COMPUTER SCIENCE AND ENGINEERING
OPERATING SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Accept input and provide output by generating voice prompts.
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Program can request a service from an operating system’s kernel.
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Allow user to interact with electronic devices using images rather than text commands.
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Allow putting jobs in a buffer, a special area in memory or on a disk where a device an access them when it is ready
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Detailed explanation-1: -A system call is a request from computer software to an operating system’s kernel. The Application Program Interface (API) connects the operating system’s functions to user programs. It acts as a link between the operating system and a process, allowing user-level programs to request operating system services.
Detailed explanation-2: -The purpose of system calls serves as the interface between an operating system and a process. System calls can typically be found as assembly language instructions. They are also covered in the manuals that the programmers working at the assembly level use.
Detailed explanation-3: -When the computer system executes on behalf of a user application, the system is in user mode. However, when a user application requests a service from the operating system via a system call, it must transition from user to kernel mode to fulfill the request.
Detailed explanation-4: -In Unix systems, a fork system call followed by an exec system call need to be performed to start a new process. The fork call clones the currently executing process, while the exec call overlays a new process based on a different executable over the calling process.
Detailed explanation-5: -Explanation: To access services of the Operating System an interface is provided by the System Calls. Generally, these are functions written in C and C++. Open, Close, Read, Write are some of most prominently used system calls.