Radhika Nanda

11. What are Linux file permissions and how do you modify them? Linux file permissions control access to files and directories using three levels: User (owner) : Permissions for the file owner Group : Permissions for members of the file's group Others : Permissions for all other users Three permission types: r (read): 4 w (write): 2 x (execute): 1 Modify permissions using: chmod 755 filename # rwxr-xr-x chmod u+x script.sh # Add execute for owner chmod g-w file.txt # Remove write for group View permissions with ls -l . Special permissions include: SetUID (4000): Execute as owner SetGID (2000): Execute as group Sticky bit (1000): Restrict file deletion 12. Explain the use of grep , awk , and sed with examples. These are powerful text...

Top 8 Linux & Shell Scripting Viva Questions | Computer Engineering Top 20 Viva Questions on Linux & Shell Scripting For Computer Engineering Students - Bharat College of Engineering (Mumbai University) 1. What is the purpose of the forward command in Linux? The forward command typically refers to port forwarding or email forwarding in Linux systems. For network port forwarding, commands like ssh -L or iptables are used to redirect traffic between ports. Email forwarding is configured using .forward files in user directories or through mail server configurations like Postfix. This functionality is crucial for server administration and remote access scenarios. Network administrators use forwarding to expose services securely. Common applications include accessing databases behind firewalls or redirecting web traffic. Always ensure proper authentication when setting up forwarding rules. Security risks like open relay...

Top 20 Viva Questions and Answers on Page Fault, Segmentation, Fragmentation, and Paging Top 20 Viva Questions and Answers on Page Fault, Segmentation, Fragmentation, and Paging Are you preparing for your Operating Systems viva? This article covers the top 20 frequently asked questions about Page Fault , Segmentation , Fragmentation , and Paging . Each answer is explained clearly in about 10 lines to help you grasp the concept better. Let's get started! 1. What is a page fault? A page fault occurs when a program tries to access a page not currently in the main memory. The operating system must bring the required page from secondary storage into RAM. This process causes a delay in program execution. Page faults are common in systems that use virtual memory. There are two types: minor and major faults. A minor fault is handled quickly if the page is already in memory. A major fault requires loading from disk, taking more time. Frequent page faults can degrade system ...

Top 10 Deadlock Viva Questions and Answers in Operating System 1. What is a deadlock in an operating system? A deadlock is a situation in an operating system where two or more processes are unable to proceed because each is waiting for the other to release resources. This results in a complete standstill where no process can complete its execution. 2. What are the necessary conditions for a deadlock to occur? Four necessary conditions must hold simultaneously for a deadlock to occur: Mutual Exclusion: At least one resource must be held in a non-shareable mode. Hold and Wait: A process holding one resource is waiting to acquire additional resources. No Preemption: Resources cannot be forcibly taken away from a process. Circular Wait: A set of processes are waiting for each other in a circular chain. 3. How can deadlocks be prevented? Deadlocks can be prevented by ensuring that at least one of the necessary conditions does not hold. Techniques include resource orde...

1. What is an Operating System? An Operating System (OS) is system software that acts as a bridge between users and computer hardware. It manages hardware resources and provides services to application software. An OS handles tasks like memory management, process scheduling, and device control. It ensures that programs and users can run smoothly without interfering with each other. Examples include Windows, Linux, macOS, and Android. The OS also provides a user interface, either graphical (GUI) or command-line (CLI). Without an OS, a computer would be unusable. It organizes files, maintains security, and manages system performance. In short, the OS is the heart of any computing device. 2. What are the main functions of an Operating System? The primary functions of an Operating System are process management, memory management, file system management, and device management. It ensures efficient execution of processes by scheduling CPU time. Memory management keeps track of ea...

1. What is an Operating System? An Operating System (OS) is system software that acts as a bridge between users and computer hardware. It manages hardware resources and provides services to application software. An OS handles tasks like memory management, process scheduling, and device control. It ensures that programs and users can run smoothly without interfering with each other. Examples include Windows, Linux, macOS, and Android. The OS also provides a user interface, either graphical (GUI) or command-line (CLI). Without an OS, a computer would be unusable. It organizes files, maintains security, and manages system performance. In short, the OS is the heart of any computing device. 2. What are the main functions of an Operating System? The primary functions of an Operating System are process management, memory management, file system management, and device management. It ensures efficient execution of processes by scheduling CPU time. Memory management keeps track of ea...