Unix Interview Questions and Answers
Question - 11 : - Differentiate between absolute and related path?
Answer - 11 : - Absolute path refers to the exact path as defined from the root directory whereas, related path refers to the path related to the current locations.
Question - 12 : - Which UNIX command lists files/folders in alphabetical order?
Answer - 12 : - The ls –l command is used to list down files and folders in alphabetical order, sorted with modified time.
Question - 13 : - Describe a link in UNIX.
Answer - 13 : - Another name for a file is a link. It is used to assign more than just one name for a file and is not valid to assign more than one name to a directory or to link filenames on different computers.
Question - 14 : - What is FIFO?
Answer - 14 : - FIFO or First In First Out is also known as named pipes and it is a special file for date transient. This data is read-only in the written order and is used to inter-process communications. Here data writes at one end and reads from another end of the pipe.
Question - 15 : - What is the fork() system call?
Answer - 15 : - The command used to create a new process from an existing process is called fork(). The main process is called the parent process and new process is called child process. The parent gets the child process is returned and the child gets 0. The returned values are used to check which process which code executed.
Question - 16 : - Explain the following statement, “It is not advisable to use root as the default login.”
Answer - 16 : - The given statement means the following;
The root account is very critical and can leads to system damage easily with abusive usage. The securities that normally apply to user accounts are not applicable to the root account. Hence, one should refrain from using root as the default login.
Question - 17 : - What is meant by the term Super User?
Answer - 17 : - The Super User is a user with access to all files and commands within the system. In general, this superuser login is to root and the login is secured with the root password.
Question - 18 : - Define a process group.
Answer - 18 : - A collection of one or more processes is called a process group. There is a unique process id for each process group. The function getpgrp returns the process group ID for the calling process.
Question - 19 : - Name the different file types available with UNIX.
Answer - 19 : - Following the different file types in UNIX;
Regular files
Directory files
Character special files
Block special files
FIFO
Symbolic links
Socket
Question - 20 : - What is the behavioural difference between cmp and diff commands?
Answer - 20 : - Despite the fact that both of these commands are meant for file comparison, there still remains a fundamental difference between the two.
Cmp compares the two given files, byte by byte and displays the first mismatch.
Diff displays the changes that need to be made in order to make both the files identical.