Shell Programming and Scripting

#!/bin/bash
f=1
echo -n "Enter number : "
read num
var=1
while (( $var <= $num ))
do
  f=$(( $f * $var ))
  let var++
done

echo $f

 
let var++

i=0
while [ $i -lt 100 ]
do 
    let i+=10
    echo $i
done

#!/bin/bash

factorial()
{
  if (( $1 > 1 )); then
    i=$(( $1 - 1 ))
    j=$(factorial $i)
    echo $(( $1 * $j ))
  else
    echo 1
  fi
}

while :
do
  read -p "Enter a number: " x
  factorial $x
done

use strict;
use warnings;

print "Enter a number: ";
my $n = <>;#getting from stdin
my $i = 1;
my $res = 1;
$res *= $i++ while ($i <= $n) ;
print "Value: $res\n";

Enter a number: 7
Value : 5040

f=1
echo "Enter a number"
read no
if [[ $no -le 1 ]];then
echo "Factorial of $no is:1"
else
#for fact in `seq $no`
for((fact=1;fact<=$no;fact++))
do
      let f*=fact
done
echo "Factorial of $no is:$f"
fi

echo "Enter a number";
read num;
i=1

for fact in `seq 1 $num`
do
                  i=$(( $i * $fact ))
          done

            echo $i