unix interview questions

Unix / Linux Command / AIX / Admin questions and answers for interview

Dear Friends,

Now i am going to share some interview question  which is mainly working  for  Unix/Linux Developer, Production support, System admin etc.. There are some question which i got very good  from company and must have to knowledge on this subject!!!!!!!

First i will suggest you some tips to face the interview.

  • First you have to go through about the company.
  • Must you have to know about the company services.
  • you have to know about the company based on and branche.
  • Good command on unix and shell scripting programming.

please go through these question too and suggest me for more improvement.

Unix questions.

1> what is inode ????. –  *****

Ans :  To every file in unix is associated with a table to know about a file except its name and contents. This table is called the inode and accessed by the inode number. The inode consists the following attributes of a file :

  • File Type (ordinary, directory, devices)
  • File size in bytes.
  • File permissions.
  • Number of links.
  • File owner identifier (UID)
  • File group owner identifier (GID)
  • Date and time of last modification.
  • Date and time of last access.

2> What is Kernel ? and what do you mean by Kernel-shell relationship ?? – 

Ans : The Kernel is the heart of  an operating system. basically it is loaded into the memory when the system is booted and directly communicates with the hardware. The kernel directly interacts with the hardware and the shell interacts with user.

3> Explain different types of Unix systems. ?? – 

Ans : The mostly  used are:

  • System V (AT&T) .
  • AIX (IBM) .
  • BSD (Berkeley).
  • Solaris (Sun) .
  • Xenix ( A PC version of Unix).

4> what is pipes. ?? – 

Ans : A pipes connect to the standard output of one command to the standard input of another command.

5> what do you mean by fork ( ) system call ?? – 

Ans :  The `fork ( )’  is used to create a new process from an existing process. The new process is called the child process, and the existing process is called the parent process. We can tell which is which by checking the return value from `fork()’. The parent gets the child’s pid returned to him, but the child gets 0 returned to him.

6> How many types of shell. ?? – 

Ans : There are three major types of shell in unix so these are :

  • sh (Bourne shell).
  • csh (C shell).
  • ksh (Korn shell) or bash (Bash shell).

7> What do you mean by  links and symbolic links in UNIX file system?? – 

Ans :  A link is a second name (not a file) for a file. Links can be used to assign more than one name to a file, but cannot be used to assign a directory more than one name or link filenames on different computers.
Symbolic link ‘is’ a file that only contains the pathname of another file or directory. it is created with ln -s . Operation on the symbolic link is directed to the file pointed by the it.Both the limitations of links are eliminated in symbolic links.
Commands for linking files are:
Link : ln filename1 filename2
Symbolic link :  ln -s filename1 filename2


thanks & goodluck..