Methodologies for Implementing Operating System Services
System programs are utilities program that helps the user and may call further system calls. System program provides a convenient environment for program development and execution. Some are simply user interfaces two system calls and other are considerably more complex. They can be divided into these categories -
File Management-These programs create, delete, copy, rename, print, dump, and generally manipulate files and directories.
Status Information-Some system programs simply ask information related to the system like date / time/ size of disc / number of users.
File Modification-Several text editors may be available to create and modify the content of files stored on disk or other storage devices. There may also be a special commands to search contents of files or perform transformation of text.
Programming language support-Compiler, assembler, debuggers and interpreters for common programming languages( such as C,C++, Java and more are open provided to the user with the operating system.
Program loading and execution-Once a program is assembled or compiled, it must be loaded into memory to be executed. The system may provide absolute loaders, relocatable loaders, linkage editors, and overlay loaders. Debugging systems for either higher level languages machine languages are needed as well.
Communications-These programs provide the mechanism for operating virtual connections Among processes, users and computer systems. They allow users to send messages to one another's screen , to browse web pages, to send electronic mail messages, to log in remotely, or to transfer files from one machine to another machine.
Some system program supplied with operating systems are text formatters, spreadsheet, compilers, web browser, database, games and many more.