IT UP. Don’t ask KB to fix it (although he probably would), instead restore the backup I just told you to make.
Here we go.
- The scrivener project is in your Documents folder.
- The project name is “Project.scriv”
- There are no spaces in the names.
If any of these are incorrect you will need to adjust what follows.
Disconnect the systems and boot the source system. Open a terminal and type:
chmod -R o+rw Project.scriv
find Project.scriv -type d -exec chmod o+x
Now boot back into target mode. Attach to other mac. Open project.
Again, you are doing this at your own risk. I did try it and it seems to work fine.
Let me know if you need more info.