摘要：
1. Operating system: Provide services for programs they run. Typical services: (1) excuting a new program. (2) opening a file, reading a file. (3) allocating a region of memory. (4) getting the current time of day and so on.2. Unix Architecture (1). Operating system in a strict sense (The kernel): 1 阅读全文
摘要：
一： Introduction二： Unix Architecture三： Loggin In四： Files And Directories五： Input And Output六： Programs And Process七： Error Handling八： User Identification九： Signals十： Time Values十一： System Calls And Library Functions十二： Summay 阅读全文