Unix interview questions

Unix Interview questions with answers

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What are the Unix system calls for I/O?

The following are the UNIX system calls for I/O: Open: to open a file. Syntax: open (pathname, flag, and mode)......

How are devices represented in UNIX?

UNIX represents all devices as files. These files are located in the directory /dev..........

Brief about the directory representation in UNIX

A UNIX directory is representing a file that consists of a correspondence between file names and inodes........

Discuss the mount and unmount system calls

The attaching of a file system to another file system is done by using mount system call........

What are the process states in Unix?

UNIX has the following process states:.......

What is use of sed command?

Sed command reads from a standard input and places it into the pattern space.......

What is 'inode'?

A file in UNIX is given a unique number. This unique number is known as ‘inode’....... 

What are links and symbolic links in UNIX file system?

Link is a utility program in UNIX which establishes a hard link from one directory to another directory........

Explain fork() system call.

fork() system call is used to create processes. It returns a process id. After calling fork() system call......

What is a zombie?

A zombie is a process which is completed the execution and still available in the process table........

How do you create special files like named pipes and device files?

Special files are created by the system call ‘mknod’. Upon using the following sequence of steps, a special file will be created.......

How do I use poll()?

poll() allows an event to wait on a file descriptor. A pointer is accepted by poll() to a list of ‘struct pollfd’........... 

More Unix interview questions

What is Linux and why is it so popular?

Answer - Linux is an operating system that uses UNIX like Operating system.......

What is LILO? 

Answer - LILO is Linux Loader is a boot loader for Linux. It is used to load Linux into the memory and start the Operating system.......

What is the difference between home directory and working directory?

Answer - Home directory is the default working directory when a user logs in. On the other hand, working directory is the user’s current directory.......

What is the difference between internal and external commands?

Answer - Internal commands are commands that are already loaded in the system. They can be executed any time and are independent.......

Explain the difference between a static library and a dynamic library?

Answer - Static libraries are loaded when the program is compiled and dynamically-linked libraries are loaded in while......