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System Commands · All 2025 papers

72 questions · 350 marks · 4 papers

Answer key

Indian Institute of Technology Madras

BS Degree Programme · Examination & Study Paper

System Commands

All 2025 papers

Official Paper

Examination Instructions & Guidelines

Solve on notebook/paper first before checking solutions.
MCQ: Exactly 1 option is correct. Negative marking applies.
MSQ: One or more options correct. Select all to score.
NAT: Numerical response. No negative marking.
Scientific calculator allowed for all calculations.
Official answer key is sealed at the end of this sheet.

Quiz 1 · 26 Oct 2025 (AN)Quiz 1

Q1MCQ3 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q2MCQ3 Marks·Choose one option
Key ↓
1. AOwner can only execute, group can only write, others can read
2. BOwner can read and execute, group can read and execute, others can read
3. COwner can read and execute, group can write and execute, others can read
4. DOwner can read and execute, group can read and write, others can read and write
Q3MCQ3 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q4MCQ3 Marks·Choose one option
Asked 2 times Key ↓
Which command will give information on open network ports on the machine?
1. A
2. B
3. C
4. D
Q5MCQ3 Marks·Choose one option
Asked 2 times Key ↓
1. A
2. B
3. C
4. D
Q6MCQ3 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q7MCQ3 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q8MCQ3 Marks·Choose one option
Key ↓
1. ALines starting with 3 letters and containing 2 digits anywhere.
2. BLines containing exactly 3 letters followed by exactly 2 digits.
3. CLines ending with 2 digits.
4. DAny line containing at least 3 letters and 2 digits.
Q9MCQ3 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q10MCQ4 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q11MSQ3 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D
Q12MSQ3 Marks·Choose all correct options
Key ↓
Which command is used to display the IP address and network interfaces of your Ubuntu system?
1. A
2. B
3. C
4. D
5. E
Q13NAT3 Marks·Write the number
Key ↓
Your answer:
Q14NAT4 Marks·Write the number
Asked 3 times Key ↓
Your answer:
Read the passage below, then answer Q15–Q16
Based on the above data, answer the given subquestions.
Q15MSQ3 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D
Q16MSQ3 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D

End Term · 31 Aug 2025 (FN)End Term

Q17MCQ5 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q18MCQ5 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
5. E
Q19MCQ5 Marks·Choose one option
Asked 2 times Key ↓
1. A
2. B
3. C
4. D
Q20MCQ5 Marks·Choose one option
Asked 2 times Key ↓
1. A
2. B
3. C
4. D
Q21MCQ5 Marks·Choose one option
Asked 2 times Key ↓
1. A
2. B
3. C
4. D
Q22MCQ5 Marks·Choose one option
Asked 3 times Key ↓
1. A
2. B
3. C
4. D
Q23MCQ5 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q24MCQ5 Marks·Choose one option
Asked 2 times Key ↓
1. A
2. B
3. C
4. D
Q25MCQ5 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q26MCQ5 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q27MCQ5 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q28MSQ5 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D
Q29MSQ5 Marks·Choose all correct options
Asked 2 times Key ↓
1. A
2. B
3. C
4. D
Q30MSQ5 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D
Q31MSQ5 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D
Q32MSQ5 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D
Q33MSQ5 Marks·Choose all correct options
Asked 4 times Key ↓
1. A
2. B
3. C
4. D
Q34MSQ5 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D
Q35NAT5 Marks·Write the number
Asked 3 times Key ↓
Your answer:
Q36NAT5 Marks·Write the number
Asked 2 times Key ↓
Your answer:

