What are the different types of utilities

Operating systems

 

 


definition


An operating system comprises all programs in a computer system that are required to operate the
Control and monitor systems.


generally


Operating systems usually consist of a kernel that manages the computer's hardware,
as well as basic system programs that are used to start the operating system and configure it.

A distinction is made between:
  

  • Single-user and multi-user systems,
  • Single-program and multi-program systems,
  • Batch processing and dialog systems.

Operating systems can be found practically everywhere: as real-time operating systems on process computers,
on normal PCs and as multiprocessor systems on servers and mainframes.


Components of an operating system


An operating system essentially consists of three main components.
These are:

  • the Bootloader:
    • This is usually based on the BIOS and takes care of the
      Startup process of the computer system (boot process)
  • the Main programs:
    • This group forms the core of the operating system.
      It includes organization programs for processor, memory, file
      and device management and for communication, e.g. a command interpreter
      and an input / output system
  • the Utilities:
    • This group forms the "command set" of the operating system.
      They include, for example, copying, formatting, editing, sorting and other auxiliary programs


Modes of operation


some examples:

  • different variants of DOS
  • different variants of Microsoft Windows
  • different variants of Apple Mac OS X
  • different variants of Unix / BSD-Unix
  • different flavors of OS / 2


tasks


An operating system has the following tasks:

  • User guidance
  • Loading and interrupting programs
  • Processor time management
  • Management of storage space for applications
  • Management of the connected devices
  • Provision of utility programs (in contrast to application programs)

 

Programs, memory and device management

  • Memory management
    • Allocation and monitoring of the storage device (main and background storage).
    • Maintenance of tables of memory usage by user jobs or processes (running programs).
    • Serving requests and releasing memory.
  • Program (process) management
    • Supervision of all processes (programs in progress) in the computer system.
    • Creation of new processes at the request of the operating system or other existing processes,
    • Removal of processes from the system.
    • Communication and synchronization of processes with each other (interprocess communication)
  • Device and file management
    • Efficient assignment of input / output devices and switching units (data channels, control units), avoidance of conflicts
    • Initiation, monitoring of execution, termination of input / output processes.
    • Management of the file system. Creation of a namespace with associated storage objects and, if necessary, other objects.
  • abstraction
    • Hide the complexity of the machine from the user
    • Abstraction of the machine concept (according to Coy):
      • Real machine = central unit + devices (hardware)
      • Abstract machine = real machine + operating system
      • User machine = abstract machine + application program

 

Utilities and application programs

Most operating systems contain utilities, also called utilities.
They enable the user or system administrator to process general and system-related tasks.
These include editors, copy programs, user administration programs, system monitoring programs and tools for data backup.

Application programs are usually not part of the actual operating system.
They come either from the manufacturer of the system or from other providers.
Application programs can also be supplied with the operating system (examples: many programs in Linux distributions or Internet Explorer as part of Microsoft Windows).


First operating systems (-1980)


The first computers did not have any operating systems.
This was due on the one hand to their construction (mechanical calculating machines such as Abacus, slide rules, etc.) or to their severely restricted area of ‚Äč‚Äčapplication (Mark I, ENIAC, Colossus).
With the invention and use of the transistor (1947) and the invention of microprogramming in 1955 by Maurice Wilkes, entire series of models were no longer used.
At that time, every manufacturer even supplied different operating systems for different model series of its products, so that programs only ran on a certain model series and were neither portable between different computers nor over different generations.

With the introduction of the System / 360 series from IBM, IBM introduced the OS / 360 operating system in 1964.
It was the first operating system that was used across all model series.
From 1963, Multics was developed in collaboration with MIT, General Electric and AT & T's Bell Labs, but it was only in use from 1969 to 2000.
Multics was programmed in PL / 1.
Inspired by the work on Multics, a group led by Ken Thompson and Dennis Ritchie at AT & T's Bell Laboratories started developing Unix in 1969.
In the years 1972-1974, with the exception of a few parts, Unix was re-implemented in the higher programming language C with the aim of portability.