Is it impermissible for someone who bought the book to lend it to a friend or give it as a gift to another, and what prevents its electronic publication, and is there in Islam any restriction on the buyer's right to the commodity?

Copyright does not diminish the buyer's rights. The buyer owns the physical book and its benefits, and has the right to dispose of it through sale, gift, or loan. However, copying or publishing the book electronically is not merely an act of disposing of the physical book; rather, it is an infringement upon the author's literary and financial rights, and the buyer does not possess this right. These rights have acquired considerable financial value in contemporary custom and are recognized by Islamic law, making it impermissible to infringe upon them.