End Term · 31 Aug 2025 (AN)End Term

Q37MCQ5 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q38MCQ5 Marks·Choose one option
Asked 2 times Key ↓
1. A
2. B
3. C
4. D
Q39MCQ5 Marks·Choose one option
Asked 2 times Key ↓
1. A
2. B
3. C
4. D
Q40MCQ5 Marks·Choose one option
Key ↓
You suspect a configuration file for the package nginx was modified manually. Which command will verify this without reinstalling or removing the package?
1. A
2. B
3. C
4. D
Q41MCQ5 Marks·Choose one option
Key ↓
A file numbers.txt contains several lines of numeric strings. You want to find lines where any digit is repeated exactly twice consecutively (like "1123", "4456"). Which command works correctly?
1. A
2. B
3. C
4. D
Q42MCQ5 Marks·Choose one option
Key ↓
You're using gawk to identify repeated words in notes.txt. Which gawk statements correctly use backreferences?
1. A
2. B
3. C
4. D
Q43MCQ5 Marks·Choose one option
Key ↓
1. AOnly link target runs
2. BBoth compile and link run
3. CNothing runs since main.o exists
4. DOnly compile runs
Q44MCQ5 Marks·Choose one option
Key ↓
1. Ared and green
2. Bred and blue
3. Cgreen and yellow
4. Dred and yellow
Q45MCQ5 Marks·Choose one option
Asked 2 times Key ↓
1. A192.168.0.1 3
2. B192.168.0.2 2
3. C192.168.0.3 1
4. DBoth 192.168.0.1 3 and 192.168.0.2 2
Q46MCQ5 Marks·Choose one option
Key ↓
1. AFirst line of each paragraph
2. BAll blank lines
3. CEntire file in one line
4. DFirst field of each line
Q47MSQ5 Marks·Choose all correct options
Asked 3 times Key ↓
1. Ased -n '1,10p' file.txt
2. Bsed 11q file.txt
3. Cawk 'NR <= 10' file.txt
4. Dcat -n 10 file.txt
Q48MSQ5 Marks·Choose all correct options
Key ↓
Below is the man page of `grep`. Which of the following commands will print only the name of all .txt files that do not contain the word "error"? Assume the current directory does not have any subdirectories. Assume the filenames are alphanumeric.
1. Agrep -L "error" *.txt
2. Bgrep -v "error" *.txt
3. Cgrep -L "error" -- *.txt
4. Dfind . -name "*.txt" | xargs grep -L "error"
Q49MSQ5 Marks·Choose all correct options
Asked 2 times Key ↓
Which of the following statements about subshells is/are true?
1. A(cd /tmp; ls) runs in a subshell
2. Bcd /tmp; ls runs in a subshell
3. CVariables set in a subshell are visible to the parent shell
4. DCommands inside $(...) are executed in a subshell
Q50MSQ5 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D
5. E
Q51MSQ5 Marks·Choose all correct options
Key ↓
Which of the following find commands will list all regular files in /var/log modified more than 7 days ago and larger than 5MB?
1. A
2. B
3. C
4. D
Q52NAT5 Marks·Write the number
Key ↓
Your answer:
Q53NAT5 Marks·Write the number
Asked 4 times Key ↓
Your answer:
Q54NAT5 Marks·Write the number
Key ↓
Your answer:
Q55NAT5 Marks·Write the number
Key ↓
Your answer:
Q56NAT5 Marks·Write the number
Asked 2 times Key ↓
Your answer:

End Term · 13 Apr 2025 (FN)End Term

Q57MCQ7 Marks·Choose one option
Asked 3 times Key ↓
1. A
2. B
3. C
4. D
Q58MCQ7 Marks·Choose one option
Key ↓
Schedule the script /home/user/backup.sh to meet the following requirements 1. The job should run at the 2nd minute of every hour, but only during weekdays (Monday to Friday). 2. Additionally, the job must not run during the first and last days of each month. 3. It should execute a script located at /home/user/backup.sh and log the output to /var/log/backup.log (append mode). Which of the following exact crontab entry is used to schedule this job.
1. A
2. B
3. C
4. D
Q59MCQ7 Marks·Choose one option
Asked 2 times Key ↓
What is the primary purpose of this AWK script?
1. ATo convert contents of file to lowercase.
2. BTo count the frequency of each word in a text file.
3. CTo count the number of lines in a file.
4. DTo replace all non-alphabetic characters in a file.
Q60MCQ7 Marks·Choose one option
Asked 2 times Key ↓
1. ADeletes all .log files in /home.
2. BLists all .log files in /sample/logs.
3. CFinds all .log files and backs them up.
4. DRenames .log files to .bak in /home.
Q61MCQ6 Marks·Choose one option
Key ↓
Select a single sed command to achieve the following. a) Find all lines that start with the word "error". b) Replace the word "error" with "warning" only on those lines. c) Append " - needs review" to the end of those same lines.
1. A
2. B
3. C
4. D
Q62MCQ6 Marks·Choose one option
Key ↓
Consider current_permissions contain the present permissions of a file. Which of the following shell script statement calculate the new permissions by removing the read permission?
1. A
2. B
3. C
4. D
Q63MCQ6 Marks·Choose one option
Asked 2 times Key ↓
Select a command to find all established suspicious TCP connections on port 80 using netstat
1. A
2. B
3. C
4. D
Q64MCQ6 Marks·Choose one option
Asked 2 times Key ↓
Which of the following vi command is used to replace the word 'apple' with 'orange' only in lines 10 to 20 of a file, and appear at the beginning or end of the line, without case sensitive and without user interaction.
1. A
2. B
3. C
4. D
Q65MCQ6 Marks·Choose one option
Key ↓
1. A
2. B
3. C
4. D
Q66MCQ6 Marks·Choose one option
Key ↓
1. ADisplay the today’s date
2. BNothing is printed
3. Clist all the lines of file1 that do not match file2
4. D0
Q67MCQ6 Marks·Choose one option
Asked 2 times Key ↓
1. ADeletes the first two fields in the CSV file.
2. BSwaps the first and second fields of the CSV file.
3. CAdds a new field to the CSV file.
4. DReplaces all commas in the CSV file with spaces.
Q68MCQ6 Marks·Choose one option
Asked 2 times Key ↓
1. ACompresses the /remove directory into a tarball, excluding the /sample subdirectory, and names it backup.tar.gz.
2. BDeletes the /sample subdirectory before creating a compressed tarball of /remove.
3. CExtracts the contents of backup.tar.gz to /remove, excluding the /sample directory.
4. DLists the contents of /remove, ignoring the /sample subdirectory.
Q69MCQ6 Marks·Choose one option
Key ↓
You are working in a team with multiple developers using Git. One of your colleagues has created a feature branch from main, but over time, the main branch has received several commits. Your colleague is now attempting to merge the feature branch into main, but a conflict arises in a file that was modified both in the main branch and in the feature branch. How would you resolve the conflict, ensuring that the feature branch is up-to-date with the latest changes from main and that no work is lost? Additionally, how would you ensure that this situation is prevented in the future?
1. Aa. Merge the feature branch into main without updating main. Resolve conflicts directly in the merge commit. b. Regularly merge main into the feature branch to avoid future conflicts.
2. Ba. Switch to the feature branch and run git pull origin feature-branch. b. Resolve the conflict directly in main, then push the changes.
3. Ca. Ensure main is up-to-date by pulling the latest changes. b. Switch to the feature branch and merge main into it. c. Resolve the conflicts, commit the changes, and push the feature branch. d. Merge the feature branch into main via a pull request. e. Prevent future conflicts by encouraging regular updates between branches.
4. Da. Merge the feature branch into main without resolving conflicts. b. Use git reset to undo any conflicts and continue with the merge.
Q70MSQ6 Marks·Choose all correct options
Key ↓
1. A
2. B
3. C
4. D
5. E
Q71NAT6 Marks·Write the number
Asked 2 times Key ↓
Your answer:
Q72NAT6 Marks·Write the number
Key ↓
Your answer:

Official Key

Master Answer Key & Explanations

Official answer keys from IIT Madras BS past papers. Click any question to review.

Reveal Key

Q1A

Q2B

Q3D

Q4A

Q5B

Q6C

Q7D

Q8B

Q9B

Q10A

Q11A, D

Q12B, E

Q137

Q145

Q15A, B

Q16A, D

Q17B

Q18E

Q19A

Q20A

Q21D

Q22B

Q23B

Q24A

Q25B

Q26B

Q27C

Q28A, C

Q29A, B, C, D

Q30B, D

Q31A, C, D

Q32B, C

Q33A, B, D

Q34A, B, C

Q354

Q3632

Q37C

Q38C

Q39D

Q40C

Q41A

Q42B

Q43B

Q44B

Q45A

Q46A

Q47A, B, C

Q48A, C, D

Q49A, D

Q50A, B, D

Q51A, B, C

Q521

Q53120

Q549

Q552

Q5625

Q57B

Q58B

Q59B

Q60C

Q61D

Q62C

Q63B

Q64D

Q65D

Q66B

Q67B

Q68A

Q69C

Q70B, E

Q713

Q72149

Questions and answer keys are reproduced from the official IIT Madras BS papers. BTechi is not affiliated with IIT Madras.