Linux Practical Set H Solution – Employee Gross Salary

In this article, we will solve VNSGU TYBCA Semester 5 Linux (UNIX) Practical – Set H using shell scripting.

This practical focuses on:

• User input
• if-else
• Arithmetic operations
• Percentage calculation
• Employee salary calculation
• awk
• bc

📌 Practical Question

Write a shell script that computes the gross salary of an employee according to the following:

If Basic Salary is less than ₹50,000

• HRA = 20% of Basic Salary
• DA = 164% of Basic Salary

If Basic Salary is greater than ₹50,000

• HRA = 15% of Basic Salary
• DA = 136% of Basic Salary

Input Requirement

The basic salary should be entered interactively through the keyboard.

Gross Salary Formula

Gross Salary = Basic Salary + DA + HRA

🧠 Understanding the Problem

Let:

Basic Salary = B

If:

B < 50000

then:

HRA = 20% of B
DA  = 164% of B

If:

B > 50000

then:

HRA = 15% of B
DA  = 136% of B

Finally:

Gross Salary = B + HRA + DA

⚠️ Important Note About ₹50,000

The original question specifies:

Basic Salary < 50000
Basic Salary > 50000

It does not explicitly define what should happen when Basic Salary is exactly ₹50,000.

Therefore, in the solutions below, the 50000 case is handled separately.

🧮 Example Calculation

Suppose:

Basic Salary = ₹40,000

Since:

40000 < 50000

we use:

HRA = 20% of 40000
    = 8000

DA = 164% of 40000
   = 65600

Therefore:

Gross Salary = 40000 + 8000 + 65600
             = ₹113600

✅ Solution 1: Using Basic Bash if-else

This is the simplest and most suitable solution for a university practical examination.

Shell Script

#!/bin/bash

echo "Enter Basic Salary:"
read basic

if [ "$basic" -lt 50000 ]
then
    hra=$((basic * 20 / 100))
    da=$((basic * 164 / 100))

elif [ "$basic" -gt 50000 ]
then
    hra=$((basic * 15 / 100))
    da=$((basic * 136 / 100))

else
    echo "Basic salary of exactly 50000 is not defined in the question."
    exit 1
fi

gross=$((basic + hra + da))

echo "-----------------------------"
echo "Basic Salary : $basic"
echo "HRA          : $hra"
echo "DA           : $da"
echo "Gross Salary : $gross"
echo "-----------------------------"

🔍 Step-by-Step Explanation

Step 1: Take Basic Salary

read basic

The salary entered by the user is stored in the variable basic.

Step 2: Check Salary Below ₹50,000

if [ "$basic" -lt 50000 ]

The -lt operator means:

Less than

So this condition checks:

basic < 50000

If the condition is true, HRA and DA are calculated using:

hra=$((basic * 20 / 100))
da=$((basic * 164 / 100))

Step 3: Check Salary Above ₹50,000

elif [ "$basic" -gt 50000 ]

The -gt operator means:

Greater than

So this condition checks:

basic > 50000

HRA and DA are then calculated using:

hra=$((basic * 15 / 100))
da=$((basic * 136 / 100))

Step 4: Calculate Gross Salary

gross=$((basic + hra + da))

The formula is:

Gross Salary = Basic Salary + HRA + DA

🖥️ Example Output – Basic Salary Less Than ₹50,000

Enter Basic Salary:
40000
-----------------------------
Basic Salary : 40000
HRA          : 8000
DA           : 65600
Gross Salary : 113600
-----------------------------

🖥️ Example Output – Basic Salary Greater Than ₹50,000

Suppose:

Basic Salary = 60000

Calculation:

HRA = 15% of 60000 = 9000
DA  = 136% of 60000 = 81600

Output:

Enter Basic Salary:
60000
-----------------------------
Basic Salary : 60000
HRA          : 9000
DA           : 81600
Gross Salary : 150600
-----------------------------

❌ Example Output – Basic Salary Exactly ₹50,000

Enter Basic Salary:
50000

Basic salary of exactly 50000 is not defined in the question.

The script handles this case separately because the original question does not specify an HRA/DA rule for exactly ₹50,000.

⚠️ Limitation of Basic Bash Arithmetic

Bash arithmetic using:

$(( ... ))

works with integers.

For example:

echo $((5 / 2))

produces:

2

not:

2.5

If decimal salary values need to be supported, awk or bc can be used.

✅ Solution 2: Using awk

awk supports floating-point arithmetic, so it is useful when the basic salary can contain decimal values.

Shell Script

#!/bin/bash

echo "Enter Basic Salary:"
read basic

awk -v basic="$basic" '
BEGIN {
    if (basic < 50000) {
        hra = basic * 20 / 100
        da = basic * 164 / 100
    }
    else if (basic > 50000) {
        hra = basic * 15 / 100
        da = basic * 136 / 100
    }
    else {
        print "Basic salary of exactly 50000 is not defined in the question."
        exit 1
    }

    gross = basic + hra + da

    printf "-----------------------------\n"
    printf "Basic Salary : %.2f\n", basic
    printf "HRA          : %.2f\n", hra
    printf "DA           : %.2f\n", da
    printf "Gross Salary : %.2f\n", gross
    printf "-----------------------------\n"
}'

🖥️ Example Output

Enter Basic Salary:
42500.50

-----------------------------
Basic Salary : 42500.50
HRA          : 8500.10
DA           : 69700.82
Gross Salary : 120701.42
-----------------------------

The %.2f format displays the values with two decimal places.

🔍 Why Use awk?

The main advantage is floating-point arithmetic.

For example:

awk 'BEGIN { printf "%.2f\n", 5 / 2 }'

Output:

2.50

So awk is useful when decimal values are required.

✅ Solution 3: Using bc

bc is another command-line calculator that can perform decimal calculations.

Shell Script

#!/bin/bash

echo "Enter Basic Salary:"
read basic

if (( $(echo "$basic < 50000" | bc -l) ))
then
    hra=$(echo "scale=2; $basic * 20 / 100" | bc)
    da=$(echo "scale=2; $basic * 164 / 100" | bc)

elif (( $(echo "$basic > 50000" | bc -l) ))
then
    hra=$(echo "scale=2; $basic * 15 / 100" | bc)
    da=$(echo "scale=2; $basic * 136 / 100" | bc)

else
    echo "Basic salary of exactly 50000 is not defined in the question."
    exit 1
fi

gross=$(echo "scale=2; $basic + $hra + $da" | bc)

echo "-----------------------------"
echo "Basic Salary : $basic"
echo "HRA          : $hra"
echo "DA           : $da"
echo "Gross Salary : $gross"
echo "-----------------------------"

🖥️ Example Output

Enter Basic Salary:
42500.50

-----------------------------
Basic Salary : 42500.50
HRA          : 8500.10
DA           : 69700.82
Gross Salary : 120701.42
-----------------------------

🔍 Understanding the bc Solution

This:

echo "$basic < 50000" | bc -l

checks the comparison using bc.

For example:

echo "42500.50 * 20 / 100" | bc

produces:

8500.10

The scale=2 option controls the number of decimal places in calculations.

📊 Comparing the Solutions

Which Solution Should You Use?

For a normal university practical with integer salary input, Solution 1 is the easiest and most suitable.

If decimal salary values are required, use Solution 2 (awk) or Solution 3 (bc).

🧠 Important Operators Used

Less Than

-lt

Example:

[ "$basic" -lt 50000 ]

Greater Than

-gt

Example:

[ "$basic" -gt 50000 ]

Equal

-eq

Example:

[ "$basic" -eq 50000 ]

⚠️ Common Mistakes

Mistake 1: Using Assignment Instead of Comparison

Wrong:

if [ basic -lt 50000 ]

Correct:

if [ "$basic" -lt 50000 ]

Mistake 2: Incorrect Percentage Calculation

Wrong:

hra=$((basic * 20%))

Correct:

hra=$((basic * 20 / 100))

Mistake 3: Forgetting DA Is More Than 100%

The question specifies:

DA = 164%

for salary below ₹50,000 and:

DA = 136%

for salary above ₹50,000.

Do not accidentally write 16.4% or 13.6%.

Mistake 4: Forgetting the Gross Salary Formula

Remember:

Gross Salary = Basic Salary + HRA + DA

Mistake 5: Ignoring the ₹50,000 Case

The question gives:

< 50000
> 50000

but does not define:

= 50000

So the script handles that case separately.

🎯 Practical Exam Tips

Remember the basic structure:

if [ "$basic" -lt 50000 ]
then
    # HRA 20%
    # DA 164%

elif [ "$basic" -gt 50000 ]
then
    # HRA 15%
    # DA 136%
fi

Percentage calculation:

value=$((basic * percentage / 100))

Gross salary:

gross=$((basic + hra + da))

📝 Quick Revision

Salary below ₹50,000

hra=$((basic * 20 / 100))
da=$((basic * 164 / 100))

Salary above ₹50,000

hra=$((basic * 15 / 100))
da=$((basic * 136 / 100))

Gross Salary

gross=$((basic + hra + da))

Compare Less Than

[ "$basic" -lt 50000 ]

Compare Greater Than

[ "$basic" -gt 50000 ]

📚 Related Linux Practical Sets

This solution is part of the VNSGU TYBCA Sem 5 Linux (UNIX) Practical – OCT/Nov 2025 solution series.

• Set A – Simple Interest & Compound Interest
• Set B – Vowels Count & Case Conversion
• Set C – Palindrome String
• Set D – File Operations & Text Processing
• Set E – Display Lines with Validation
• Set F – Count Files & Directories
• Set G – Recently Modified Files
• Set H – Employee Gross Salary

🐧 Conclusion

The Set H practical is a good exercise for understanding conditional statements, percentage calculations, user input, and arithmetic operations in shell scripting.

The basic logic is:

Read Basic Salary
       ↓
Check Salary
       ↓
Calculate HRA and DA
       ↓
Calculate Gross Salary
       ↓
Display Result

For a basic university practical, the Bash if-else solution is usually enough.

If decimal calculations are required, awk or bc can be used.

💬 What Do You Prefer?

For salary calculations in shell scripting, which approach do you prefer?

Basic Bash arithmetic, awk, or bc?

Share your approach in the comments! 🐧💻

📌 Tags

linux shell unix beginners