OPERATING SYSTEM SERVICES o One set of operating-system services provides functions that are helpful to the user: User interface-Almost all operating systems have a user interface UI) o Varies between Command-Line (CLI),Graphics User Interface (GUI),Batch Program execution-The system must be able to load a program into memory and to run that program,end execution,either normally or abnormally (indicating error) I/O operations-A running program may require I/O,which may involve a file or an I/O device. File-system manipulation-The file system is of particular interest. Obviously,programs need to read and write files and directories, create and delete them,search them,list file Information,permission management.OPERATING SYSTEM SERVICES  One set of operating-system services provides functions that are helpful to the user:  User interface - Almost all operating systems have a user interface (UI)  Varies between Command-Line (CLI), Graphics User Interface (GUI), Batch  Program execution - The system must be able to load a program into memory and to run that program, end execution, either normally or abnormally (indicating error)  I/O operations - A running program may require I/O, which may involve a file or an I/O device.  File-system manipulation - The file system is of particular interest. Obviously, programs need to read and write files and directories, create and delete them, search them, list file Information, permission management