Here is an explanation of the script:

This program prompts the user to enter a positive integer and calculates its factorial ($n! = n \times (n-1) \times \dots \times 1$).

User Input (read): Captures data entered by the user.
Variables: Stores values in memory (n and ans).
C-Style for Loop: Repeats a block of code a set number of times.
Arithmetic Expansion ($(( ... ))): Performs mathematical operations in Bash.

#!/bin/bash: The Shebang line telling the system to run this script using the Bash interpreter.
read -p "..." n: Displays a prompt message and stores the entered number into the variable n.
ans=1: Initializes the accumulator variable ans to 1 (since multiplying by 1 doesn't alter the result).
for((i=1;i<=n;i++)): A loop that starts a counter variable i at 1 and increments it by 1 until it reaches n.
ans=$((ans*i)): Inside the loop, multiplies the current value of ans by i and updates ans.
echo $ans: Prints the final result to the terminal.

If you run the program and enter 5:

To Find Factorial of number, Enter a number: 5
120

(Explanation: $1 \times 2 \times 3 \times 4 \times 5 = 120$)

Here is an explanation of the script:

This program prompts the user to enter a positive integer and calculates its factorial ($n! = n \times (n-1) \times \dots \times 1$).

User Input (read): Captures data entered by the user.
Variables: Stores values in memory (n and ans).
C-Style for Loop: Repeats a block of code a set number of times.
Arithmetic Expansion ($(( ... ))): Performs mathematical operations in Bash.

#!/bin/bash: The Shebang line telling the system to run this script using the Bash interpreter.
read -p "..." n: Displays a prompt message and stores the entered number into the variable n.
ans=1: Initializes the accumulator variable ans to 1 (since multiplying by 1 doesn't alter the result).
for((i=1;i<=n;i++)): A loop that starts a counter variable i at 1 and increments it by 1 until it reaches n.
ans=$((ans*i)): Inside the loop, multiplies the current value of ans by i and updates ans.
echo $ans: Prints the final result to the terminal.

If you run the program and enter 5:

To Find Factorial of number, Enter a number: 5
120

(Explanation: $1 \times 2 \times 3 \times 4 \times 5 = 120$)

Shell Script Programming