linux commands

Question 1

Which command shows the size of files and folders in the current directory?

Answer 1

du -h

Question 2

How to display the contents of a file line by line with line numbers?

Answer 2

nl filename

Question 3

How to execute a file if it is executable? Provide an example

Answer 3

./script.sh

Question 4

How to set permissions for groups and users using the chmod command?

Answer 4

chmod u+x file:
chmod g+w file:

Question 5

Which command shows the available free space on the disk?

Answer 5

df -h

Question 6

How to check the last modification date and time of a file?

Answer 6

stat filename

Question 7

What is the difference between the commands ls -l and ls -a?

Answer 7

is the difference between the commands ls -l and ls -a?
o ls -l: Lists files in long format, showing permissions, owners, size, and
modification date.
o ls -a: Lists all files, including hidden files (those starting with a dot)

Question 8

How to display the structure of a directory as a tree? Specify the command.

Answer 8

tree

Question 9

How to run an application or command in the background?

Answer 9

./myprogram &

Question 10

Write a command to display the last 20 commands executed in the terminal.

Answer 10

history | tail -20

Question 11

How to clear the terminal screen?

Answer 11

clear

Question 12

How to redirect the output of a command to a file?

Answer 12

command > filename

Question 13

Write an example of creating a symbolic link to a file.

Answer 13

ln -s /path/to/file /path/to/symlink

Question 14

How to find all files of a specific size in a directory?

Answer 14

find . -size +100M

Question 15

How to delete all files with the .log extension in the current directory?

Answer 15

rm *.log

Question 16

how to create a bash script and make it executable?

Answer 16

nano script.sh.
chmod +x script.sh.

Question 17

How to automate script execution during system startup?

Answer 17

/etc/rc.local

Question 18

How to check which packages are installed on the system using apt?

Answer 18

pt list –installed

Question 19

What is the .bashrc file, and what is it used for?

Answer 19

What is the .bashrc file, and what is it used for?

Question 20

How to enable error output in a bash script?

Answer 20

Add set -e at the beginning of the script to stop the execution on errors or set -
x to print each command before executing it

Question 21

How to find the current user in Linux? Specify the command.

Answer 21

whoami

Question 22

How to terminate a process using the kill command?

Answer 22

kill PID (replace PID with the process ID, which you can find using ps or top)

Question 23

Which command is used to change the user password in Linux?

Answer 23

passwd

Question 24

4. How to display the contents of a file with line numbers, starting from a specific line?

Answer 24

sed -n ‘5,$=’ filename

Question 25

How to move a file from one directory to another?

Answer 25

mv /path/to/file /path/to/destination

Question 26

Which command combines the contents of multiple files into one file?

Answer 26

cat file1 file2 > combinedfile

Question 27

How to find files in the current directory modified in the last 7 days?

Answer 27

find . -type f -mtime -7