Basic UNIX/Linux commands for Interview Questions – Part 1
Some basic UNIX/Linux commands:
… from College notes !
Q1. Start UNIX/Linux while logging in remotely to telnet
Ans: [student@localhost student]$ telnet 192.168.0.4
Q2. Enter the user name as student and password as student.
Ans: [student@localhost student]$
Q3. Display all files starting with a dot and filename more than three characters.
Ans: [student@localhost student]$ ls .???*
Q4. Create files chap01,chap02,chap05,chap07,chap*,chap[0-3]
Ans: [student@localhost student]$ cat > chap01
[student@localhost student]$ cat > chap02
[student@localhost student]$ cat > chap05
[student@localhost student]$ cat > chap07
[student@localhost student]$ cat > chap0*
Q5. Display all files starting with an alphabet irrespective of the case.
Ans: [student@localhost student]$ ls [a-Za-z]*
Q6. Try the command pwd to see the present working directory
Ans: [student@localhost student]$ /home/student
Q7. Create files namely abc.txt ,aby.txt ,xdf ,x02,x04,ab4.
Ans: [student@localhost student]$ cat > abc.txt
[student@localhost student]$ cat > aby.txt
[student@localhost student]$ cat > xdf
[student@localhost student]$ cat > x02
[student@localhost student]$ cat > x04
[student@localhost student]$ cat > ab4
Q8. Display the files starting with a or t and second character b or x and length of the files should be only 3 characters.
Ans: [student@localhost student]$ ls [a,t][b,x]?
Q9. Create directories namely dir1,dir2,dir3
Ans: [student@localhost student]$ mkdir dir1,dir2,dir3.
Q10. Create three files in each of the directory.
Ans: [student@localhost student]$ cat > /home/student/dir1/file01
[student@localhost student]$ cat > /home/student/dir2/file02
[student@localhost student]$ cat > /home/student/dir3/file03
Q11. Copy all the files from these directories to the current directory.
Ans: [student@localhost student]$
Q12. Copy recursively the three directories include , bin, lib from / to directory.
Ans: [student@localhost student]$ cp –R { nitin1,nitin2,nitin3 }
/home/student/kap
Q13. Remove the file chap*
Ans: [student@localhost student]$ rm chap*
Q14. Display the file contents of file chap[0-3].
Ans: [student@localhost student]$ cat chap[0-3]
Q15. Create a file hello.
Ans: [student@localhost student]$ cat > hello
Q16. Create a hard link of the file hello name it as hai.
Ans: [student@localhost student]$ ln hello hai
Q17. Display the listing of both hello and hai files along either their i-node number.
Ans. [student@localhost student]$ ls –i hello hai
Q18. Create the symbolic link of file hello as hellohai
Ans. [student@localhost student]$ ln –s hello hai
Q19. Display the listing of both hello and hellohai files along with their i-node number.
Ans. [student@localhost student]$ ls –i hello hellohai
Q20. Display the process status of all the processes running on linux.
Ans. [student@localhost student]$ ps
Q21. Display the hidden files and also marked them as executable and directory.
Ans. [student@localhost student]$ ls –Fa
Q22. Display all the directories, sub- directories and files.
Ans. [student@localhost student]$ls -R
Q23. Create a file name in file at 3 to 4 line of text to it.
Ans. [student@localhost student]$cat >infile
Q24. Count number of lines, words and characters in the filename infile.
Ans. [student@localhost student]$wc –lwm infile
Q25. Count number of words in infile with and without redirection.
Ans. [student@localhost student]$wc –w<infile
Q26. In a single command except data as well as display contents of the file infile.
Ans. [student@localhost student]$cat infile –
Q27. Display all the files starting with an alphabetic irrespective of the case.
Ans. [student@localhost student]$ls [a-zA-Z]*
Q28. Display the number of users logged on.
Ans. [student@localhost student]$who | wc-l
Q29. Display the number of files present in the current directory.
Ans. [student@localhost student]$ls –l | wc-l
Q30. Count number of bytes of all the .c files individually present in the current directory.
Ans. [student@localhost student]$wc –c *.c
Q31. Count total number of bytes of all the .c files present in the current directory.
Ans. [student@localhost student]$wc –c *.c | tail -1 –
Q32. Display the statement as there are _ files in the current directory using command substitution.
Ans. [student@localhost student]$echo “There are `ls –l –R | wc –l` files in current dir.”
Q33. Try the two statement echo the average pay is $1000
echo ‘the average pay is $1000’
echo “the average pay is $1000”
Ans. [student@localhost student]$echo ‘the average pay is $1000’
the average pay is $1000
echo “the average pay is $1000”
the average pay is 000
Q34. Create a shell variable as work and store the present working directory in it and display the same.
Ans. [student@localhost student]$ work=`pwd`
Q35. Try the command cat alone without using an argument.
Ans. [student@localhost student]$cat
(With only cat command with no file name it only read standard input.)
Check [Part-2] for next set of Questions.
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March 18, 2016 at 7:25 pmBasic UNIX/Linux commands for Interview Questions – Part 2 | SQL with Manoj