MacBook Pro early 2008; Yosemite OSX. My hard drive is full and I need to empty out Trash. Unable to do normal re-boot. I’ve had to use Command-R. In Terminal, it showed that all the files in Trash are “read-only” and cannot be erased. I can regain a lot of GB if only I can remove the “read-only” files in the Trash folder.
So, what is the Terminal command for changing “read-only” attributes to “read and write” that will allow me to erase the files?
You shouldn't need to use the Terminal for that. You can select the files then bring up the Get Info inspector by using Command+Option+i. Don't forget the Option or you will get a separate Get Info window for each file.
Now look for the section Sharing & Permissions. GO into that and you can change the Privileges for the files there, assuming that is what is wrong.