Unix Operating System
1. What are The Three Important Parts Of Unix Operating System, Explain Them?
Answer: UNIX is an operating system which was first developed in the 1960s, and has been under constant development ever since. It is a stable, multi-user, multi-tasking system for servers, desktops and laptops. The UNIX operating system is made up of three parts; the kernel, the shell and the utilities (programs).
THE KERNEL:
The kernel of UNIX is the hub of the operating system: it allocates time and memory to programs and handles the file store and communications in response to system calls. The kernel handles the following operations:
1. It is responsible for scheduling running of user and other processes.
2. It is responsible for allocating memory.
3. It is responsible for managing the swapping between memory and disk.
4. It is responsible for moving data to and from the peripherals.
5. it receives service requests from the processes and honors them.
THE SHELL:
The shell is a command programming language that provides an interface to the UNIX operating system. Its features include control-flow primitives, parameter passing, variables and string substitution. Constructs such as while, if then else, case and for are available. Two-way communication is possible between the shell and commands. String-valued parameters, typically file names or flags, may be passed to a command. A return code is set by commands that may be used to determine control-flow, and the standard output from a command may be used as shell input.
The shell can modify the environment in which commands run. Input and output can be redirected to files, and processes that communicate through `pipes' can be invoked. Commands are found by searching directories in the file system in a sequence that can be defined by the user. Commands can be read either from the terminal or from a file, which allows command procedures to be stored for later use.
UTILITIES (THE PROGRAMS):
Utilities are commands that,
Answer: UNIX is an operating system which was first developed in the 1960s, and has been under constant development ever since. It is a stable, multi-user, multi-tasking system for servers, desktops and laptops. The UNIX operating system is made up of three parts; the kernel, the shell and the utilities (programs).
THE KERNEL:
The kernel of UNIX is the hub of the operating system: it allocates time and memory to programs and handles the file store and communications in response to system calls. The kernel handles the following operations:
1. It is responsible for scheduling running of user and other processes.
2. It is responsible for allocating memory.
3. It is responsible for managing the swapping between memory and disk.
4. It is responsible for moving data to and from the peripherals.
5. it receives service requests from the processes and honors them.
THE SHELL:
The shell is a command programming language that provides an interface to the UNIX operating system. Its features include control-flow primitives, parameter passing, variables and string substitution. Constructs such as while, if then else, case and for are available. Two-way communication is possible between the shell and commands. String-valued parameters, typically file names or flags, may be passed to a command. A return code is set by commands that may be used to determine control-flow, and the standard output from a command may be used as shell input.
The shell can modify the environment in which commands run. Input and output can be redirected to files, and processes that communicate through `pipes' can be invoked. Commands are found by searching directories in the file system in a sequence that can be defined by the user. Commands can be read either from the terminal or from a file, which allows command procedures to be stored for later use.
UTILITIES (THE PROGRAMS):
Utilities are commands that,