Unix Interview Questions and Answers
Question - 31 : - What does the “echo” command do?
Answer - 31 : - The echo command outputs the strings it is being passed as arguments.
Question - 32 : - What is the explanation for protection fault?
Answer - 32 : - When the process accesses a page which does not have access permission, it is referred to as protection fault. Also when a process attempts to write on a page whose copy on write bit was set during the fork() system call, it is incurred for protection fault.
Question - 33 : - Describe the concept of “Region”.
Answer - 33 : - A region is a continuous area of processes address space (text, data, and stack). Regions are shareable amongst the processes.
Question - 34 : - What is meant by u-area?
Answer - 34 : - The area contains information specific to the process and is only manipulated by the kernel. It contains the private data unique to the process allocated to u-area.
Question - 35 : - What do you understand by UNIX shell?
Answer - 35 : - The UNIX shell serves as an environment to run commands, programs, and shell scripts. In addition to that, it also acts as an interface between the user and the Unix OS. Shell issues $ as the command prompt, which reads input and determines the command to execute.
For example: $date
The command above will display the current date and time.
Question - 36 : - What is the description of Kernel?
Answer - 36 : - Kernel is the master program that controls the resources of the computer. The resource allocation to different users and tasks is handled by this section. The kernel does not communicate directly with the user and instead, it starts separate interactive program call shell to each user when logged in to the system.
Question - 37 : - What is a single-user system?
Answer - 37 : - A single-user system is a personal computer with an operating system, designed to operate by a single user at a given time. These systems become more popular since low-cost hardware and availability of a wide range of software to perform different tasks.
Question - 38 : - What are the main features of UNIX?
Answer - 38 : -
Main features of UNIX are as follows:
- Machine independent
- Portability
- Multi-user operations
- Unix Shells
- Hierarchical file system
- Pipes and filters
- Background processors
- Utilities
- Development tools.
Answer - 39 : - The interface between the user and the system is called the shell. Shell accepts commands and set them to execute for user operations.
Question - 40 : - What are the responsibilities of a shell?
Answer - 40 : -
Responsibilities of a shell can be enlisted as:
- Program execution
- Input/output redirection
- Filename and variable substitution
- Pipeline hookup
- Environment control
- Integrated programming language