Ans: Two prompts, PS1 (Primary Prompt), PS2 (Secondary Prompt).

Ans: ‘inode’, each file has a separate inode and a unique inode number.

Ans: Yes, using the ‘mesg’ command.

Ans: Yes, ‘mkfs’ is used to create a new file system..

Ans: Mount system call makes a directory accessible by attaching a root directory of one file system to another directory. In UNIX directories are represented by a tree structure, and hence mounting would mean attaching them to the branches. This ...  

Ans: A parent and child can communicate through any of the normal inter-process communication schemes (pipes, sockets, message queues, shared memory), but also have some special ways to communicate that take advantage of their relationship as a parent and child. One of the most obvious is that the parent can get the exit status of the child.

Ans: Getting the value of an environment variable is done by using `getenv ()'. Setting the value of an environment variable is done by using `putenv ()'.

Ans: System calls Description
fork() To create a new process
exec() To execute a new program in a process
wait() To wait until a created process completes its execution
exit() To exit from a process execution
getpid() To get a process identifier of the current process
getppid() To get parent process identifier
nice() To bias the existing priority of a process
brk() To increase/decrease the data segment size of a process.

main () { fork(); fork(); fork(); printf("Hello World!"); } Ans: "Hello World" will be printed 8 times. Explanation: 2^n times where n is the number of calls to fork() ...  

main() {   fork();   printf("Hello World!"); }   Ans: Hello World! Hello World! Explanation: The fork creates a child that is a duplicate of the parent process. The child begins from the ...