The concept of an operating system. The internal architecture of an operating system. The architecture of the Linux operating system in more detail.
Different design issues and choices are examined and compared, and the basic structure of several popular OSes are presented. User Interfaces - Means by which users can issue commands to the system.
Depending on the system these may be a command-line interface e. The latter are generally older systems using punch cards of job-control language, JCL, but may still be used today for specialty systems designed for a single purpose. Program Execution - The OS must be able to load a program into RAM, run the program, and terminate the program, either normally or abnormally.
File-System Manipulation - In addition to raw data storage, the OS is also responsible for maintaining directory and subdirectory structures, mapping file names to specific blocks of data storage, and providing tools for navigating and utilizing the file system.
Communications - Inter-process communications, IPC, either between processes running on the same processor, or between processes running on separate processors or separate machines. May be implemented as either shared memory or message passing, or some systems may offer both.
Error Detection - Both hardware and software errors must be detected and handled appropriately, with a minimum of harmful repercussions. Some systems may include complex error avoidance or recovery systems, including backups, RAID drives, and other redundant systems.
Debugging and diagnostic tools aid users and administrators in tracing down the cause of problems. Other systems aid in the efficient operation of the OS itself: Resource Allocation - E. CPU cycles, main memory, storage space, and peripheral devices.
Some resources are managed with generic systems and others with very carefully designed and specially tuned systems, customized for a particular resource and operating environment.
Accounting - Keeping track of system activity and resource usage, either for billing purposes or for statistical record keeping that can be used to optimize future performance. Protection and Security - Preventing harm to the system and to resources, either through wayward internal processes or malicious outsiders.
Authentication, ownership, and restricted access are obvious parts of this system. Highly secure systems may log all process activity down to excruciating detail, and security regulation dictate the storage of those records on permanent non-erasable medium for extended times in secure off-site facilities.
In some systems the CI may be incorporated directly into the kernel. More commonly the CI is a separate program that launches once the user logs in or otherwise accesses the system. UNIX, for example, provides the user with a choice of different shells, which may either be configured to launch automatically at login, or which may be changed on the fly.
Each of these shells uses a different configuration file of initial settings and commands that are executed upon startup. Different shells provide different functionality, in terms of certain commands that are implemented directly by the shell without launching any external programs.
Most provide at least a rudimentary command interpretation structure for use in shell script programming loops, decision constructs, variables, etc. On UNIX systems those details are handled by the shell, and the program which is launched sees only a list of filenames generated by the shell from the wild cards.
On a DOS system, the wild cards are passed along to the programs, which can interpret the wild cards as the program sees fit. Icons represent some item on the system, and respond accordingly when the icon is activated.
In some systems the GUI is just a front end for activating a traditional command line interpreter running in the background. In others the GUI is a true graphical shell in its own right.Main features and commands. UNIX / Linux .. Jelena Mamčenko Operating Systems Lecture Notes on Operating Systems 4 2 History of Operating Systems An operating system (OS) is a software program that manages the hardware and software resources of a computer.
The OS performs basic tasks, such as controlling and allocating memory.
System Library − System libraries are special functions or programs using which application programs or system utilities accesses Kernel's features. These libraries implement most of the functionalities of the operating system and do not requires kernel module's code access rights.
The Free Software Foundation uses the name GNU/Linux to refer to the operating system family, as well as specific distributions, to emphasize that most Linux distributions are not just the Linux kernel, and that they have in common not only the kernel, but also numerous utilities and libraries, a large proportion of which are from the GNU regardbouddhiste.com model: Mainly open-source, proprietary software is also available.
Jun 15, · Modbus Test Tool / Modbus Master Simulator. Modbus test utilities are used to diagnose Modbus communication and verifying the data in specific address.
The utility is used for testing Modbus slave device. What a Modbus Test Utility Can do (Application / Features)? File management system calls include create file, delete file, open, close, read, write, reposition, get file attributes, and set file attributes.
These operations may also . An operating system (OS) is the software component of a computer system that is responsible for the management and coordination of activities and the sharing of the resources of the computer. The OS acts as a host for application programs that are run on the machine.