Programs 4 to 10 B.Sc Computer Science BCA Linux and Shell Programming - Lab Bharathiar University

 

B.Sc Computer Science 

Linux and Shell Programming - Lab  

Bharathiar University 

4.Write a shell script for displaying current date, user name, file listing and directories by getting user choice. 

Source Code

while true; do

echo "Select an option:"

echo "1. Display current date"

echo "2. Display current user name"

echo "3. List files in the current directory"

echo "4. List directories in the current directory"

echo "5. Exit"

echo "Enter your choice: "

read choice

case $choice in

    1)  echo "Current date: $(date)"

      echo;;

    2)  echo "Current user name: $(whoami)"

        echo;;

    3)  echo "Files in the current directory:"

        ls -l | grep "^-"

        echo;;

    4)  echo "Directories in the current directory:"

        ls -l | grep "^d"

        echo;;

    5)  echo "Exiting..."; exit;;

    *)  echo "Invalid choice. Please enter a valid option (1/2/3/4)." ;;

esac

done

Sample OUTPUT:

5. Write a shell script to implement the filter commands.
 

Source Code

text="apple banana grape orange

apple grape lemon

banana lemon orange

grape lemon orange"

# Using grep to filter lines containing a specific word

echo "Lines containing the word 'grape':"

echo "$text" | grep 'grape'

echo

# Using sort to sort lines alphabetically

echo "Sorted lines:"

echo "$text" | sort

echo

# Using wc to count the number of words, lines, and characters

echo "Word count:"

echo "$text" | wc -w

echo "Line count:"

echo "$text" | wc -l

echo "Character count:"

echo "$text" | wc -c

echo

# Using tr to translate characters to uppercase

echo "Text converted to uppercase:"

echo "$text" | tr '[:lower:]' '[:upper:]'

SAMPLE OUTPUT:

 6. Write a shell script to remove the files which has file size as zero bytes.

 

Source Code

# Find files with size zero and remove them

find . -type f -size 0 | while read file; do

    rm "$file"

    echo "Removed: $file"

done

SAMPLE OUTPUT:

7. Write a shell script to find the sum of the individual digits of a given number.
  

Source Code

sum_of_digits() {

    number=$1

    sum=0

   

    # Loop through each digit of the number

    while [ $number -gt 0 ]; do

        # Extract the last digit

        digit=$((number % 10))

        # Add the digit to the sum

        sum=$((sum + digit))

        # Remove the last digit from the number

        number=$((number / 10))

    done

    # Print the sum of digits

    echo "Sum of digits: $sum"

}

# Prompt user for input

echo "Enter a number: "

read num

# Call the function with the provided number

sum_of_digits $num

SAMPLE OUTPUT:

8. Write a shell script to find the greatest among the given set of numbers using command line arguments.
  

Source Code

# Check if no arguments are provided

if [ $# -eq 0 ]; then

    echo "Please Enter: $0 <number1> <number2> ... <numberN>"

    exit 1

fi

# Initialize variable to store the maximum value

max=$1

# Loop through all command-line arguments

for num in "$@"; do

    # Compare each number with the current maximum

    if [ $num -gt $max ]; then

        max=$num

    fi

done

# Print the maximum value

echo "The greatest number is: $max"

SAMPLE OUTPUT:

9. Write a shell script for palindrome checking.

  
  

Source Code

# Main program starts here

# Prompt the user to enter the string

    echo "Enter the string: "

    read str

    reversed=$(echo "$str" | rev)

    if [ "$str" = "$reversed" ]; then

        echo "The string '$str' is a palindrome."

    else

        echo "The string '$str' is not a palindrome."

    fi

SAMPLE OUTPUT:

10. Write a shell script to print the multiplication table of the given argument using for loop.

  
  

Source Code

# Check if argument is provided

if [ $# -eq 0 ]; then

    echo "Please Enter: <number>"

    exit 1

fi

# Store the number from command-line argument

number=$1

# Print the multiplication table

echo "Multiplication table of $number:"

for (( i = 1; i <= 10; i++ )); do

    # Perform multiplication

    result=$((number * i))

    # Print the result

    echo "$number x $i = $result"

done

SAMPLE OUTPUT: