Functions

A function may return a value in one of four different ways:

Change the state of a variable or variables
Use the exit command to end the shell script
Use the return command to end the function, and return the supplied value to the calling section of the shell script
echo output to stdout, which will be caught by the caller just as c=`expr $a + $b` is caught

Example1:

myfunc()

{

echo "I was called as : $@"

x=2

}

### Main script starts here

echo "Script was called with $@"

x=1

echo "x is $x"

myfunc 1 2 3

echo "x is $x"

Example-2:
#!/bin/sh

factorial()
{
if [ "$1" -gt "1" ]; then
i=`expr $1 - 1`
j=`factorial $i`
k=`expr $1 \* $j`
echo $k
else
echo 1
fi
}
while :
do
echo "Enter a number:"
read x
factorial $x
done