Thanks for the link :-) My first Unix book was from McKusick ( https://openlibrary.org/books/OL7407817M/The_Design_and_Implementation_of_the_4.4_BSD_Operating_S

Thanks for the link :-) My first Unix book was from McKusick ( https://openlibrary.org/books/OL7407817M/The_Design_and_Implementation_of_the_4.4_BSD_Operating_System_%28Unix_and_Open_Systems_Series.%29 https://openlibrary.org/books/OL7407817M/The_Design_and_Impl... ). I bouth it after some years playing with wirh DEC OSF1, SunOS, Linux, and Irix :-)